1
|
Kuypers KLAM, Dekker J, Crossley KJ, Wallace MJ, Cramer SJE, Davies IM, Jurkschat D, Kitchen MJ, Te Pas AB, Hooper SB. Slowing lung deflation by increasing the expiratory resistance enhances FRC in preterm rabbits. Pediatr Res 2024:10.1038/s41390-024-03388-w. [PMID: 38977795 DOI: 10.1038/s41390-024-03388-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 06/14/2024] [Accepted: 06/21/2024] [Indexed: 07/10/2024]
Abstract
BACKGROUND As very preterm infants have surfactant-deficient and highly incompliant lungs, slowing lung deflation during expiration might help preserve functional residual capacity(FRC) during lung aeration. In this study, we investigated the effect of expiratory resistance(Re) on lung aeration during positive pressure ventilation in preterm rabbits immediately after birth. METHODS Preterm rabbit pups were delivered at 29 days gestation, mechanically ventilated from birth and simultaneously imaged to measure lung aeration using phase-contrast X-ray. Re was varied by altering the length (0, 60 or 1000 mm) of the expiratory circuit. RESULTS Increasing Re led to a decrease in lung deflation rates and both peak expiratory flows and flow rates at mid-deflation. As a result, the rate of de-acceleration(slowing) in lung deflation when approaching FRC was markedly reduced with increasing resistance. During lung aeration, FRC was significantly different between resistance groups and was significantly higher over time in the high compared to the low resistance group. While FRC values tended to be higher with higher Re, they were not significantly different at end-ventilation (t = 7 min). CONCLUSION Increasing Re of the ventilation circuit during lung aeration in preterm rabbits immediately after birth decreased lung deflation rates and increased the accumulation of FRC over time. IMPACT The expiratory phase of the ventilatory cycle has been largely overlooked as an opportunity to improve ventilation in preterm infants after birth. Increasing the expiratory resistance of the ventilator circuit during lung aeration in preterm rabbits immediately after birth markedly decreased lung deflation rates and increased FRC accumulation, compared to a low expiratory resistance. This indicates that ventilation devices that reduce the "work of breathing" by reducing the expiratory resistance, may have the unintended effect of reducing FRC, particularly in extremely preterm infants that have surfactant deficient highly incompliant lungs.
Collapse
Affiliation(s)
- Kristel L A M Kuypers
- Division of Neonatology, department of paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands.
| | - Janneke Dekker
- Division of Neonatology, department of paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Megan J Wallace
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Sophie J E Cramer
- Division of Neonatology, department of paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
| | - Indya M Davies
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Dominic Jurkschat
- School of Physics and Astronomy, Monash University, Melbourne, VIC, Australia
| | - Marcus J Kitchen
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- School of Physics and Astronomy, Monash University, Melbourne, VIC, Australia
| | - Arjan B Te Pas
- Division of Neonatology, department of paediatrics, Willem-Alexander Children's Hospital, Leiden University Medical Centre, Leiden, the Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
2
|
Tran NT, Somers A, Vidinopoulos K, Azman Z, Pham Y, Zahra VA, Chan KYY, Hooper S, Crossley K, Allison BJ, Galinsky R, Polglase GR. The synergistic effects of mechanical ventilation and intrauterine inflammation on cerebral inflammation in preterm fetal sheep. Front Cell Neurosci 2024; 18:1397658. [PMID: 38962513 PMCID: PMC11220153 DOI: 10.3389/fncel.2024.1397658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/31/2024] [Indexed: 07/05/2024] Open
Abstract
Background Intrauterine inflammation and the requirement for mechanical ventilation independently increase the risk of perinatal brain injury and adverse neurodevelopmental outcomes. We aimed to investigate the effects of mechanical ventilation for 24 h, with and without prior exposure to intrauterine inflammation, on markers of brain inflammation and injury in the preterm sheep brain. Methods Chronically instrumented fetal sheep at ~115 days of gestation were randomly allocated to receive a single intratracheal dose of 1 mg lipopolysaccharide (LPS) or isovolumetric saline, then further randomly allocated 1 h after to receive mechanical ventilation with room air or no mechanical ventilation (unventilated control + saline [UVC, n = 7]; in utero mechanical ventilation + saline [VENT, n = 8], unventilated control + intratracheal LPS [UVC + LPS, n = 7]; in utero ventilation + intratracheal LPS [VENT + LPS, n = 7]). Serial fetal blood and plasma samples were collected throughout the experimental protocol for assessment of blood biochemistry and plasma interleukin (IL)-6 levels. After 24 h of mechanical ventilation, fetal brains were collected for RT-qPCR and immunohistochemical analyses. Results LPS exposure increased numbers of microglia and upregulated pro-inflammatory related genes within the cortical gray matter (GM) and subcortical white matter (SCWM) (pLPS < 0.05). Mechanical ventilation alone increased astrocytic cell density in the periventricular white matter (PVWM) (pVENT = 0.03) but had no effect on pro-inflammatory gene expression. The combination of ventilation and LPS increased plasma IL-6 levels (p < 0.02 vs. UVC and VENT groups), and exacerbated expression of pro-inflammatory-related genes (IL1β, TLR4, PTGS2, CXCL10) and microglial density (p < 0.05 vs. VENT). Conclusion This study demonstrates that 24 h of mechanical ventilation after exposure to intrauterine inflammation increased markers of systemic and brain inflammation and led to the upregulation of pro-inflammatory genes in the white matter. We conclude that 24 h of mechanical ventilation following intrauterine inflammation may precondition the preterm brain toward being more susceptible to inflammation-induced injury.
Collapse
Affiliation(s)
- Nhi T. Tran
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Ainsley Somers
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kayla Vidinopoulos
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Zahrah Azman
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Yen Pham
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Valerie A. Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kyra Y. Y. Chan
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Stuart Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kelly Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Beth J. Allison
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Paediatrics, Monash University, Clayton, VIC, Australia
| |
Collapse
|
3
|
Boyd SM, Kluckow M, McNamara PJ. Targeted Neonatal Echocardiography in the Management of Neonatal Pulmonary Hypertension. Clin Perinatol 2024; 51:45-76. [PMID: 38325947 DOI: 10.1016/j.clp.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Pulmonary hypertension (PH) in neonates, originating from a range of disease states with heterogeneous underlying pathophysiology, is associated with significant morbidity and mortality. Although the final common pathway is a state of high right ventricular afterload leading to compromised cardiac output, multiple hemodynamic phenotypes exist in acute and chronic PH, for which cardiorespiratory treatment strategies differ. Comprehensive appraisal of pulmonary pressure, pulmonary vascular resistance, cardiac function, pulmonary and systemic blood flow, and extrapulmonary shunts facilitates delivery of individualized cardiovascular therapies in affected newborns.
Collapse
Affiliation(s)
- Stephanie M Boyd
- Grace Centre for Newborn Intensive Care, The Children's Hospital at Westmead, Corner Hawkesbury Road, Hainsworth Street, Westmead, Sydney 2145, Australia; The University of Sydney, Sydney, Australia
| | - Martin Kluckow
- The University of Sydney, Sydney, Australia; Department of Neonatology, Royal North Shore Hospital, Reserve Road, St Leonards 2065, Sydney, Australia
| | - Patrick J McNamara
- Division of Neonatology, The University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| |
Collapse
|
4
|
Dahm SI, Kenna KR, Stewart D, Pereira-Fantini PM, McCall KE, Perkins EJ, Sourial M, Tingay DG. Aeration strategy at birth does not impact carotid haemodynamics in preterm lambs. Pediatr Res 2023; 93:1226-1232. [PMID: 35974157 PMCID: PMC10132978 DOI: 10.1038/s41390-022-02244-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND The impact of different respiratory strategies at birth on the preterm lung is well understood; however, concerns have been raised that lung recruitment may impede cerebral haemodynamics. This study aims to examine the effect of three different ventilation strategies on carotid blood flow, carotid artery oxygen content and carotid oxygen delivery. METHODS 124-127-day gestation apnoeic intubated preterm lambs studied as part of a larger programme primarily assessing lung injury were randomised to positive pressure ventilation with positive end-expiratory pressure (PEEP) 8 cmH2O (No-RM; n = 12), sustained inflation (SI; n = 15) or dynamic PEEP strategy (DynPEEP; maximum PEEP 14 or 20 cmH2O, n = 41) at birth, followed by 90 min of standardised ventilation. Haemodynamic data were continuously recorded, with intermittent arterial blood gas analysis. RESULTS Overall carotid blood flow measures were comparable between strategies. Except for mean carotid blood flow that was significantly lower for the SI group compared to the No-RM and DynPEEP groups over the first 3 min (p < 0.0001, mixed effects model). Carotid oxygen content and oxygen delivery were similar between strategies. Maximum PEEP level did not alter cerebral haemodynamic measures. CONCLUSIONS Although there were some short-term variations in cerebral haemodynamics between different PEEP strategies and SI, these were not sustained. IMPACT Different pressure strategies to facilitate lung aeration at birth in preterm infants have been proposed. There is minimal information on the effect of lung recruitment on cerebral haemodynamics. This is the first study that compares the effect of sustained lung inflation and dynamic and static positive end-expiratory pressure on cerebral haemodynamics. We found that the different ventilation strategies did not alter carotid blood flow, carotid oxygen content or carotid oxygen delivery. This preclinical study provides some reassurance that respiratory strategies designed to focus on lung aeration at birth may not impact cerebral haemodynamics in preterm neonates.
Collapse
Affiliation(s)
- Sophia I Dahm
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.
| | - Kelly R Kenna
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - David Stewart
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
- Department of Neonatology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia
| | - Karen E McCall
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
- Department of Neonatology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
- Department of Neonatology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Magdy Sourial
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
- Department of Neonatology, The Royal Children's Hospital, Parkville, VIC, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
5
|
Inocencio IM, Kaur N, Tran NT, Wong FY. Cerebral haemodynamic response to somatosensory stimulation in preterm lambs is enhanced following sildenafil and inhaled nitric oxide administration. Front Physiol 2023; 14:1101647. [PMID: 36760535 PMCID: PMC9905131 DOI: 10.3389/fphys.2023.1101647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/11/2023] [Indexed: 01/26/2023] Open
Abstract
Background: Neurovascular coupling (NVC) leads to an increase in local cerebral blood flow and oxygenation in response to increased neural activity and metabolic demand. Impaired or immature NVC reported in the preterm brain, potentially reduces cerebral oxygenation following increased neural activity, predisposing to cerebral tissue hypoxia. Endogenous nitric oxide (NO) is a potent vasodilator and a major mediator of NVC and the cerebral haemodynamic response. NO modulators, such as inhaled nitric oxide (iNO) and sildenafil, induce vasodilation and are used clinically to treat pulmonary hypertension in preterm neonates. However, their impact on NVC in the preterm brain are unknown. We aimed to characterise the cerebral functional haemodynamic response in the preterm brain exposed to NO modulators. We hypothesized that iNO and sildenafil in clinical dosages would increase the baseline cerebral perfusion and the cerebral haemodynamic response to neural activation. Methods: Preterm lambs (126-7 days' gestation) were delivered and mechanically ventilated. The cerebral functional haemodynamic response was measured using near infrared spectroscopy as changes in cerebral oxy- and deoxyhaemoglobin (ΔoxyHb, ΔdeoxyHb), following left median nerve stimulations of 1.8, 4.8, and 7.8 s durations in control preterm lambs (n = 11), and following 4.8 and 7.8 s stimulations in preterm lambs receiving either sildenafil citrate (n = 6, 1.33 mcg/kg/hr) or iNO (n = 8, 20 ppm). Results: Following 1.8, 4.8, and 7.8 s stimulations, ∆oxyHb in the contralateral cortex increased (positive functional response) in 7/11 (64%), 7/11 (64%), and 4/11 (36%) control lambs respectively (p < 0.05). Remaining lambs showed decreased ΔoxyHb (negative functional response). Following 4.8 s stimulations, more lambs receiving sildenafil or iNO (83% and 100% respectively) showed positive functional response compared to the controls (p < 0.05). No significant difference between the three groups was observed at 7.8 s stimulations. Conclusion: In the preterm brain, prolonged somatosensory stimulations increased the incidence of negative functional responses with decreased cerebral oxygenation, suggesting that cerebral oxygen delivery may not match the oxygen demand. Sildenafil and iNO increased the incidence of positive functional responses, potentially enhancing NVC, and cerebral oxygenation.
Collapse
Affiliation(s)
- Ishmael Miguel Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Navneet Kaur
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Nhi T. Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Flora Y. Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia,Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia,*Correspondence: Flora Y. Wong,
| |
Collapse
|
6
|
Chang HP, Lien R, Chu SM, Lin JJ, Chiang MC. Outcomes of and factors associated with the development of bronchopulmonary dysplasia with pulmonary hypertension in very low birth weight infants: A retrospective study in a medical center. Front Pediatr 2023; 11:1055439. [PMID: 37020649 PMCID: PMC10067740 DOI: 10.3389/fped.2023.1055439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 02/27/2023] [Indexed: 04/07/2023] Open
Abstract
Introduction Bronchopulmonary dysplasia (BPD) with pulmonary hypertension (PH) leads to increased morbidity and mortality in extremely preterm infants. Recent studies have analyzed factors associated with development of PH in BPD; however, this research remains inconclusive, and controversy exists regarding the correlation between BPD and PH. This study aimed to investigate potential associated factors, clinical characteristics, and outcomes of BPD with pulmonary hypertension in very low birth weight (VLBW) preterm infants. Methods We conducted a retrospective study, reviewing the records of infants with gestational age (GA) <32 weeks and birth weight <1,500 g admitted to a tertiary neonatal intensive care unit between January 2020 and October 2021 who were diagnosed with moderate to severe BPD. Echocardiogram was performed at the postmenstrual age of 36 weeks or before discharge. The diagnosis of PH was based on the findings of echocardiogram. Prenatal and postnatal characteristics, demographic data, treatment details, and outcomes were collected and analyzed. Results A total of 139 VLBW infants with BPD were enrolled and divided into a PH group (n = 25) and a non-PH group (n = 114). The mean GA was 27.3 ± 2.3 weeks and the mean birth weight of infants with BPD was 927.3 ± 293.3 g. A multivariate logistic regression model revealed that a high positive end-expiratory pressure (PEEP) setting (OR: 2.105; 95% CI: 1.472-3.011; p < 0.001) in established BPD and surgical closure of patent ductus arteriosus (PDA; OR: 6.273; 95% CI: 1.574-24.977; p = 0.009) were associated with BPD-PH. Neonates with BPD who developed pulmonary hypertension remained hospitalized for longer (p < 0.001), received invasive mechanical ventilation support for longer (p < 0.001), had a higher incidence of retinopathy of prematurity (ROP; OR: 4.201; 95% CI: 1.561-11.304; p = 0.003), were more likely to require oxygen support at discharge (OR: 5.600; 95% CI: 2.175-14.416; p < 0.001), and were more likely to undergo tracheostomy (OR: 35.368; 95% CI: 4.03-310.43; p < 0.001). Conclusion PDA ligation and a higher PEEP setting were associated with BPD-PH in our cohort study. Compared with VLBW infants with BPD but without PH, infants with BPD and PH were hospitalized for longer, and also had a higher incidence of oxygen support after discharge, ROP, and tracheostomy.
Collapse
Affiliation(s)
- Han-Pi Chang
- Division of Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Reyin Lien
- Division of Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Pediatrics, New Taipei Municipal TuCheng Hospital, New Taipei, Taiwan
| | - Shih-Ming Chu
- Division of Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
- Division of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jainn-Jim Lin
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
- Division of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ming-Chou Chiang
- Division of Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
- Division of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Graduate Institute of Clinical Medical Sciences, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Correspondence: Ming-Chou Chiang
| |
Collapse
|
7
|
Higher CPAP levels improve functional residual capacity at birth in preterm rabbits. Pediatr Res 2022; 91:1686-1694. [PMID: 34294868 DOI: 10.1038/s41390-021-01647-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/03/2021] [Accepted: 06/17/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Preterm infants are commonly supported with 4-8 cm H2O continuous positive airway pressures (CPAP), although higher CPAP levels may improve functional residual capacity (FRC). METHODS Preterm rabbits delivered at 29/32 days (~26-28 weeks human) gestation received 0, 5, 8, 12, 15 cm H2O of CPAP or variable CPAP of 15 to 5 or 15 to 8 cm H2O (decreasing ~2 cm H2O/min) for up to 10 min after birth. RESULTS FRC was lower in the 0 (6.8 (1.0-11.2) mL/kg) and 5 (10.1 (1.1-16.8) mL/kg) compared to the 15 (18.8 (10.9-22.4) mL/kg) cm H2O groups (p = 0.003). Fewer kittens achieved FRC > 15 mL/kg in the 0 (20%), compared to 8 (36%), 12 (60%) and 15 (73%) cm H2O groups (p = 0.008). While breathing rates were not different (p = 0.096), apnoea tended to occur more often with CPAP < 8 cm H2O (p = 0.185). CPAP belly and lung bulging rates were similar whereas pneumothoraces were rare. Lowering CPAP from 15 to 5, but not 15 to 8 cm H2O, decreased FRC and breathing rates. CONCLUSION In all, 15 cm H2O of CPAP improved lung aeration and reduced apnoea, but did not increase the risk of lung over-expansion, pneumothorax or CPAP belly immediately after birth. FRC and breathing rates were maintained when CPAP was decreased to 8 cm H2O. IMPACT Although preterm infants are commonly supported with 4-8 cm H2O CPAP at birth, preclinical studies have shown that higher PEEP levels improve lung aeration. In this study, CPAP levels of 15 cm H2O improved lung aeration and reduced apnoea in preterm rabbit kittens immediately after birth. In all, 15 cm H2O CPAP did not increase the risk of lung over-expansion (indicated by bulging between the ribs), pneumothorax, or CPAP belly. These results can be used when designing future studies on CPAP strategies for preterm infants in the delivery room.
Collapse
|
8
|
Yamaoka S, Crossley KJ, McDougall AR, Rodgers K, Zahra VA, Moxham A, Te Pas AB, McGillick EV, Hooper SB. Increased airway liquid volumes at birth impairs cardiorespiratory function in preterm and near-term lambs. J Appl Physiol (1985) 2022; 132:1080-1090. [PMID: 35271407 DOI: 10.1152/japplphysiol.00640.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Respiratory distress is relatively common in infants born at or near-term, particularly in infants delivered following elective cesarean section. The pathophysiology underlying respiratory distress at term has largely been explained by a failure to clear airway liquid, but recent physiological evidence has indicated that it results from elevated airway liquid at the onset of air-breathing. We have investigated the effect of elevated airway liquid volumes at birth on cardiorespiratory function in preterm and near-term lambs. Preterm (130 ± 0 days gestation, term ~147 days gestation; n=13) and near-term (139 ± 1 days gestation; n=13) lambs were instrumented (to measure blood pressure, blood flow and blood gas status) and at delivery airway liquid volumes were adjusted to mimic levels expected following vaginal delivery (Controls; ~7mL/kg) or elective caesarean section with no labour (elevated liquid; EL; 37mL/kg). Lambs were delivered, mechanically ventilated and monitored for blood gas status, oxygenation, ventilator requirements, blood flows (carotid artery and pulmonary artery) and blood pressure during the first few hours of life. Preterm and near-term EL lambs had poorer gas exchange and required greater ventilatory support to maintain adequate oxygenation. Pulmonary blood flow was reduced and carotid artery blood flow, mean arterial blood pressure and heart rate were reduced in EL near-term but not preterm lambs. These data provide further evidence that greater airway liquid volumes at birth adversely effects newborn cardiorespiratory function, with the effects being greater in near-term newborns.
Collapse
Affiliation(s)
- Shigeo Yamaoka
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Division of Neonatology, Department of Pediatrics, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka, Japan
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Annie Ra McDougall
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Karyn Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
| | - Valerie A Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
| | - Alison Moxham
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Erin Victoria McGillick
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
9
|
The cerebral haemodynamic response to somatosensory stimulation in preterm newborn lambs is reduced following intrauterine inflammation and dopamine infusion. Exp Neurol 2022; 352:114049. [DOI: 10.1016/j.expneurol.2022.114049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/01/2022] [Accepted: 03/13/2022] [Indexed: 11/18/2022]
|
10
|
Inocencio IM, Tran NT, Nakamura S, Khor SJ, Wiersma M, Stoecker K, Maksimenko A, Polglase GR, Walker DW, Pearson JT, Wong FY. Cerebral haemodynamic response to somatosensory stimulation in preterm lambs and 7-10-day old lambs born at term: Direct synchrotron microangiography assessment. J Cereb Blood Flow Metab 2022; 42:315-328. [PMID: 34551607 PMCID: PMC9122524 DOI: 10.1177/0271678x211045848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neurovascular coupling has been well-defined in the adult brain, but variable and inconsistent responses have been observed in the neonatal brain. The mechanisms that underlie functional haemodynamic responses in the developing brain are unknown. Synchrotron radiation (SR) microangiography enables in vivo high-resolution imaging of the cerebral vasculature. We exploited SR microangiography to investigate the microvascular changes underlying the cerebral haemodynamic response in preterm (n = 7) and 7-10-day old term lambs (n = 4), following median nerve stimulation of 1.8, 4.8 and 7.8 sec durations.Increasing durations of somatosensory stimulation significantly increased the number of cortical microvessels of ≤200 µm diameter in 7-10-day old term lambs (p < 0.05) but not preterm lambs where, in contrast, stimulation increased the diameter of cerebral microvessels with a baseline diameter of ≤200 µm. Preterm lambs demonstrated positive functional responses with increased oxyhaemoglobin measured by near infrared spectroscopy, while 7-10-day old term lambs demonstrated both positive and negative responses. Our findings suggest the vascular mechanisms underlying the functional haemodynamic response differ between the preterm and 7-10-day old term brain. The preterm brain depends on vasodilatation of microvessels without recruitment of additional vessels, suggesting a limited capacity to mount higher cerebral haemodynamic responses when faced with prolonged or stronger neural stimulation.
Collapse
Affiliation(s)
- Ishmael M Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia.,*Co-first authors who contributed equally to this work
| | - Nhi T Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia.,School of Health & Biomedical Sciences, RMIT University, Melbourne, Australia.,*Co-first authors who contributed equally to this work
| | - Shinji Nakamura
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Song J Khor
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | - Manon Wiersma
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | - Katja Stoecker
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | - Anton Maksimenko
- Imaging and Medical Beamline, Australian Synchrotron, ANSTO, Melbourne, Australia
| | - Graeme R Polglase
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - David W Walker
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,School of Health & Biomedical Sciences, RMIT University, Melbourne, Australia
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre, Osaka, Japan.,Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - Flora Y Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia.,Monash Newborn, Monash Children's Hospital, Melbourne, Australia
| |
Collapse
|
11
|
Shah D, Tracy M, Hinder M, Badawi N. Positive end expiratory pressure and respiratory system resistance between self-inflating bag and T-piece resuscitator in a cadaveric piglet lung model. Front Pediatr 2022; 10:1014311. [PMID: 36467494 PMCID: PMC9714259 DOI: 10.3389/fped.2022.1014311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/24/2022] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION In neonatal resuscitation, T-piece resuscitator (TPR) are used widely, but the evidence is limited for their use in infants born at term gestation. The aim of this study was to compare the delivered positive end expiratory pressure (PEEP) and respiratory system resistance (Rrs) using TPR and self-inflating bag (SIB) in a cadaveric piglet model. METHODS Cadaveric newborn piglets were tracheotomised, intubated (cuffed tube) and leak tested. Static lung compliance was measured. Positive pressure ventilation was applied by TPR and SIB in a randomized sequence with varying, inflations per minute (40, 60 and 80 min) and peak inspiratory pressures (18 and 30 cmH2O). PEEP was constant at 5 cmH2O. The lungs were washed with saline and static lung compliance was re-measured; ventilation sequences were repeated. Lung inflation data for the respiratory mechanics were measured using a respiratory function monitor and digitally recorded for both pre and post-lung wash inflation sequences. A paired sample t-test was used to compare the mean and standard deviation. RESULTS The mean difference in PEEP (TPR vs. SIB) was statistically significant at higher inflation rates of 60 and 80 bpm. At normal lung compliance, mean difference was 1.231 (p = 0.000) and 2.099 (p = 0.000) with PIP of 18 and 30 cmH2O respectively. Significantly higher Rrs were observed when using a TPR with higher inflation rates of 60 and 80 bpm at varying lung compliance. CONCLUSION TPR is associated with significantly higher PEEP in a compliant lung model, which is probably related to the resistance of the TPR circuit. The effect of inadvertent PEEP on lung mechanics and hemodynamics need to be examined in humans. Further studies are needed to assess devices used to provide PEEP (TPR, SIB with PEEP valve, Anaesthetic bag with flow valve) during resuscitation of the newborn.
Collapse
Affiliation(s)
- Dharmesh Shah
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Mark Tracy
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Murray Hinder
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Nadia Badawi
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Grace Centre for Newborn Care, Children's Hospital at Westmead, Westmead, NSW, Australia.,Cerebral Palsy Alliance Research Institute, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
12
|
Schwaberger B, Urlesberger B, Schmölzer GM. Delivery Room Care for Premature Infants Born after Less than 25 Weeks' Gestation-A Narrative Review. CHILDREN-BASEL 2021; 8:children8100882. [PMID: 34682147 PMCID: PMC8534639 DOI: 10.3390/children8100882] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022]
Abstract
Premature infants born after less than 25 weeks' gestation are particularly vulnerable at birth and stabilization in the delivery room (DR) is challenging. After birth, infants born after <25 weeks' gestation develop respiratory and hemodynamic instability due to their immature physiology and anatomy. Successful stabilization at birth has the potential to reduce morbidities and mortalities, while suboptimal DR care could increase long-term sequelae. This article reviews current neonatal resuscitation guidelines and addresses challenges during DR stabilization in extremely premature infants born after <25 weeks' gestation at the threshold of viability.
Collapse
Affiliation(s)
- Bernhard Schwaberger
- Division of Neonatology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, 8036 Graz, Austria; (B.S.); (B.U.)
| | - Berndt Urlesberger
- Division of Neonatology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, 8036 Graz, Austria; (B.S.); (B.U.)
| | - Georg M. Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, AB T5H 3V9, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T5H 3V9, Canada
- Correspondence: ; Tel.: +1-780-735-4660
| |
Collapse
|
13
|
Stimulating and maintaining spontaneous breathing during transition of preterm infants. Pediatr Res 2021; 90:722-730. [PMID: 31216570 DOI: 10.1038/s41390-019-0468-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/25/2019] [Accepted: 06/03/2019] [Indexed: 01/30/2023]
Abstract
Most preterm infants breathe at birth, but need additional respiratory support due to immaturity of the lung and respiratory control mechanisms. To avoid lung injury, the focus of respiratory support has shifted from invasive towards non-invasive ventilation. However, applying effective non-invasive ventilation is difficult due to mask leak and airway obstruction. The larynx has been overlooked as one of the causes for obstruction, preventing face mask ventilation from inflating the lung. The larynx remains mostly closed at birth, only opening briefly during a spontaneous breath. Stimulating and supporting spontaneous breathing could enhance the success of non-invasive ventilation by ensuring that the larynx remains open. Maintaining adequate spontaneous breathing and thereby reducing the need for invasive ventilation is not only important directly after birth, but also in the first hours after admission to the NICU. Respiratory distress syndrome is an important cause of respiratory failure. Traditionally, treatment of RDS required intubation and mechanical ventilation to administer exogenous surfactant. However, new ways have been implemented to administer surfactant and preserve spontaneous breathing while maintaining non-invasive support. In this narrative review we aim to describe interventions focused on stimulation and maintenance of spontaneous breathing of preterm infants in the first hours after birth.
Collapse
|
14
|
Donaldsson S, Drevhammar T, Li Y, Bartocci M, Rettedal SI, Lundberg F, Odelberg-Johnson P, Szczapa T, Thordarson T, Pilypiene I, Thorkelsson T, Soderstrom L, Chijenas V, Jonsson B. Comparison of Respiratory Support After Delivery in Infants Born Before 28 Weeks' Gestational Age: The CORSAD Randomized Clinical Trial. JAMA Pediatr 2021; 175:911-918. [PMID: 34125148 PMCID: PMC8424478 DOI: 10.1001/jamapediatrics.2021.1497] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
IMPORTANCE Establishing stable breathing is a key event for preterm infants after birth. Delivery of pressure-stable continuous positive airway pressure and avoiding face mask use could be of importance in the delivery room. OBJECTIVE To determine whether using a new respiratory support system with low imposed work of breathing and short binasal prongs decreases delivery room intubations or death compared with a standard T-piece system with a face mask. DESIGN, SETTING, AND PARTICIPANTS In this unblinded randomized clinical trial, mothers threatening preterm delivery before week 28 of gestation were screened. A total of 365 mothers were enrolled, and 250 infants were randomized before birth and 246 liveborn infants were treated. The trial was conducted in 7 neonatal intensive care units in 5 European countries from March 2016 to May 2020. The follow-up period was 72 hours after intervention. INTERVENTIONS Infants were randomized to either the new respiratory support system with short binasal prongs (n = 124 infants) or the standard T-piece system with face mask (n = 122 infants). The intervention was providing continuous positive airway pressure for 10 to 30 minutes and positive pressure ventilation, if needed, with the randomized system. MAIN OUTCOMES AND MEASURES The primary outcome was delivery room intubation or death within 30 minutes of birth. Secondary outcomes included respiratory and safety variables. RESULTS Of 246 liveborn infants treated, the mean (SD) gestational age was 25.9 (1.3) weeks, and 127 (51.6%) were female. A total of 41 infants (33.1%) receiving the new respiratory support system were intubated or died in the delivery room compared with 55 infants (45.1%) receiving standard care. The adjusted odds ratio was statistically significant after adjusting for stratification variables (adjusted odds ratio, 0.53; 95% CI, 0.30-0.94; P = .03). No significant differences were seen in secondary outcomes or safety variables. CONCLUSIONS AND RELEVANCE In this study, using the new respiratory support system reduced delivery room intubation in extremely preterm infants. Stabilizing preterm infants with a system that has low imposed work of breathing and binasal prongs as interface is safe and feasible. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02563717.
Collapse
Affiliation(s)
- Snorri Donaldsson
- Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden,Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Thomas Drevhammar
- Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden,Department of Anesthesiology and ICU, Östersund Hospital, Östersund, Sweden
| | - Yinghua Li
- Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden,Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | - Marco Bartocci
- Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden,Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | | | - Fredrik Lundberg
- Department of Neonatology, Linköping University Hospital, Linköping, Sweden
| | | | - Tomasz Szczapa
- Department of Neonatology, Neonatal Biophysical Monitoring and Cardiopulmonary Therapies Research Unit, Poznan University of Medical Sciences, Poznan, Poland
| | - Thordur Thordarson
- Department of Neonatology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ingrida Pilypiene
- Department of Neonatology, Vilnius University Hospital, Vilnius, Lithuania
| | - Thordur Thorkelsson
- Department of Neonatology, The National University Hospital of Iceland, Reykjavík, Iceland
| | - Lars Soderstrom
- Unit of Research, Education and Development, Östersund Hospital, Östersund, Sweden
| | | | - Baldvin Jonsson
- Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden,Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden
| | | |
Collapse
|
15
|
McGillick EV, Te Pas AB, Croughan MK, Crossley KJ, Wallace MJ, Lee K, Thio M, DeKoninck PLJ, Dekker J, Flemmer AW, Cramer SJE, Hooper SB, Kitchen MJ. Increased end-expiratory pressures improve lung function in near-term newborn rabbits with elevated airway liquid volume at birth. J Appl Physiol (1985) 2021; 131:997-1008. [PMID: 34351817 DOI: 10.1152/japplphysiol.00918.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Approximately 53% of near-term newborns admitted to intensive care experience respiratory distress. These newborns are commonly delivered by cesarean section and have elevated airway liquid volumes at birth, which can cause respiratory morbidity. We investigated the effect of providing respiratory support with a positive end-expiratory pressure (PEEP) of 8 cmH2O on lung function in newborn rabbit kittens with elevated airway liquid volumes at birth. Near-term rabbits (30 days; term = 32 days) with airway liquid volumes that corresponded to vaginal delivery (∼7 mL/kg, control, n = 11) or cesarean section [∼37 mL/kg; elevated liquid (EL), n = 11] were mechanically ventilated (tidal volume = 8 mL/kg). The PEEP was changed after lung aeration from 0 to 8 to 0 cmH2O (control, n = 6; EL, n = 6), and in a separate group of kittens, PEEP was changed after lung aeration from 8 to 0 to 8 cmH2O (control, n = 5; EL, n = 5). Lung function (ventilator parameters, compliance, lung gas volumes, and distribution of gas within the lung) was evaluated using plethysmography and synchrotron-based phase-contrast X-ray imaging. EL kittens initially receiving 0 cmH2O PEEP had reduced functional residual capacities and lung compliance, requiring higher inflation pressures to aerate the lung compared with control kittens. Commencing ventilation with 8 cmH2O PEEP mitigated the adverse effects of EL, increasing lung compliance, functional residual capacity, and the uniformity and distribution of lung aeration, but did not normalize aeration of the distal airways. Respiratory support with PEEP supports lung function in near-term newborn rabbits with elevated airway liquid volumes at birth who are at a greater risk of suffering respiratory distress.NEW & NOTEWORTHY Term babies born by cesarean section have elevated airway liquid volumes, which predisposes them to respiratory distress. Treatments targeting molecular mechanisms to clear lung liquid are ineffective for term newborn respiratory distress. We showed that respiratory support with an end-expiratory pressure supports lung function in near-term rabbits with elevated airway liquid volumes at birth. This study provides further physiological understanding of lung function in newborns with elevated airway liquid volumes at risk of respiratory distress.
Collapse
Affiliation(s)
- Erin V McGillick
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Michelle K Croughan
- School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Megan J Wallace
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Katie Lee
- School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia
| | - Marta Thio
- Newborn Research, The Royal Women's Hospital, Melbourne, Victoria, Australia.,The Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Philip L J DeKoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia.,Division of Obstetrics and Fetal Medicine, Department of Obstetrics and Gynecology, Erasmus Medical Center University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Janneke Dekker
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Andreas W Flemmer
- Division of Neonatology, University Children's Hospital and Perinatal Centre, Ludwig-Maximilians University, Munich, Germany
| | - Sophie J E Cramer
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Marcus J Kitchen
- School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
16
|
Inocencio IM, Tran NT, Khor SJ, Wiersma M, Nakamura S, Walker DW, Wong FY. The cerebral haemodynamic response to somatosensory stimulation in preterm newborn lambs is reduced with dopamine or dobutamine infusion. Exp Neurol 2021; 341:113687. [PMID: 33713656 DOI: 10.1016/j.expneurol.2021.113687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/03/2021] [Accepted: 03/07/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND In the adult brain, increases in neural activity lead to increases in local blood flow. However, in the preterm neonate, studies of cerebral functional haemodynamics have yielded inconsistent results, including negative responses suggesting decreased perfusion and localised tissue hypoxia, probably due to immature neurovascular coupling. Furthermore, the impact of vasoactive medications, such as dopamine and dobutamine used as inotropic therapies in preterm neonates, on cerebrovascular responses to somatosensory input is unknown. We aimed to characterise the cerebral haemodynamic functional response after somatosensory stimulation in the preterm newborn brain, with and without dopamine or dobutamine treatment. METHODS We studied the cerebral haemodynamic functional response in 13 anaesthetised preterm lambs, using near infrared spectroscopy to measure changes in cerebral oxy- and deoxyhaemoglobin (ΔoxyHb, ΔdeoxyHb) following left median nerve stimulation using stimulus trains of 1.8, 4.8 and 7.8 s. The 4.8 and 7.8 s stimulations were repeated during dopamine or dobutamine infusion. RESULTS Stimulation always produced a somatosensory evoked response. Majority of preterm lambs demonstrated positive functional responses (i.e. increased ΔoxyHb) in the contralateral cortex following stimulus trains of all durations. Dopamine increased baseline oxyHb and total Hb, whereas dobutamine increased baseline deoxyHb. Both dopamine and dobutamine reduced the evoked ΔoxyHb responses to 4.8 and 7.8 s stimulations. CONCLUSIONS Somatosensory stimulation increases cerebral oxygenation in the preterm brain, consistent with increased cerebral blood flow due to neurovascular coupling. Notably, our results show that dopamine/dobutamine reduces oxygen delivery relative to consumption in the preterm brain during somatosensory stimulations, suggesting there may be a risk of intermittent localised tissue hypoxia which has clear implications for clinical practice and warrants further investigation.
Collapse
Affiliation(s)
- Ishmael M Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Nhi T Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; School of Health & Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Song J Khor
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Manon Wiersma
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia
| | - Shinji Nakamura
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - David W Walker
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; School of Health & Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Flora Y Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, Australia; Department of Paediatrics, Monash University, Melbourne, Australia; Monash Newborn, Monash Medical Centre, Melbourne, Australia.
| |
Collapse
|
17
|
Cardiovascular management following hypoxic-ischemic encephalopathy in North America: need for physiologic consideration. Pediatr Res 2021; 90:600-607. [PMID: 33070162 PMCID: PMC8249436 DOI: 10.1038/s41390-020-01205-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/19/2020] [Accepted: 07/06/2020] [Indexed: 01/29/2023]
Abstract
BACKGROUND Hypotension and hypoxemic respiratory failure are common among neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). Right ventricular (RV) dysfunction is associated with adverse neurodevelopment. Individualized management utilizing targeted neonatal echocardiography (TnECHO) may enhance care. METHODS We evaluated the influence of TnECHO programs on cardiovascular practices in HIE/TH patients utilizing a 77-item REDCap survey. Nominated representatives of TnECHO (n = 19) or non-TnECHO (n = 96) sites were approached. RESULTS Seventy-one (62%) sites responded. Baseline neonatal intensive care unit characteristics and HIE volume were comparable between groups. Most centers monitor invasive blood pressure; however, we identified 17 unique definitions of hypotension. TnECHO centers were likelier to trend systolic/diastolic blood pressure and request earlier echocardiography. TnECHO responders were less likely to use fluid boluses; TnECHO responders more commonly chose an inotrope first-line, while non-TnECHO centers used a vasopressor. For HRF, TnECHO centers chose vasopressors with a favorable pulmonary vascular profile. Non-TnECHO centers used more dopamine and more extracorporeal membrane oxygen for patients with HRF. CONCLUSIONS Cardiovascular practices in neonates with HIE differ between centers with and without TnECHO. Consensus regarding the definition of hypotension is lacking and dopamine use is common. The merits of these practices among these patients, who frequently have comorbid pulmonary hypertension and RV dysfunction, need prospective evaluation. IMPACT Cardiovascular care following HIE while undergoing therapeutic hypothermia varies between centers with access to trained hemodynamics specialists and those without. Because cardiovascular dysfunction is associated with brain injury, precision medicine-based care may be an avenue to improving outcomes. Therapeutic hypothermia has introduced new physiological considerations and enhanced survival. It is essential that hemodynamic strategies evolve to keep pace; however, little literature exists. Lack of consensus regarding fundamental definitions (e.g., hypotension) highlights the importance of collaboration among the scientific community to advance the field. The value of enhanced cardiovascular care guided by hemodynamic specialists requires prospective evaluation.
Collapse
|
18
|
Feng SYS, Rao S, Patole S. A survey on criteria for intubation in moderate to late preterm infants with respiratory distress. Pediatr Pulmonol 2020; 55:2970-2982. [PMID: 32886426 DOI: 10.1002/ppul.25054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/14/2020] [Accepted: 08/26/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Majority of preterm infants do well with continuous positive airway pressure (CPAP) as the sole respiratory management; but some require endotracheal intubation and surfactant administration. While intubation is needed predominantly in extremely preterm infants (<28 weeks); some of the more mature preterm infants also require it. Currently, there are no clear guidelines regarding indications for endotracheal intubation in such infants. AIMS To understand the current practice regarding "criteria for intubation" in moderate to late preterm infants with respiratory distress. METHODS A survey of neonatologists in Australia New Zealand Neonatal Network (ANZNN) was conducted between April and June 2019. RESULTS At least one neonatologist each from 29 of the 30 tertiary ANZNN Neonatal Intensive Care Units (NICUs) responded to the survey. In total, 118/200 (59%) neonatologists responded. The most common criteria for intubation were CPAP = 8 cmH2 O (61%), pH < 7.2 (55%), pCO2 > 70 mmHg (48%), FiO2 > 40% (40%), chest retractions (48%), more than two episodes of apnea requiring intervention (54%), and chest X-ray (CXR) showing moderate-severe hyaline membrane disease (HMD, 49%). CONCLUSION While there were variations in practice, nearly 50% of the neonatologists shared a common threshold with regards to the CPAP level, FiO2 , blood gas parameters, and clinical and radiological findings. The results of this survey will help in designing future randomized controlled trials (RCTs) on this subject.
Collapse
Affiliation(s)
- Susan Y S Feng
- Neonatal Directorate, King Edward Memorial Hospital and Perth Children's Hospital, Subiaco, Western Australia, Australia
| | - Shripada Rao
- Neonatal Directorate, King Edward Memorial Hospital and Perth Children's Hospital, Subiaco, Western Australia, Australia
| | - Sanjay Patole
- Neonatal Directorate, King Edward Memorial Hospital and Perth Children's Hospital, Subiaco, Western Australia, Australia
| |
Collapse
|
19
|
Inocencio IM, Tran NT, Nakamura S, Khor SJ, Wiersma M, Stoecker K, Polglase GR, Pearson JT, Wong FY. Increased peak end-expiratory pressure in ventilated preterm lambs changes cerebral microvascular perfusion: direct synchrotron microangiography assessment. J Appl Physiol (1985) 2020; 129:1075-1084. [PMID: 32909920 DOI: 10.1152/japplphysiol.00652.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Positive end-expiratory pressure (PEEP) improves oxygenation in mechanically ventilated preterm neonates by preventing lung collapse. However, high PEEP may alter cerebral blood flow secondarily to the increased intrathoracic pressure, predisposing to brain injury. The precise effects of high PEEP on cerebral hemodynamics in the preterm brain are unknown. We aimed to assess the effect of PEEP on microvessels in the preterm brain by using synchrotron radiation (SR) microangiography, which enables in vivo real-time high-resolution imaging of the cerebral vasculature. Preterm lambs (0.8 gestation, n = 4) were delivered via caesarean section, anesthetized, and ventilated. SR microangiography of the right cerebral hemisphere was performed with iodine contrast administered into the right carotid artery during PEEP ventilation of 5 and 10 cmH2O. Carotid blood flow was measured using an ultrasonic flow probe placed around the left carotid artery. An increase of PEEP from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm) in all four lambs. Additionally, the higher PEEP increased the cerebral contrast transit time in three of the four lambs. Carotid blood flow increased in two lambs, which also had increased carbon dioxide levels during PEEP 10. Our results suggest that PEEP of 10 cmH2O alters the preterm cerebral hemodynamics, with prolonged cerebral blood flow transit and engorgement of small cerebral microvessels likely due to the increased intrathoracic pressure. These microvascular changes are generally not reflected in global assessment of cerebral blood flow or oxygenation.NEW & NOTEWORTHY An increase of positive end-expiratory pressure (PEEP) from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm). This suggests increased intrathoracic pressure due to high PEEP can drive microvessel engorgement in the preterm brain, which may play a role in cerebrovascular injury.
Collapse
Affiliation(s)
- Ishmael Miguel Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Nhi Thao Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Shinji Nakamura
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Song J Khor
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Manon Wiersma
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Katja Stoecker
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre, Osaka, Japan.,Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Flora Y Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia.,Monash Newborn, Monash Medical Centre, Melbourne, VIC, Australia
| |
Collapse
|
20
|
Martherus T, Crossley KJ, Rodgers KA, Dekker J, Demel A, Moxham AM, Zahra VA, Polglase GR, Roberts CT, Te Pas AB, Hooper SB. High-CPAP Does Not Impede Cardiovascular Changes at Birth in Preterm Sheep. Front Pediatr 2020; 8:584138. [PMID: 33553064 PMCID: PMC7862825 DOI: 10.3389/fped.2020.584138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/22/2020] [Indexed: 12/04/2022] Open
Abstract
Objective: Continuous positive airway pressures (CPAP) used to assist preterm infants at birth are limited to 4-8 cmH2O due to concerns that high-CPAP may cause pulmonary overexpansion and adversely affect the cardiovascular system. We investigated the effects of high-CPAP on pulmonary (PBF) and cerebral (CBF) blood flows and jugular vein pressure (JVP) after birth in preterm lambs. Methods: Preterm lambs instrumented with flow probes and catheters were delivered at 133/146 days gestation. Lambs received low-CPAP (LCPAP: 5 cmH2O), high-CPAP (HCPAP: 15 cmH2O) or dynamic HCPAP (15 decreasing to 8 cmH2O at ~2 cmH2O/min) for up to 30 min after birth. Results: Mean PBF was lower in the LCPAP [median (Q1-Q3); 202 (48-277) mL/min, p = 0.002] compared to HCPAP [315 (221-365) mL/min] and dynamic HCPAP [327 (269-376) mL/min] lambs. CBF was similar in LCPAP [65 (37-78) mL/min], HCPAP [73 (41-106) mL/min], and dynamic HCPAP [66 (52-81) mL/min, p = 0.174] lambs. JVP was similar at CPAPs of 5 [8.0 (5.1-12.4) mmHg], 8 [9.4 (5.3-13.4) mmHg], and 15 cmH2O [8.6 (6.9-10.5) mmHg, p = 0.909]. Heart rate was lower in the LCPAP [134 (101-174) bpm; p = 0.028] compared to the HCPAP [173 (139-205)] and dynamic HCPAP [188 (161-207) bpm] groups. Ventilation or additional caffeine was required in 5/6 LCPAP, 1/6 HCPAP, and 5/7 dynamic HCPAP lambs (p = 0.082), whereas 3/6 LCPAP, but no HCPAP lambs required intubation (p = 0.041), and 1/6 LCPAP, but no HCPAP lambs developed a pneumothorax (p = 0.632). Conclusion: High-CPAP did not impede the increase in PBF at birth and supported preterm lambs without affecting CBF and JVP.
Collapse
Affiliation(s)
- Tessa Martherus
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Karyn A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Janneke Dekker
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands.,The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Anja Demel
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Alison M Moxham
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Valerie A Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynecology, Monash University, Melbourne, VIC, Australia
| | - Calum T Roberts
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Monash Newborn, Monash Medical Centre, Melbourne, VIC, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynecology, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
21
|
Lambert CJ, Hooper SB, Te Pas AB, McGillick EV. Improving Newborn Respiratory Outcomes With a Sustained Inflation: A Systematic Narrative Review of Factors Regulating Outcome in Animal and Clinical Studies. Front Pediatr 2020; 8:516698. [PMID: 33194881 PMCID: PMC7658322 DOI: 10.3389/fped.2020.516698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 08/13/2020] [Indexed: 11/13/2022] Open
Abstract
Respiratory support is critically important for survival of newborns who fail to breathe spontaneously at birth. Although there is no internationally accepted definition of a sustained inflation (SI), it has commonly been defined as a positive pressure inflation designed to establish functional residual capacity and applied over a longer time period than normally used in standard respiratory support (SRS). Outcomes vary distinctly between studies and to date there has been no comprehensive investigation of differences in SI approach and study outcome in both pre-clinical and clinical studies. A systematic literature search was performed and, after screening, identified 17 animal studies and 17 clinical studies evaluating use of a SI in newborns compared to SRS during neonatal resuscitation. Study demographics including gestational age, SI parameters (length, repetitions, pressure, method of delivery) and study outcomes were compared. Animal studies provide mechanistic understanding of a SI on the physiology underpinning the cardiorespiratory transition at birth. In clinical studies, there is considerable difference in study quality, delivery of SIs (number, pressure, length) and timing of primary outcome evaluation which limits direct comparison between studies. The largest difference is method of delivery, where the role of a SI has been observed in intubated animals, as the inflation pressure is directly applied to the lung, bypassing the obstructed upper airway in an apnoeic state. This highlights a potential limitation in clinical use of a SI applied non-invasively. Further research is required to identify if a SI may have greater benefits in subpopulations of newborns.
Collapse
Affiliation(s)
- Calista J Lambert
- The Ritchie Centre Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Stuart B Hooper
- The Ritchie Centre Hudson Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Erin V McGillick
- The Ritchie Centre Hudson Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
22
|
Allison BJ, Youn H, Malhotra A, McDonald CA, Castillo-Melendez M, Pham Y, Sutherland AE, Jenkin G, Polglase GR, Miller SL. Is Umbilical Cord Blood Therapy an Effective Treatment for Early Lung Injury in Growth Restriction? Front Endocrinol (Lausanne) 2020; 11:86. [PMID: 32194502 PMCID: PMC7063054 DOI: 10.3389/fendo.2020.00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/11/2020] [Indexed: 11/22/2022] Open
Abstract
Fetal growth restriction (FGR) and prematurity are often co-morbidities, and both are risk factors for lung disease. Despite advances in early delivery combined with supportive ventilation, rates of ventilation-induced lung injury (VILI) remain high. There are currently no protective treatments or interventions available that target lung morbidities associated with FGR preterm infants. Stem cell therapy, such as umbilical cord blood (UCB) cell administration, demonstrates an ability to attenuate inflammation and injury associated with VILI in preterm appropriately grown animals. However, no studies have looked at the effects of stem cell therapy in growth restricted newborns. We aimed to determine if UCB treatment could attenuate acute inflammation in the first 24 h of ventilation, comparing effects in lambs born preterm following FGR with those born preterm but appropriately grown (AG). Placental insufficiency (FGR) was induced by single umbilical artery ligation in twin-bearing ewes at 88 days gestation, with twins used as control (appropriately grown, AG). Lambs were delivered preterm at ~126 days gestation (term is 150 days) and randomized to either immediate euthanasia (unventilated controls, AGUVC and FGRUVC) or commenced on 24 h of gentle supportive ventilation (AGV and FGRV) with additional cohorts receiving UCB treatment at 1 h (AGCELLS, FGRCELLS). Lungs were collected at post-mortem for histological and biochemical examination. Ventilation caused lung injury in AG lambs, as indicated by decreased septal crests and elastin density, as well as increased inflammation. Lung injury in AG lambs was attenuated with UCB therapy. Ventilated FGR lambs also sustained lung injury, albeit with different indices compared to AG lambs; in FGR, ventilation reduced septal crest density, reduced alpha smooth muscle actin density and reduced cell proliferation. UCB treatment in ventilated FGR lambs further decreased septal crest density and increased collagen deposition, however, it increased angiogenesis as evidenced by increased vascular endothelial growth factor (VEGF) expression and vessel density. This is the first time that a cell therapy has been investigated in the lungs of growth restricted animals. We show that the uterine environment can alter the response to both secondary stress (ventilation) and therapy (UCB). This study highlights the need for further research on the potential impact of novel therapies on a growth restricted offspring.
Collapse
Affiliation(s)
- Beth J. Allison
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
- *Correspondence: Beth J. Allison
| | - Hannah Youn
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Atul Malhotra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Monash Newborn, Monash Medical Centre, Clayton, VIC, Australia
| | - Courtney A. McDonald
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Margie Castillo-Melendez
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Yen Pham
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Amy E. Sutherland
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Graham Jenkin
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| | - Suzanne L. Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology and Paediatrics, Monash University, Clayton, VIC, Australia
| |
Collapse
|
23
|
Gomo ØH, Eilevstjønn J, Holte K, Yeconia A, Kidanto H, Ersdal HL. Delivery of Positive End-Expiratory Pressure Using Self-Inflating Bags during Newborn Resuscitation Is Possible Despite Mask Leak. Neonatology 2020; 117:341-348. [PMID: 32610333 DOI: 10.1159/000507829] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/08/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Ventilation is the key intervention to resuscitate non-breathing newborns. Positive end-expiratory pressure (PEEP) may facilitate lung-liquid clearance and help establish functional residual capacity. OBJECTIVES The aim of this study was to describe how mask leak and ventilation rates affect delivered PEEP and tidal volumes during newborn resuscitations using a self-inflating bag with an integrated PEEP valve. METHODS This was an observational study including near-term/term newborns who received bag-mask ventilation (BMV) with a new self-inflating bag with a novel 6 mbar PEEP valve, without external gas flow, between October 1, 2016 and June 30, 2018 in rural Tanzania. Helping Babies Breathe-trained midwives performed most of the resuscitations. Pressures and flow were continuously measured and recorded by resuscitation monitors. RESULTS In total, 198 newborns with a median gestation of 39 weeks (25th, 75th percentiles 37, 40) and birth weight of 3,100 g (2,580, 3,500) were included. The median delivered PEEP and expired (tidal) volume at different levels of mask leak were 6.0 mbar and 11.3 mL/kg at 0-20% mask leak, 5.5 mbar and 9.3 mL/kg at 20-40%, 5.2 mbar and 7.8 mL/kg at 40-60%, 4.6 mbar and 5.0 mL/kg at 60-80%, and 1.0 mbar and 0.6 mL/kg at 80-100% mask leak. A high ventilation rate (>60/min) nearly halved expired volumes compared to <60/min for 0-60% leak. The BMV rate had a negligible effect on peak inflation pressure (PIP) and PEEP. CONCLUSIONS Mask leak up to 80% did not impair the provision of recommended PEEP or tidal volumes during BMV with a self-inflating bag. High or low ventilation rates did not significantly affect PIP or PEEP. Expired volumes were reduced at ventilation rates >60/min.
Collapse
Affiliation(s)
| | - Joar Eilevstjønn
- Research and Development Department, Laerdal Medical, Stavanger, Norway
| | - Kari Holte
- Neonatal Department, Østfold Hospital Trust, Grålum, Norway
| | - Anita Yeconia
- Research Department, Haydom Lutheran Hospital, Haydom, Tanzania
| | - Hussein Kidanto
- Medical College, Aga Khan University, Dar es Salaam, Tanzania.,Department of Anesthesiology and Intensive Care, Stavanger University Hospital, Stavanger, Norway
| | - Hege Langli Ersdal
- Department of Anesthesiology and Intensive Care, Stavanger University Hospital, Stavanger, Norway.,Faculty of Health Sciences, University of Stavanger, Stavanger, Norway
| |
Collapse
|
24
|
Kashyap AJ, Hodges RJ, Thio M, Rodgers KA, Amberg BJ, McGillick EV, Hooper SB, Crossley KJ, DeKoninck PLJ. Physiologically based cord clamping improves cardiopulmonary haemodynamics in lambs with a diaphragmatic hernia. Arch Dis Child Fetal Neonatal Ed 2020; 105:18-25. [PMID: 31123056 DOI: 10.1136/archdischild-2019-316906] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Lung hypoplasia associated with congenital diaphragmatic hernia (CDH) results in respiratory insufficiency and pulmonary hypertension after birth. We have investigated whether aerating the lung before removing placental support (physiologically based cord clamping (PBCC)), improves the cardiopulmonary transition in lambs with a CDH. METHODS At ≈138 days of gestational age, 17 lambs with surgically induced left-sided diaphragmatic hernia (≈d80) were delivered via caesarean section. The umbilical cord was clamped either immediately prior to ventilation onset (immediate cord clamping (ICC); n=6) or after achieving a target tidal volume of 4 mL/kg, with a maximum delay of 10 min (PBCC; n=11). Lambs were ventilated for 120 min and physiological changes recorded. RESULTS Pulmonary blood flow (PBF) increased following ventilation onset in both groups, but was 19-fold greater in PBCC compared with ICC lambs at cord clamping (19±6.3 vs 1.0±0.5 mL/min/kg, p<0.001). Cerebral tissue oxygenation was higher in PBCC than ICC lambs during the first 10 min after cord clamping (59%±4% vs 30%±5%, p<0.001). PBF was threefold higher (23±4 vs 8±2 mL/min/kg, p=0.01) and pulmonary vascular resistance (PVR) was threefold lower (0.6±0.1 vs 2.2±0.6 mm Hg/(mL/min), p<0.001) in PBCC lambs compared with ICC lambs at 120 min after ventilation onset. CONCLUSIONS Compared with ICC, PBCC prevented the severe asphyxia immediately after birth and resulted in a higher PBF due to a lower PVR, which persisted for at least 120 min after birth in CDH lambs.
Collapse
Affiliation(s)
- Aidan J Kashyap
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Ryan J Hodges
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Monash Women's Service, Monash Health, Melbourne, Victoria, Australia
| | - Marta Thio
- Newborn Research, Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Karyn A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Ben J Amberg
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Erin V McGillick
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Stuart B Hooper
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia.,The Ritchie Centre, The Hudson Institute for Medical Research, Clayton, Victoria, Australia
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Philip L J DeKoninck
- The Ritchie Centre, The Hudson Institute for Medical Research, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Erasmus MC, Rotterdam, Zuid-Holland, The Netherlands
| |
Collapse
|
25
|
Su LX, Shang XL, Zhu R, He W, Pan P, Zhang HM, Zhang LN, Liu DW, Yu RG, Wang XT. A cross-sectional study of acute cor pulmonale in acute respiratory distress syndrome patients in China. Chin Med J (Engl) 2019; 132:2842-2847. [PMID: 31856056 PMCID: PMC6940069 DOI: 10.1097/cm9.0000000000000531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Increased right ventricle afterload during acute respiratory distress syndrome (ARDS) may induce acute cor pulmonale (ACP), which is associated with a poor clinical outcome. Echocardiography is now considered as a rapid and non-invasive tool for diagnosis of ACP. The aims of this study were to investigate the morbidity and mortality rates of ACP in ARDS patients in intensive care units (ICUs) across the mainland of China and to determine the severity and prognosis of ACP in ARDS patients through an ultrasound protocol (TRIP). And the association between ACP related factors and the ICU mortality will be revealed. METHODS This study is a multicenter and cross-sectional study in China which will include ICU participants when diagnosed as ARDS. The ultrasound protocol, known as the TRIP, is proposed as severity assessment for ACP, which includes tricuspid regurgitation velocity (T), right ventricular size (R), inferior vena cava diameter fluctuation (I), and pulmonary regurgitation velocity (P). The 28-day mortality, ICU/hospital mortality, the length of stay in ICU, mechanical ventilation days, hemodynamic parameters and lab parameters of liver function and kidney function are all recorded. DISCUSSION This large-scale study would give a sufficient epidemic investigation of ACP in ARDS patients in China. In addition, with the TRIP protocol, we expect that we could stratify ACP with more echocardiography parameters. TRIAL REGISTRATION NCT03827863, https://clinicaltrials.gov/ct2/show/NCT03827863.
Collapse
Affiliation(s)
- Long-Xiang Su
- Department of Critical Care Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Xiu-Ling Shang
- Department of Critical Care Medicine, Fujian Provincial Hospital, Fujian Provincial Center for Critical Care Medicine, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Ran Zhu
- Department of Critical Care Medicine, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Wei He
- Department of Critical Care Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Pan Pan
- Department of Respiratory and Critical Care Medicine, Chinese PLA General Hospital, Beijing 100853, China
| | - Hong-Min Zhang
- Department of Critical Care Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Li-Na Zhang
- Department of Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Da-Wei Liu
- Department of Critical Care Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Rong-Guo Yu
- Department of Critical Care Medicine, Fujian Provincial Hospital, Fujian Provincial Center for Critical Care Medicine, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Xiao-Ting Wang
- Department of Critical Care Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| |
Collapse
|
26
|
DeKoninck PLJ, Crossley KJ, Kashyap AJ, Skinner SM, Thio M, Rodgers KA, Deprest JA, Hooper SB, Hodges RJ. Effects of tracheal occlusion on the neonatal cardiopulmonary transition in an ovine model of diaphragmatic hernia. Arch Dis Child Fetal Neonatal Ed 2019; 104:F609-F616. [PMID: 30728180 DOI: 10.1136/archdischild-2018-316047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/27/2018] [Accepted: 01/02/2019] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Fetoscopic endoluminal tracheal occlusion (FETO) aims to reverse pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and mitigate the associated respiratory insufficiency and pulmonary hypertension after birth. We aimed to determine whether FETO improves the cardiopulmonary transition at birth in an ovine model of CDH. METHODS In 12 ovine fetuses with surgically induced diaphragmatic hernia (DH; 80 dGA), an endotracheal balloon was placed tracheoscopically at ≈110 dGA and removed at ≈131 dGA (DH+FETO), while 10 were left untreated (DH). At ≈138 dGA, all lambs (survival at delivery: 67% [DH+FETO], 70% [DH]) were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood-gas values were measured. RESULTS Compared with DH, DH+FETO lambs had increased wet lung-to-body-weight ratio (0.031±0.004 vs 0.016±0.002) and dynamic lung compliance (0.7±0.1 vs 0.4±0.1 mL/cmH2O). Pulmonary vascular resistance was lower in DH+FETO lambs (0.44±0.11 vs 1.06±0.17 mm Hg/[mL/min]). However, after correction for lung weight, pulmonary blood flow was not significantly different between the groups (4.19±0.57 vs 4.05±0.60 mL/min/g). Alveolar-arterial difference in oxygen tension was not significantly different between DH+FETO and DH (402±41mm Hg vs 401±45 mm Hg). CONCLUSIONS FETO accelerated lung growth in fetuses with CDH and improved neonatal respiratory function during the cardiopulmonary transition at birth. However, despite improved lung compliance and reduced pulmonary vascular resistance, there were less pronounced benefits for gas exchange during the first 2 hours of life.
Collapse
Affiliation(s)
- Philip L J DeKoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Erasmus MC, Rotterdam, The Netherlands
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Aidan J Kashyap
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Sasha M Skinner
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Marta Thio
- Newborn Research, The Royal Women's Hospital, Melbourne, Victoria, Australia.,The Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Karyn A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Jan A Deprest
- Department of Obstetrics and Gynaecology, Division Woman and Child, University Hospitals Leuven, Leuven, Belgium.,Department of Development and Regeneration, Cluster Woman and Child, Faculty of Medicine, KU Leuven, Leuven, Belgium.,Institute for Women's Health, University College London Hospital, London, UK
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Ryan J Hodges
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia.,Monash Women's Service, Monash Health, Melbourne, Victoria, Australia
| |
Collapse
|
27
|
Kashyap AJ, Crossley KJ, DeKoninck PLJ, Rodgers KA, Thio M, Skinner SM, Deprest JA, Hooper SB, Hodges RJ. Neonatal cardiopulmonary transition in an ovine model of congenital diaphragmatic hernia. Arch Dis Child Fetal Neonatal Ed 2019; 104:F617-F623. [PMID: 30728182 DOI: 10.1136/archdischild-2018-316045] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 01/04/2019] [Accepted: 01/15/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Infants with a congenital diaphragmatic hernia (CDH) are at high risk of developing pulmonary hypertension after birth, but little is known of their physiological transition at birth. We aimed to characterise the changes in cardiopulmonary physiology during the neonatal transition in an ovine model of CDH. METHODS A diaphragmatic hernia (DH) was surgically created at 80 days of gestational age (dGA) in 10 fetuses, whereas controls underwent sham surgery (n=6). At 138 dGA, lambs were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood gas values were measured. RESULTS DH lambs had lower wet lung-to-body-weight ratio (0.016±0.002vs0.033±0.004), reduced dynamic lung compliance (0.4±0.1mL/cmH2O vs1.2±0.1 mL/cmH2O) and reduced arterial pH (7.11±0.05vs7.26±0.05), compared with controls. While measured pulmonary blood flow (PBF) was lower in DH lambs, after correction for lung weight, PBF was not different between groups (4.05±0.60mL/min/gvs4.29±0.57 mL/min/g). Cerebral tissue oxygen saturation was lower in DH compared with control lambs (55.7±3.5vs67.7%±3.9%). CONCLUSIONS Immediately after birth, DH lambs have small, non-compliant lungs, respiratory acidosis and poor cerebral oxygenation that reflects the clinical phenotype of human CDH. PBF (indexed to lung weight) was similar in DH and control lambs, suggesting that the reduction in PBF associated with CDH is proportional to the degree of lung hypoplasia during the neonatal cardiopulmonary transition.
Collapse
Affiliation(s)
- Aidan J Kashyap
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Kelly J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Philip L J DeKoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Erasmus MC, Rotterdam, Zuid-Holland, The Netherlands
| | - Karyn A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Marta Thio
- Newborn Research, Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia.,The Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Sasha M Skinner
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Jan A Deprest
- Fetal Medicine Unit, Division Woman and Child, Department of Obstetrics and Gynecology, Katholieke Univ Leuven, Leuven, Belgium.,Institute of Women's Health, University College London Hospitals, University College London Medical School, London, UK
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Ryan J Hodges
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Monash Women's Service, Monash Health, Melbourne, Victoria, Australia
| |
Collapse
|
28
|
Kashyap AJ, Dekoninck PLJ, Rodgers KA, Thio M, Mcgillick EV, Amberg BJ, Skinner SM, Moxham AM, Russo FM, Deprest JA, Hooper SB, Crossley KJ, Hodges RJ. Antenatal sildenafil treatment improves neonatal pulmonary hemodynamics and gas exchange in lambs with diaphragmatic hernia. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2019; 54:506-516. [PMID: 31364206 DOI: 10.1002/uog.20415] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 07/06/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES Infants with congenital diaphragmatic hernia (CDH) are predisposed to pulmonary hypertension after birth, owing to lung hypoplasia that impairs fetal pulmonary vascular development. Antenatal sildenafil treatment attenuates abnormal pulmonary vascular and alveolar development in rabbit and rodent CDH models, but whether this translates to functional improvements after birth remains unknown. We aimed to evaluate the effect of antenatal sildenafil on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia (DH). METHODS DH was surgically induced at approximately 80 days' gestation in 16 lamb fetuses (term in lambs is approximately 147 days). From 105 days' gestation, ewes received either sildenafil (0.21 mg/kg/h intravenously) or saline infusion until delivery (n = 8 fetuses in each group). At approximately 138 days' gestation, all lambs were instrumented and then delivered via Cesarean section. The lambs were ventilated for 120 min with continuous recording of physiological (pulmonary and carotid artery blood flow and pressure; cerebral oxygenation) and ventilatory parameters, and regular assessment of arterial blood gas tensions. Only lambs that survived until delivery and with a confirmed diaphragmatic defect at postmortem examination were included in the analysis; these comprised six DH-sildenafil lambs and six DH-saline control lambs. RESULTS Lung-to-body-weight ratio (0.016 ± 0.001 vs 0.013 ± 0.001; P = 0.06) and dynamic lung compliance (0.8 ± 0.2 vs 0.7 ± 0.2 mL/cmH2 O; P = 0.72) were similar in DH-sildenafil lambs and controls. Pulmonary vascular resistance decreased following lung aeration to a greater degree in DH-sildenafil lambs, and was 4-fold lower by 120 min after cord clamping than in controls (0.6 ± 0.1 vs 2.2 ± 0.6 mmHg/(mL/min); P = 0.002). Pulmonary arterial pressure was also lower (46 ± 2 vs 59 ± 2 mmHg; P = 0.048) and pulmonary blood flow higher (25 ± 3 vs 8 ± 2 mL/min/kg; P = 0.02) in DH-sildenafil than in DH-saline lambs at 120 min. Throughout the 120-min ventilation period, the partial pressure of arterial carbon dioxide tended to be lower in DH-sildenafil lambs than in controls (63 ± 8 vs 87 ± 8 mmHg; P = 0.057), and there was no significant difference in partial pressure of arterial oxygen between the two groups. CONCLUSIONS Sustained maternal antenatal sildenafil infusion reduced pulmonary arterial pressure and increased pulmonary blood flow in DH lambs for the first 120 min after birth. These findings of improved pulmonary vascular function are consistent with improved pulmonary vascular structure seen in two previous animal models. The data support the rationale for a clinical trial investigating the effect of antenatal sildenafil in reducing the risk of neonatal pulmonary hypertension in infants with CDH. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Collapse
Affiliation(s)
- A J Kashyap
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - P L J Dekoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Erasmus MC, Rotterdam, The Netherlands
| | - K A Rodgers
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - M Thio
- Newborn Research Centre, The Royal Women's Hospital, Melbourne, Australia
- Department of Obstetrics and Gynaecology, The University of Melbourne, Australia
| | - E V Mcgillick
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - B J Amberg
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - S M Skinner
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - A M Moxham
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - F M Russo
- Department of Obstetrics and Gynaecology, Division of Woman and Child, University Hospitals Leuven, Leuven, Belgium
| | - J A Deprest
- Department of Obstetrics and Gynaecology, Division of Woman and Child, University Hospitals Leuven, Leuven, Belgium
- Institute for Women's Health, University College London Hospital, London, UK
| | - S B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - K J Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - R J Hodges
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
- Monash Women's and Newborn Program, Monash Health, Melbourne, Australia
| |
Collapse
|
29
|
Martherus T, Oberthuer A, Dekker J, Hooper SB, McGillick EV, Kribs A, Te Pas AB. Supporting breathing of preterm infants at birth: a narrative review. Arch Dis Child Fetal Neonatal Ed 2019; 104:F102-F107. [PMID: 30049727 DOI: 10.1136/archdischild-2018-314898] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/14/2018] [Accepted: 07/02/2018] [Indexed: 11/03/2022]
Abstract
Most very preterm infants have difficulty aerating their lungs and require respiratory support at birth. Currently in clinical practice, non-invasive ventilation in the form of continuous positive airway pressure (CPAP) and positive pressure ventilation (PPV) is applied via facemask. As most very preterm infants breathe weakly and unnoticed at birth, PPV is often administered. PPV is, however, frequently ineffective due to pressure settings, mask leak and airway obstruction. Meanwhile, high positive inspiratory pressures and spontaneous breathing coinciding with inflations can generate high tidal volumes. Evidence from preclinical studies demonstrates that high tidal volumes can be injurious to the lungs and brains of premature newborns. To reduce the need for PPV in the delivery room, it should be considered to optimise spontaneous breathing with CPAP. CPAP is recommended in guidelines and commonly used in the delivery room after a period of PPV, but little data is available on the ideal CPAP strategy and CPAP delivering devices and interfaces used in the delivery room. This narrative review summarises the currently available evidence for why PPV can be inadequate at birth and what is known about different CPAP strategies, devices and interfaces used the delivery room.
Collapse
Affiliation(s)
- Tessa Martherus
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - André Oberthuer
- Department of Neonatology, Children's Hospital University of Cologne, Cologne, Germany
| | - Janneke Dekker
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute for Medical Research, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Erin V McGillick
- The Ritchie Centre, Hudson Institute for Medical Research, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Angela Kribs
- Department of Neonatology, Children's Hospital University of Cologne, Cologne, Germany
| | - Arjan B Te Pas
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
30
|
Mian Q, Cheung PY, O'Reilly M, Barton SK, Polglase GR, Schmölzer GM. Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room. Arch Dis Child Fetal Neonatal Ed 2019; 104:F57-F62. [PMID: 29353261 DOI: 10.1136/archdischild-2017-313864] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 11/04/2022]
Abstract
BACKGROUND AND OBJECTIVES Delivery of inadvertent high tidal volume (VT) during positive pressure ventilation (PPV) in the delivery room is common. High VT delivery during PPV has been associated with haemodynamic brain injury in animal models. We examined if VT delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks' gestation. METHODS A flow-sensor was placed between the mask and the ventilation device. VT values were compared with recently described reference ranges for VT in spontaneously breathing preterm infants at birth. Infants were divided into two groups: VT<6 mL/kg or VT>6 mL/kg (normal and high VT, respectively). Brain injury (eg, intraventricular haemorrhage (IVH)) was assessed using routine ultrasound imaging within the first days after birth. RESULTS A total of 165 preterm infants were included, 124 (75%) had high VT and 41 (25%) normal VT. The mean (SD) gestational age and birth weight in high and normal VT group was similar, 26 (2) and 26 (1) weeks, 858 (251) g and 915 (250) g, respectively. IVH in the high VT group was diagnosed in 63 (51%) infants compared with 5 (13%) infants in the normal VT group (P=0.008).Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the high VT group and 2/41 (6%) in the normal VT group (P=0.01). CONCLUSIONS High VT delivery during mask PPV at birth was associated with brain injury. Strategies to limit VT delivery during mask PPV should be used to prevent high VT delivery.
Collapse
Affiliation(s)
- Qaasim Mian
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Po-Yin Cheung
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Megan O'Reilly
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Georg M Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
31
|
Martherus T, Oberthuer A, Dekker J, Kirchgaessner C, van Geloven N, Hooper SB, Kribs A, Te Pas AB. Comparison of Two Respiratory Support Strategies for Stabilization of Very Preterm Infants at Birth: A Matched-Pairs Analysis. Front Pediatr 2019; 7:3. [PMID: 30761276 PMCID: PMC6362425 DOI: 10.3389/fped.2019.00003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/04/2019] [Indexed: 01/19/2023] Open
Abstract
Objective: Respiratory support for stabilizing very preterm infants at birth varies between centers. We retrospectively compared two strategies that involved either increasing continuous positive airway pressures (CPAP), or increasing oxygen supplementation. Methods: Matched-pairs of infants (<28 weeks of gestation) were born either at the Leiden University Medical Center [low-pressure: CPAP 5-8 cmH2O and/or positive pressure ventilation (PPV) and fraction of inspired oxygen (FiO2) 0.3-1.0; n = 27], or at the University Hospital of Cologne (high-pressure: CPAP 12-35 cmH2O, no PPV and FiO2 0.3-0.4; n = 27). Respiratory support was initiated non-invasively via facemask at both units. Infants (n = 54) were matched between centers for gestational age and birth weight, to compare physiological and short-term clinical outcomes. Results: In the low-pressure group, 20/27 (74%) infants received 1-2 sustained inflations (20, 25 cm H2O) and 22/27 (81%) received PPV (1:19-3:01 min) using pressures of 25-27 cm H2O. Within 3 min of birth [median (IQR)], mean airway pressures [12 (6-15) vs. 19 (16-23) cmH2O, p < 0.001] and FiO2 [0.30 (0.28-0.31) vs. 0.22 (0.21-0.30), p < 0.001] were different in low- vs. high-pressure groups, respectively. SpO2 and heart rates were similar. After 3 min, higher FiO2 levels [0.62 (0.35-0.98) vs. 0.28 (0.22-0.38), p = 0.005] produced higher SpO2 levels [77 (50-92) vs. 53 (42-69)%, p < 0.001] in the low-pressure group, but SpO2/FiO2 and heart rates were similar. While intubation rates during admission were significantly different (70 vs. 30%, p = 0.013), pneumothorax rates (4 vs. 19%, p = 0.125) and the occurrence of spontaneous intestinal perforations (0 vs. 15%, p = 0.125) were similar between groups. Conclusion: Infants (<28 weeks) can be supported non-invasively at birth with either higher or lower pressures and while higher-pressure support may require less oxygen, it does not eliminate the need for oxygen supplementation. Future studies need to examine the effect of high pressures and pressure titration in the delivery room.
Collapse
Affiliation(s)
- Tessa Martherus
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - André Oberthuer
- Department of Neonatology, Children's Hospital University of Cologne, Cologne, Germany
| | - Janneke Dekker
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| | | | - Nan van Geloven
- Medical Statistics, Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, Netherlands
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Angela Kribs
- Department of Neonatology, Children's Hospital University of Cologne, Cologne, Germany
| | - Arjan B Te Pas
- Department of Paediatrics, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
32
|
Vali P, Gugino S, Koenigsknecht C, Helman J, Chandrasekharan P, Rawat M, Lakshminrusimha S, Nair J. The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation. J Vis Exp 2018. [PMID: 30175999 DOI: 10.3791/57553] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Birth asphyxia accounts for nearly one million deaths worldwide each year, and is one of the primary causes of early neonatal morbidity and mortality. Many aspects of the current neonatal resuscitation guidelines remain controversial given the difficulties in conducting randomized clinical trials owing to the infrequent and often unpredictable need for extensive resuscitation. Most studies on neonatal resuscitation stem from manikin models that fail to truly reflect physiologic changes or piglet models that have cleared their lung fluid and that have completed the transition from fetal to neonatal circulation. The present protocol provides a detailed step-by-step description on how to create a perinatal asphyxiated fetal lamb model. The proposed model has a transitioning circulation and fluid-filled lungs, which mimics human newborns following delivery, and is, therefore, an excellent animal model to study newborn physiology. An important limitation to lamb experiments is the higher associated cost.
Collapse
Affiliation(s)
- Payam Vali
- Department of Pediatrics, University of California Davis
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Mirza H, Garcia JA, Crawford E, Pepe J, Zussman M, Wadhawan R, Oh W. Natural History of Postnatal Cardiopulmonary Adaptation in Infants Born Extremely Preterm and Risk for Death or Bronchopulmonary Dysplasia. J Pediatr 2018; 198:187-193.e1. [PMID: 29625730 DOI: 10.1016/j.jpeds.2018.02.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 01/04/2018] [Accepted: 02/13/2018] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To study the natural history of postnatal cardiopulmonary adaptation in infants born extremely preterm and establish its association with death or bronchopulmonary dysplasia (BPD). STUDY DESIGN This was a prospective, observational, cohort study of infants born extremely preterm (<29 weeks). Initial echocardiogram was performed at <48 hours of life, followed by serial echocardiograms every 24-48 hours until 14 days of life. Resolution or no resolution of pulmonary hypertension (PH) at 72-96 hours was considered normal or delayed postnatal cardiopulmonary adaptation, respectively. PH between 96 hours and 14 days was defined as subsequent PH. Elevated pulmonary artery pressure throughout the 14 days of life was considered persistent PH. BPD was assessed at 36 weeks of postmenstrual age. RESULTS Sixty infants were enrolled; 2 died before a sequential echocardiogram could be done at 72-96 hours. Normal and delayed cardiopulmonary adaptation were noted in 26 (45%) and 32 (55%) infants, respectively. Five patterns of postnatal cardiopulmonary adaptation were recognized: normal without subsequent PH (n = 20), normal with subsequent PH (n = 6), delayed adaptation without subsequent PH (n = 6), delayed adaptation with subsequent PH (n = 16), and persistent PH (n = 10). Infants with delayed cardiopulmonary adaptation were of lower gestation and birth weight and required prolonged ventilation and supplemental oxygen (P < .05). On multivariate analysis, the incidence of death or BPD was significantly greater among infants with delayed adaptation (P < .001). CONCLUSION Infants born extremely preterm have normal or delayed postnatal cardiopulmonary adaptation that can be complicated by subsequent or persistent PH. Delayed cardiopulmonary adaptation is associated independently with death or BPD.
Collapse
Affiliation(s)
- Hussnain Mirza
- Center for Neonatal Care, Florida Hospital for Children/University of Central Florida College of Medicine, Orlando, FL.
| | - Jorge A Garcia
- Division of Pediatric Cardiology, Florida Hospital for Children, Orlando, FL
| | - Elizabeth Crawford
- Division of Pediatric Echocardiography, Florida Hospital Cardiovascular Institute, Orlando, FL
| | - Julie Pepe
- Office of Research Advancement and Support, Florida Hospital, Orlando, FL
| | - Matthew Zussman
- Division of Pediatric Cardiology, Florida Hospital for Children, Orlando, FL
| | - Rajan Wadhawan
- Center for Neonatal Care, Florida Hospital for Children/University of Central Florida College of Medicine, Orlando, FL
| | - William Oh
- Center for Pediatric Research, Florida Hospital for Children, Orlando, FL
| |
Collapse
|
34
|
Lio A, Aurilia C, Zahra V, Moss TJ, LaRosa DA, Hooper SB, Gill AW, Kluckow M, Nitsos I, Vento G, Polglase GR. Ventilation Prior to Umbilical Cord Clamping Improves Cardiovascular Stability and Oxygenation in Preterm Lambs After Exposure to Intrauterine Inflammation. Front Pediatr 2018; 6:286. [PMID: 30410874 PMCID: PMC6209675 DOI: 10.3389/fped.2018.00286] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/17/2018] [Indexed: 11/30/2022] Open
Abstract
Background: Delaying umbilical cord clamping until after aeration of the lung (physiological-based cord clamping; PBCC) maintains cardiac output and oxygenation in preterm lambs at birth, however, its efficacy after intrauterine inflammation is not known. Given the high incidence of chorioamnionitis in preterm infants, we investigated whether PBCC conferred any benefits compared to immediate cord clamping (ICC) in preterm lambs exposed antenatally to 7 days of intrauterine inflammation. Methods: Ultrasound guided intraamniotic injection of 20 mg Lipopolysaccharide (from E. coli:055:B5) was administered to pregnant ewes at 0.8 gestation. Seven days later, ewes were anesthetized, preterm fetuses exteriorised via cesarean section, and instrumented for continuous measurement of pulmonary, systemic and cerebral pressures and flows, and systemic, and cerebral oxygenation. Lambs were then randomized to either PBCC, whereupon ventilation was initiated and maintained for 3 min prior to umbilical cord clamping, or ICC where the umbilical cord was cut and ventilation initiated 30 s later. Ventilation was maintained for 30 min. Results: ICC caused a rapid fall in systemic (by 25%) and cerebral (by 11%) oxygen saturation in ICC lambs, concurrent with a rapid increase in carotid arterial pressure and heart rate. The overshoot in carotid arterial pressure was sustained in ICC lambs for the first 20 min of the study. PBCC maintained cardiac output and prevented the fall in cerebral oxygen delivery at birth. PBCC lambs had lower respiratory compliance and higher respiratory requirements throughout the study. Conclusion: PBCC mitigated the adverse effects of ICC on oxygenation and cardiac output, and therefore could be more beneficial in preterm babies exposed to antenatal inflammation as it maintains cardiac output and oxygen delivery. The increased respiratory requirements require further investigation in this sub-group of preterm infants.
Collapse
Affiliation(s)
- Alessandra Lio
- Division of Neonatology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Claudia Aurilia
- Division of Neonatology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Valerie Zahra
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Timothy J Moss
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Domenic A LaRosa
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Stuart B Hooper
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, University of Western Australia, Perth, WA, Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney, NSW, Australia
| | - Ilias Nitsos
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Giovanni Vento
- Division of Neonatology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Division of Neonatology, Universita Cattolica del Sacro Cuore, Rome, Italy
| | - Graeme R Polglase
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Melbourne, VIC, Australia
| |
Collapse
|
35
|
Controversies in the identification and management of acute pulmonary hypertension in preterm neonates. Pediatr Res 2017; 82:901-914. [PMID: 28820870 DOI: 10.1038/pr.2017.200] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 08/05/2017] [Indexed: 12/22/2022]
Abstract
It is increasingly recognized that the abnormal physiologic consequences of pulmonary hypertension (PH) may contribute to poor cardiopulmonary health in premature babies. Conflicting literature has led to clinical uncertainty, pathological misinterpretation, and variability in treatment approaches among practitioners. There are several disorders with overlapping and interrelated presentations, and other disorders with a similar clinical phenotype but diverse pathophysiological contributors. In this review, we provide a diagnostic approach for acute hypoxemic respiratory failure in the preterm neonate, outline the pathophysiological conditions that may present as acute PH, and discuss the implications of high pulmonary vascular resistance (PVR) on the cardiovascular system. Although PVR and respiratory management are highly interrelated, there may be a population of preterm neonates in whom inhaled nitric oxide may improve illness severity and may relate to outcomes. A management approach based on physiology that considers common clinical conundrums is provided. A more comprehensive understanding of the physiology may help in informed decision-making in clinical situations where conclusive scientific evidence is lacking. Regardless, high-quality research is required, and appropriate definition of the target population is paramount. A thoughtful approach to cardiovascular therapy may also provide an avenue to improve neurodevelopmental outcomes while awaiting more clear answers.
Collapse
|
36
|
McGillick EV, Lee K, Yamaoka S, te Pas AB, Crossley KJ, Wallace MJ, Kitchen MJ, Lewis RA, Kerr LT, DeKoninck P, Dekker J, Thio M, McDougall AR, Hooper SB. Elevated airway liquid volumes at birth: a potential cause of transient tachypnea of the newborn. J Appl Physiol (1985) 2017; 123:1204-1213. [DOI: 10.1152/japplphysiol.00464.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/28/2017] [Accepted: 07/28/2017] [Indexed: 11/22/2022] Open
Abstract
Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ± 0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60 ± 6 inflations, P = 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P < 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 ± 8%, P = 0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth. NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due to elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.
Collapse
Affiliation(s)
- Erin V. McGillick
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Katie Lee
- School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia
| | - Shigeo Yamaoka
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Arjan B. te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Kelly J. Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Megan J. Wallace
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Marcus J. Kitchen
- School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia
| | - Robert A. Lewis
- Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Victoria, Australia
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Lauren T. Kerr
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Philip DeKoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Janneke Dekker
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Marta Thio
- Women’s Newborn Research Centre, The Royal Women’s Hospital, Melbourne, Victoria, Australia
- Murdoch Children’s Research Institute, Melbourne, Australia; and
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
| | - Annie R.A. McDougall
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| | - Stuart B. Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
37
|
Hinder M, Jani P, Priyadarshi A, McEwan A, Tracy M. Neopuff T-piece resuscitator: does device design affect delivered ventilation? Arch Dis Child Fetal Neonatal Ed 2017; 102:F220-F224. [PMID: 27645491 DOI: 10.1136/archdischild-2016-311164] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 08/18/2016] [Accepted: 08/23/2016] [Indexed: 11/04/2022]
Abstract
BACKGROUND The T-piece resuscitator (TPR) is in common use worldwide to deliver positive pressure ventilation during resuscitation of infants <10 kg. Ease of use, ability to provide positive end-expiratory pressure (PEEP), availability of devices inbuilt into resuscitaires and cheaper disposable options have increased its popularity as a first-line device for term infant resuscitation. Research into its ventilation performance is limited to preterm infant and animal studies. Efficacy of providing PEEP and the use of TPR during term infant resuscitation are not established. AIM The aim of this study is to determine if delivered ventilation with the Neopuff brand TPR varied with differing (preterm to term) test lung compliances (Crs) and set peak inspiratory pressures (PIP). DESIGN A single operator experienced in newborn resuscitation provided positive pressure ventilation in a randomised sequence to three different Crs models (0.5, 1 and 3 mL/cmH2O) at three different set PIP (20, 30 and 40 cmH2O). Set PEEP (5 cmH2O), gas flow rate and inflation rate were the same for each sequence. RESULTS A total of 1087 inflations were analysed. The delivered mean PEEP was Crs dependent across set PIP range, rising from 4.9 to 8.2 cmH2O. At set PIP 40 cmH2O and Crs 3 mL/cmH2O, the delivered mean PIP was significantly lower at 35.3 cmH2O. CONCLUSIONS As Crs increases, the Neopuff TPR can produce clinically significant levels of auto-PEEP and thus may not be optimal for the resuscitation of term infants with healthy lungs.
Collapse
Affiliation(s)
- Murray Hinder
- Neonatal Intensive Care, Westmead Hospital, Westmead, New South Wales, Australia.,Faculty of Engineering and Information Technologies, BMET Institute, Sydney University, Sydney, New South Wales, Australia
| | - Pranav Jani
- Neonatal Intensive Care, Westmead Hospital, Westmead, New South Wales, Australia.,Department of Paediatrics and Child Health, Sydney University, Westmead, New South Wales, Australia
| | - Archana Priyadarshi
- Neonatal Intensive Care, Westmead Hospital, Westmead, New South Wales, Australia.,Department of Paediatrics and Child Health, Sydney University, Westmead, New South Wales, Australia
| | - Alistair McEwan
- Faculty of Engineering and Information Technologies, BMET Institute, Sydney University, Sydney, New South Wales, Australia
| | - Mark Tracy
- Neonatal Intensive Care, Westmead Hospital, Westmead, New South Wales, Australia.,Department of Paediatrics and Child Health, Sydney University, Westmead, New South Wales, Australia
| |
Collapse
|
38
|
Zannin E, Doni D, Ventura ML, Fedeli T, Rigotti C, Dellacá RL, Tagliabue PE. Relationship between Mean Airways Pressure, Lung Mechanics, and Right Ventricular Output during High-Frequency Oscillatory Ventilation in Infants. J Pediatr 2017; 180:110-115. [PMID: 27745747 DOI: 10.1016/j.jpeds.2016.09.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/28/2016] [Accepted: 09/08/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To characterize changes in lung mechanics and right ventricular output (RVO) during incremental/decremental continuous distending pressure (CDP) maneuvers in newborn infants receiving high-frequency oscillatory ventilation, with the aim of evaluating when open lung maneuvers are needed and whether they are beneficial. STUDY DESIGN Thirteen infants on high-frequency oscillatory ventilation were studied with a median (IQR) gestational age of 261 (253-291) weeks and median (IQR) body weight of 810 (600-1020) g. CDP was increased stepwise from 8 cmH2O to a maximum pressure and subsequently decreased until oxygenation deteriorated or a CDP of 8 cmH2O was reached. The lowest CDP that maintained good oxygenation was considered the clinically optimal CDP. At each CDP, the following variables were evaluated: oxygenation, respiratory system reactance (Xrs), and RVO by Doppler echocardiography. RESULTS At maximal CDP reached during the trial, 19 [1] cmH2O (mean [SEM]), oxygenation markedly improved, and Xrs and RVO decreased. During deflation, oxygenation remained stable over a wide range of CDP settings, Xrs returned to the baseline values, and RVO increased but the baseline values were not readily restored in all patients. CONCLUSION These results suggest that Xrs and RVO are more sensitive than oxygenation to overdistension and they may be useful in clinical practice to guide open lung maneuvers.
Collapse
Affiliation(s)
- Emanuela Zannin
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
| | - Daniela Doni
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Tiziana Fedeli
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Raffaele L Dellacá
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
| | | |
Collapse
|
39
|
van Vonderen JJ, Roest AA, Klumper FJ, Hooper SB, te Pas AB. The effect of breathing on ductus arteriosus blood flow directly after birth. Eur J Pediatr 2017; 176:1581-1585. [PMID: 28879564 PMCID: PMC5682873 DOI: 10.1007/s00431-017-2994-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 03/29/2017] [Accepted: 08/09/2017] [Indexed: 11/25/2022]
Abstract
UNLABELLED Spontaneous breathing at birth influences ductus arteriosus (DA) flow. This study quantifies the effect of breathing on DA shunting directly after birth. In healthy term infants born by elective cesarean section, simultaneous measurements of DA shunting and tidal volumes during spontaneous breathing were performed at 2-5, 5-8, and 10-13 min after birth. Eight infants with a mean (SD) gestational age of 40 (1) weeks and 3216 (616) grams were studied. Inspiratory tidal volume was 5.8 (3.3-7.7), 5.7 (4.0-7.1), and 5.2 (4.3-6.1) mL/kg at 2-5, 5-8, and 10-13 min. The velocity time integral of left-to-right shunting significantly increased during inspiration when compared to expiration (8.4 (5.2) vs. 3.7 (2.3) cm, 8.9 (4.4) vs. 5.6 (3.4) cm, and 14.0 (6.7) vs. 8.4 (6.9) cm; all p < 0.0001) at 2-5, 5-8, and 10-13 min, respectively. In contrast, right-to-left shunting was not different between inspiration and expiration at 2-5 and 10-13 min (11.1 (2.4) vs. 11.1 (2.6) cm and 10.7 (2.3) vs. 10.6 (3.0) cm; p > 0.05), but there was a small increase at 5-8 min (12.1 (2.4) vs. 10.8 (2.9) cm; p = 0.001) during expiration. CONCLUSION Directly after birth, ductal shunting is influenced by breathing effort, predominantly with an increase in left-to-right shunt due to inspiration. What is Known: • Spontaneous breathing at birth influences ductus arteriosus flow and pulmonary blood flow. • Crying causes a significant increase in left-to-right ductus arteriosus shunting. What is New: • Left-to-right ductus arteriosus shunting increases during inspiration compared to expiration. • Breathing is important for ductal shunting and contributes to pulmonary blood flow.
Collapse
Affiliation(s)
- Jeroen J. van Vonderen
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, J6-S, PO Box 9600, 2300 RC Leiden, the Netherlands
| | - Arno A.W. Roest
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands
| | - Frans J.C. Klumper
- Department of Gynecology and Obstetrics, Leiden University Medical Center, Leiden, the Netherlands
| | - Stuart B. Hooper
- The Ritchie Centre, MIMR-PHI, Monash University, Clayton, Victoria Australia
| | - Arjan B. te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, J6-S, PO Box 9600, 2300 RC Leiden, the Netherlands
| |
Collapse
|
40
|
Altered cardiovascular function at birth in growth-restricted preterm lambs. Pediatr Res 2016; 80:538-46. [PMID: 27356081 DOI: 10.1038/pr.2016.104] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 03/01/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cardiovascular dysfunction at birth may underlie poor outcomes after fetal growth restriction (FGR) in neonates. We compared the cardiovascular transition between FGR and appropriately grown (AG) preterm lambs and examined possible mechanisms underlying any cardiovascular dysfunction in FGR lambs. METHODS FGR was induced in ewes bearing twins at 0.7 gestation; the twin was used as an internal control (AG). At 0.8 gestation, lambs were delivered and either euthanized with their arteries isolated for in vitro wire myography, or ventilated for 2 h. At 60 min, inhaled nitric oxide (iNO) was administered in a subgroup for 30 min. Molecular assessment of the nitric oxide (NO) pathway within lung tissue was conducted. RESULTS FGR lambs had lower left ventricular output and cerebral blood flow (CBF) and higher systemic vascular resistance compared with AG lambs. INO administration to FGR lambs rapidly improved cardiovascular and systemic hemodynamics but resulted in decreased CBF in AG lambs. Isolated arteries from FGR lambs showed impaired sensitivity to NO donors, but enhanced vasodilation to Sildenafil and Sodium nitroprusside, and altered expression of components of the NO pathway. CONCLUSION Cardiovascular dysfunction at birth may underlie the increased morbidity and mortality observed in preterm FGR newborns. Impaired NO signaling likely underlies the abnormal vascular reactivity.
Collapse
|
41
|
Smolich JJ, Mynard JP. Major contribution of central pulmonary reservoir discharge to increased pulmonary arterial diastolic blood flow after birth in near-term lambs. Am J Physiol Regul Integr Comp Physiol 2016; 311:R702-R709. [DOI: 10.1152/ajpregu.00077.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 08/04/2016] [Indexed: 11/22/2022]
Abstract
Recent fetal lamb data have suggested that the pulmonary trunk (PT) region displays a reservoir function and that a pharmacologically induced fall in pulmonary vascular resistance (PVR) increases and redistributes diastolic discharge from this central pulmonary reservoir toward the lungs, thereby producing a positive diastolic offset in the pulmonary arterial (PA) blood flow profile. As a similar offset in PA flow characteristically occurs after birth, this study tested the hypotheses that 1) central pulmonary reservoir discharge is both redistributed toward the lungs and increased in magnitude during the birth transition and 2) discharge from this reservoir constitutes a major component of increased PA diastolic blood flow after birth. Six anesthetized near-term fetal lambs were instrumented with PT, ductal and left PA transit-time flow probes, and aortic, PT and left atrial catheters. Hemodynamic data were recorded in fetuses and at regular intervals during 2-h mechanical ventilation following cesarean section delivery. Diastolic PA blood flow rose from near zero in fetuses to 468 ± 188 ml/min by 15 min ( P < 0.001). Central pulmonary reservoir discharge in fetuses (99 ± 44 ml/min) passed primarily right-to-left across the ductus. However, this reservoir discharge redistributed entirely to the lungs by 1 min after birth, and then doubled to a peak of 214 ± 167 ml/min at 15 min ( P < 0.001). Reservoir discharge subsequently stabilized at 151 ± 60 ml/min at 30–120 min, which comprised ∼50% of diastolic and ∼20% of mean PA blood flow. These findings suggest that enhanced diastolic central pulmonary reservoir discharge plays a major role in supporting an increased pulmonary perfusion after birth.
Collapse
Affiliation(s)
- Joseph J. Smolich
- Heart Research, Clinical Sciences, Murdoch Childrens Research Institute; and
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Jonathan P. Mynard
- Heart Research, Clinical Sciences, Murdoch Childrens Research Institute; and
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| |
Collapse
|
42
|
Hooper SB, Binder-Heschl C, Polglase GR, Gill AW, Kluckow M, Wallace EM, Blank D, Te Pas AB. The timing of umbilical cord clamping at birth: physiological considerations. Matern Health Neonatol Perinatol 2016; 2:4. [PMID: 27298730 PMCID: PMC4904360 DOI: 10.1186/s40748-016-0032-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/10/2016] [Indexed: 11/10/2022] Open
Abstract
While it is now recognized that umbilical cord clamping (UCC) at birth is not necessarily an innocuous act, there is still much confusion concerning the potential benefits and harms of this common procedure. It is most commonly assumed that delaying UCC will automatically result in a time-dependent net placental-to-infant blood transfusion, irrespective of the infant's physiological state. Whether or not this occurs, will likely depend on the infant's physiological state and not on the amount of time that has elapsed between birth and umbilical cord clamping (UCC). However, we believe that this is an overly simplistic view of what can occur during delayed UCC and ignores the benefits associated with maintaining the infant's venous return and cardiac output during transition. Recent experimental evidence and observations in humans have provided compelling evidence to demonstrate that time is not a major factor influencing placental-to-infant blood transfusion after birth. Indeed, there are many factors that influence blood flow in the umbilical vessels after birth, which depending on the dominating factors could potentially result in infant-to-placental blood transfusion. The most dominant factors that influence umbilical artery and venous blood flows after birth are lung aeration, spontaneous inspirations, crying and uterine contractions. It is still not entirely clear whether gravity differentially alters umbilical artery and venous flows, although the available data suggests that its influence, if present, is minimal. While there is much support for delaying UCC at birth, much of the debate has focused on a time-based approach, which we believe is misguided. While a time-based approach is much easier and convenient for the caregiver, ignoring the infant's physiology during delayed UCC can potentially be counter-productive for the infant.
Collapse
Affiliation(s)
- Stuart B Hooper
- The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia ; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | | | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia ; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Crawley, WA 6008 Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney, NSW 2065 Australia
| | - Euan M Wallace
- The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia ; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Douglas Blank
- The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia ; Neonatal Services, The Royal Women's Hospital, Melbourne, Australia
| | - Arjan B Te Pas
- Department of Neonatology, Leiden University Medical Centre, Leiden, The Netherlands
| |
Collapse
|
43
|
Allison BJ, Hooper SB, Coia E, Zahra VA, Jenkin G, Malhotra A, Sehgal A, Kluckow M, Gill AW, Sozo F, Miller SL, Polglase GR. Ventilation-induced lung injury is not exacerbated by growth restriction in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2016; 310:L213-23. [DOI: 10.1152/ajplung.00328.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022] Open
Abstract
Intrauterine growth restriction (IUGR) and preterm birth are frequent comorbidities and, combined, increase the risk of adverse respiratory outcomes compared with that in appropriately grown (AG) infants. Potential underlying reasons for this increased respiratory morbidity in IUGR infants compared with AG infants include altered fetal lung development, fetal lung inflammation, increased respiratory requirements, and/or increased ventilation-induced lung injury. IUGR was surgically induced in preterm fetal sheep (0.7 gestation) by ligation of a single umbilical artery. Four weeks later, preterm lambs were euthanized at delivery or delivered and ventilated for 2 h before euthanasia. Ventilator requirements, lung inflammation, early markers of lung injury, and morphological changes in lung parenchymal and vascular structure and surfactant composition were analyzed. IUGR preterm lambs weighed 30% less than AG preterm lambs, with increased brain-to-body weight ratio, indicating brain sparing. IUGR did not induce lung inflammation or injury or alter lung parenchymal and vascular structure compared with AG fetuses. IUGR and AG lambs had similar oxygenation and respiratory requirements after birth and had significant, but similar, increases in proinflammatory cytokine expression, lung injury markers, gene expression, and surfactant phosphatidylcholine species compared with unventilated controls. IUGR does not induce pulmonary structural changes in our model. Furthermore, IUGR and AG preterm lambs have similar ventilator requirements in the immediate postnatal period. This study suggests that increased morbidity and mortality in IUGR infants is not due to altered lung tissue or vascular structure, or to an altered response to early ventilation.
Collapse
Affiliation(s)
- Beth J. Allison
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Stuart B. Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Elise Coia
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Valerie A. Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Graham Jenkin
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Atul Malhotra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Monash Newborn, Monash Medical Centre, and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
| | - Arvind Sehgal
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Monash Newborn, Monash Medical Centre, and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney, New South Wales, Australia
| | - Andrew W. Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Western Australia, Australia; and
| | - Foula Sozo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Suzanne L. Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
44
|
Musk GC, Polglase GR, Bunnell JB, Nitsos I, Tingay D, Pillow JJ. A comparison of high-frequency jet ventilation and synchronised intermittent mandatory ventilation in preterm lambs. Pediatr Pulmonol 2015; 50:1286-93. [PMID: 25823397 DOI: 10.1002/ppul.23187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/08/2015] [Accepted: 03/15/2015] [Indexed: 01/12/2023]
Abstract
PURPOSE Synchronised intermittent mandatory ventilation (SIMV) and high-frequency jet ventilation (HFJV) are accepted ventilatory strategies for treatment of respiratory distress syndrome (RDS) in preterm babies. We hypothesised that SIMV and HFJV both facilitate adequate oxygenation and ventilation but that HFJV is associated with less lung injury. RESULTS There were no differences in arterial oxygenation or partial pressure of carbon dioxide despite lower mean airway pressure during SIMV for most of the study. There were no consistent significant differences in end systolic and end diastolic PBF, lung injury data and static lung compliance. METHODS Preterm lambs of anaesthetised ewes were instrumented, intubated and delivered by caesarean section after intratracheal suction and instillation of surfactant. Each lamb was managed for 3 hr according to a predetermined algorithm for ventilatory support consistent with open lung ventilation. Pulmonary blood flow (PBF) was measured continuously and pulsatility index was calculated. Ventilatory parameters were recorded and arterial blood gases were measured at intervals. At postmortem, in situ pressure-volume deflation curves were recorded, and bronchoalveolar lavage fluid and lung tissue were obtained to assess inflammation. CONCLUSIONS SIMV and HFJV have comparable clinical efficacy and ventilator pressure requirements when applied with a targeted lung volume recruitment strategy.
Collapse
Affiliation(s)
- Gabrielle C Musk
- Animal Care Services, Faculty of Medicine Dentistry and Health Sciences, University of Western Australia, Perth, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Australia
| | - J Bert Bunnell
- Department of Bioengineering, University of Utah, Bunnell Inc, Salt Lake City, Utah
| | - Ilias Nitsos
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Australia
| | - David Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia
| | - J Jane Pillow
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia.,School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Australia
| |
Collapse
|
45
|
Hooper SB, Polglase GR, te Pas AB. A physiological approach to the timing of umbilical cord clamping at birth. Arch Dis Child Fetal Neonatal Ed 2015; 100:F355-60. [PMID: 25540147 DOI: 10.1136/archdischild-2013-305703] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/01/2014] [Indexed: 11/03/2022]
Abstract
Umbilical cord clamping at birth has a major impact on an infant's cardiovascular system that varies in significance depending upon whether the infant has commenced breathing. As umbilical venous return is a major source of preload for the left ventricle during fetal life, recent experimental evidence has shown that clamping the umbilical cord severely limits cardiac venous return in the absence of pulmonary ventilation. As a result, cardiac output greatly reduces and remains low until breathing commences. Once the infant begins breathing, aeration of the lung triggers a large increase in pulmonary blood flow, which replaces umbilical venous return as the source of preload for the left ventricle. As a result, cardiac output markedly increases, as indicated by an increase in heart rate immediately after birth. Thus, infants born apnoeic and hypoxic and have their cords immediately clamped, are likely to have a restricted cardiac output combined with hypoxia. As increased cardiac output is a major physiological defence mechanism that counteracts the effects of hypoxaemia, limiting the increase in cardiac output exposes the infant to ischaemia along with hypoxia. However, if the infant commences breathing, aerates its lungs and increases pulmonary blood flow before the umbilical cord is clamped, then pulmonary venous return can immediately take over the supply of left ventricular preload upon cord clamping. As a result, there is no intervening period of reduced preload and cardiac output and the large swings in arterial pressures and flows are reduced leading to a more stable circulatory transition.
Collapse
Affiliation(s)
- Stuart B Hooper
- Ritchie Centre, MIMR-PHI Institute of Medical Research, Monash University, Melbourne, Victoria, Australia Department of Obstetrics & Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Graeme R Polglase
- Ritchie Centre, MIMR-PHI Institute of Medical Research, Monash University, Melbourne, Victoria, Australia Department of Obstetrics & Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Arjan B te Pas
- Department of Pediatrics, Leiden University Medical Centre, Leiden, the Netherlands
| |
Collapse
|
46
|
Hooper SB, Polglase GR, Roehr CC. Cardiopulmonary changes with aeration of the newborn lung. Paediatr Respir Rev 2015; 16:147-50. [PMID: 25870083 PMCID: PMC4526381 DOI: 10.1016/j.prrv.2015.03.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 03/12/2015] [Indexed: 10/23/2022]
Abstract
The newborn's transition from fetal to neonatal life includes aeration of the lungs, establishment of pulmonary gas exchange and changing the fetal circulation into the adult phenotype. This review summarizes the latest research findings, which show that lung aeration, airway liquid clearance and cardiovascular changes are directly interconnected at birth. The mechanisms of airway liquid clearance at birth are reviewed and the particular importance of the transpulmonary pressure gradient during lung aeration is discussed. Further, we summarize research findings which prove that lung aeration triggers the increase in pulmonary blood flow (PBF) at birth, and how the increase in PBF secures the preload for left ventricular output. Consequently, we review animal experiments which suggest that delaying umbilical cord clamping until breathing commences facilitates hemodynamic stability during transition. These data are reviewed with respect to the clinical applicability: As lung aeration is the key to successful transition to newborn life, providing adequate respiratory support at birth must be the primary objective of neonatal staff attending to the newborn infant. Clinical studies are needed to demonstrate whether the obvious benefits of delaying cord clamping until breathing commences hold true in human babies.
Collapse
Affiliation(s)
- Stuart Brian Hooper
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
| | - Graeme Roger Polglase
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia, Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Charles Christoph Roehr
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Melbourne, Australia, Newborn Services, John Radcliffe Hospital, Oxford University Hospitals, Oxford, United Kingdom, Dept. Neonatology, Charité University Medical Centre, Berlin, Germany
| |
Collapse
|
47
|
Smolich JJ, Kenna KR, Cheung MM. Onset of asphyxial state in nonrespiring interval between cord clamping and ventilation increases hemodynamic lability of birth transition in preterm lambs. J Appl Physiol (1985) 2015; 118:675-83. [PMID: 25614604 DOI: 10.1152/japplphysiol.01147.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Experimentally, a typical ∼2-min cord clamp-to-ventilation interval in preterm lambs is accompanied by increased hemodynamic lability of the birth transition. However, whether this lability is related to development of asphyxia after cord clamping, or can be avoided with a shorter clamp-to-ventilation interval, is unknown. To address these questions, anesthetized preterm fetal lambs (gestation 127 ± 2 days) were instrumented with ductus arteriosus and left pulmonary artery flow probes to obtain right ventricular (RV) output, brachiocephalic trunk and aortic isthmus flow probes to measure left ventricular (LV) output, and aortic trunk catheters for pressure measurement and blood gas analysis. With hemodynamics recorded continuously, fetuses were delivered onto the ewe's abdomen and the cord clamped for 1.5 min before ventilation (n = 8), with aortic sampling at 15, 30, 45, and 60 s, or for 0.5 min, with sampling at 15 s (n = 4). With 1.5-min cord clamping, an asphyxial state (Po2 < 10 mmHg) was evident at ≥45 s, with bradycardia and marked falls in LV and RV outputs (by 60% and 50%, P < 0.001), followed after ventilation onset by tachycardia and LV and RV output surges (4- and 3-fold, P < 0.001). By contrast, heart rate and outputs remained stable after 0.5-min cord clamping, with no postventilation change in heart rate or RV output, and a lesser rise in LV output (22%, P < 0.005). In preterm lambs, rapid development of an asphyxial state within 45 s in the cord clamp-to-ventilation interval increased hemodynamic lability of the birth transition, which was reduced with a shorter (∼0.5 min) cord clamp-to-ventilation interval.
Collapse
Affiliation(s)
- Joseph J Smolich
- Heart Research Group, Murdoch Childrens Research Institute, Parkville, Australia; Department of Paediatrics, University of Melbourne, Parkville, Australia
| | - Kelly R Kenna
- Heart Research Group, Murdoch Childrens Research Institute, Parkville, Australia
| | - Michael M Cheung
- Heart Research Group, Murdoch Childrens Research Institute, Parkville, Australia; Department of Cardiology, Royal Children's Hospital, Parkville, Australia; and Department of Paediatrics, University of Melbourne, Parkville, Australia
| |
Collapse
|
48
|
Barton SK, Tolcos M, Miller SL, Roehr CC, Schmölzer GM, Davis PG, Moss TJM, LaRosa DA, Hooper SB, Polglase GR. Unraveling the Links Between the Initiation of Ventilation and Brain Injury in Preterm Infants. Front Pediatr 2015; 3:97. [PMID: 26618148 PMCID: PMC4639621 DOI: 10.3389/fped.2015.00097] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/26/2015] [Indexed: 11/13/2022] Open
Abstract
The initiation of ventilation in the delivery room is one of the most important but least controlled interventions a preterm infant will face. Tidal volumes (V T) used in the neonatal intensive care unit are carefully measured and adjusted. However, the V Ts that an infant receives during resuscitation are usually unmonitored and highly variable. Inappropriate V Ts delivered to preterm infants during respiratory support substantially increase the risk of injury and inflammation to the lungs and brain. These may cause cerebral blood flow instability and initiate a cerebral inflammatory cascade. The two pathways increase the risk of brain injury and potential life-long adverse neurodevelopmental outcomes. The employment of new technologies, including respiratory function monitors, can improve and guide the optimal delivery of V Ts and reduce confounders, such as leak. Better respiratory support in the delivery room has the potential to improve both respiratory and neurological outcomes in this vulnerable population.
Collapse
Affiliation(s)
- Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia
| | - Mary Tolcos
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Suzie L Miller
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Charles C Roehr
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Newborn Services, John Radcliffe Hospital, Oxford University Hospitals , Oxford , UK
| | - Georg M Schmölzer
- Department of Pediatrics, University of Alberta , Edmonton, AB , Canada ; Centre for the Study of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Alberta Health Services , Edmonton, AB , Canada
| | - Peter G Davis
- Neonatal Services, Newborn Research Centre, The Royal Women's Hospital , Melbourne, VIC , Australia
| | - Timothy J M Moss
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Domenic A LaRosa
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| |
Collapse
|
49
|
Bancalari E. Interaction between respiratory cardiovascular function. Early Hum Dev 2014; 90 Suppl 2:S3-4. [PMID: 25220124 DOI: 10.1016/s0378-3782(14)50002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Eduardo Bancalari
- Department of Pediatrics, Division of Neonatology, University of Miami Miller School of Medicine Miami Florida USA.
| |
Collapse
|
50
|
Szyld E, Aguilar A, Musante GA, Vain N, Prudent L, Fabres J, Carlo WA. Comparison of devices for newborn ventilation in the delivery room. J Pediatr 2014; 165:234-239.e3. [PMID: 24690329 DOI: 10.1016/j.jpeds.2014.02.035] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 02/03/2014] [Accepted: 02/18/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To evaluate the effectiveness and safety of a T-piece resuscitator compared with a self-inflating bag for providing mask ventilation to newborns at birth. STUDY DESIGN Newborns at ≥26 weeks gestational age receiving positive-pressure ventilation at birth were included in this multicenter cluster-randomized 2-period crossover trial. Positive-pressure ventilation was provided with either a self-inflating bag (self-inflating bag group) with or without a positive end-expiratory pressure valve or a T-piece with a positive end-expiratory pressure valve (T-piece group). Delivery room management followed American Academy of Pediatrics and International Liaison Committee on Resuscitation guidelines. The primary outcome was the proportion of newborns with heart rate (HR)≥100 bpm at 2 minutes after birth. RESULTS A total of 1027 newborns were included. There was no statistically significant difference in the incidence of HR≥100 bpm at 2 minutes after birth between the T-piece and self-inflating bag groups: 94% (479 of 511) and 90% (466 of 516), respectively (OR, 0.65; 95% CI, 0.41-1.05; P=.08). A total of 86 newborns (17%) in the T-piece group and 134 newborns (26%) in the self-inflating bag group were intubated in the delivery room (OR, 0.58; 95% CI, 0.4-0.8; P=.002). The mean±SD maximum positive inspiratory pressure was 26±2 cm H2O in the T-piece group vs 28±5 cm H2O in the self-inflating bag group (P<.001). Air leaks, use of drugs/chest compressions, mortality, and days on mechanical ventilation did not differ significantly between groups. CONCLUSION There was no difference between the T-piece resuscitator and a self-inflating bag in achieving an HR of ≥100 bpm at 2 minutes in newborns≥26 weeks gestational age resuscitated at birth. However, use of the T-piece decreased the intubation rate and the maximum pressures applied.
Collapse
Affiliation(s)
- Edgardo Szyld
- Research Department, FUNDASAMIN, Fundación para la Salud Materno Infantil, Buenos Aires, Argentina.
| | - Adriana Aguilar
- Research Department, FUNDASAMIN, Fundación para la Salud Materno Infantil, Buenos Aires, Argentina; Masters Program in Clinical Trials, Universidad Abierta Interamericana, Buenos Aires, Argentina
| | - Gabriel A Musante
- Research Department, FUNDASAMIN, Fundación para la Salud Materno Infantil, Buenos Aires, Argentina; Department of Pediatrics, Facultad de Ciencias Biomédicas, Universidad Austral, Buenos Aires, Argentina
| | - Nestor Vain
- Research Department, FUNDASAMIN, Fundación para la Salud Materno Infantil, Buenos Aires, Argentina
| | - Luis Prudent
- Research Department, FUNDASAMIN, Fundación para la Salud Materno Infantil, Buenos Aires, Argentina
| | - Jorge Fabres
- Division of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Waldemar A Carlo
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL
| |
Collapse
|