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Bizzotto D, Dahl MJ, Veneroni C, Lavizzari A, Rebentisch A, Dawson E, Bowen S, Zuspan K, Yoder BA, Albertine KH, Dellacà RL. Impact of neonatal noninvasive resuscitation strategies on lung mechanics, tracheal pressure, and tidal volume in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2024; 327:L203-L217. [PMID: 38771135 DOI: 10.1152/ajplung.00236.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/22/2024] Open
Abstract
This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first 2 h of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs. The first main finding is that sustained inflation (SI) applied noninvasively (Mask SI; n = 7) or invasively [endotracheal tube (ETT) SI; n = 6] led to similar rapid lung volume recruitment (∼6 min). In contrast, Mask continuous positive airway pressure (CPAP) without SI (n = 6) resuscitation took longer (∼30-45 min) to reach similar lung volume recruitment. The second main finding is that, in the first 15 min of postnatal life, the Mask CPAP without SI group closed their larynx during custom ventilator-driven expiration, leading to intratracheal positive end-expiratory pressure of ∼17 cmH2O (instead of 8 cmH2O provided by the ventilator). In contrast, the Mask SI group used the larynx to limit inspiratory pressure to ∼26 cmH2O (instead of 30 cmH2O provided by the ventilator). These different responses affected tidal volume, being larger in the Mask CPAP without SI group [8.4 mL/kg; 6.7-9.3 interquartile range (IQR)] compared to the Mask SI (5.0 mL/kg; 4.4-5.2 IQR) and ETT SI groups (3.3 mL/kg; 2.6-3.7 IQR). Distinct physiological responses suggest that spontaneous respiratory activity of the larynx of preterm lambs at birth can uncouple pressure applied by the ventilator to that applied to the lung, leading to unpredictable lung pressure and tidal volume delivery independently from the ventilator settings.NEW & NOTEWORTHY We compared invasive and noninvasive resuscitation on lambs at birth, including or not sustained inflation (SI). Lung volume recruitment was faster in those receiving SI. During noninvasive resuscitation, larynx modulation reduced tracheal pressure from that applied to the mask in lambs receiving SI, while it led to increased auto-positive end-expiratory pressure and very large tidal volumes in lambs not receiving SI. Our results highlight the need for individualizing pressures and monitoring tidal volumes during resuscitation at birth.
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Affiliation(s)
- Davide Bizzotto
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Mar Janna Dahl
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Chiara Veneroni
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Anna Lavizzari
- NICU, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Andrew Rebentisch
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Elaine Dawson
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Sydney Bowen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Kaitlin Zuspan
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Bradley A Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Kurt H Albertine
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States
| | - Raffaele L Dellacà
- TechRes Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
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2
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Pearson-Lemme J, Halibullah I, Becher T, Tingay HD, Douglas E, Fatmous M, Kenna KR, Pereira-Fantini PM, Tingay DG, Sett A. Mechanical power made simple: validating a simplified calculation of mechanical power in preterm lungs. Pediatr Res 2024:10.1038/s41390-024-03339-5. [PMID: 38886507 DOI: 10.1038/s41390-024-03339-5] [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: 04/15/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND The incidence of chronic lung disease is increasing, suggesting a need to explore novel ways to understand ventilator induced lung injury (VILI) in preterm infants. Mechanical power (MP) is a unifying measure of energy transferred to the respiratory system and a proposed determinant of VILI. The gold-standard method for calculating MP (geometric method) is not feasible in the clinical setting. This has prompted the derivation of simplified equations for calculating MP. OBJECTIVE To validate the agreement between a simplified calculation of MP (MPSimple) and the true MP calculated using the geometric method (MPRef). METHODS MPSimple and MPRef was calculated in mechanically ventilated preterm lambs (n = 71) and the agreement between both measures was determined using intraclass correlation coefficients (ICC), linear regression, and Bland-Altman analysis. RESULTS A strong linear relationship (adjusted R2 = 0.98), and excellent agreement (ICC = 0.99, 95% CI = 0.98-0.99) between MPSimple and MPRef was demonstrated. Bland-Altman analysis demonstrated a negligible positive bias (mean difference = 0.131 J/min·kg). The 95% limits of agreement were -0.06 to 0.32 J/min·kg. CONCLUSIONS In a controlled setting, there was excellent agreement between MPSimple and gold-standard calculations. MPSimple should be validated and explored in preterm neonates to assess the cause-effect relationship with VILI and neonatal outcomes. IMPACT STATEMENT Mechanical power (MP) unifies the individual components of ventilator induced lung injury (VILI) and provides an estimate of total energy transferred to the respiratory system during mechanical ventilation. As gold-standard calculations of mechanical power at the bedside are not feasible, alternative simplified equations have been proposed. In this study, MP calculated using a simplified equation had excellent agreement with true MP in mechanically ventilated preterm lambs. These results lay foundations to explore the role of MP in neonatal VILI and determine its relationship with short and long term respiratory outcomes.
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Affiliation(s)
- Jack Pearson-Lemme
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
- Newborn Services, Joan Kirner Women's and Children's, Sunshine Hospital, Western Health, Melbourne, VIC, Australia
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Ikhwan Halibullah
- Newborn Services, Joan Kirner Women's and Children's, Sunshine Hospital, Western Health, Melbourne, VIC, Australia
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Tobias Becher
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Schleswig-Holstein, Germany
| | - Hamish D Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Ellen Douglas
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Monique Fatmous
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Kelly R Kenna
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Prue M Pereira-Fantini
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - David G Tingay
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Arun Sett
- Newborn Services, Joan Kirner Women's and Children's, Sunshine Hospital, Western Health, Melbourne, VIC, Australia.
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.
- Department of Obstetrics, Gynaecology and Newborn Health, University of Melbourne, Melbourne, Victoria, Australia.
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3
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Smolich JJ, Kenna KR, Mynard JP. Extended period of ventilation before delayed cord clamping augments left-to-right shunting and decreases systemic perfusion at birth in preterm lambs. J Physiol 2024; 602:1791-1813. [PMID: 38532618 DOI: 10.1113/jp285799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/26/2024] [Indexed: 03/28/2024] Open
Abstract
Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40 s, n = 11), moderate (∼2 min, n = 11) or extended (∼5 min, n = 12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P = 0.005) that persisted for 4 min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40 s), moderate (∼2 min) or extended (∼5 min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.
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Affiliation(s)
- Joseph J Smolich
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Kelly R Kenna
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Jonathan P Mynard
- Heart Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- Department of Biomedical Engineering, University of Melbourne, Parkville, Victoria, Australia
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Cai BB, Wang DP. Risk factors for postoperative pulmonary complications in neonates: a retrospective cohort study. WORLD JOURNAL OF PEDIATRIC SURGERY 2023; 6:e000657. [PMID: 38025904 PMCID: PMC10668248 DOI: 10.1136/wjps-2023-000657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023] Open
Abstract
Objective Postoperative pulmonary complications (PPCs) are an important quality indicator and are associated with significantly increased mortality in infants. The objective of this study was to identify risk factors for PPCs in neonates undergoing non-cardiothoracic surgery. Methods In this retrospective study, all neonates who underwent non-cardiothoracic surgery in a children's hospital from October 2020 to September 2022 were included for analysis. Demographic data and perioperative variables were obtained. The primary outcome was the occurrence of PPCs. Univariate analysis and multivariable logistic regression analysis were used to investigate the effect of patient-related factors on the occurrence of PPCs. Results Totally, 867 neonatal surgery patients met the inclusion criteria in this study, among which 35.3% (306/867) patients experienced pulmonary complications within 1 week postoperatively. The PPCs observed in this study were 51 exacerbations of pre-existing pneumonia, 198 new patchy shadows, 123 new pulmonary atelectasis, 10 new pneumothorax, and 6 new pleural effusion. Patients were divided into two groups: PPCs (n=306) and non-PPCs (n=561). The multivariate stepwise logistic regression analysis revealed five independent risk factors for PPCs: corrected gestational age (OR=0.938; 95% CI 0.890 to 0.988), preoperative pneumonia (OR=2.139; 95% CI 1.033 to 4.426), length of surgery (> 60 min) (OR=1.699; 95% CI 1.134 to 2.548), preoperative mechanical ventilation (OR=1.857; 95% CI 1.169 to 2.951), and intraoperative albumin infusion (OR=1.456; 95% CI 1.041 to 2.036) in neonates undergoing non-cardiothoracic surgery. Conclusion Identifying risk factors for neonatal PPCs will allow for the identification of patients who are at higher risk and intervention for any modifiable risk factors identified.
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Affiliation(s)
- Bin Bin Cai
- Department of Anesthesiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hang Zhou, China
| | - Dong Pi Wang
- Department of Anesthesiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hang Zhou, China
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5
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Pereira-Fantini PM, Kenna KR, Fatmous M, Sett A, Douglas E, Dahm S, Sourial M, Fang H, Greening DW, Tingay DG. Impact of tidal volume strategy at birth on initiating lung injury in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2023; 325:L594-L603. [PMID: 37727901 DOI: 10.1152/ajplung.00159.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/05/2023] [Accepted: 09/14/2023] [Indexed: 09/21/2023] Open
Abstract
Tidal ventilation is essential in supporting the transition to air-breathing at birth, but excessive tidal volume (VT) is an important factor in preterm lung injury. Few studies have assessed the impact of specific VT levels on injury development. Here, we used a lamb model of preterm birth to investigate the role of different levels of VT during positive pressure ventilation (PPV) in promoting aeration and initiating early lung injury pathways. VT was delivered as 1) 7 mL/kg throughout (VTstatic), 2) begun at 3 mL/kg and increased to a final VT of 7 mL/kg over 3 min (VTinc), or 3) commenced at 7 mL/kg, decreased to 3 mL/kg, and then returned to 7 mL/kg (VTalt). VT, inflating pressure, lung compliance, and aeration were similar in all groups from 4 min, as was postmortem histology and lung lavage protein concentration. However, transient decrease in VT in the VTalt group caused increased ventilation heterogeneity. Following TMT-based quantitative mass spectrometry proteomics, 1,610 proteins were identified in the lung. Threefold more proteins were significantly altered with VTalt compared with VTstatic or VTinc strategies. Gene set enrichment analysis identified VTalt specific enrichment of immune and angiogenesis pathways and VTstatic enrichment of metabolic processes. Our finding of comparable lung physiology and volutrauma across VT groups challenges the paradigm that there is a need to rapidly aerate the preterm lung at birth. Increased lung injury and ventilation heterogeneity were identified when initial VT was suddenly decreased during respiratory support at birth, further supporting the benefit of a gentle VT approach.NEW & NOTEWORTHY There is little evidence to guide the best tidal volume (VT) strategy at birth. In this study, comparable aeration, lung mechanics, and lung morphology were observed using static, incremental, and alternating VT strategies. However, transient reduction in VT was associated with ventilation heterogeneity and inflammation. Our results suggest that rapidly aerating the preterm lung may not be as clinically critical as previously thought, providing clinicians with reassurance that gently supporting the preterm lung maybe permissible at birth.
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Affiliation(s)
- Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Kelly R Kenna
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Monique Fatmous
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Arun Sett
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Newborn Services, Joan Kirner Women's and Children's Hospital, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Ellen Douglas
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Sophia Dahm
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Magdy Sourial
- Translational Research Unit, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Haoyun Fang
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - David W Greening
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, Victoria, Australia
| | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
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6
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Tingay DG, Fatmous M, Kenna K, Dowse G, Douglas E, Sett A, Perkins EJ, Sourial M, Pereira-Fantini PM. Inflating Pressure and Not Expiratory Pressure Initiates Lung Injury at Birth in Preterm Lambs. Am J Respir Crit Care Med 2023; 208:589-599. [PMID: 37276583 DOI: 10.1164/rccm.202301-0104oc] [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] [Received: 01/17/2023] [Accepted: 05/31/2023] [Indexed: 06/07/2023] Open
Abstract
Rationale: Inflation is essential for aeration at birth, but current inflating pressure settings are without an evidence base. Objectives: To determine the role of inflating pressure (ΔP), and its relationship with positive end-expiratory pressure (PEEP), in initiating early lung injury pathways in the preterm lamb lung. Methods: Preterm (124 to 127 d) steroid-exposed lambs (n = 45) were randomly allocated (8-10 per group) to 15 minutes of respiratory support with placental circulation and 20 or 30 cm H2O ΔP, with an initial high PEEP (maximum, 20 cm H2O) recruitment maneuver known to facilitate aeration (dynamic PEEP), and compared with dynamic PEEP with no ΔP or 30 cm H2O ΔP and low (4 cm H2O) PEEP. Lung mechanics and aeration were measured throughout. After an additional 30 minutes of apneic placental support, lung tissue and bronchoalveolar fluid were analyzed for regional lung injury, including proteomics. Measurements and Main Results: The 30 cm H2O ΔP and dynamic PEEP strategies resulted in quicker aeration and better compliance but higher tidal volumes (often >8 ml/kg, all P < 0.0001; mixed effects) and injury. ΔP 20 cm H2O with dynamic PEEP resulted in the same lung mechanics and aeration, but less energy transmission (tidal mechanical power), as ΔP 30 cm H2O with low PEEP. Dynamic PEEP without any tidal inflations resulted in the least lung injury. Use of any tidal inflating pressures altered metabolic, coagulation and complement protein pathways within the lung. Conclusions: Inflating pressure is essential for the preterm lung at birth, but it is also the primary mediator of lung injury. Greater focus is needed on strategies that identify the safest application of pressure in the delivery room.
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Affiliation(s)
- David G Tingay
- Neonatal Research and
- Translational Research Unit, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics and
| | | | | | | | | | - Arun Sett
- Neonatal Research and
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
- Newborn Services, Joan Kirner Women's and Children's, Sunshine Hospital, Western Health, St. Albans, Victoria, Australia
| | | | - Magdy Sourial
- Neonatal Research and
- Translational Research Unit, Murdoch Children's Research Institute, Parkville, Victoria, Australia
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7
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Pereira-Fantini PM, Ferguson K, McCall K, Oakley R, Perkins E, Byars S, Williamson N, Nie S, Tingay DG. Respiratory strategy at birth initiates distinct lung injury phenotypes in the preterm lamb lung. Respir Res 2022; 23:346. [DOI: 10.1186/s12931-022-02244-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/07/2022] [Indexed: 12/15/2022] Open
Abstract
Abstract
Background
A lack of clear trial evidence often hampers clinical decision-making during support of the preterm lung at birth. Protein biomarkers have been used to define acute lung injury phenotypes and improve patient selection for specific interventions in adult respiratory distress syndrome. The objective of the study was to use proteomics to provide a deeper biological understanding of acute lung injury phenotypes resulting from different aeration strategies at birth in the preterm lung.
Methods
Changes in protein abundance against an unventilated group (n = 7) were identified via mass spectrometry in a biobank of gravity dependent and non-dependent lung tissue from preterm lambs managed with either a Sustained Inflation (SI, n = 20), Dynamic PEEP (DynPEEP, n = 19) or static PEEP (StatPEEP, n = 11). Ventilation strategy-specific pathways and functions were identified (PANTHER and WebGestalt Tool) and phenotypes defined using integrated analysis of proteome, physiological and clinical datasets (MixOmics package).
Results
2372 proteins were identified. More altered proteins were identified in the non-dependent lung, and in SI group than StatPEEP and DynPEEP. Different inflammation, immune system, apoptosis and cytokine pathway enrichment were identified for each strategy and lung region. Specific integration maps of clinical and physiological outcomes to specific proteins could be generated for each strategy.
Conclusions
Proteomics mapped the molecular events initiating acute lung injury and identified detailed strategy-specific phenotypes. This study demonstrates the potential to characterise preterm lung injury by the direct aetiology and response to lung injury; the first step towards true precision medicine in neonatology.
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8
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Sett A, Foo GWC, Kenna KR, Sutton RJ, Perkins EJ, Sourial M, Rogerson SR, Manley BJ, Davis PG, Pereira-Fantini PM, Tingay DG. Quantitative lung ultrasound detects dynamic changes in lung recruitment in the preterm lamb. Pediatr Res 2022; 93:1591-1598. [PMID: 36167816 PMCID: PMC10172106 DOI: 10.1038/s41390-022-02316-0] [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: 07/11/2022] [Revised: 08/24/2022] [Accepted: 09/07/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Lung ultrasound (LUS) may not detect small, dynamic changes in lung volume. Mean greyscale measurement using computer-assisted image analysis (Q-LUSMGV) may improve the precision of these measurements. METHODS Preterm lambs (n = 40) underwent LUS of the dependent or non-dependent lung during static pressure-volume curve mapping. Total and regional lung volumes were determined using the super-syringe technique and electrical impedance tomography. Q-LUSMGV and gold standard measurements of lung volume were compared in 520 images. RESULTS Dependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.60, 95% CI 0.51-0.67) and fairly with right whole (rho = 0.39, 0.27-0.49), central (rho = 0.38, 0.27-0.48), ventral (rho = 0.41, 0.31-0.51) and dorsal regional lung volumes (rho = 0.32, 0.21-0.43). Non-dependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.57, 0.48-0.65) and fairly with right whole (rho = 0.43, 0.32-0.52), central (rho = 0.46, 0.35-0.55), ventral (rho = 0.36, 0.25-0.47) and dorsal lung volumes (rho = 0.36, 0.25-0.47). All correlation coefficients were statistically significant. Distinct inflation and deflation limbs, and sonographic pulmonary hysteresis occurred in 95% of lambs. The greatest changes in Q-LUSMGV occurred at the opening and closing pressures. CONCLUSION Q-LUSMGV detected changes in total and regional lung volume and offers objective quantification of LUS images, and may improve bedside discrimination of real-time changes in lung volume. IMPACT Lung ultrasound (LUS) offers continuous, radiation-free imaging that may play a role in assessing lung recruitment but may not detect small changes in lung volume. Mean greyscale image analysis using computer-assisted quantitative LUS (Q-LUSMGV) moderately correlated with changes in total and regional lung volume. Q-LUSMGV identified opening and closing pressure and pulmonary hysteresis in 95% of lambs. Computer-assisted image analysis may enhance LUS estimation of lung recruitment at the bedside. Future research should focus on improving precision prior to clinical translation.
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Affiliation(s)
- Arun Sett
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia. .,Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia. .,Joan Kirner Women's and Children's Hospital, Western Health, St Albans, VIC, Australia. .,Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia. .,Paediatric Infant Perinatal Emergency Retrieval, The Royal Children's Hospital, Parkville, VIC, Australia.
| | - Gillian W C Foo
- Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia
| | - Kelly R Kenna
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Rebecca J Sutton
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Translational Research Unit, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Magdy Sourial
- Translational Research Unit, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Sheryle R Rogerson
- Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia.,Paediatric Infant Perinatal Emergency Retrieval, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Brett J Manley
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia
| | - Peter G Davis
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia
| | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Newborn Research Centre, The Royal Women's Hospital, Parkville, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia.,Department of Neonatology, The Royal Children's Hospital, Parkville, VIC, Australia
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9
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Brabant OA, Byrne DP, Sacks M, Moreno Martinez F, Raisis AL, Araos JB, Waldmann AD, Schramel JP, Ambrosio A, Hosgood G, Braun C, Auer U, Bleul U, Herteman N, Secombe CJ, Schoster A, Soares J, Beazley S, Meira C, Adler A, Mosing M. Thoracic Electrical Impedance Tomography-The 2022 Veterinary Consensus Statement. Front Vet Sci 2022; 9:946911. [PMID: 35937293 PMCID: PMC9354895 DOI: 10.3389/fvets.2022.946911] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Electrical impedance tomography (EIT) is a non-invasive real-time non-ionising imaging modality that has many applications. Since the first recorded use in 1978, the technology has become more widely used especially in human adult and neonatal critical care monitoring. Recently, there has been an increase in research on thoracic EIT in veterinary medicine. Real-time imaging of the thorax allows evaluation of ventilation distribution in anesthetised and conscious animals. As the technology becomes recognised in the veterinary community there is a need to standardize approaches to data collection, analysis, interpretation and nomenclature, ensuring comparison and repeatability between researchers and studies. A group of nineteen veterinarians and two biomedical engineers experienced in veterinary EIT were consulted and contributed to the preparation of this statement. The aim of this consensus is to provide an introduction to this imaging modality, to highlight clinical relevance and to include recommendations on how to effectively use thoracic EIT in veterinary species. Based on this, the consensus statement aims to address the need for a streamlined approach to veterinary thoracic EIT and includes: an introduction to the use of EIT in veterinary species, the technical background to creation of the functional images, a consensus from all contributing authors on the practical application and use of the technology, descriptions and interpretation of current available variables including appropriate statistical analysis, nomenclature recommended for consistency and future developments in thoracic EIT. The information provided in this consensus statement may benefit researchers and clinicians working within the field of veterinary thoracic EIT. We endeavor to inform future users of the benefits of this imaging modality and provide opportunities to further explore applications of this technology with regards to perfusion imaging and pathology diagnosis.
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Affiliation(s)
- Olivia A. Brabant
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - David P. Byrne
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Muriel Sacks
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | | | - Anthea L. Raisis
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Joaquin B. Araos
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Andreas D. Waldmann
- Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, Rostock, Germany
| | - Johannes P. Schramel
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Aline Ambrosio
- Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Giselle Hosgood
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Christina Braun
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Ulrike Auer
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Ulrike Bleul
- Clinic of Reproductive Medicine, Department of Farm Animals, Vetsuisse-Faculty University Zurich, Zurich, Switzerland
| | - Nicolas Herteman
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Cristy J. Secombe
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Angelika Schoster
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Joao Soares
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Shannon Beazley
- Department of Small Animal Clinical Sciences, Western College Veterinary Medicine, Saskatoon, SK, Canada
| | - Carolina Meira
- Department of Clinical Diagnostics and Services, Anaesthesiology, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, ON, Canada
| | - Martina Mosing
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
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10
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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.
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11
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Owen LS, Manley BJ, Hodgson KA, Roberts CT. Impact of early respiratory care for extremely preterm infants. Semin Perinatol 2021; 45:151478. [PMID: 34474939 DOI: 10.1016/j.semperi.2021.151478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Despite advances in neonatal intensive care, more than half of surviving infants born extremely preterm (EP; < 28 weeks' gestation) develop bronchopulmonary dysplasia (BPD). Prevention of BPD is critical because of its associated mortality and morbidity, including adverse neurodevelopmental outcomes and respiratory health in later childhood and beyond. The respiratory care of EP infants begins before birth, then continues in the delivery room and throughout the primary hospitalization. This chapter will review the evidence for interventions after birth that might improve outcomes for infants born EP, including the timing of umbilical cord clamping, strategies to avoid or minimize exposure to mechanical ventilation, modes of mechanical ventilation and non-invasive respiratory support, oxygen saturation targets, postnatal corticosteroids and other adjunct therapies.
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Affiliation(s)
- Louise S Owen
- Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Australia; Newborn Research Centre, The Royal Women's Hospital, Flemington Road, Parkville, Melbourne, VIC 3052, Australia; Clinical Sciences, Murdoch Children's Research Institute, Melbourne, Australia.
| | - Brett J Manley
- Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Australia; Newborn Research Centre, The Royal Women's Hospital, Flemington Road, Parkville, Melbourne, VIC 3052, Australia; Clinical Sciences, Murdoch Children's Research Institute, Melbourne, Australia
| | - Kate A Hodgson
- Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Australia; Newborn Research Centre, The Royal Women's Hospital, Flemington Road, Parkville, Melbourne, VIC 3052, Australia
| | - Calum T Roberts
- Monash Newborn, Monash Children's Hospital, Monash University, Clayton, VIC, Australia; Department of Paediatrics, Monash University, Clayton, VIC, Australia; The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
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12
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Tingay DG, Farrell O, Thomson J, Perkins EJ, Pereira-Fantini PM, Waldmann AD, Rüegger C, Adler A, Davis PG, Frerichs I. Imaging the Respiratory Transition at Birth: Unraveling the Complexities of the First Breaths of Life. Am J Respir Crit Care Med 2021; 204:82-91. [PMID: 33545023 DOI: 10.1164/rccm.202007-2997oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Rationale: The transition to air breathing at birth is a seminal respiratory event common to all humans, but the intrathoracic processes remain poorly understood. Objectives: The objectives of this prospective, observational study were to describe the spatiotemporal gas flow, aeration, and ventilation patterns within the lung in term neonates undergoing successful respiratory transition. Methods: Electrical impedance tomography was used to image intrathoracic volume patterns for every breath until 6 minutes from birth in neonates born by elective cesearean section and not needing resuscitation. Breaths were classified by video data, and measures of lung aeration, tidal flow conditions, and intrathoracic volume distribution calculated for each inflation. Measurements and Main Results: A total of 1,401 breaths from 17 neonates met all eligibility and data analysis criteria. Stable FRC was obtained by median (interquartile range) 43 (21-77) breaths. Breathing patterns changed from predominantly crying (80.9% first min) to tidal breathing (65.3% sixth min). From birth, tidal ventilation was not uniform within the lung, favoring the right and nondependent regions; P < 0.001 versus left and dependent regions (mixed-effects model). Initial crying created a unique volumetric pattern with delayed midexpiratory gas flow associated with intrathoracic volume redistribution (pendelluft flow) within the lung. This preserved FRC, especially within the dorsal and right regions. Conclusions: The commencement of air breathing at birth generates unique flow and volume states associated with marked spatiotemporal ventilation inhomogeneity not seen elsewhere in respiratory physiology. At birth, neonates innately brake expiratory flow to defend FRC gains and redistribute gas to less aerated regions.
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Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia.,Neonatology, Royal Children's Hospital, Melbourne, Australia.,Neonatal Research, The Royal Women's Hospital, Melbourne, Australia
| | - Olivia Farrell
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Jessica Thomson
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Andreas D Waldmann
- Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Germany
| | | | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada; and
| | - Peter G Davis
- Neonatal Research, The Royal Women's Hospital, Melbourne, Australia
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
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13
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Kapadia VS, Urlesberger B, Soraisham A, Liley HG, Schmölzer GM, Rabi Y, Wyllie J, Wyckoff MH. Sustained Lung Inflations During Neonatal Resuscitation at Birth: A Meta-analysis. Pediatrics 2021; 147:peds.2020-021204. [PMID: 33361356 DOI: 10.1542/peds.2020-021204] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 11/24/2022] Open
Abstract
CONTEXT The International Liaison Committee on Resuscitation prioritized review of sustained inflation (SI) of the lung at birth. OBJECTIVE To complete a systematic review and meta-analysis comparing strategies using 1 or more SI ≥1 second with intermittent inflations <1 second for newborns at birth. DATA SOURCES Medline, Embase, and Evidence-Based Medicine Reviews were searched from January 1, 1946, to July 20, 2020. STUDY SELECTION Studies were selected by pairs of independent reviewers in 2 stages. DATA EXTRACTION Reviewers extracted data, appraised risk of bias, and assessed certainty of evidence for each outcome. RESULTS Ten trials enrolling 1502 preterm newborns were included. Five studies included newborns who did not receive assisted ventilation at the outset. There were no differences between SI and control groups for death before discharge or key morbidities. For death within the first 2 days, comparing SI with the controls, risk ratio was 2.42 (95% confidence interval = 1.15-5.09). In subgroup analysis of preterm infants ≤28 + 0 weeks' gestation, for death before discharge, risk ratio was 1.38 (95% confidence interval = 1.00-1.91). Together, these findings suggest the potential for harm of SI. LIMITATIONS The certainty of evidence was very low for death in the delivery room and low for all other outcomes. CONCLUSIONS In this systematic review, we did not find benefit in using 1 or more SI >5 seconds for preterm infants at birth. SI(s) may increase death before discharge among the subgroup born ≤28 + 0 weeks' gestation. There is insufficient evidence to determine the likely effect of SI(s) on other key morbidities.
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Affiliation(s)
| | | | | | | | | | | | - Jonathan Wyllie
- James Cook University Hospital, South Tees National Health Service Foundation Trust, Middlesbrough, United Kingdom
| | - Myra H Wyckoff
- University of Texas Southwestern Medical Center, Dallas, Texas
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14
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Feasibility of combining two individualized lung recruitment maneuvers at birth for very low gestational age infants: a retrospective cohort study. BMC Pediatr 2020; 20:144. [PMID: 32238150 PMCID: PMC7114798 DOI: 10.1186/s12887-020-02055-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 03/27/2020] [Indexed: 01/21/2023] Open
Abstract
Background Lung recruitment at birth has been advocated as an effective method of improving the respiratory transition at birth. Sustained inflations (SI) and dynamic positive end-expiratory pressure (PEEP) were assessed in clinical and animal studies to define the optimal level. Our working hypothesis was that very low gestational age infants (VLGAI) < 32 weeks’ gestation require an individualized lung recruitment based on combining both manoeuvers. Methods Between 2014 and 2016, 91 and 72 inborn VLGAI, requiring a respiratory support beyond a continuous positive airway pressure (CPAP) = 5 cmH2O, were enrolled before and after introducing these manoeuvers based on progressive increase in SI up to 15 s, with simultaneous gradual increase in PEEP up to 15 cmH2O, according to the cardiorespiratory response. Retrospective comparisons of the incidence of mechanical ventilation (MV) < 72 h of life, short-term and before discharge morbidity were then performed. Results Among extremely low gestational age infants (ELGAI) < 29 weeks’ gestation, the following outcomes decreased significantly: intubation (90 to 55%) and surfactant administration (54 to 12%) in the delivery room, MV (92 to 71%) and its mean duration < 72 h of life (45 h to 13 h), administration of a 2nd dose of surfactant (35 to 12%) and postnatal corticosteroids (52 to 19%), and the rate of bronchopulmonary dysplasia (23 to 5%). Among VLGAI, all of these results were also significant. Neonatal mortality and morbidity were not different. Conclusions In our setting, combining two individualized lung recruitment maneuvers at birth was feasible and may be beneficial on short-term and before discharge pulmonary outcomes. A randomized controlled trial is needed to confirm these results.
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15
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Tingay DG, Pereira-Fantini PM, Oakley R, McCall KE, Perkins EJ, Miedema M, Sourial M, Thomson J, Waldmann A, Dellaca RL, Davis PG, Dargaville PA. Gradual Aeration at Birth Is More Lung Protective Than a Sustained Inflation in Preterm Lambs. Am J Respir Crit Care Med 2020; 200:608-616. [PMID: 30730759 DOI: 10.1164/rccm.201807-1397oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Rationale: The preterm lung is susceptible to injury during transition to air breathing at birth. It remains unclear whether rapid or gradual lung aeration at birth causes less lung injury.Objectives: To examine the effect of gradual and rapid aeration at birth on: 1) the spatiotemporal volume conditions of the lung; and 2) resultant regional lung injury.Methods: Preterm lambs (125 ± 1 d gestation) were randomized at birth to receive: 1) tidal ventilation without an intentional recruitment (no-recruitment maneuver [No-RM]; n = 19); 2) sustained inflation (SI) until full aeration (n = 26); or 3) tidal ventilation with an initial escalating/de-escalating (dynamic) positive end-expiratory pressure (DynPEEP; n = 26). Ventilation thereafter continued for 90 minutes at standardized settings, including PEEP of 8 cm H2O. Lung mechanics and regional aeration and ventilation (electrical impedance tomography) were measured throughout and correlated with histological and gene markers of early lung injury.Measurements and Main Results: DynPEEP significantly improved dynamic compliance (P < 0.0001). An SI, but not DynPEEP or No-RM, resulted in preferential nondependent lung aeration that became less uniform with time (P = 0.0006). The nondependent lung was preferential ventilated by 5 minutes in all groups, with ventilation only becoming uniform with time in the No-RM and DynPEEP groups. All strategies generated similar nondependent lung injury patterns. Only an SI caused greater upregulation of dependent lung gene markers compared with unventilated fetal controls (P < 0.05).Conclusions: Rapidly aerating the preterm lung at birth creates heterogeneous volume states, producing distinct regional injury patterns that affect subsequent tidal ventilation. Gradual aeration with tidal ventilation and PEEP produced the least lung injury.
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Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatology, The Royal Children's Hospital, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia.,Department of Paediatrics and
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics and
| | - Regina Oakley
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Karen E McCall
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Martijn Miedema
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatology, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Magdy Sourial
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Jessica Thomson
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | | | - Raffaele L Dellaca
- Dipartimento di Elettronica, Informazione e Ingegneria Biomedica, Politecnico di Milano University, Milan, Italy
| | - Peter G Davis
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter A Dargaville
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatal and Paediatric Intensive Care Unit, Royal Hobart Hospital, Hobart, Tasmania, Australia; and.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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16
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Veneroni C, Tingay DG, McCall KE, Pereira-Fantini PM, Perkins EJ, Dargaville PA, Dellacà RL. Respiratory mechanics during initial lung aeration at birth in the preterm lamb. Am J Physiol Lung Cell Mol Physiol 2020; 318:L525-L532. [PMID: 31913650 DOI: 10.1152/ajplung.00302.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite recent insights into the dynamic processes during lung aeration at birth, several aspects remain poorly understood. We aimed to characterize changes in lung mechanics during the first inflation at birth and their relationship to changes in lung volume. Intubated preterm lambs (gestational age, 124-127 days; n = 17) were studied at birth. Lung volume changes were measured by electrical impedance tomography (VLEIT). Respiratory system resistance (R5) and oscillatory compliance (Cx5) were monitored with the forced oscillation technique at 5 Hz. Lambs received 3-7 s of 8 cmH2O of continuous distending pressure (CDP) before delivery of a sustained inflation (SI) of 40 cmH2O. The SI was then applied until either Cx5 or the VLEIT or the airway opening volume was stable. CDP was resumed for 3-7 s before commencement of mechanical ventilation. The exponential increases with time of Cx5 and VLEIT from commencement of the SI were characterized by estimating their time constants (τCx5 and τVLEIT, respectively). During SI, a fast decrease in R5 and an exponential increase in Cx5 and VLEIT were observed. Cx5 and VLEIT provided comparable information on the dynamics of lung aeration in all lambs, with τCx5 and τVLEIT being highly linearly correlated (r2 = 0.87, P < 0.001). Cx5 and VLEIT decreased immediately after SI. Despite the standardization of the animal model, changes in Cx5 and R5 both during and after SI were highly variable. Lung aeration at birth is characterized by a fast reduction in resistance and a slower increase in oscillatory compliance, the latter being a direct reflection of the amount of lung aeration.
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Affiliation(s)
- Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.,Department of Neonatology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Karen E McCall
- Department of Neonatology, Wishaw General Hospital, Wishaw, United Kingdom.,School of Medicine and Medical Sciences, University College Dublin, Ireland
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Peter A Dargaville
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
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17
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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.
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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
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18
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Tingay DG, Togo A, Pereira-Fantini PM, Miedema M, McCall KE, Perkins EJ, Thomson J, Dowse G, Sourial M, Dellacà RL, Davis PG, Dargaville PA. Aeration strategy at birth influences the physiological response to surfactant in preterm lambs. Arch Dis Child Fetal Neonatal Ed 2019; 104:F587-F593. [PMID: 31498776 DOI: 10.1136/archdischild-2018-316240] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/26/2018] [Accepted: 12/19/2018] [Indexed: 11/03/2022]
Abstract
BACKGROUND The influence of pressure strategies to promote lung aeration at birth on the subsequent physiological response to exogenous surfactant therapy has not been investigated. OBJECTIVES To compare the effect of sustained inflation (SI) and a dynamic positive end-expiratory pressure (PEEP) manoeuvre at birth on the subsequent physiological response to exogenous surfactant therapy in preterm lambs. METHODS Steroid-exposed preterm lambs (124-127 days' gestation; n=71) were randomly assigned from birth to either (1) positive-pressure ventilation (PPV) with no recruitment manoeuvre; (2) SI until stable aeration; or (3) 3 min dynamic stepwise PEEP strategy (maximum 14-20 cmH2O; dynamic PEEP (DynPEEP)), followed by PPV for 60 min using a standardised protocol. Surfactant (200 mg/kg poractant alfa) was administered at 10 min. Dynamic compliance, gas exchange and regional ventilation and aeration characteristics (electrical impedance tomography) were measured throughout and compared between groups, and with a historical group (n=38) managed using the same strategies without surfactant. RESULTS Compliance increased after surfactant only in the DynPEEP group (p<0.0001, repeated measures analysis of variance), being 0.17 (0.10, 0.23) mL/kg/cmH2O higher at 60 min than the SI group. An SI resulted in the least uniform aeration, and unlike the no-recruitment and DynPEEP groups, the distribution of aeration and tidal ventilation did not improve with surfactant. All groups had similar improvements in oxygenation post-surfactant compared with the corresponding groups not treated with surfactant. CONCLUSIONS A DynPEEP strategy at birth may improve the response to early surfactant therapy, whereas rapid lung inflation with SI creates non-uniform aeration that appears to inhibit surfactant efficacy.
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Affiliation(s)
- David Gerald Tingay
- Neonatology, Royal Children's Hospital, Parkville, Victoria, Australia.,Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia
| | - Andrea Togo
- Neonatology, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Martijn Miedema
- Neonatology, Royal Children's Hospital, Parkville, Victoria, Australia.,Neonatology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Karen E McCall
- Neonatology, Royal Children's Hospital, Parkville, Victoria, Australia.,Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Elizabeth J Perkins
- Neonatology, Royal Children's Hospital, Parkville, Victoria, Australia.,Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Jessica Thomson
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Georgie Dowse
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Magdy Sourial
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Raffaele L Dellacà
- TBM Lab, Dipartimento di Elettronica, Informazione e BioIngegneria (DEIB), Politecnico di Milano University, Milan, Italy
| | - Peter G Davis
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter Anderson Dargaville
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Neonatal and Paediatric Intensive Care Unit, Royal Hobart Hospital, Hobart, Tasmania, Australia.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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19
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Fathi O, Bapat R, G. Shepherd E, Wells Logan J. Golden Hours: An Approach to Postnatal Stabilization and Improving Outcomes. NEONATAL MEDICINE 2019. [DOI: 10.5772/intechopen.82810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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20
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Miedema M, Adler A, McCall KE, Perkins EJ, van Kaam AH, Tingay DG. Electrical impedance tomography identifies a distinct change in regional phase angle delay pattern in ventilation filling immediately prior to a spontaneous pneumothorax. J Appl Physiol (1985) 2019; 127:707-712. [PMID: 31268827 DOI: 10.1152/japplphysiol.00973.2018] [Citation(s) in RCA: 4] [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
Pneumothoraxes are common in preterm infants and are a major cause of morbidity. Early detection and treatment of pneumothoraxes are vital to minimize further respiratory compromise. Electrical impedance tomography (EIT) has been suggested as a method of rapidly detecting pneumothoraxes at the bedside. Our objective was to define the EIT-derived regional phase angle differences in filling characteristics before and during spontaneous pneumothoraxes in preterm lambs. Preterm lambs (124-127-day gestation) were ventilated with high-frequency oscillatory ventilation for 120 min. EIT data and cardiorespiratory parameters were monitored continuously and recorded for 3 min every 15 min. Six animals spontaneously developed a pneumothorax within a gravity-nondependent quadrant of the lung and were included for this analysis. Changes in end-expiratory lung impedance (EELI), ventilation, and phase angle delay were calculated in the four lung quadrants at the onset of the pneumothorax and 15 and 30 min prior. At the onset of the pneumothorax, all animals showed a clear increase in EELI in the affected lung quadrant. Fifteen and thirty minutes before the pneumothorax there was a significant phase angle delay between the nondependent and dependent lung. At 1 min before pneumothorax this phase angle delay was isolated just to the affected quadrant (nondependent). These findings are the first description of the events within the lung at initiation of a pneumothorax, demonstrating distinct predictive changes in air-filling characteristics before the occurrence of pneumothorax. This suggests that EIT may be able to accurately identify the onset of a pneumothorax.NEW & NOTEWORTHY In this article we describe for the first time predictive changes in electrical impedance tomography-based regional filling characteristics of the lung before the onset of a one-sided pneumothorax in six preterm lambs ventilated with high-frequency oscillatory ventilation. This can give clinicians bedside information to change treatment of preterm infants and prevent pneumothorax as life-threatening event from happening.
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Affiliation(s)
- Martijn Miedema
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Neonatology, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Karen E McCall
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Anton H van Kaam
- Department of Neonatology, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Neonatology, Royal Children's Hospital, Melbourne, Victoria, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Victoria, Australia
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21
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Hinder M, McEwan A, Drevhammer T, Donaldson S, Tracy MB. T-piece resuscitators: how do they compare? Arch Dis Child Fetal Neonatal Ed 2019; 104:F122-F127. [PMID: 29728414 DOI: 10.1136/archdischild-2018-314860] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/09/2018] [Accepted: 04/18/2018] [Indexed: 11/04/2022]
Abstract
BACKGROUND The T-piece resuscitator (TPR) has seen increased use as a primary resuscitation device with newborns. Traditional TPR design uses a high resistance expiratory valve to produce positive end expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) at resuscitation. A new TPR device that uses a dual flow ratio valve (fluidic flip) to produce PEEP/CPAP is now available (rPAP). We aimed to compare the measured ventilation performance of different TPR devices in a controlled bench test study. DESIGN/METHODS Single operator provided positive pressure ventilation to an incremental testlung compliance (Crs) model (0.5-5 mL/cmH2O) with five different brands of TPR device (Atom, Neopuff, rPAP, GE Panda warmer and Draeger Resuscitaire). At recommended peak inflation pressure (PIP) 20 cmH2O, PEEP of 5 cmH2O and rate of 60 inflations per minute. RESULTS 1864 inflations were analysed. Four of the five devices tested demonstrated inadvertent elevations in mean PEEP (5.5-10.3 cmH2O, p<0.001) from set value as Crs was increased, while one device (rPAP) remained at the set value. Measured PIP exceeded the set value in two infant warmer devices (GE and Draeger) with inbuilt TPR at Crs of 0.5 (24.5 and 23.5 cmH2O, p<0.001). Significant differences were seen in tidal volumes across devices particularly at higher Crs (p<0.001). CONCLUSIONS Results show important variation in delivered ventilation from set values due to inherent TPR device design characteristics with a range of lung compliances expected at birth. Device-generated inadvertent PEEP and overdelivery of PIP may be clinically deleterious for term and preterm newborns or infants with larger Crs during resuscitation.
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Affiliation(s)
- Murray Hinder
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, New South Wales, Australia.,Faculty of Engineering and Information Technologies, BMET Institute, Sydney University, Sydney, New South Wales, Australia
| | - Alistair McEwan
- Faculty of Engineering and Information Technologies, BMET Institute, Sydney University, Sydney, New South Wales, Australia
| | - Thomas Drevhammer
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Snorri Donaldson
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Mark Brian Tracy
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, New South Wales, Australia.,Department of Paediatrics and Child Health, Sydney University, Westmead, New South Wales, Australia
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22
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Oakley RB, Tingay DG, McCall KE, Perkins EJ, Sourial M, Dargaville PA, Pereira-Fantini PM. Gestational Age Influences the Early Microarchitectural Changes in Response to Mechanical Ventilation in the Preterm Lamb Lung. Front Pediatr 2019; 7:325. [PMID: 31497582 PMCID: PMC6712425 DOI: 10.3389/fped.2019.00325] [Citation(s) in RCA: 5] [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: 04/01/2019] [Accepted: 07/19/2019] [Indexed: 11/13/2022] Open
Abstract
Background: Preterm birth is associated with abnormal lung architecture, and a reduction in pulmonary function related to the degree of prematurity. A thorough understanding of the impact of gestational age on lung microarchitecture requires reproducible quantitative analysis of lung structure abnormalities. The objectives of this study were (1) to use quantitative histological software (ImageJ) to map morphological patterns of injury resulting from delivery of an identical ventilation strategy to the lung at varying gestational ages and (2) to identify associations between gestational age-specific morphological alterations and key functional outcomes. Method: Lung morphology was compared after 60 min of a standardized ventilation protocol (40 cm H2O sustained inflation and then volume-targeted positive pressure ventilation with positive end-expiratory pressure 8 cm H2O) in lambs at different gestations (119, 124, 128, 133, 140d) representing the spectrum of premature developmental lung states and the term lung. Age-matched controls were compared at 124 and 128d gestation. Automated and manual functions of Image J were used to measure key histological features. Correlation analysis compared morphological and functional outcomes in lambs aged ≤128 and >128d. Results: In initial studies, unventilated lung was indistinguishable at 124 and 128d. Ventilated lung from lambs aged 124d gestation exhibited increased numbers of detached epithelial cells and lung tissue compared with 128d lambs. Comparing results from saccular to alveolar development (120-140d), lambs aged ≤124d exhibited increased lung tissue, average alveolar area, and increased numbers of detached epithelial cells. Alveolar septal width was increased in lambs aged ≤128d. These findings were mirrored in the measures of gas exchange, lung mechanics, and molecular markers of lung injury. Correlation analysis confirmed the gestation-specific relationships between the histological assessments and functional measures in ventilated lambs at gestation ≤128 vs. >128d. Conclusion: Image J allowed rapid, quantitative assessment of alveolar morphology, and lung injury in the preterm lamb model. Gestational age-specific patterns of injury in response to delivery of an identical ventilation strategy were identified, with 128d being a transition point for associations between morphological alterations and functional outcomes. These results further support the need to develop individualized respiratory support approaches tailored to both the gestational age of the infant and their underlying injury response.
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Affiliation(s)
- Regina B Oakley
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - David G Tingay
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Department of Neonatology, Royal Children's Hospital, Parkville, VIC, Australia.,Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Karen E McCall
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia.,School of Medicine and Medicinal Sciences, University College Dublin, Dublin, Ireland
| | - Elizabeth J Perkins
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Magdy Sourial
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Peter A Dargaville
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research Group, Murdoch Children's Research Institute, Parkville, VIC, Australia.,Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
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23
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Thio M, Dawson JA, Crossley KJ, Moss TJ, Roehr CC, Polglase GR, Davis PG, Hooper SB. Delivery of positive end-expiratory pressure to preterm lambs using common resuscitation devices. Arch Dis Child Fetal Neonatal Ed 2019; 104:F83-F88. [PMID: 29500315 DOI: 10.1136/archdischild-2017-314064] [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: 09/05/2017] [Revised: 01/29/2018] [Accepted: 02/06/2018] [Indexed: 11/03/2022]
Abstract
BACKGROUND In neonatal resuscitation, a ventilation device providing positive end-expiratory pressure (PEEP) is recommended. There is limited information about PEEP delivery in vivo, using different models of self-inflating bag (SIB) at different inflation rates and PEEP settings. METHODS We compared PEEP delivery to intubated preterm lambs using four commonly available models of paired SIBs and PEEP valves, with a T-piece, with gas flow of 8 L/min. Peak inspiratory pressure inflations of 30 cmH2O, combined with set PEEP of 5, 7 and 10 cmH2O, were delivered at rates of 20, 40 and 60/min. These combinations were repeated without gas flow. We measured mean PEEP, maximum and minimum PEEP, and its difference (PEEP reduction). RESULTS A total of 3288 inflations were analysed. The mean PEEP delivered by all SIBs was lower than set PEEP (P<0.001), although some differences were <0.5 cmH2O. In 55% of combinations, the presence of gas flow resulted in increased PEEP delivery (range difference 0.3-2 cmH2O). The mean PEEP was closer to set PEEP with faster inflation rates and higher set PEEPs. The mean (SD) PEEP reduction was 3.9 (1.6), 8.2 (1.8), 2 (0.6) and 1.1 (0.6) cmH2O with the four SIBs, whereas it was 0.5 (0.2) cmH2O with the T-piece. CONCLUSIONS PEEP delivery with SIBs depends on the set PEEP, inflation rate, device model and gas flow. At recommended inflation rates of 60/min, some devices can deliver PEEP close to the set level, although the reduction in PEEP makes some SIBs potentially less effective for lung recruitment than a T-piece.
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Affiliation(s)
- Marta Thio
- Newborn Research Centre, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia.,PIPER - Neonatal Retrieval Services Victoria, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Jennifer A Dawson
- Newborn Research Centre, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia
| | - 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
| | - Timothy J Moss
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Charles C Roehr
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Paediatrics, Newborn Services, University of Oxford, John Radcliffe Hospital, NHS Foundation Trust, Oxford, UK
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Peter G Davis
- Newborn Research Centre, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, The University of Melbourne, 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
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24
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Pereira-Fantini PM, Byars SG, McCall KE, Perkins EJ, Oakley RB, Dellacà RL, Dargaville PA, Davis PG, Ignjatovic V, Tingay DG. Plasma proteomics reveals gestational age-specific responses to mechanical ventilation and identifies the mechanistic pathways that initiate preterm lung injury. Sci Rep 2018; 8:12616. [PMID: 30135517 PMCID: PMC6105628 DOI: 10.1038/s41598-018-30868-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/02/2018] [Indexed: 12/15/2022] Open
Abstract
The preterm lung is particularly vulnerable to ventilator-induced lung injury (VILI) as a result of mechanical ventilation. However the developmental and pathological cellular mechanisms influencing the changing patterns of VILI have not been comprehensively delineated, preventing the advancement of targeted lung protective therapies. This study aimed to use SWATH-MS to comprehensively map the plasma proteome alterations associated with the initiation of VILI following 60 minutes of standardized mechanical ventilation from birth in three distinctly different developmental lung states; the extremely preterm, preterm and term lung using the ventilated lamb model. Across these gestations, 34 proteins were differentially altered in matched plasma samples taken at birth and 60 minutes. Multivariate analysis of the plasma proteomes confirmed a gestation-specific response to mechanical ventilation with 79% of differentially-expressed proteins altered in a single gestation group only. Six cellular and molecular functions and two physiological functions were uniquely enriched in either the extremely preterm or preterm group. Correlation analysis supported gestation-specific protein-function associations within each group. In identifying the gestation-specific proteome and functional responses to ventilation we provide the founding evidence required for the potential development of individualized respiratory support approaches tailored to both the developmental and pathological state of the lung.
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Affiliation(s)
- Prue M Pereira-Fantini
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia. .,Department of Paediatrics, University of Melbourne, Parkville, Australia.
| | - Sean G Byars
- Department of Pathology, University of Melbourne, Parkville, Australia.,Centre for Systems Genomics, University of Melbourne, Parkville, Australia
| | - Karen E McCall
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia.,University College Dublin, Dublin, Ireland
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - Regina B Oakley
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - R L Dellacà
- Laboratorio di Tecnologie Biomediche, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Peter A Dargaville
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Peter G Davis
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia.,The Royal Women's Hospital, Parkville, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Australia
| | - Vera Ignjatovic
- Department of Paediatrics, University of Melbourne, Parkville, Australia.,Haematology Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - David G Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Australia.,Department of Neonatology, Royal Children's Hospital, Parkville, Australia
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25
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Miedema M, McCall KE, Perkins EJ, Oakley RB, Pereira-Fantini PM, Rajapaksa AE, Waldmann AD, Tingay DG, van Kaam AH. Lung Recruitment Strategies During High Frequency Oscillatory Ventilation in Preterm Lambs. Front Pediatr 2018; 6:436. [PMID: 30723711 PMCID: PMC6349831 DOI: 10.3389/fped.2018.00436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/31/2018] [Indexed: 01/28/2023] Open
Abstract
Background: High frequency oscillatory ventilation (HFOV) is considered a lung protective ventilation mode in preterm infants only if lung volume is optimized. However, whilst a "high lung volume strategy" is advocated for HFOV in preterm infants this strategy is not precisely defined. It is not known to what extent lung recruitment should be pursued to provide lung protection. In this study we aimed to determine the relationship between the magnitude of lung volume optimization and its effect on gas exchange and lung injury in preterm lambs. Methods: 36 surfactant-deficient 124-127 d lambs commenced HFOV immediately following a sustained inflation at birth and were allocated to either (1) no recruitment (low lung volume; LLV), (2) medium- (MLV), or (3) high lung volume (HLV) recruitment strategy. Gas exchange and lung volume changes over time were measured. Lung injury was analyzed by post mortem pressure-volume curves, alveolar protein leakage, gene expression, and histological injury score. Results: More animals in the LLV developed a pneumothorax compared to both recruitment groups. Gas exchange was superior in both recruitment groups compared to LLV. Total lung capacity tended to be lower in the LLV group. Other parameters of lung injury were not different. Conclusions: Lung recruitment during HFOV optimizes gas exchange but has only modest effects on lung injury in a preterm animal model. In the HLV group aiming at a more extensive lung recruitment gas exchange was better without affecting lung injury.
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Affiliation(s)
- Martijn Miedema
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Karen E McCall
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Regina B Oakley
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | | | - Anushi E Rajapaksa
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Neonatology, Royal Children's Hospital, Melbourne, VIC, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | | | - David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Neonatology, Royal Children's Hospital, Melbourne, VIC, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Anton H van Kaam
- Department of Neonatology, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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26
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Lista G, Maturana A, Moya FR. Achieving and maintaining lung volume in the preterm infant: from the first breath to the NICU. Eur J Pediatr 2017; 176:1287-1293. [PMID: 28795220 DOI: 10.1007/s00431-017-2984-y] [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: 06/29/2017] [Revised: 07/24/2017] [Accepted: 08/03/2017] [Indexed: 12/31/2022]
Abstract
UNLABELLED The main goal for the neonatologist is to facilitate the adaptation to extra-uterine life during initial transition, while minimizing lung injury opening and protecting the premature lung from the first breath onwards. An appropriate management from birth should lead to the achievement of an early functional residual capacity (FRC), and the following steps should aim at maintaining an adequate lung volume. To date, different strategies are available to optimize fetal-neonatal transition and promote lung recruitment. New ventilation approaches, such as sustained lung inflation (SLI) and "open lung strategy", well-established ventilation techniques with a more tailored application and less invasive modalities to administer surfactant have been recently introduced in clinical practice with promising results. CONCLUSIONS given the current status of neonatal care, it seems that lung injury and BPD could be reduced with multiple strategies starting early in the delivery room. Literature underlines the importance of a respiratory tailored management of preterm infants from birth and during the whole NICU stay. What is Known: • Experimental and clinical studies have shown that the transition from fetal to adult type cardiorespiratory circulation needs an adequate lung ventilation. An appropriate management in the delivery room should lead to the achievement of an early FRC, and through the following steps, the neonatologist should aim at maintaining an adequate lung volume. • Literature underlines the importance of a respiratory tailored management of preterm infants during the whole NICU stay to maintain the benefits of a successful postnatal adaption. What is New: • Herewith, we describe the most relevant and recent interventions which can be performed from the delivery room to the NICU stay to guarantee an adequate tradition to postnatal life and an effective cardiorespiratory stability.
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Affiliation(s)
- Gianluca Lista
- NICU "V. Buzzi" Children's Hospital, ASST-FBF-Sacco, Via Castelvetro, 32, 20154, Milan, Italy.
| | | | - Fernando R Moya
- Coastal Carolina Neonatology, Coastal Children's Services, PLLC, Wilmington, NC, 28401, USA
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27
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McCall KE, Waldmann AD, Pereira-Fantini P, Oakley R, Miedema M, Perkins EJ, Davis PG, Dargaville PA, Böhm SH, Dellacà R, Sourial M, Zannin E, Rajapaksa AE, Tan A, Adler A, Frerichs I, Tingay DG. Time to lung aeration during a sustained inflation at birth is influenced by gestation in lambs. Pediatr Res 2017; 82:712-720. [PMID: 28604757 DOI: 10.1038/pr.2017.141] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/20/2017] [Indexed: 11/10/2022]
Abstract
BackgroundCurrent sustained lung inflation (SI) approaches use uniform pressures and durations. We hypothesized that gestational-age-related mechanical and developmental differences would affect the time required to achieve optimal lung aeration, and resultant lung volumes, during SI delivery at birth in lambs.Methods49 lambs, in five cohorts between 118 and 139 days of gestation (term 142 d), received a standardized 40 cmH2O SI, which was delivered until 10 s after lung volume stability (optimal aeration) was visualized on real-time electrical impedance tomography (EIT), or to a maximum duration of 180 s. Time to stable lung aeration (Tstable) within the whole lung, gravity-dependent, and non-gravity-dependent regions, was determined from EIT recordings.ResultsTstable was inversely related to gestation (P<0.0001, Kruskal-Wallis test), with the median (range) being 229 (85,306) s and 72 (50,162) s in the 118-d and 139-d cohorts, respectively. Lung volume at Tstable increased with gestation from a mean (SD) of 20 (17) ml/kg at 118 d to 56 (13) ml/kg at 139 d (P=0.002, one-way ANOVA). There were no gravity-dependent regional differences in Tstable or aeration.ConclusionsThe trajectory of aeration during an SI at birth is influenced by gestational age in lambs. An understanding of this may assist in developing SI protocols that optimize lung aeration for all infants.
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Affiliation(s)
- Karen E McCall
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | | | - Prue Pereira-Fantini
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Regina Oakley
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Martijn Miedema
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Peter G Davis
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter A Dargaville
- Department of Paediatrics, Royal Hobart Hospital, Hobart, Tasmania, Australia.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Raffaele Dellacà
- TBM Lab, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Magdy Sourial
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Emanuela Zannin
- TBM Lab, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Anushi E Rajapaksa
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Andre Tan
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - David G Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia.,Department of Neonatology, The Royal Children's Hospital, Parkville, Victoria, Australia
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28
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Supraglottic Atomization of Surfactant in Spontaneously Breathing Lambs Receiving Continuous Positive Airway Pressure. Pediatr Crit Care Med 2017; 18:e428-e434. [PMID: 28742723 DOI: 10.1097/pcc.0000000000001267] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To determine the short-term tolerance, efficacy, and lung deposition of supraglottic atomized surfactant in spontaneously breathing lambs receiving continuous positive airway pressure. DESIGN Prospective, randomized animal study. SETTING Animal research laboratory. SUBJECTS Twenty-two preterm lambs on continuous positive airway pressure (132 ± 1 d gestational age). INTERVENTIONS Animals receiving continuous positive airway pressure via binasal prongs at 8 cm H2O were randomized to receive atomized surfactant at approximately 60-minute of life (atom; n = 15) or not (control; n = 7). The atom group received 200 mg/kg of poractant alfa (Curosurf; Chiesi Farmaceutici SpA, Parma, Italy) over 45 minutes via a novel atomizer located in the upper pharynx that synchronized surfactant delivery with the inspiratory phase. MEASUREMENTS AND MAIN RESULTS Arterial blood gas, regional distribution of tidal ventilation (electrical impedance tomography), and carotid blood flow were recorded every 15 minutes until 90 minutes after stabilizing on continuous positive airway pressure. Gas exchange, respiratory rate, and hemodynamic variables, including carotid blood flow, remained stable during surfactant treatment. There was a significant improvement in arterial alveolar ratio after surfactant delivery in the atom group (p < 0.05; Sidak posttests), while there was no difference in PaCO2. Electrical impedance tomography data showed a more uniform pattern of ventilation in the atom group. In the atom group, the median (interquartile range) deposition of surfactant in the lung was 32% (22-43%) of the delivered dose, with an even distribution between the right and the left lungs. CONCLUSIONS In our model of spontaneously breathing lambs receiving CPAP, supraglottic atomization of Curosurf via a novel device was safe, improved oxygenation and ventilation homogeneity compared with CPAP only, and provided a relatively large lung deposition suggesting clinical utility.
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Abstract
Lung aeration is the most critical task newborns must accomplish after birth. Almost all extremely preterm infants require respiratory support during this process, but the best method to promote lung aeration in preterm infants is unknown. The current standard practice is intermittent positive pressure ventilation with positive end-expiratory pressure. Sustained inflation is a promising alternative strategy for lung liquid clearance and aeration. Here we review the physiologic rationale for sustained inflation and the available clinical evidence for sustained inflation in preterm infants.
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Affiliation(s)
- Elizabeth E Foglia
- Division of Neonatology, The Children's Hospital of Philadelphia, The Hospital of the University of Pennsylvania, The University of Pennsylvania Perelman School of Medicine, 8th Floor Ravdin Building, 3400 Spruce Street, Philadelphia, PA 19104, USA.
| | - Arjan B Te Pas
- Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, Netherlands
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30
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Tingay DG, Rajapaksa A, Zannin E, Pereira-Fantini PM, Dellaca RL, Perkins EJ, Zonneveld CEE, Adler A, Black D, Frerichs I, Lavizzari A, Sourial M, Grychtol B, Mosca F, Davis PG. Effectiveness of individualized lung recruitment strategies at birth: an experimental study in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2016; 312:L32-L41. [PMID: 27881405 DOI: 10.1152/ajplung.00416.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/20/2016] [Indexed: 02/02/2023] Open
Abstract
Respiratory transition at birth involves rapidly clearing fetal lung liquid and preventing efflux back into the lung while aeration is established. We have developed a sustained inflation (SIOPT) individualized to volume response and a dynamic tidal positive end-expiratory pressure (PEEP) (open lung volume, OLV) strategy that both enhance this process. We aimed to compare the effect of each with a group managed with PEEP of 8 cmH2O and no recruitment maneuver (No-RM), on gas exchange, lung mechanics, spatiotemporal aeration, and lung injury in 127 ± 1 day preterm lambs. Forty-eight fetal-instrumented lambs exposed to antenatal steroids were ventilated for 60 min after application of the allocated strategy. Spatiotemporal aeration and lung mechanics were measured with electrical impedance tomography and forced-oscillation, respectively. At study completion, molecular and histological markers of lung injury were analyzed. Mean (SD) aeration at the end of the SIOPT and OLV groups was 32 (22) and 38 (15) ml/kg, compared with 17 (10) ml/kg (180 s) in the No-RM (P = 0.024, 1-way ANOVA). This translated into better oxygenation at 60 min (P = 0.047; 2-way ANOVA) resulting from better distal lung tissue aeration in SIOPT and OLV. There was no difference in lung injury. Neither SIOPT nor OLV achieved homogeneous aeration. Histological injury and mRNA biomarker upregulation were more likely in the regions with better initial aeration, suggesting volutrauma. Tidal ventilation or an SI achieves similar aeration if optimized, suggesting that preventing fluid efflux after lung liquid clearance is at least as important as fluid clearance during the initial inflation at birth.
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Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia; .,Neonatology, The Royal Children's Hospital, Parkville, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Anushi Rajapaksa
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Emanuela Zannin
- TBM Laboratory, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Raffaele L Dellaca
- TBM Laboratory, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia.,Neonatology, The Royal Children's Hospital, Parkville, Australia
| | | | - Andy Adler
- Systems and Computer Engineering, Carleton University, Ottawa, Canada
| | - Don Black
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Anna Lavizzari
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia.,NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università degli Studi di Milano, Milano, Italy
| | - Magdy Sourial
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
| | - Bartłomiej Grychtol
- Fraunhofer Project Group for Automation in Medicine and Biotechnology, Mannheim, Germany; and
| | - Fabio Mosca
- NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università degli Studi di Milano, Milano, Italy
| | - Peter G Davis
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia.,Neonatal Research, The Royal Women's Hospital, Parkville, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
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31
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Milesi I, Tingay DG, Zannin E, Bianco F, Tagliabue P, Mosca F, Lavizzari A, Ventura ML, Zonneveld CE, Perkins EJ, Black D, Sourial M, Dellacá RL. Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome. Pediatr Res 2016; 80:92-100. [PMID: 26954481 DOI: 10.1038/pr.2016.39] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/21/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Aerosolization of exogenous surfactant remains a challenge. This study is aimed to evaluate the efficacy of atomized poractant alfa (Curosurf) administered with a novel atomizer in preterm lambs with respiratory distress syndrome. METHODS Twenty anaesthetized lambs, 127 ± 1 d gestational age, (mean ± SD) were instrumented before birth and randomized to receive either (i) positive pressure ventilation without surfactant (Control group), (ii) 200 mg/kg of bolus instilled surfactant (Bolus group) at 10 min of life or (iii) 200 mg/kg of atomized surfactant (Atomizer group) over 60 min from 10 min of life. All lambs were ventilated for 180 min with a standardized protocol. Lung mechanics, regional lung compliance (electrical impedance tomography), and carotid blood flow (CBF) were measured with arterial blood gas analysis. RESULTS Dynamic compliance and oxygenation responses were similar in the Bolus and Atomizer groups, and both better than Control by 180 min (all P < 0.05; two-way ANOVA). Both surfactant groups demonstrated more homogeneous regional lung compliance throughout the study period. There were no differences in CBFConclusion:In a preterm lamb model, atomized surfactant resulted in similar gas exchange and mechanics as bolus administration. This study suggests evaluation of supraglottic atomization with this system when noninvasive support is warranted.
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Affiliation(s)
- Ilaria Milesi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy
| | - David G Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia.,Neonatology, The Royal Children's Hospital, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Emanuela Zannin
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy
| | - Federico Bianco
- Research and Development Department, Chiesi Farmaceutici SpA, Parma, Italy
| | | | - Fabio Mosca
- NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università degli Studi di Milano
| | - Anna Lavizzari
- NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università degli Studi di Milano
| | | | - C Elroy Zonneveld
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Elizabeth J Perkins
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Don Black
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Magdy Sourial
- Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Raffaele L Dellacá
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy
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32
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Lista G, Cavigioli F, Castoldi F, Zimmermann LJI. Sustained inflation: Prophylactic or rescue maneuver? Semin Fetal Neonatal Med 2016; 21:135-8. [PMID: 26923502 DOI: 10.1016/j.siny.2016.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Application of nasal continuous positive airway pressure (nCPAP) in the delivery room is a valid alternative to mechanical ventilation in the management of respiratory failure of preterm infants, with reduced occurrence of bronchopulmonary dysplasia and death. nCPAP at birth is still burdened by a high failure rate. Sustained inflation appears to be an intriguing approach to allow the respiratory transition at birth by clearing the lung fluid, thus obtaining an adequate functional residual capacity. This may enhance nCPAP success. Sustained inflation reduces the need for mechanical ventilation in the first 72 h of life, with no changes in the incidence of bronchopulmonary dysplasia and death. The efficacy of sustained inflation seems to be related to the presence of open glottis with active breathing of the infant. Further studies are needed to recommend the application of sustained inflation during delivery room management of preterm infants at risk of respiratory distress or with clinical signs of respiratory failure.
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Affiliation(s)
- G Lista
- NICU -"V. Buzzi" Children's Hospital, ICP, Milan, Italy.
| | - F Cavigioli
- NICU -"V. Buzzi" Children's Hospital, ICP, Milan, Italy
| | - F Castoldi
- NICU -"V. Buzzi" Children's Hospital, ICP, Milan, Italy
| | - L J I Zimmermann
- Faculty of Health, Medicine and Life Sciences, School of Oncology and Developmental Biology, Department of Pediatrics, Maastricht University, Maastricht, The Netherlands
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33
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Tingay DG, Rajapaksa A, McCall K, Zonneveld CEE, Black D, Perkins E, Sourial M, Lavizzari A, Davis PG. The interrelationship of recruitment maneuver at birth, antenatal steroids, and exogenous surfactant on compliance and oxygenation in preterm lambs. Pediatr Res 2016; 79:916-21. [PMID: 26866905 DOI: 10.1038/pr.2016.25] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/07/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND To describe the interrelationship between antenatal steroids, exogenous surfactant, and two approaches to lung recruitment at birth on oxygenation and respiratory system compliance (Cdyn) in preterm lambs. METHODS Lambs (n = 63; gestational age 127 ± 1 d) received either surfactant at 10-min life (Surfactant), antenatal corticosteroids (Steroid), or neither (Control). Within each epoch lambs were randomly assigned to a 30-s 40 cmH2O sustained inflation (SI) or an initial stepwise positive end-expiratory pressure (PEEP) open lung ventilation (OLV) maneuver at birth. All lambs then received the same management for 60-min with alveolar-arterial oxygen difference (AaDO2) and Cdyn measured at regular time points. RESULTS Overall, the OLV strategy improved Cdyn and AaDO2 (all epochs except Surfactant) compared to SI (all P < 0.05; two-way ANOVA). Irrespective of strategy, Cdyn was better in the Steroid group in the first 10 min (all P < 0.05). Thereafter, Cdyn was similar to Steroid epoch in the OLV + Surfactant, but not SI + Surfactant group. OLV influenced the effect of steroid and surfactant (P = 0.005) on AaDO2 more than SI (P = 0.235). CONCLUSIONS The antenatal state of the lung influences the type and impact of a recruitment maneuver at birth. The effectiveness of surfactant maybe enhanced using PEEP-based time-dependent recruitment strategies rather than approaches solely aimed at initial lung liquid clearance.
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Affiliation(s)
- David G Tingay
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Neonatology, The Royal Children's Hospital, Melbourne, Victoria, Australia.,Neonatal Research Group, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Anushi Rajapaksa
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Karen McCall
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Cornelis E E Zonneveld
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Don Black
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Elizabeth Perkins
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Magdy Sourial
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Neonatology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Anna Lavizzari
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università degli Studi di Milano, Milano, Italy
| | - Peter G Davis
- Neonatal Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Neonatal Research Group, The Royal Women's Hospital, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
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34
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Pereira-Fantini PM, Rajapaksa AE, Oakley R, Tingay DG. Selection of Reference Genes for Gene Expression Studies related to lung injury in a preterm lamb model. Sci Rep 2016; 6:26476. [PMID: 27210246 PMCID: PMC4876477 DOI: 10.1038/srep26476] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/04/2016] [Indexed: 12/13/2022] Open
Abstract
Preterm newborns often require invasive support, however even brief periods of supported ventilation applied inappropriately to the lung can cause injury. Real-time quantitative reverse transcriptase-PCR (qPCR) has been extensively employed in studies of ventilation-induced lung injury with the reference gene 18S ribosomal RNA (18S RNA) most commonly employed as the internal control reference gene. Whilst the results of these studies depend on the stability of the reference gene employed, the use of 18S RNA has not been validated. In this study the expression profile of five candidate reference genes (18S RNA, ACTB, GAPDH, TOP1 and RPS29) in two geographical locations, was evaluated by dedicated algorithms, including geNorm, Normfinder, Bestkeeper and ΔCt method and the overall stability of these candidate genes determined (RefFinder). Secondary studies examined the influence of reference gene choice on the relative expression of two well-validated lung injury markers; EGR1 and IL1B. In the setting of the preterm lamb model of lung injury, RPS29 reference gene expression was influenced by tissue location; however we determined that individual ventilation strategies influence reference gene stability. Whilst 18S RNA is the most commonly employed reference gene in preterm lamb lung studies, our results suggest that GAPDH is a more suitable candidate.
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Affiliation(s)
| | - Anushi E Rajapaksa
- Neonatal Research Group, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Australia
| | - Regina Oakley
- Neonatal Research Group, Murdoch Childrens Research Institute, Parkville, Australia
| | - David G Tingay
- Neonatal Research Group, Murdoch Childrens Research Institute, Parkville, Australia.,Department of Neonatology, Royal Children's Hospital, Parkville, Australia.,Department of Paediatrics, University of Melbourne, Parkville, Australia
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35
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Patel PN, Banerjee J, Godambe SV. Resuscitation of extremely preterm infants - controversies and current evidence. World J Clin Pediatr 2016; 5:151-8. [PMID: 27170925 PMCID: PMC4857228 DOI: 10.5409/wjcp.v5.i2.151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/24/2015] [Accepted: 01/16/2016] [Indexed: 02/06/2023] Open
Abstract
Despite significant advances in perinatal medicine, the management of extremely preterm infants in the delivery room remains a challenge. There is an increasing evidence for improved outcomes regarding the resuscitation and stabilisation of extremely preterm infants but there is a lack of evidence in the periviable (gestational age 23-25 wk) preterm subgroup. Presence of an experienced team during the delivery of extremely preterm infant to improve outcome is reviewed. Adaptation from foetal to neonatal cardiorespiratory haemodynamics is dependent on establishing an optimal functional residual capacity in the extremely preterm infants, thus enabling adequate gas exchange. There is sufficient evidence for a gentle approach to stabilisation of these fragile infants in the delivery room. Evidence for antenatal steroids especially in the periviable infants, delayed cord clamping, strategies to establish optimal functional residual capacity, importance of temperature control and oxygenation in delivery room in extremely premature infants is reviewed in this article.
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Multifrequency Oscillatory Ventilation in the Premature Lung: Effects on Gas Exchange, Mechanics, and Ventilation Distribution. Anesthesiology 2016; 123:1394-403. [PMID: 26495977 DOI: 10.1097/aln.0000000000000898] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Despite the theoretical benefits of high-frequency oscillatory ventilation (HFOV) in preterm infants, systematic reviews of randomized clinical trials do not confirm improved outcomes. The authors hypothesized that oscillating a premature lung with multiple frequencies simultaneously would improve gas exchange compared with traditional single-frequency oscillatory ventilation (SFOV). The goal of this study was to develop a novel method for HFOV, termed "multifrequency oscillatory ventilation" (MFOV), which relies on a broadband flow waveform more suitable for the heterogeneous mechanics of the immature lung. METHODS Thirteen intubated preterm lambs were randomly assigned to either SFOV or MFOV for 1 h, followed by crossover to the alternative regimen for 1 h. The SFOV waveform consisted of a pure sinusoidal flow at 5 Hz, whereas the customized MFOV waveform consisted of a 5-Hz fundamental with additional energy at 10 and 15 Hz. Per standardized protocol, mean pressure at airway opening ((Equation is included in full-text article.)) and inspired oxygen fraction were adjusted as needed, and root mean square of the delivered oscillatory volume waveform (Vrms) was adjusted at 15-min intervals. A ventilatory cost function for SFOV and MFOV was defined as (Equation is included in full-text article.), where Wt denotes body weight. RESULTS Averaged over all time points, MFOV resulted in significantly lower VC (246.9 ± 6.0 vs. 363.5 ± 15.9 ml mmHg kg) and (Equation is included in full-text article.)(12.8 ± 0.3 vs. 14.1 ± 0.5 cm H2O) compared with SFOV, suggesting more efficient gas exchange and enhanced lung recruitment at lower mean airway pressures. CONCLUSION Oscillation with simultaneous multiple frequencies may be a more efficient ventilator modality in premature lungs compared with traditional single-frequency HFOV.
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McCall KE, Davis PG, Owen LS, Tingay DG. Sustained lung inflation at birth: what do we know, and what do we need to know? Arch Dis Child Fetal Neonatal Ed 2016; 101:F175-80. [PMID: 26527635 DOI: 10.1136/archdischild-2015-309611] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/10/2015] [Indexed: 11/04/2022]
Abstract
A sustained inflation has been advocated as a potential method of augmenting lung aeration at birth. Clinical trials have suggested that a sustained inflation may lead to a reduced need for intubation and ventilation in the first few days of life, without cardiovascular compromise or increased lung injury. Despite this, a sustained inflation is not currently a standard of practice, mainly due to a lack of clarity regarding the optimal delivery method. Animal trials have sought to refine delivery techniques. This review will outline current recommendations regarding a sustained inflation, discuss potential strategies for its optimal delivery and suggest priorities for future research.
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Affiliation(s)
- Karen E McCall
- Newborn Research, Murdoch Children's Research Institute, Melbourne, Australia School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Peter G Davis
- Newborn Research, Murdoch Children's Research Institute, Melbourne, Australia Department of Obstetrics, University of Melbourne, Melbourne, Australia Neonatal Research, Royal Women's Hospital, Melbourne, Australia
| | - Louise S Owen
- Newborn Research, Murdoch Children's Research Institute, Melbourne, Australia Department of Obstetrics, University of Melbourne, Melbourne, Australia Neonatal Research, Royal Women's Hospital, Melbourne, Australia
| | - David G Tingay
- Newborn Research, Murdoch Children's Research Institute, Melbourne, Australia Neonatal Research, Royal Women's Hospital, Melbourne, Australia Department of Neonatology, Royal Children's Hospital, Melbourne, Australia Department of Paediatrics, University of Melbourne, Melbourne, Australia
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Tingay DG, Rajapaksa A, Zonneveld CE, Black D, Perkins EJ, Adler A, Grychtol B, Lavizzari A, Frerichs I, Zahra VA, Davis PG. Spatiotemporal Aeration and Lung Injury Patterns Are Influenced by the First Inflation Strategy at Birth. Am J Respir Cell Mol Biol 2016; 54:263-72. [DOI: 10.1165/rcmb.2015-0127oc] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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39
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Tingay DG, Lavizzari A, Zonneveld CEE, Rajapaksa A, Zannin E, Perkins E, Black D, Sourial M, Dellacà RL, Mosca F, Adler A, Grychtol B, Frerichs I, Davis PG. An individualized approach to sustained inflation duration at birth improves outcomes in newborn preterm lambs. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1138-49. [DOI: 10.1152/ajplung.00277.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 09/17/2015] [Indexed: 01/18/2023] Open
Abstract
A sustained first inflation (SI) at birth may aid lung liquid clearance and aeration, but the impact of SI duration relative to the volume-response of the lung is poorly understood. We compared three SI strategies: 1) variable duration defined by attaining volume equilibrium using real-time electrical impedance tomography (EIT; SIplat); 2) 30 s beyond equilibrium (SIlong); 3) short 30-s SI (SI30); and 4) positive pressure ventilation without SI (no-SI) on spatiotemporal aeration and ventilation (EIT), gas exchange, lung mechanics, and regional early markers of injury in preterm lambs. Fifty-nine fetal-instrumented lambs were ventilated for 60 min after applying the allocated first inflation strategy. At study completion molecular and histological markers of lung injury were analyzed. The time to SI volume equilibrium, and resultant volume, were highly variable; mean (SD) 55 (34) s, coefficient of variability 59%. SIplat and SIlong resulted in better lung mechanics, gas exchange and lower ventilator settings than both no-SI and SI30. At 60 min, alveolar-arterial difference in oxygen was a mean (95% confidence interval) 130 (13, 249) higher in SI30 vs. SIlong group (two-way ANOVA). These differences were due to better spatiotemporal aeration and tidal ventilation, although all groups showed redistribution of aeration towards the nondependent lung by 60 min. Histological lung injury scores mirrored spatiotemporal change in aeration and were greatest in SI30 group ( P < 0.01, Kruskal-Wallis test). An individualized volume-response approach to SI was effective in optimizing aeration, homogeneous tidal ventilation, and respiratory outcomes, while an inadequate SI duration had no benefit over positive pressure ventilation alone.
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Affiliation(s)
- David G. Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
- Neonatology, The Royal Children's Hospital, Parkville, Australia
- Neonatal Research, The Royal Women's Hospital, Parkville, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Anna Lavizzari
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
- Neonatal Intensive Care Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milano, Italy
| | | | - Anushi Rajapaksa
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - Emanuela Zannin
- Laboratorio di Tecnologie Biomediche, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Elizabeth Perkins
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - Don Black
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - Magdy Sourial
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
| | - Raffaele L. Dellacà
- Laboratorio di Tecnologie Biomediche, Dipartimento di Elettronica, Informazione e Ingegneria Biomedica-DEIB, Politecnico di Milano University, Milano, Italy
| | - Fabio Mosca
- Neonatal Intensive Care Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milano, Italy
| | - Andy Adler
- Systems and Computer Engineering, Carleton University, Ottawa, Canada
| | - Bartłomiej Grychtol
- Fraunhofer Project Group for Automation in Medicine and Biotechnology, Mannheim, Germany
| | - Inéz Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Kiel, Germany; and
| | - Peter G. Davis
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
- Neonatal Research, The Royal Women's Hospital, Parkville, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
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40
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Perlman JM, Wyllie J, Kattwinkel J, Wyckoff MH, Aziz K, Guinsburg R, Kim HS, Liley HG, Mildenhall L, Simon WM, Szyld E, Tamura M, Velaphi S. Part 7: Neonatal Resuscitation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (Reprint). Pediatrics 2015; 136 Suppl 2:S120-66. [PMID: 26471381 DOI: 10.1542/peds.2015-3373d] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Wyllie J, Perlman JM, Kattwinkel J, Wyckoff MH, Aziz K, Guinsburg R, Kim HS, Liley HG, Mildenhall L, Simon WM, Szyld E, Tamura M, Velaphi S. Part 7: Neonatal resuscitation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation 2015; 95:e169-201. [PMID: 26477424 DOI: 10.1016/j.resuscitation.2015.07.045] [Citation(s) in RCA: 193] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Perlman JM, Wyllie J, Kattwinkel J, Wyckoff MH, Aziz K, Guinsburg R, Kim HS, Liley HG, Mildenhall L, Simon WM, Szyld E, Tamura M, Velaphi S. Part 7: Neonatal Resuscitation. Circulation 2015; 132:S204-41. [DOI: 10.1161/cir.0000000000000276] [Citation(s) in RCA: 413] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mian Q, Cheung PY, O'Reilly M, Pichler G, van Os S, Kushniruk K, Aziz K, Schmölzer GM. Spontaneously Breathing Preterm Infants Change in Tidal Volume to Improve Lung Aeration Immediately after Birth. J Pediatr 2015; 167:274-8.e1. [PMID: 25998060 DOI: 10.1016/j.jpeds.2015.04.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/26/2015] [Accepted: 04/16/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To examine the temporal course of lung aeration at birth in preterm infants <33 weeks gestation. STUDY DESIGN The research team attended deliveries of preterm infants <33 weeks gestation at the Royal Alexandra Hospital. Infants who received only continuous positive airway pressure were eligible for inclusion. A combined carbon dioxide (CO2) and flow-sensor was placed between the mask and the ventilation device. To analyze lung aeration patterns during spontaneous breathing, tidal volume (VT), and exhaled CO2 (ECO2) were recorded for the first 100 breaths. RESULTS Thirty preterm infants were included with a total of 1512 breaths with mask leak <30%. Mean (SD) gestational age and birth weight was 30 (1) weeks and 1478 (430) g. Initial VT and ECO2 for the first 30 breaths was 5-6 mL/kg and 15-22 mm Hg, respectively. VT and ECO2 increased over the next 20 breaths to 7-8 mL/kg and 25-32 mm Hg, respectively. For the remaining observation period VT decreased to 4-6 mL/kg and ECO2 continued to increase to 35-37 mm Hg. CONCLUSIONS Preterm infants begin taking deeper breaths approximately 30 breaths after initiating spontaneous breathing to inflate their lungs. Concurrent CO2 removal rises as alveoli are recruited. Lung aeration occurs in 2 phases: initially, large volume breaths with poor alveolar aeration followed by smaller breaths with elimination of CO2 as a consequence of adequate aeration.
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Affiliation(s)
- Qaasim Mian
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Po-Yin Cheung
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Megan O'Reilly
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Gerhard Pichler
- Department of Pediatrics, Medical University Graz, Graz, Austria
| | - Sylvia van Os
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada
| | - Karin Kushniruk
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada
| | - Khalid Aziz
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Georg M Schmölzer
- Center for the Studies of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Edmonton, Canada; Department of Pediatrics, University of Alberta, Edmonton, Canada
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Tingay DG, Polglase GR, Bhatia R, Berry CA, Kopotic RJ, Kopotic CP, Song Y, Szyld E, Jobe AH, Pillow JJ. Pressure-limited sustained inflation vs. gradual tidal inflations for resuscitation in preterm lambs. J Appl Physiol (1985) 2015; 118:890-7. [PMID: 25635005 DOI: 10.1152/japplphysiol.00985.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 01/26/2015] [Indexed: 01/09/2023] Open
Abstract
Support of the mechanically complex preterm lung needs to facilitate aeration while avoiding ventilation heterogeneities: whether to achieve this gradually or quickly remains unclear. We compared the effect of gradual vs. constant tidal inflations and a pressure-limited sustained inflation (SI) at birth on gas exchange, lung mechanics, gravity-dependent lung volume distribution, and lung injury in 131-day gestation preterm lambs. Lambs were resuscitated with either 1) a 20-s, 40-cmH2O pressure-limited SI (PressSI), 2) a gradual increase in tidal volume (Vt) over 5-min from 3 ml/kg to 7 ml/kg (IncrVt), or 3) 7 ml/kg Vt from birth. All lambs were subsequently ventilated for 15 min with 7 ml/kg Vt with the same end-expiratory pressure. Lung mechanics, gas exchange and spatial distribution of end-expiratory volume (EEV), and tidal ventilation (electrical impedance tomography) were recorded regularly. At 15 min, early mRNA tissue markers of lung injury were assessed. The IncrVt group resulted in greater tissue hysteresivity at 5 min (P = 0.017; two-way ANOVA), higher alveolar-arterial oxygen difference from 10 min (P < 0.01), and least uniform gravity-dependent distribution of EEV. There were no other differences in lung mechanics between groups, and the PressSI and 7 ml/kg Vt groups behaved similarly throughout. EEV was more uniformly distributed, but Vt least so, in the PressSI group. There were no differences in mRNA markers of lung injury. A gradual increase in Vt from birth resulted in less recruitment of the gravity-dependent lung with worse oxygenation. There was no benefit of a SI at birth over mechanical ventilation with 7 ml/kg Vt.
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Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Neonatology, The Royal Children's Hospital, Melbourne, Victoria, Australia; Neonatal Research, The Royal Women's Hospital, Melbourne, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Graeme R Polglase
- The Ritchie Centre, MIMR-PHI Institute of Medical Research, Clayton, Victoria, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Risha Bhatia
- Neonatal Research, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Neonatology, The Royal Children's Hospital, Melbourne, Victoria, Australia; Neonatal Research, The Royal Women's Hospital, Melbourne, Victoria, Australia
| | - Clare A Berry
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Perth, Australia
| | | | | | - Yong Song
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Perth, Australia; School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Edgardo Szyld
- Universidad Abierta Interamericana (UAI), Buenos Aires, Argentina; Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Alan H Jobe
- Cincinnati Children's Hospital Medical Centre, Cincinnati, Ohio
| | - J Jane Pillow
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, University of Western Australia, Perth, Australia; School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia;
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Hummler HD, Parys E, Mayer B, Essers J, Fuchs H, Schmid M. Risk Indicators for Air Leaks in Preterm Infants Exposed to Restrictive Use of Endotracheal Intubation. Neonatology 2015; 108:1-7. [PMID: 25825229 DOI: 10.1159/000375361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 01/20/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To identify perinatal risk indicators for air leaks in preterm infants treated with a policy of restrictive use of endotracheal intubation based on sustained inflations followed by noninvasive ventilation in the delivery room. METHODS Perinatal variables and variables of respiratory support in the delivery room were analyzed retrospectively in a cohort of 297 inborn preterm infants with a gestational age <29 weeks born in 2005-2009 in a tertiary care center with respect to their associations with air leaks. Multivariate logistic regression analysis was performed to analyze independent risk indicators. RESULTS Gestational age was 26 weeks + 0 days (22+3 to 28+6), birth weight was 790 g (265-1,660) and 270/297 survived (91.0%). A total of 63 (21.2%) developed air leaks, 32 (10.8%) pneumothorax, 44 (14.8%) pulmonary interstitial emphysema, and 1 (0.3%) pneumopericardium. The infants with air leaks had a higher risk of death (p < 0.01) and of intraventricular hemorrhage grade 3/4 (p < 0.05). Air leaks were associated with less use of prenatal steroids (p < 0.01), more frequent use of cardiac compressions (p < 0.01), use of a pressure of 30 cm H2O for sustained inflations (p < 0.05), and intubation in the delivery room (p < 0.01). After multivariate logistic regression only prenatal steroids (OR 0.41, 0.20-0.85), epinephrine (OR 3.56, 1.55-8.15) and surfactant use (OR 12.03, 3.39-42.72) remained significant. CONCLUSIONS Our approach resulted in a high survival rate but was associated with a substantial rate of air leaks, which were associated with death and severe intraventricular hemorrhage. Prenatal steroids were protective, and epinephrine and surfactant use were significant risk indicators, whereas the use of sustained inflations was not a risk factor.
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Affiliation(s)
- Helmut D Hummler
- Division of Neonatology and Pediatric Critical Care, Department of Pediatrics, Children's Hospital, University of Ulm, Ulm, Germany
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Tingay DG, Wallace MJ, Bhatia R, Schmölzer GM, Zahra VA, Dolan MJ, Hooper SB, Davis PG. Surfactant before the first inflation at birth improves spatial distribution of ventilation and reduces lung injury in preterm lambs. J Appl Physiol (1985) 2013; 116:251-8. [PMID: 24356523 DOI: 10.1152/japplphysiol.01142.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The interrelationship between the role of surfactant and a sustained inflation (SI) to aid ex utero transition of the preterm lung is unknown. We compared the effect of surfactant administered before and after an initial SI on gas exchange, lung mechanics, spatial distribution of ventilation, and lung injury in preterm lambs. Gestational-age lambs (127 days; 9 per group) received 100 mg/kg of a surfactant (Curosurf) either prior (Surf+SI) or 10 min after birth (SI+Surf). At birth, a 20-s, 35 cmH2O SI was applied, followed by 70 min of positive pressure ventilation. Oxygenation, carbon dioxide removal, respiratory system compliance, end-expiratory thoracic volume (via respiratory inductive plethysmography), and distribution of end-expiratory volume and ventilation (via electrical impedance tomography) were measured throughout. Early markers of lung injury were analyzed using quantitative RT-PCR. During the first 15 min, oxygenation, carbon dioxide removal, and compliance were better in the Surf+SI group (all P < 0.05). End-expiratory volume on completion of the sustained inflation was higher in the Surf+SI group than the SI+Surf group; 11 ± 1 ml/kg vs. 7 ± 1 ml/kg (mean ± SE) (P = 0.043; t-test), but was not different at later time points. Although neither achieved homogenous aeration, spatial ventilation was more uniform in the Surf+SI group throughout; 50.1 ± 10.9% of total ventilation in the left hemithorax at 70 min vs. 42.6 ± 11.1% in the SI+Surf group. Surf+SI resulted in lower mRNA levels of CYR61 and EGR1 compared with SI+Surf (P < 0.001, one-way ANOVA). Surfactant status of the fetal preterm lung at birth influences the mechanical and injury response to a sustained inflation and ventilation by changing surface tension of the air/fluid interface.
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Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Childrens Research Institute, Parkville, Australia
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