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Youssef AM, El-Ozairy HS, El-Hennawy AM, Amer AM. Inverse ratio ventilation versus conventional ratio ventilation during one lung ventilation in neonatal open repair of esophageal atresia/tracheoesophageal fistula: A randomized clinical trial. Paediatr Anaesth 2024; 34:332-339. [PMID: 38189583 DOI: 10.1111/pan.14836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND Maintaining oxygenation during neonatal open repair of esophageal atresia/tracheoesophageal fistula is difficult. Inverse ratio ventilation can be used during one lung ventilation to improve the oxygenation and lung mechanics. OBJECTIVE The aim of this study was to describe the impact of two different ventilatory strategies (inverse ratio ventilation vs. conventional ratio ventilation) during one lung ventilation in neonatal open repair of esophageal atresia/tracheoesophageal fistula on the incidence of oxygen desaturation episodes. METHODS We enrolled 40 term neonates undergoing open right thoracotomy for esophageal atresia/tracheoesophageal fistula repair and randomly assigned into two groups based on inspiratory to expiratory ratio of mechanical ventilation parameters (2:1 in inverse ratio ventilation "IRV" and 1:2 in conventional ratio ventilation "CRV"). The incidence of desaturation episodes that required stopping the procedure and reinflation of the lung were recorded as the primary outcome while hemodynamic parameters, incidence of complications, and length of surgical procedure were recorded as the secondary outcomes. RESULTS There was a trend toward a reduction in the incidence of severe desaturations (requiring stopping of surgery) with the use of inverse ratio ventilation (15% in IRV vs. 35% in CRV, RR [95% CI] 0.429 [0.129-1.426]). Incidence of all desaturations (including those requiring only an increase in ventilatory support or inspired oxygen saturation) was also reduced (40% in IRV vs. 75% in CRV, RR [95% CI] 0.533 [0.295-0.965]). This in turn affected the length of surgical procedure being significantly shorter in inverse ratio ventilation group (mean difference -16.3, 95% CI -31.64 to -0.958). The intraoperative fraction of inspired oxygen required to maintain adequate oxygen saturation was significantly lower in the inverse ratio ventilation group than in the conventional ratio ventilation group (mean difference -0.22, 95% CI -0.33 to -0.098), with no significant difference in hemodynamic stability or complications apart from higher blood loss in inverse ratio group. CONCLUSION There may be a role for inverse ratio ventilation with appropriate positive end-expiratory pressure to reduce the incidence of hypoxemia during open repair of esophageal atresia/tracheoesophageal fistula in neonates, further studies are required to establish the safety and efficacy of this technique.
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Affiliation(s)
- Azza M Youssef
- Department of Anesthesiology, Intensive Care and Pain Management, Ain Shams University Faculty of Medicine, Cairo, Egypt
| | - Hala S El-Ozairy
- Department of Anesthesiology, Intensive Care and Pain Management, Ain Shams University Faculty of Medicine, Cairo, Egypt
| | - Ahmed M El-Hennawy
- Department of Anesthesiology, Intensive Care and Pain Management, Ain Shams University Faculty of Medicine, Cairo, Egypt
| | - Akram M Amer
- Department of Anesthesiology, Intensive Care and Pain Management, Ain Shams University Faculty of Medicine, Cairo, Egypt
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2
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Wheeler CR, Vogel ER, Cusano MA, Friedman KG, Callahan R, Porras D, Ibla JC, Levy PT. Definitive Closure of the Patent Ductus Arteriosus in Preterm Infants and Subsequent Short-Term Respiratory Outcomes. Respir Care 2022; 67:594-606. [PMID: 35473850 PMCID: PMC9994254 DOI: 10.4187/respcare.09489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
A persistent patent ductus arteriosus (PDA) can have significant clinical consequences in preterm infants, depending on the degree of left-to-right shunting, its impact on cardiac performance, and associated perinatal risk factors that can mitigate or exacerbate the shunt. Although the best management strategy remains contentious, PDAs that have contraindications to, or have failed medical management have historically undergone surgical ligation. Recently smaller occluder devices and delivery systems have allowed for minimally invasive closure in the catheterization laboratory even in extremely premature infants. The present review summarizes the pathophysiologic manifestations, treatment options and management of hemodynamically significant PDA in preterm infants. Additionally, we review the available literature surrounding the respiratory support and outcomes of preterm infants following definitive PDA closure.
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Affiliation(s)
- Craig R Wheeler
- Department of Respiratory Care, Boston Children's Hospital, Boston, Massachusetts.
| | - Elizabeth R Vogel
- Division of Pediatric Cardiac Anesthesia, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Michael A Cusano
- Department of Respiratory Care, Boston Children's Hospital, Boston, Massachusetts
| | - Kevin G Friedman
- Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Ryan Callahan
- Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Diego Porras
- Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Juan C Ibla
- Division of Cardiac Anesthesia, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Philip T Levy
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Harvard University, Boston, Massachusetts
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3
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Shah D, Tracy M, Hinder M, Badawi N. Positive end expiratory pressure and respiratory system resistance between self-inflating bag and T-piece resuscitator in a cadaveric piglet lung model. Front Pediatr 2022; 10:1014311. [PMID: 36467494 PMCID: PMC9714259 DOI: 10.3389/fped.2022.1014311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/24/2022] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION In neonatal resuscitation, T-piece resuscitator (TPR) are used widely, but the evidence is limited for their use in infants born at term gestation. The aim of this study was to compare the delivered positive end expiratory pressure (PEEP) and respiratory system resistance (Rrs) using TPR and self-inflating bag (SIB) in a cadaveric piglet model. METHODS Cadaveric newborn piglets were tracheotomised, intubated (cuffed tube) and leak tested. Static lung compliance was measured. Positive pressure ventilation was applied by TPR and SIB in a randomized sequence with varying, inflations per minute (40, 60 and 80 min) and peak inspiratory pressures (18 and 30 cmH2O). PEEP was constant at 5 cmH2O. The lungs were washed with saline and static lung compliance was re-measured; ventilation sequences were repeated. Lung inflation data for the respiratory mechanics were measured using a respiratory function monitor and digitally recorded for both pre and post-lung wash inflation sequences. A paired sample t-test was used to compare the mean and standard deviation. RESULTS The mean difference in PEEP (TPR vs. SIB) was statistically significant at higher inflation rates of 60 and 80 bpm. At normal lung compliance, mean difference was 1.231 (p = 0.000) and 2.099 (p = 0.000) with PIP of 18 and 30 cmH2O respectively. Significantly higher Rrs were observed when using a TPR with higher inflation rates of 60 and 80 bpm at varying lung compliance. CONCLUSION TPR is associated with significantly higher PEEP in a compliant lung model, which is probably related to the resistance of the TPR circuit. The effect of inadvertent PEEP on lung mechanics and hemodynamics need to be examined in humans. Further studies are needed to assess devices used to provide PEEP (TPR, SIB with PEEP valve, Anaesthetic bag with flow valve) during resuscitation of the newborn.
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Affiliation(s)
- Dharmesh Shah
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Mark Tracy
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Murray Hinder
- Neonatal Intensive Care Unit, Westmead Hospital, Westmead, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Nadia Badawi
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Grace Centre for Newborn Care, Children's Hospital at Westmead, Westmead, NSW, Australia.,Cerebral Palsy Alliance Research Institute, University of Sydney, Sydney, NSW, Australia
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4
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Van Wyk L, Smith J, Lawrenson J, Lombard CJ, de Boode WP. Bioreactance-derived haemodynamic parameters in the transitional phase in preterm neonates: a longitudinal study. J Clin Monit Comput 2021; 36:861-870. [PMID: 33983533 DOI: 10.1007/s10877-021-00718-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/06/2021] [Indexed: 11/26/2022]
Abstract
Bioreactance (BR) is a novel, non-invasive technology that is able to provide minute-to-minute monitoring of cardiac output and additional haemodynamic variables. This study aimed to determine the values for BR-derived haemodynamic variables in stable preterm neonates during the transitional period. A prospective observational study was performed in a group of stable preterm (< 37 weeks) infants in the neonatal service of Tygerberg Children's Hospital, Cape Town, South Africa. All infants underwent continuous bioreactance (BR) monitoring until 72 h of life. Sixty three preterm infants with a mean gestational age of 31 weeks and mean birth weight of 1563 g were enrolled. Summary data and time series graphs were drawn for BR-derived heart rate, non-invasive blood pressure, stroke volume, cardiac output and total peripheral resistance index. All haemodynamic parameters were significantly associated with postnatal age, after correction for clinical variables (gestational age, birth weight, respiratory support mode). To our knowledge, this is the first paper to present longitudinal BR-derived haemodynamic variable data in a cohort of stable preterm infants, not requiring invasive ventilation or inotropic support, during the first 72 h of life. Bioreactance-derived haemodynamic monitoring is non-invasive and offers the ability to simultaneously monitor numerous haemodynamic parameters of global systemic blood flow. Moreover, it may provide insight into transitional physiology and its pathophysiology.
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Affiliation(s)
- Lizelle Van Wyk
- Division Neonatology, Dept. Pediatrics & Child Health, Stellenbosch University and Tygerberg Children's Hospital, Cape Town, South Africa.
| | - Johan Smith
- Division Neonatology, Dept. Pediatrics & Child Health, Stellenbosch University and Tygerberg Children's Hospital, Cape Town, South Africa
| | - John Lawrenson
- Pediatric Cardiology Unit, Dept. Pediatrics & Child Health, Stellenbosch University, Cape Town, South Africa
| | - Carl J Lombard
- Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, Cape Town, South Africa
- Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa
| | - Willem Pieter de Boode
- Division of Neonatology, Dept. of Perinatology, Radboud University Medical Center, Radboud Institute for Health Sciences, Amalia Children's Hospital, Nijmegen, The Netherlands
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5
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Ericksen K, Alpan G, La Gamma EF. Effect of ventilator modes on neonatal cerebral and peripheral oxygenation using near-infrared spectroscopy. Acta Paediatr 2021; 110:1151-1156. [PMID: 32989810 DOI: 10.1111/apa.15600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/27/2020] [Accepted: 09/23/2020] [Indexed: 12/01/2022]
Abstract
AIM The effect of ventilator modes on regional tissue oxygenation in premature neonates with respiratory distress syndrome (RDS) has yet to be delineated. Previous studies have looked at global oxygen delivery and have not assessed the effects on regional tissue oxygenation. Our aim in this study was to assess such tissue oxygenation in premature babies with RDS in relation to differing modes of ventilation using near-infrared spectroscopy (NIRS). METHODS In 24 stable preterm infants with RDS, undergoing elective wean in ventilator mode, cerebral and muscle tissue oxygenation were assessed using NIRS. Infants were weaned from high-frequency oscillator or jet ventilator to conventional invasive ventilation (CV) or extubated from CV to non-invasive mechanical ventilation. Data at 30 minutes prior and at one hour after change in ventilator mode were compared (paired t test). RESULTS In babies changed from high-frequency oscillation to CV, jet to CV and CV to non-invasive ventilation, the differences in cerebral NIRS (mean ± SD) were 1.7 ± 9.9%, 2.3 ± 5.7% and 2.1 ± 8.4%, respectively. The concomitant changes in muscle NIRS were -2.9 ± 8.5%, 8.1 ± 9.7% and 3.6 ± 22.4%, respectively. No changes were statistically significant. CONCLUSION Our data suggest that there is no alteration in regional tissue oxygenation related to ventilator mode in stable preterm infants with improving RDS.
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Affiliation(s)
- Kristina Ericksen
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
| | - Gad Alpan
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
| | - Edmund F. La Gamma
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
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6
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de Waal K, Kluckow M. Superior vena cava flow: Role, assessment and controversies in the management of perinatal perfusion. Semin Fetal Neonatal Med 2020; 25:101122. [PMID: 32467039 DOI: 10.1016/j.siny.2020.101122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The superior vena cava (SVC) is a large vein responsible for the venous return of blood from structures located superior to the diaphragm. The flow in the SVC can be assessed with Doppler ultrasound and can be used as a proxy for cerebral perfusion. Early clinical research studies showed that low SVC flow, particularly if for a prolonged period, was associated with short term morbidity such as intraventricular hemorrhage, mortality, and poorer neurodevelopmental outcomes. However, these findings have not been consistently reported in more recent studies, and the role of SVC flow in early management and as a predictor of poor long-term neurodevelopment has been questioned. This paper provides an overview of SVC assessment, the expected range of findings, and reviews the role of SVC flow as a diagnostic and monitoring tool for the assessment of perinatal perfusion.
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Affiliation(s)
- Koert de Waal
- John Hunter Children's Hospital Department of Neonatology and University of Newcastle, Newcastle, NSW, Australia.
| | - Martin Kluckow
- Royal North Shore Hospital Department of Neonatology and University of Sydney, Sydney, NSW, Australia
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7
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Inocencio IM, Tran NT, Nakamura S, Khor SJ, Wiersma M, Stoecker K, Polglase GR, Pearson JT, Wong FY. Increased peak end-expiratory pressure in ventilated preterm lambs changes cerebral microvascular perfusion: direct synchrotron microangiography assessment. J Appl Physiol (1985) 2020; 129:1075-1084. [PMID: 32909920 DOI: 10.1152/japplphysiol.00652.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Positive end-expiratory pressure (PEEP) improves oxygenation in mechanically ventilated preterm neonates by preventing lung collapse. However, high PEEP may alter cerebral blood flow secondarily to the increased intrathoracic pressure, predisposing to brain injury. The precise effects of high PEEP on cerebral hemodynamics in the preterm brain are unknown. We aimed to assess the effect of PEEP on microvessels in the preterm brain by using synchrotron radiation (SR) microangiography, which enables in vivo real-time high-resolution imaging of the cerebral vasculature. Preterm lambs (0.8 gestation, n = 4) were delivered via caesarean section, anesthetized, and ventilated. SR microangiography of the right cerebral hemisphere was performed with iodine contrast administered into the right carotid artery during PEEP ventilation of 5 and 10 cmH2O. Carotid blood flow was measured using an ultrasonic flow probe placed around the left carotid artery. An increase of PEEP from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm) in all four lambs. Additionally, the higher PEEP increased the cerebral contrast transit time in three of the four lambs. Carotid blood flow increased in two lambs, which also had increased carbon dioxide levels during PEEP 10. Our results suggest that PEEP of 10 cmH2O alters the preterm cerebral hemodynamics, with prolonged cerebral blood flow transit and engorgement of small cerebral microvessels likely due to the increased intrathoracic pressure. These microvascular changes are generally not reflected in global assessment of cerebral blood flow or oxygenation.NEW & NOTEWORTHY An increase of positive end-expiratory pressure (PEEP) from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm). This suggests increased intrathoracic pressure due to high PEEP can drive microvessel engorgement in the preterm brain, which may play a role in cerebrovascular injury.
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Affiliation(s)
- Ishmael Miguel Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Nhi Thao Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Shinji Nakamura
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Song J Khor
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Manon Wiersma
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Katja Stoecker
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Graeme R Polglase
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre, Osaka, Japan.,Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Flora Y Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia.,Department of Paediatrics, Monash University, Melbourne, VIC, Australia.,Monash Newborn, Monash Medical Centre, Melbourne, VIC, Australia
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8
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Fiorenzano DM, Leal GN, Sawamura KSS, Lianza AC, Carvalho WBD, Krebs VLJ. Respiratory distress syndrome: influence of management on the hemodynamic status of ≤ 32-week preterm infants in the first 24 hours of life. Rev Bras Ter Intensiva 2019; 31:312-317. [PMID: 31618349 PMCID: PMC7005966 DOI: 10.5935/0103-507x.20190056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/09/2019] [Indexed: 11/21/2022] Open
Abstract
Objective To investigate the influence of respiratory distress syndrome management on clinical and echocardiographic parameters used for hemodynamic evaluation in ≤ 32- week newborns. Methods Thirty-three ≤ 32-week newborns were prospectively evaluated and subjected to invasive mechanical ventilation. The need for exogenous surfactant and clinical and echocardiographic parameters in the first 24 hours of life was detailed in this group of patients. Results The mean airway pressure was significantly higher in newborn infants who required inotropes [10.8 (8.8 - 23) cmH2O versus 9 (6.2 - 12) cmH2O; p = 0.04]. A negative correlation was found between the mean airway pressure and velocity-time integral of the pulmonary artery (r = -0.39; p = 0.026), right ventricular output (r = -0.43; p = 0.017) and measurements of the tricuspid annular plane excursion (r = -0.37; p = 0.036). A negative correlation was found between the number of doses of exogenous surfactant and the right ventricular output (r = -0.39; p = 0.028) and pulmonary artery velocity-time integral (r = -0.35; p = 0.043). Conclusion In ≤ 32-week newborns under invasive mechanical ventilation, increases in the mean airway pressure and number of surfactant doses are correlated with the worsening of early cardiac function. Therefore, more aggressive management of respiratory distress syndrome may contribute to the hemodynamic instability of these patients.
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Affiliation(s)
- Daniela Matos Fiorenzano
- Disciplina de Neonatologia, Departamento de Pediatria, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
| | - Gabriela Nunes Leal
- Serviço de Ecocardiografia Neonatal e Pediátrica, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
| | - Karen Saori Shiraishi Sawamura
- Serviço de Ecocardiografia Neonatal e Pediátrica, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
| | - Alessandro Cavalcanti Lianza
- Serviço de Ecocardiografia Neonatal e Pediátrica, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
| | - Werther Brunow de Carvalho
- Disciplina de Neonatologia, Departamento de Pediatria, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
| | - Vera Lúcia Jornada Krebs
- Disciplina de Neonatologia, Departamento de Pediatria, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo - São Paulo (SP), Brasil
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9
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Zeng Y, Wang H, Zhang L, Tang J, Shi J, Xiao D, Qu Y, Mu D. The optimal choices of animal models of white matter injury. Rev Neurosci 2019; 30:245-259. [PMID: 30379639 DOI: 10.1515/revneuro-2018-0044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/16/2018] [Indexed: 12/25/2022]
Abstract
White matter injury, the most common neurological injury in preterm infants, is a major cause of chronic neurological morbidity, including cerebral palsy. Although there has been great progress in the study of the mechanism of white matter injury in newborn infants, its pathogenesis is not entirely clear, and further treatment approaches are required. Animal models are the basis of study in pathogenesis, treatment, and prognosis of white matter injury in preterm infants. Various species have been used to establish white matter injury models, including rodents, rabbits, sheep, and non-human primates. Small animal models allow cost-effective investigation of molecular and cellular mechanisms, while large animal models are particularly attractive for pathophysiological and clinical-translational studies. This review focuses on the features of commonly used white matter injury animal models, including their modelling methods, advantages, and limitations, and addresses some clinically relevant animal models that allow reproduction of the insults associated with clinical conditions that contribute to white matter injury in human infants.
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Affiliation(s)
- Yan Zeng
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Huiqing Wang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Li Zhang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Jun Tang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Jing Shi
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Dongqiong Xiao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Yi Qu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Dezhi Mu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, No. 20, section 3, Renmin South Road, Chengdu, Sichuan 610041, China.,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu 610041, China, Telephone: +86-28-85503226, Fax: +86-28-85559065
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10
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Optimal Conventional Mechanical Ventilation in Full-Term Newborns: A Systematic Review. Adv Neonatal Care 2018; 18:451-461. [PMID: 30036198 DOI: 10.1097/anc.0000000000000525] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Most studies examining the best mechanical ventilation strategies in newborn infants have been performed in premature infants with respiratory distress syndrome. PURPOSE To identify and synthesize the evidence regarding optimal mechanical ventilation strategies in full-term newborns. METHODS Systematic review carried out according to the methods described in the PRISMA statement. SEARCH STRATEGY Searches in MEDLINE, EMBASE, CINAHL, and the Cochrane Library in March 2017, with an updated search and hand searches of reference lists of relevant articles in August 2017. STUDY SELECTION Studies were included if they were published between 1996 and 2017, involved newborns with gestational age of 37 to 42 weeks, were randomized controlled trials, intervention or crossover studies, and addressed outcomes affecting oxygenation and/or ventilation, and/or short-term outcomes including duration of mechanical ventilation. Because of the large heterogeneity between the studies, it was not possible to synthesize the results in meta-analyses. The results are presented according to thematic analysis. RESULTS No individual study reported research exclusively in newborns 37 to 42 weeks of gestation. Eight studies fulfilled the inclusion criteria, but the population in all these studies included both premature and term newborns. Evidence about mechanical ventilation tailored exclusively to full-term newborns is scarce. IMPLICATION FOR PRACTICE Synchronized intermittent mandatory ventilation with a 6 mL/kg tidal volume and a positive end-expiratory pressure of 8 cm H2O may be advantageous in full-term newborns. IMPLICATION FOR RESEARCH There is an urgent need for high-quality studies, preferably randomized controlled trials, in full-term newborns requiring mechanical ventilation to optimize oxygenation, ventilation, and short-term outcomes, potentially stratified according to the underlying pathology.
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11
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Kluckow M. The Pathophysiology of Low Systemic Blood Flow in the Preterm Infant. Front Pediatr 2018; 6:29. [PMID: 29503814 PMCID: PMC5820306 DOI: 10.3389/fped.2018.00029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/31/2018] [Indexed: 11/13/2022] Open
Abstract
Assessment and treatment of the VLBW infant with cardiovascular impairment requires understanding of the underlying physiology of the infant in transition. The situation is dynamic with changes occurring in systemic blood pressure, pulmonary pressures, myocardial function, and ductal shunt in the first postnatal days. New insights into the role of umbilical cord clamping in the transitional circulation have been provided by large clinical trials of early versus later cord clamping and a series of basic science reports describing the physiology in an animal model. Ultrasound assessment is invaluable in assessment of the physiology of the transition and can provide information about the size and shunt direction of the ductus arteriosus, the function of the myocardium and its filling as well as measurements of the cardiac output and an estimate of the state of peripheral vascular resistance. This information not only allows more specific treatment but it will often reduce the need for treatment.
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Affiliation(s)
- Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital, University of Sydney, Sydney, NSW, Australia
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12
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Vrancken SL, van Heijst AF, de Boode WP. Neonatal Hemodynamics: From Developmental Physiology to Comprehensive Monitoring. Front Pediatr 2018; 6:87. [PMID: 29675404 PMCID: PMC5895966 DOI: 10.3389/fped.2018.00087] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/19/2018] [Indexed: 12/16/2022] Open
Abstract
Maintenance of neonatal circulatory homeostasis is a real challenge, due to the complex physiology during postnatal transition and the inherent immaturity of the cardiovascular system and other relevant organs. It is known that abnormal cardiovascular function during the neonatal period is associated with increased risk of severe morbidity and mortality. Understanding the functional and structural characteristics of the neonatal circulation is, therefore, essential, as therapeutic hemodynamic interventions should be based on the assumed underlying (patho)physiology. The clinical assessment of systemic blood flow (SBF) by indirect parameters, such as blood pressure, capillary refill time, heart rate, urine output, and central-peripheral temperature difference is inaccurate. As blood pressure is no surrogate for SBF, information on cardiac output and systemic vascular resistance should be obtained in combination with an evaluation of end organ perfusion. Accurate and reliable hemodynamic monitoring systems are required to detect inadequate tissue perfusion and oxygenation at an early stage before this result in irreversible damage. Also, the hemodynamic response to the initiated treatment should be re-evaluated regularly as changes in cardiovascular function can occur quickly. New insights in the understanding of neonatal cardiovascular physiology are reviewed and several methods for current and future neonatal hemodynamic monitoring are discussed.
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Affiliation(s)
- Sabine L Vrancken
- Department of Perinatology (Neonatology), Amalia Children's Hospital, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Arno F van Heijst
- Department of Perinatology (Neonatology), Amalia Children's Hospital, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Willem P de Boode
- Department of Perinatology (Neonatology), Amalia Children's Hospital, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
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13
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Van Laere D, Voeten M, O' Toole JM, Dempsey E. Monitoring Circulation During Transition in Extreme Low Gestational Age Newborns: What's on the Horizon? Front Pediatr 2018; 6:74. [PMID: 29632852 PMCID: PMC5879103 DOI: 10.3389/fped.2018.00074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/12/2018] [Indexed: 11/20/2022] Open
Abstract
Echocardiography and near-infrared spectroscopy have significantly changed our view on hemodynamic transition of the extreme preterm infant. Instead of focusing on maintaining an arbitrary target value of blood pressure, we aim for circulatory well-being by a comprehensive holistic assessment of markers of cardiovascular instability. Most of these clinical and biochemical indices are influenced by transition itself and remain poor discriminators to identify patients with a potential need for therapeutic intervention. At the same time, the evolution in data capturing and storage has led to a change in our approach to monitor vital parameters. Continuous trend monitoring has become more and more relevant. By using signal extraction methods, changes in trends over time can be quantified. In this review, we will discuss the impact of these innovations on the current monitoring practices and explore some of the potential benefits these techniques may have in improving real-time detection of extreme low birth weight infants at risk for morbidity related to impaired hemodynamic transition.
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Affiliation(s)
- David Van Laere
- Department of Neonatal Intensive Care, Antwerp University Hospital, Antwerp, Belgium.,Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Michiel Voeten
- Department of Neonatal Intensive Care, Antwerp University Hospital, Antwerp, Belgium.,Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - John M O' Toole
- Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland
| | - Eugene Dempsey
- Irish Centre for Fetal and Neonatal Translational Research, University College Cork, Cork, Ireland
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Zannin E, Doni D, Ventura ML, Fedeli T, Rigotti C, Dellacá RL, Tagliabue PE. Relationship between Mean Airways Pressure, Lung Mechanics, and Right Ventricular Output during High-Frequency Oscillatory Ventilation in Infants. J Pediatr 2017; 180:110-115. [PMID: 27745747 DOI: 10.1016/j.jpeds.2016.09.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/28/2016] [Accepted: 09/08/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To characterize changes in lung mechanics and right ventricular output (RVO) during incremental/decremental continuous distending pressure (CDP) maneuvers in newborn infants receiving high-frequency oscillatory ventilation, with the aim of evaluating when open lung maneuvers are needed and whether they are beneficial. STUDY DESIGN Thirteen infants on high-frequency oscillatory ventilation were studied with a median (IQR) gestational age of 261 (253-291) weeks and median (IQR) body weight of 810 (600-1020) g. CDP was increased stepwise from 8 cmH2O to a maximum pressure and subsequently decreased until oxygenation deteriorated or a CDP of 8 cmH2O was reached. The lowest CDP that maintained good oxygenation was considered the clinically optimal CDP. At each CDP, the following variables were evaluated: oxygenation, respiratory system reactance (Xrs), and RVO by Doppler echocardiography. RESULTS At maximal CDP reached during the trial, 19 [1] cmH2O (mean [SEM]), oxygenation markedly improved, and Xrs and RVO decreased. During deflation, oxygenation remained stable over a wide range of CDP settings, Xrs returned to the baseline values, and RVO increased but the baseline values were not readily restored in all patients. CONCLUSION These results suggest that Xrs and RVO are more sensitive than oxygenation to overdistension and they may be useful in clinical practice to guide open lung maneuvers.
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Affiliation(s)
- Emanuela Zannin
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
| | - Daniela Doni
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Tiziana Fedeli
- Neonatal Intensive Care Unit, Fondazione MBBM, Monza, Italy
| | | | - Raffaele L Dellacá
- Department of Electronics, Informatics and Bioengineering, Politecnico di Milano University, Milan, Italy
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15
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McGovern M, Miletin J. A review of superior vena cava flow measurement in the neonate by functional echocardiography. Acta Paediatr 2017; 106:22-29. [PMID: 27611695 DOI: 10.1111/apa.13584] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/29/2016] [Accepted: 09/07/2016] [Indexed: 11/27/2022]
Abstract
Neonatologists have begun using superior vena cava flow as assessed by functional echocardiography to facilitate real-time decision-making on cardiovascular care. This review aims to describe the basis of the technique, summarise the evidence for its use and compare the technique to existing clinical, biochemical and radiological techniques for assessing neonatal circulatory status. CONCLUSION Although echocardiographic measurements of superior vena cava flow, like other measures of perfusion, are not perfect, their noninvasive nature and ability to facilitate real-time decision-making means that at present, they remain the best available methodology of monitoring central perfusion in the neonatal population.
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Affiliation(s)
- Matthew McGovern
- Neonatology Department; Coombe Women and Infant University Hospital; Dublin Ireland
| | - Jan Miletin
- Neonatology Department; Coombe Women and Infant University Hospital; Dublin Ireland
- Institute for the Care of Mother and Child; Prague Czech Republic
- 3rd School of Medicine; Charles University; Prague Czech Republic
- UCD School of Medicine and Medical Sciences; Dublin Ireland
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16
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Dempsey EM. Challenges in Treating Low Blood Pressure in Preterm Infants. CHILDREN-BASEL 2015; 2:272-88. [PMID: 27417363 PMCID: PMC4928758 DOI: 10.3390/children2020272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/05/2015] [Indexed: 01/02/2023]
Abstract
Whilst the prevalence of low blood pressure in preterm infants seems to have fallen over the last number of years, the problem is still frequently encountered in the neonatal intensive care unit and many babies continue to receive intervention. Great variability in practice persists, with a significant number of extremely low gestational age newborns in some institutions receiving some form of intervention, and in other units substantially less. A great degree of this variability relates to the actual criteria used to define hypotension, with some using blood pressure values alone to direct therapy and others using a combination of clinical, biochemical and echocardiography findings. The choice of intervention remains unresolved with the majority of centres continuing to administer volume followed by dopamine as a first line inotrope/vasopressor agent. Despite over 40 years of use there is little evidence that dopamine is of benefit both in the short term and long-term. Long-term follow up is available in only two randomised trials, which included a total of 99 babies. An under recognized problem relates to the administration of inotrope infusions in very preterm infants. There are no pediatric specific inotrope formulations available and so risks of errors in preparation and administration remain. This manuscript outlines these challenges and proposes some potential solutions.
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Affiliation(s)
- Eugene M Dempsey
- Department of Paediatrics and Child Health, University College Cork, Cork City post code, Ireland.
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland.
- Department of Paediatrics and Child Health, Cork University Maternity Hospital, Wilton Cork, Ireland.
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17
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Beker F, Rogerson SR, Hooper SB, Sehgal A, Davis PG. Hemodynamic effects of nasal continuous positive airway pressure in preterm infants with evolving chronic lung disease, a crossover randomized trial. J Pediatr 2015; 166:477-9. [PMID: 25454930 DOI: 10.1016/j.jpeds.2014.10.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/25/2014] [Accepted: 10/03/2014] [Indexed: 11/26/2022]
Abstract
Previous studies suggest that high airway pressure may compromise cardiac output. We investigated the effect of 3 nasal continuous positive airway pressure levels on cardiac output in preterm infants with evolving chronic lung disease. We found that brief changes in continuous positive airway pressure did not affect cardiac output.
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Affiliation(s)
- Friederike Beker
- The Royal Women's Hospital, Parkville, Victoria, Australia; The Mercy Hospital for Women, Heidelberg, Victoria, Australia; Monash Medical Centre, Clayton, Victoria, Australia
| | | | - Stuart B Hooper
- The Ritchie Centre, Monash Institute for Medical Research, Clayton, Victoria, Australia
| | | | - Peter G Davis
- The Royal Women's Hospital, Parkville, Victoria, Australia
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18
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Bancalari E. Interaction between respiratory cardiovascular function. Early Hum Dev 2014; 90 Suppl 2:S3-4. [PMID: 25220124 DOI: 10.1016/s0378-3782(14)50002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Eduardo Bancalari
- Department of Pediatrics, Division of Neonatology, University of Miami Miller School of Medicine Miami Florida USA.
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19
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Lakkundi A, Wright I, de Waal K. Transitional hemodynamics in preterm infants with a respiratory management strategy directed at avoidance of mechanical ventilation. Early Hum Dev 2014; 90:409-12. [PMID: 24951077 DOI: 10.1016/j.earlhumdev.2014.04.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 04/04/2014] [Accepted: 04/28/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Early respiratory management of very low birth weight infants has changed over recent years to a practice of early use of CPAP with early selective surfactant administration, and decreased use of mechanical ventilation. One strategy is to use the combination of surfactant and prompt extubation to nasal continuous positive airway pressure (INtubate, SURfactant, Extubate, or INSURE). The aim of this study is to describe blood flow and ductal flow in a prospective cohort during the transitional period when this respiratory management strategy is used. METHODS Inborn infants <29week gestation underwent INSURE within 30min of birth using 200mg/kg Curosurf. Blood pressure and blood flow parameters (RVO, LVO, SVC flow, ductus arteriosus) were measured at 6, 24 and 72h of age and information on morbidity was collected. RESULTS Sixty-eight infants with a median (range) weight of 940 (450-1380) g were studied. 13 (19%) patients needed mechanical ventilation within 72h of life (INSURE failure). Blood flows and blood pressure were within reported ranges. Eleven (16%) patients had a blood pressure <gestational age and 9 (13%) patients had low blood flow. CONCLUSION These data show a low prevalence of low blood pressure and low blood flow in the first 3days after INSURE as compared to cohorts where mechanical ventilation was preferred during transition. We speculate that altered ventilation strategies have helped decrease the incidence of low blood flow and low blood pressure.
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Affiliation(s)
- Anil Lakkundi
- Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle NSW, Australia; University of Newcastle, Newcastle, Australia
| | - Ian Wright
- Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle NSW, Australia; University of Newcastle, Newcastle, Australia; University of Wollongong, Wollongong, Australia
| | - Koert de Waal
- Neonatal Intensive Care Unit, John Hunter Children's Hospital, Newcastle NSW, Australia; University of Newcastle, Newcastle, Australia.
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20
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Aquilano G, Galletti S, Aceti A, Vitali F, Faldella G. Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome. Ital J Pediatr 2014; 40:60. [PMID: 24952579 PMCID: PMC4122055 DOI: 10.1186/1824-7288-40-60] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 06/11/2014] [Indexed: 11/16/2022] Open
Abstract
Background Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. Objective To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. Design A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4–5 cmH2O) because they developed RDS within the first 24–72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4–5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support. Results No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ = 0.11, p = 0,657; RVO: ρ = −0.307, p = 0.216; SVC: ρ = −0.13, p = 0.197). Conclusions Central blood flow doesn’t change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants.
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Affiliation(s)
| | - Silvia Galletti
- Neonatology and Neonatal Intensive Care Unit, Department of Medical and Surgical Sciences, St, Orsola-Malpighi Hospital - University of Bologna, Via Massarenti, 11 40138 Bologna, Italy.
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21
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Polglase GR, Miller SL, Barton SK, Kluckow M, Gill AW, Hooper SB, Tolcos M. Respiratory support for premature neonates in the delivery room: effects on cardiovascular function and the development of brain injury. Pediatr Res 2014; 75:682-8. [PMID: 24614803 DOI: 10.1038/pr.2014.40] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 12/16/2013] [Indexed: 02/02/2023]
Abstract
The transition to newborn life in preterm infants is complicated by immature cardiovascular and respiratory systems. Consequently, preterm infants often require respiratory support immediately after birth. Although aeration of the lung underpins the circulatory transition at birth, positive pressure ventilation can adversely affect cardiorespiratory function during this vulnerable period, reducing pulmonary blood flow and left ventricular output. Furthermore, pulmonary volutrauma is known to initiate pulmonary inflammatory responses, resulting in remote systemic involvement. This review focuses on the downstream consequences of positive pressure ventilation, in particular, interactions between cardiovascular output and the initiation of a systemic inflammatory cascade, on the immature brain. Recent studies have highlighted that positive pressure ventilation strategies are precursors of cerebral injury, probably mediated through cerebral blood flow instability. The presence of, or initiation of, an inflammatory cascade accentuates adverse cerebral blood flow, in addition to being a direct source of brain injury. Importantly, the degree of brain injury is dependent on the nature of the initial ventilation strategy used.
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Affiliation(s)
- Graeme R Polglase
- 1] The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia [2] Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Samantha K Barton
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Martin Kluckow
- Department of Neonatalogy, Royal North Shore Hospital, University of Sydney, Sydney, New South Wales, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Western Australia, Australia
| | - Stuart B Hooper
- 1] The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia [2] Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Mary Tolcos
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
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22
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Beker F, Rogerson SR, Hooper SB, Wong C, Davis PG. The effects of nasal continuous positive airway pressure on cardiac function in premature infants with minimal lung disease: a crossover randomized trial. J Pediatr 2014; 164:726-9. [PMID: 24345453 DOI: 10.1016/j.jpeds.2013.10.087] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/18/2013] [Accepted: 10/30/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the effects of different nasal continuous positive airway pressure (nCPAP) pressures on cardiac performance in preterm infants with minimal lung disease, we conducted a randomized, blinded crossover study. STUDY DESIGN We studied infants between 28 and 34 weeks' corrected gestational age, treated with nCPAP of 5 cm H2O, in air. Infants with significant cardiac shunts were excluded. Infants were randomly assigned to nCPAP levels of 4, 6, and 8 cm H2O for 15 minutes each. Right and left ventricular outputs and left pulmonary artery and superior vena cava flows were measured 15 minutes after each change. RESULTS Thirty-four infants born at a mean gestational age of 29 weeks with a birth weight of 1.3 kg were studied. There were no significant differences in right and left ventricular outputs and left pulmonary artery and superior vena cava flows at different levels of nCPAP. CONCLUSION We investigated the effect of increasing nCPAP levels on cardiac output. We conclude that nCPAP levels between 4 and 8 cm H2O did not have an effect on cardiac output in stable preterm infants with minimal lung disease.
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Affiliation(s)
- Friederike Beker
- Neonatal Intensive and Special Care, The Royal Women's Hospital, Parkville, Victoria, Australia; Newborn Intensive Care Unit, The Mercy Hospital for Women, Heidelberg, Victoria, Australia
| | - Sheryle R Rogerson
- Neonatal Intensive and Special Care, The Royal Women's Hospital, Parkville, Victoria, Australia
| | - Stuart B Hooper
- The Ritchie Center, Monash Institute for Medical Research, Monash University, Clayton, Victoria, Australia
| | - Connie Wong
- Neonatal Intensive and Special Care, The Royal Women's Hospital, Parkville, Victoria, Australia
| | - Peter G Davis
- Neonatal Intensive and Special Care, The Royal Women's Hospital, Parkville, Victoria, Australia
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23
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Fajardo MF, Claure N, Swaminathan S, Sattar S, Vasquez A, D'Ugard C, Bancalari E. Effect of positive end-expiratory pressure on ductal shunting and systemic blood flow in preterm infants with patent ductus arteriosus. Neonatology 2014; 105:9-13. [PMID: 24193163 DOI: 10.1159/000355146] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/20/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Left to right (L-R) shunting through a patent ductus arteriosus (PDA) can reduce systemic and cerebral blood flow in preterm infants. To minimize this, the positive end-expiratory pressure (PEEP) is often raised to increase pulmonary vascular resistance and reduce L-R shunting. The effects of this maneuver on systemic and cerebral hemodynamics and oxygenation are not well documented. OBJECTIVE To compare the effects of different PEEP on the left ventricular output (LVO), superior vena cava (SVC) flow, LVO/SVC flow ratio, cerebral oxygenation (CrSO2) and gas exchange in mechanically ventilated preterm infants with PDA. METHODS Sixteen mechanically ventilated infants of 23-30 weeks' gestational age with L-R shunting through the PDA were studied. Ultrasound measurements of LVO and SVC flow, CrSO2, arterial oxygen saturation and transcutaneous CO2 tension (TcPCO2) obtained at PEEP of 2 and 8 cm H2O were compared with baseline values at 5 cm H2O. RESULTS There was a small but significant reduction in LVO and the LVO/SVC flow ratio at PEEP of 8 compared to 5 cm H2O. SVC flow and CrSO2 did not differ significantly. CONCLUSIONS Increasing PEEP to 8 cm H2O in ventilated preterm infants with a PDA produced a modest decrease in L-R ductal shunting as indicated by a lower LVO/SVC flow ratio. The higher PEEP did not have a significant effect on cerebral perfusion or oxygenation.
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Affiliation(s)
- Maria Florencia Fajardo
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Fla., USA
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24
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Weight corrected percentiles for blood vessel diameters used in flow measurements in preterm infants. Early Hum Dev 2013; 89:939-42. [PMID: 24113211 DOI: 10.1016/j.earlhumdev.2013.09.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/19/2013] [Accepted: 09/22/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Blood flow measurements are an integral part of haemodynamic assessment of the newborn infant. Most variability of Doppler derived blood flow is caused by diameter measurements. Population based percentiles of diameter measurements would be useful for training of clinicians undertaking blood flow measurements and allow rapid identification of outliers. METHODS Diameter measurements of pulmonary valve annulus, ascending aorta and the superior vena cava using standardised methodology were collected retrospectively from 9 prospective studies on transitional haemodynamics in preterm infants. Data were analysed to calculate weight corrected percentiles of diameters used for blood flow measurements. RESULTS We analysed 2870 measurements in 694 preterm infants less than 1750 g. The median gestational age was 27 weeks (range 23 to 34 weeks) and the median time of measurement was 22 h after birth (range 0.5 h to 70 days). 76% of measurements were performed while the infant received mechanical ventilation and 20% received cardiovascular support. Mean diameters increased with weight and standard deviations were comparable over the weight range. CONCLUSION Data from this large combined series provide a reference range for blood vessel diameters in the population most often measured. The data permits recognition of outliers and could be used to trigger review of measurements that fall outside the normal range.
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25
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Duerden EG, Brown-Lum M, Chau V, Poskitt KJ, Grunau RE, Synnes A, Miller SP. Resuscitation intensity at birth is associated with changes in brain metabolic development in preterm neonates. Neuroradiology 2013; 55 Suppl 2:47-54. [PMID: 23921419 DOI: 10.1007/s00234-013-1243-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/10/2013] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Intensive resuscitation at birth has been linked to intraventricular haemorrhage (IVH) in the preterm neonate. However, the impact of less intensive resuscitation on more subtle alterations in brain metabolic development is largely unknown. Our objective was to determine the relationship between the intensity of neonatal resuscitation following preterm birth on brain metabolic development. METHODS One hundred thirty-three very preterm-born neonates (median gestational age [GA] 27 ± 2 weeks) underwent MR spectroscopic imaging early in life (median postmenstrual age 32 weeks) and again at term-equivalent age (median 40 weeks). Severity of white matter injury, IVH and cerebellar haemorrhage on magnetic resonance imaging were scored. Ratios of N-acetylaspartate (NAA) and lactate to choline (Cho) were calculated in eight regions of interest and were assessed in relation to intensiveness of resuscitation strategy (bag and mask, continuous positive airway pressure [CPAP], intubation, cardiopulmonary resuscitation [CPR]). RESULTS Within the first hour of life, 14 newborns had no intervention, 3 received bag and mask, 30 had CPAP, 79 were intubated and 7 had CPR. Resuscitated infants were more likely to have IVH (p = 0.02). More intensive resuscitation was associated with decreased NAA/Cho maturation (p < 0.001, adjusting for birth GA). Metabolic development was similar in neonates requiring CPAP in comparison to those receiving no intervention. The change in lactate/Cho did not differ across resuscitation categories (p = 0.8). CONCLUSIONS Intensity of resuscitation at birth is related to changes in metabolic brain development from early in life to term-equivalent age. Results suggest that preventing the need for intensive neonatal resuscitation may provide an opportunity to improve brain development in preterm neonates.
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Affiliation(s)
- Emma G Duerden
- Department of Paediatrics, The Hospital for Sick Children and the University of Toronto, Toronto, ON, Canada
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26
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Pellicer A, Greisen G, Benders M, Claris O, Dempsey E, Fumagalli M, Gluud C, Hagmann C, Hellström-Westas L, Hyttel-Sorensen S, Lemmers P, Naulaers G, Pichler G, Roll C, van Bel F, van Oeveren W, Skoog M, Wolf M, Austin T. The SafeBoosC phase II randomised clinical trial: a treatment guideline for targeted near-infrared-derived cerebral tissue oxygenation versus standard treatment in extremely preterm infants. Neonatology 2013; 104:171-8. [PMID: 23921600 DOI: 10.1159/000351346] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/12/2013] [Indexed: 11/19/2022]
Abstract
UNLABELLED Near-infrared spectroscopy-derived regional tissue oxygen saturation of haemoglobin (rStO2) reflects venous oxygen saturation. If cerebral metabolism is stable, rStO2 can be used as an estimate of cerebral oxygen delivery. The SafeBoosC phase II randomised clinical trial hypothesises that the burden of hypo- and hyperoxia can be reduced by the combined use of close monitoring of the cerebral rStO2 and a treatment guideline to correct deviations in rStO2 outside a predefined target range. AIMS To describe the rationale for and content of this treatment guideline. METHODS Review of the literature and assessment of the quality of evidence and the grade of recommendation for each of the interventions. RESULTS AND CONCLUSIONS A clinical intervention algorithm based on the main determinants of cerebral perfusion-oxygenation changes during the first hours after birth was generated. The treatment guideline is presented to assist neonatologists in making decisions in relation to cerebral oximetry readings in preterm infants within the SafeBoosC phase II randomised clinical trial. The evidence grades were relatively low and the guideline cannot be recommended outside a research setting.
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Affiliation(s)
- Adelina Pellicer
- Department of Neonatology, La Paz University Hospital, Madrid, Spain
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27
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Abstract
The lungs of an extremely preterm infant ≤28 weeks gestation are structurally and biochemically immature and vulnerable to injury from positive pressure ventilation. A lung protective approach to respiratory support is vital, aiming to ventilate an open lung, using the lowest pressure settings that maintain recruitment and oxygenation and avoiding hyperinflation with each tidal breath. For infants with severe respiratory distress syndrome and persistent atelectasis, lung protective ventilation requires recruitment using stepwise pressure increments, followed by reduction in ventilator pressures in search of an optimal point at which to maintain ventilation. Several studies, including a single randomised controlled trial, have found this lung protective strategy to be more effectively administered using high-frequency oscillatory ventilation rather than conventional ventilation. Many extremely preterm infants have minimal atelectasis and low oxygen requirements in the first days of life, and the ventilatory approach in this case should be one of avoidance of factors including overdistension that are known to contribute to later pulmonary deterioration. From a practical perspective, this means setting positive end-expiratory pressure at the lowest value that maintains oxygenation and restricting tidal volume using a volume-targeted mode of ventilation.
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Affiliation(s)
- Peter A Dargaville
- Department of Paediatrics, Royal Hobart Hospital and University of Tasmania, Hobart, Tasmania, Australia.
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28
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Witt L, Osthaus WA, Schröder T, Teich N, Dingemann C, Kübler J, Böthig D, Sümpelmann R. Single-lung ventilation with carbon dioxide hemipneumothorax: hemodynamic and respiratory effects in piglets. Paediatr Anaesth 2012; 22:793-8. [PMID: 22171739 DOI: 10.1111/j.1460-9592.2011.03766.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Video-assisted thoracoscopic surgery (VATS) has become a standard procedure in pediatric surgery. To facilitate surgical access, the dependent lung has to collapse using intrathoracic carbon dioxide insufflation and/or single-lung ventilation. These procedures can induce hemodynamic deteriorations in adults. The potential impacts of single-lung ventilation in combination with capnothorax on hemodynamics in infants have never been studied before. AIM We conducted a randomized experimental study focusing on hemodynamic and respiratory changes during single-lung ventilation with or without capnothorax in a pediatric animal model. METHODS Twelve piglets were randomly assigned to receive single-lung ventilation with (SLV-CO(2) ) or without (SLV) capnothorax with an insufflation pressure of 5 mmHg for a period of two hours. Before, during, and after single-lung ventilation, hemodynamic and respiratory parameters were measured. RESULTS Although mean arterial pressure remained stable during the course of the study and no critical incidents were monitored, cardiac index (CI) decreased significantly with SLV-CO(2) (baseline 3.6 ± 1.6 l · min(-1) · m(-2) vs 2.9 ± 1.1 l · min(-1) · m(-2) at 120 min, P < 0.05). Furthermore, global end-diastolic volume and intrathoracic blood volume (ITBV) decreased as well significantly with SLV-CO(2) , causing a significant between-group difference in ITBV (P < 0.05). CONCLUSIONS Despite a decrease in CI and preload parameters, the combination of single-lung ventilation and low-pressure capnothorax was well tolerated in piglets and could justify further clinical studies to be performed in infants and children focusing on hemodynamic and respiratory changes during VATS.
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Affiliation(s)
- Lars Witt
- Clinic of Anaesthesiology, Hannover Medical School, Hannover, Germany.
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29
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Polglase GR, Miller SL, Barton SK, Baburamani AA, Wong FY, Aridas JDS, Gill AW, Moss TJM, Tolcos M, Kluckow M, Hooper SB. Initiation of resuscitation with high tidal volumes causes cerebral hemodynamic disturbance, brain inflammation and injury in preterm lambs. PLoS One 2012; 7:e39535. [PMID: 22761816 PMCID: PMC3382197 DOI: 10.1371/journal.pone.0039535] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 05/23/2012] [Indexed: 11/21/2022] Open
Abstract
AIMS Preterm infants can be inadvertently exposed to high tidal volumes (V(T)) in the delivery room, causing lung inflammation and injury, but little is known about their effects on the brain. The aim of this study was to compare an initial 15 min of high V(T) resuscitation strategy to a less injurious resuscitation strategy on cerebral haemodynamics, inflammation and injury. METHODS Preterm lambs at 126 d gestation were surgically instrumented prior to receiving resuscitation with either: 1) High V(T) targeting 10-12 mL/kg for the first 15 min (n = 6) or 2) a protective resuscitation strategy (Prot V(T)), consisting of prophylactic surfactant, a 20 s sustained inflation and a lower initial V(T) (7 mL/kg; n = 6). Both groups were subsequently ventilated with a V(T) 7 mL/kg. Blood gases, arterial pressures and carotid blood flows were recorded. Cerebral blood volume and oxygenation were assessed using near infrared spectroscopy. The brain was collected for biochemical and histologic assessment of inflammation, injury, vascular extravasation, hemorrhage and oxidative injury. Unventilated controls (UVC; n = 6) were used for comparison. RESULTS High V(T) lambs had worse oxygenation and required greater ventilatory support than Prot V(T) lambs. High V(T) resulted in cerebral haemodynamic instability during the initial 15 min, adverse cerebral tissue oxygenation index and cerebral vasoparalysis. While both resuscitation strategies increased lung and brain inflammation and oxidative stress, High V(T) resuscitation significantly amplified the effect (p = 0.014 and p<0.001). Vascular extravasation was evident in the brains of 60% of High V(T) lambs, but not in UVC or Prot V(T) lambs. CONCLUSION High V(T) resulted in greater cerebral haemodynamic instability, increased brain inflammation, oxidative stress and vascular extravasation than a Prot V(T) strategy. The initiation of resuscitation targeting Prot V(T) may reduce the severity of brain injury in preterm neonates.
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Affiliation(s)
- Graeme R Polglase
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia.
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30
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Polglase GR, Nitsos I, Baburamani AA, Crossley KJ, Slater MK, Gill AW, Allison BJ, Moss TJM, Pillow JJ, Hooper SB, Kluckow M. Inflammation in utero exacerbates ventilation-induced brain injury in preterm lambs. J Appl Physiol (1985) 2011; 112:481-9. [PMID: 22052871 DOI: 10.1152/japplphysiol.00995.2011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral blood flow disturbance is a major contributor to brain injury in the preterm infant. The initiation of ventilation may be a critical time for cerebral hemodynamic disturbance leading to brain injury in preterm infants, particularly if they are exposed to inflammation in utero. We aimed to determine whether exposure to inflammation in utero alters cardiopulmonary hemodynamics, resulting in cerebral hemodynamic disturbance and related brain injury during the initiation of ventilation. Furthermore, we aimed to determine whether inflammation in utero alters the cerebral hemodynamic response to challenge induced by high mean airway pressures. Pregnant ewes received intra-amniotic lipopolysaccharide (LPS) or saline either 2 or 4-days before preterm delivery (at 128 ± 1 days of gestation). Lambs were surgically instrumented for assessment of pulmonary and cerebral hemodynamics before delivery and positive pressure ventilation. After 30 min, lambs were challenged hemodynamically by incrementing and decrementing positive end-expiratory pressure. Blood gases, arterial pressures, and blood flows were recorded. The brain was collected for biochemical and histological assessment of inflammation, brain damage, vascular extravasation, hemorrhage, and oxidative injury. Carotid arterial pressure was higher and carotid blood flow was more variable in 2-day LPS lambs than in controls during the initial 15 min of ventilation. All lambs responded similarly to the hemodynamic challenge. Both 2- and 4-day LPS lambs had increased brain interleukin (IL)-1β, IL-6, and IL-8 mRNA expression; increased number of inflammatory cells in the white matter; increased incidence and severity of brain damage; and vascular extravasation relative to controls. Microvascular hemorrhage was increased in 2-day LPS lambs compared with controls. Cerebral oxidative injury was not different between groups. Antenatal inflammation causes adverse cerebral hemodynamics and increases the incidence and severity of brain injury in ventilated preterm lambs.
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Affiliation(s)
- Graeme R Polglase
- Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia.
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31
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Andersen CC, Pillow JJ, Gill AW, Allison BJ, Moss TJM, Hooper SB, Nitsos I, Kluckow M, Polglase GR. The cerebral critical oxygen threshold of ventilated preterm lambs and the influence of antenatal inflammation. J Appl Physiol (1985) 2011; 111:775-81. [PMID: 21719723 DOI: 10.1152/japplphysiol.00214.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Perinatal inflammation is associated with adverse neurodevelopmental outcomes, which may be partly due to changes in the cerebral oxygen delivery/consumption relationship. We aimed to determine the critical oxygen delivery threshold of the brain of preterm, ventilated lambs and to determine whether the critical threshold is affected by exposure to inflammation in utero. Pregnant ewes received intra-amniotic injection of lipopolysaccharide or saline at 125 or 127 days of gestation. Pulmonary and systemic flow probes and catheters were surgically positioned in the fetus immediately before delivery at 129 days of gestation. After delivery, lambs were ventilated for 90 min using a positive end-expiratory pressure recruitment strategy. Cardio-respiratory variables and blood gases were measured regularly. Systemic and cerebral oxygen delivery, consumption (Fick), and extraction were calculated, and the relationship between cerebral delivery and consumption analyzed. Linear regression was used to define the transition or "critical" oxygen threshold as the point at which the slope of the oxygen delivery/consumption curve changed to be > 10°. Four subgroups were defined according to the calculated critical threshold. A total of 150 measurements were recorded in 18 lambs. Fetal cerebral oxygen consumption was increased by antenatal lipopolysaccharide (P < 0.05). The postnatal critical oxygen threshold was 3.6 ml·kg⁻¹·min⁻¹, corresponding to cerebral oxygen consumption of 0.73 ml·kg⁻¹·min⁻¹. High oxygen delivery and consumption were associated with increased pulmonary and carotid blood flow and systemic extraction compared with low oxygen delivery and consumption. No postnatal effect of antenatal inflammation was observed. Inflammation in utero increases fetal, but not postnatal, cerebral oxygen consumption. Adverse alterations to pulmonary blood flow can result in reduced cerebral blood flow, oxygen delivery, and consumption. Regardless of exposure to inflammation, there is a consistent postnatal relationship between cerebral oxygen delivery and consumption.
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Affiliation(s)
- C C Andersen
- Perinatal Medicine, Women's and Children's Hospital, 72 King William Rd., North Adelaide, South Australia, Australia.
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de Waal K, Evans N, van der Lee J, van Kaam A. Effect of lung recruitment on pulmonary, systemic, and ductal blood flow in preterm infants. J Pediatr 2009; 154:651-5. [PMID: 19364558 DOI: 10.1016/j.jpeds.2009.01.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 11/26/2008] [Accepted: 01/08/2009] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To determine the effect of lung recruitment on pulmonary, systemic, and ductal blood flow in preterm infants treated with primary high-frequency ventilation (HFV). STUDY DESIGN Thirty-four infants (median gestational age, 28 weeks) were included in this prospective cohort study. Changes in oxygenation in response to stepwise changes in the continuous distending pressure (CDP) were used to monitor lung recruitment during HFV. For each individual patient, the opening pressure (CDPo), closing pressure (CDPc), and optimal pressure (CDPopt) were determined. Ultrasound measurements of right ventricular output (RVO), superior vena cava (SVC), and ductus arteriosus (DA) flow were performed at the start of recruitment (CDPs), CDPo, and CDPopt. RESULTS Increasing the CDP from 8 (CDPs) to 20 (CDPo) cmH(2)O resulted in a decreased RVO (mean difference, -17%; 95% CI, -24, -10%) and unchanged SVC flow and ductal shunting. Transient low RVO and SVC flow values at CDPo were seen in 3 and 2 infants, respectively. CONCLUSIONS Lung recruitment during HFV in preterm infants does not appear to result in clinically relevant changes in pulmonary, systemic, and ductal blood flow.
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Affiliation(s)
- Koert de Waal
- Emma Children's Hospital AMC, Department of Neonatology, Amsterdam, The Netherlands.
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Support of the preterm circulation: keynote address to the Fifth Evidence vs Experience Conference, Chicago, June 2008. J Perinatol 2009; 29 Suppl 2:S50-7. [PMID: 19399010 DOI: 10.1038/jp.2009.22] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hemodynamics is an area of neonatology that is marked more by what we do not know than what we do. What is clear is that it is much more complex than just measuring blood pressure (BP). Early postnatal preterm hemodynamic pathophysiology is characterized by low systemic blood flow (SBF), possibly relating to a mix of afterload compromise, left-to-right shunting through the unconstricted ductus and to the circulatory effects of ventilation. After approximately 24 h of age, vasodilatation seems to be the dominant pathology. In the face of this complexity, a one-size-fits-all approach to treatment that will be applicable in a large clinical trial may prove elusive. The possibility of using a measure of both BP and SBF to target an appropriate treatment needs to be explored.
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Abdel-Hady H, Matter M, Hammad A, El-Refaay A, Aly H. Hemodynamic changes during weaning from nasal continuous positive airway pressure. Pediatrics 2008; 122:e1086-90. [PMID: 18977958 DOI: 10.1542/peds.2008-1193] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Nasal continuous positive airway pressure is frequently used to support preterm infants with respiratory distress syndrome. Little is known about the hemodynamic changes that occur, particularly during the weaning phase when lung compliance has improved and most of the airway pressure can be transmitted to the heart and major blood vessels. METHODS We conducted a prospective study on preterm infants (gestational age <or=32 weeks) with resolving respiratory distress syndrome, who were receiving nasal continuous positive airway pressure of 5 cm H(2)O and 21% oxygen. While cycling nasal continuous positive airway pressure, we performed 2-dimensional M-mode and pulsed Doppler echocardiography on all infants during nasal continuous positive airway pressure and 1 hour after being off nasal continuous positive airway pressure. RESULTS A total of 25 preterm infant were studied. The use of nasal continuous positive airway pressure significantly decreased right ventricular output (320 +/- 22.7 vs 410.5 +/- 44.1 mL/kg per min); right ventricular end diastolic diameter (6 +/- 0.7 vs 6.4 +/- 0.4 mm), left ventricular end diastolic diameter (11.6 +/- 0.9 vs 13.6 +/- 0.7 mm), left ventricular end systolic diameter (7.1 +/- 0.6 vs 8.3 +/- 0.4 mm), left atrial diameter (6.3 +/- 0.5 vs 8 +/- 0.5 mm), aortic root diameter (6.4 +/- 0.3 vs 6.6 +/- 0.4 mm), superior vena cava flow (70.2 +/- 8.5 vs 91.1 +/- 4 mL/kg per minute), and pulmonary maximum velocity (0.6 +/- 0.1 vs 0.7 +/- 0.1 m/seconds). It significantly increased mean inferior vena cava diameter (4.3 +/- 0.5 vs 3.5 +/- 0.6 mm), whereas nasal continuous positive airway pressure did not influence left ventricular output, aortic maximum velocity, fractional shortening, heart rate, or mean arterial blood pressure. Changes associated with nasal continuous positive airway pressure were similar in infants with (n = 8) and without (n = 17) patent ductus arteriosus. CONCLUSIONS In infants with resolving respiratory distress syndrome, nasal continuous positive airway pressure can impede systemic and pulmonary venous return, but it does not compromise systemic arterial pressure or heart rate. It is not clear whether the degree of these hemodynamic changes can affect the success of weaning off nasal continuous positive airway pressure.
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