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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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DiBlasi RM, Crandall CN, Engberg RJ, Bijlani K, Ledee D, Kajimoto M, Walther FJ. Evaluation of a Novel Dry Powder Surfactant Aerosol Delivery System for Use in Premature Infants Supported with Bubble CPAP. Pharmaceutics 2023; 15:2368. [PMID: 37896128 PMCID: PMC10609757 DOI: 10.3390/pharmaceutics15102368] [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: 07/31/2023] [Revised: 09/05/2023] [Accepted: 09/08/2023] [Indexed: 10/29/2023] Open
Abstract
Aerosolized lung surfactant therapy during nasal continuous positive airway pressure (CPAP) support avoids intubation but is highly complex, with reported poor nebulizer efficiency and low pulmonary deposition. The study objective was to evaluate particle size, operational compatibility, and drug delivery efficiency with various nasal CPAP interfaces and gas humidity levels of a synthetic dry powder (DP) surfactant aerosol delivered by a low-flow aerosol chamber (LFAC) inhaler combined with bubble nasal CPAP (bCPAP). A particle impactor characterized DP surfactant aerosol particle size. Lung pressures and volumes were measured in a preterm infant nasal airway and lung model using LFAC flow injection into the bCPAP system with different nasal prongs. The LFAC was combined with bCPAP and a non-heated passover humidifier. DP surfactant mass deposition within the nasal airway and lung was quantified for different interfaces. Finally, surfactant aerosol therapy was investigated using select interfaces and bCPAP gas humidification by active heating. Surfactant aerosol particle size was 3.68 µm. Lung pressures and volumes were within an acceptable range for lung protection with LFAC actuation and bCPAP. Aerosol delivery of DP surfactant resulted in variable nasal airway (0-20%) and lung (0-40%) deposition. DP lung surfactant aerosols agglomerated in the prongs and nasal airways with significant reductions in lung delivery during active humidification of bCPAP gas. Our findings show high-efficiency delivery of small, synthetic DP surfactant particles without increasing the potential risk for lung injury during concurrent aerosol delivery and bCPAP with passive humidification. Specialized prongs adapted to minimize extrapulmonary aerosol losses and nasal deposition showed the greatest lung deposition. The use of heated, humidified bCPAP gases compromised drug delivery and safety. Safety and efficacy of DP aerosol delivery in preterm infants supported with bCPAP requires more research.
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Affiliation(s)
- Robert M. DiBlasi
- Department of Respiratory Care Therapy, Seattle Children’s Hospital, Seattle, WA 98105, USA
- Center for Respiratory Biology and Therapeutics, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (C.N.C.); (R.J.E.); (M.K.)
| | - Coral N. Crandall
- Center for Respiratory Biology and Therapeutics, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (C.N.C.); (R.J.E.); (M.K.)
- Quality and Clinical Effectiveness, Seattle Children’s Hospital, Seattle, WA 98105, USA
- Center for Clinical and Translational Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Rebecca J. Engberg
- Center for Respiratory Biology and Therapeutics, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (C.N.C.); (R.J.E.); (M.K.)
- Center for Clinical and Translational Research, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Kunal Bijlani
- Mechanical Engineering, Zewski Corporation, Magnolia, TX 77354, USA;
| | - Dolena Ledee
- Division of Cardiology, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA;
| | - Masaki Kajimoto
- Center for Respiratory Biology and Therapeutics, Seattle Children’s Research Institute, Seattle, WA 98101, USA; (C.N.C.); (R.J.E.); (M.K.)
| | - Frans J. Walther
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA;
- Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
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Dankhara N, Holla I, Ramarao S, Kalikkot Thekkeveedu R. Bronchopulmonary Dysplasia: Pathogenesis and Pathophysiology. J Clin Med 2023; 12:4207. [PMID: 37445242 DOI: 10.3390/jcm12134207] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
Bronchopulmonary dysplasia (BPD), also known as chronic lung disease, is the most common respiratory morbidity in preterm infants. "Old" or "classic" BPD, as per the original description, is less common now. "New BPD", which presents with distinct clinical and pathological features, is more frequently observed in the current era of advanced neonatal care, where extremely premature infants are surviving because of medical advancements. The pathogenesis of BPD is complex and multifactorial and involves both genetic and environmental factors. This review provides an overview of the pathology of BPD and discusses the influence of several prenatal and postnatal factors on its pathogenesis, such as maternal factors, genetic susceptibility, ventilator-associated lung injury, oxygen toxicity, sepsis, patent ductus arteriosus (PDA), and nutritional deficiencies. This in-depth review draws on existing literature to explore these factors and their potential contribution to the development of BPD.
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Affiliation(s)
- Nilesh Dankhara
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Ira Holla
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Sumana Ramarao
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Kalikkot Thekkeveedu R, El-Saie A, Prakash V, Katakam L, Shivanna B. Ventilation-Induced Lung Injury (VILI) in Neonates: Evidence-Based Concepts and Lung-Protective Strategies. J Clin Med 2022; 11:jcm11030557. [PMID: 35160009 PMCID: PMC8836835 DOI: 10.3390/jcm11030557] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/05/2022] [Accepted: 01/19/2022] [Indexed: 02/04/2023] Open
Abstract
Supportive care with mechanical ventilation continues to be an essential strategy for managing severe neonatal respiratory failure; however, it is well known to cause and accentuate neonatal lung injury. The pathogenesis of ventilator-induced lung injury (VILI) is multifactorial and complex, resulting predominantly from interactions between ventilator-related factors and patient-related factors. Importantly, VILI is a significant risk factor for developing bronchopulmonary dysplasia (BPD), the most common chronic respiratory morbidity of preterm infants that lacks specific therapies, causes life-long morbidities, and imposes psychosocial and economic burdens. Studies of older children and adults suggest that understanding how and why VILI occurs is essential to developing strategies for mitigating VILI and its consequences. This article reviews the preclinical and clinical evidence on the pathogenesis and pathophysiology of VILI in neonates. We also highlight the evidence behind various lung-protective strategies to guide clinicians in preventing and attenuating VILI and, by extension, BPD in neonates. Further, we provide a snapshot of future directions that may help minimize neonatal VILI.
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Affiliation(s)
| | - Ahmed El-Saie
- Section of Neonatology, Department of Pediatrics, Children’s Mercy Hospital, Kansas City, MO 64106, USA;
- Department of Pediatrics, Cairo University, Cairo 11956, Egypt
| | - Varsha Prakash
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA;
| | - Lakshmi Katakam
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Binoy Shivanna
- Section of Neonatology, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA;
- Correspondence: ; Tel.: +832-824-6474; Fax: +832-825-3204
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Abstract
Mechanical ventilation can be life-saving for the premature infant, but is often injurious to immature and underdeveloped lungs. Lung injury is caused by atelectrauma, oxygen toxicity, and volutrauma. Lung protection must include appropriate lung recruitment starting in the delivery suite and throughout mechanical ventilation. Strategies include open lung ventilation, positive end-expiratory pressure, and volume-targeted ventilation. Respiratory function monitoring, such as capnography and ventilator graphics, provides clinicians with continuous real-time information and an adjunct to optimize lung-protective ventilatory strategies. Further research is needed to assess which lung-protective strategies result in a decrease in long-term respiratory morbidity.
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Tidal volume measurements in the delivery room in preterm infants requiring positive pressure ventilation via endotracheal tube-feasibility study. J Perinatol 2021; 41:1930-1935. [PMID: 34112962 PMCID: PMC8191447 DOI: 10.1038/s41372-021-01113-7] [Citation(s) in RCA: 3] [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: 02/08/2021] [Revised: 05/05/2021] [Accepted: 05/18/2021] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Current delivery room (DR) resuscitation utilizes pressure-limited devices without tidal volume (TV) measurements. Clinicians use chest expansion as a surrogate, which is a poor indicator of TV. TV in early life can be highly variable due to rapidly changing lung compliance. Our objectives were to assess feasibility of measuring TV in DR, and to report the generated TV in intubated patients. STUDY DESIGN Prospective, observational, feasibility study in infants <32 weeks GA and intubated in DR. TV was measured using a respiratory function monitor. RESULT Ten infants with mean GA 23.9(±1.5) weeks and mean BW 618.5(±155) gram were included. Total of 178 min (mean 17.8 min/patient) with 8175 individual breaths (mean 817.5 breaths/patient) were analyzed. Goal TV of 4-6 ml/kg was provided 23.5% of times with high TV (>6 ml/kg) provided 47.7% of times. CONCLUSION TV measurement in DR is feasible. It is associated with high intra and inter-patient variability.
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Aziz K, Lee HC, Escobedo MB, Hoover AV, Kamath-Rayne BD, Kapadia VS, Magid DJ, Niermeyer S, Schmölzer GM, Szyld E, Weiner GM, Wyckoff MH, Yamada NK, Zaichkin J. Part 5: Neonatal Resuscitation: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2020; 142:S524-S550. [DOI: 10.1161/cir.0000000000000902] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Hillman NH, Kothe TB, Schmidt AF, Kemp MW, Royse E, Fee E, Salomone F, Clarke MW, Musk GC, Jobe AH. Surfactant plus budesonide decreases lung and systemic responses to injurious ventilation in preterm sheep. Am J Physiol Lung Cell Mol Physiol 2020; 318:L41-L48. [PMID: 31617728 PMCID: PMC6985873 DOI: 10.1152/ajplung.00203.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 09/09/2019] [Accepted: 09/30/2019] [Indexed: 11/22/2022] Open
Abstract
Mechanical ventilation from birth with normal tidal volumes (VT) causes lung injury and systemic responses in preterm sheep. The addition of budesonide to surfactant therapy decreases these injury markers. Budesonide and surfactant will decrease the injury from injurious VT ventilation in preterm sheep. Lambs at 126 ± 1 day gestational age were ventilated from birth with either: 1) Normal VT [surfactant 200 mg/kg before ventilation, positive end expiratory pressure (PEEP) 5 cmH2O, VT 8 mL/kg] or 2) Injury VT (high pressure, 100% oxygen, no PEEP) for 15 min, then further randomized to surfactant + saline or surfactant + 0.25 mg/kg budesonide with Normal VT for 6 h. Lung function and lung, liver, and brain tissues were evaluated for indicators of injury. Injury VT + saline caused significant injury and systemic responses, and Injury VT + budesonide improved lung physiology. Budesonide decreased lung inflammation and decreased pro-inflammatory cytokine mRNA in the lung, liver, and brain to levels similar to Normal VT + saline. Budesonide was present in plasma within 15 min of treatment in both ventilation groups, and less than 5% of the budesonide remained in the lung at 6 h. mRNA sequencing of liver and periventricular white matter demonstrated multiple pathways altered by both Injury VT and budesonide and the combination exposure. In lambs receiving Injury VT, the addition of budesonide to surfactant improved lung physiology and decreased pro-inflammatory cytokine responses in the lung, liver, and brain to levels similar to lambs receiving Normal VT.
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Affiliation(s)
- Noah H Hillman
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, St. Louis, Missouri
| | - T Brett Kothe
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, St. Louis, Missouri
| | - Augusto F Schmidt
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Matthew W Kemp
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
| | - Emily Royse
- Division of Neonatology, Cardinal Glennon Children's Hospital, Saint Louis University, St. Louis, Missouri
| | - Erin Fee
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
| | - Fabrizio Salomone
- Department of Preclinical Pharmacology R&D, Chiesi Farmaceutici S.p.A, Parma, Italy
| | - Michael W Clarke
- Metabolomics Australia, Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia, Australia
| | - Gabrielle C Musk
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
- Animal Care Services, University of Western Australia, Perth, Western Australia, Australia
| | - Alan H Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
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Prediction of prolonged ventilator dependence in preterm infants. Eur J Pediatr 2019; 178:1063-1068. [PMID: 31076842 DOI: 10.1007/s00431-019-03394-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/18/2019] [Accepted: 04/26/2019] [Indexed: 10/26/2022]
Abstract
Volutrauma is an important factor in the pathogenesis of bronchopulmonary dysplasia (BPD). Our aims were to identify risk factors in the first 24 h for prolonged ventilator dependence and assess volume delivery and carbon dioxide levels in infants with evolving BPD. A retrospective study was undertaken of 41 infants born at less than 32 weeks of gestational age (GA). A higher tidal volume, minute volume and resistance and a lower GA, birth weight and compliance were associated with a significantly higher risk of ventilator dependence at 28 days. The strongest relationships were with birth weight (area under the receiver operating characteristic curve, AUROC = 0.771) and GA (AUROC = 0.813). Tidal volume remained significantly higher after adjusting for GA in those who remained ventilator dependent at 28 days. The 18 who remained ventilator dependent at 28 days had increased mean carbon dioxide (PCO2) levels with increasing age from a mean of 41 mmHg in the first 24 h to 65 mmHg at 28 days PMA (p < 0.001). The increase in PCO2 occurred despite increases in peak inflation pressures (p < 0.001), tidal volumes (p = 0.002) and minute volumes (p < 0.001).Conclusion: These results suggest that initial volutrauma may contribute to the development of chronic ventilator dependence. What is Known: • In prematurely born infants, excessive tidal volumes are important in the pathogenesis of bronchopulmonary dysplasia (BPD), but a tidal volume that is too low will increase the risk of atelectasis, work of breathing and energy expenditure. What is New: • A high tidal volume in the first 24 h was associated with an increased risk of ventilator dependence at 28 days, which remained significant after adjusting for gestational age. Carbon dioxide levels significantly increased over the first month despite increased pressures and volumes in those who remained ventilator dependent.
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Mian Q, Cheung PY, O'Reilly M, Barton SK, Polglase GR, Schmölzer GM. Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room. Arch Dis Child Fetal Neonatal Ed 2019; 104:F57-F62. [PMID: 29353261 DOI: 10.1136/archdischild-2017-313864] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 11/04/2022]
Abstract
BACKGROUND AND OBJECTIVES Delivery of inadvertent high tidal volume (VT) during positive pressure ventilation (PPV) in the delivery room is common. High VT delivery during PPV has been associated with haemodynamic brain injury in animal models. We examined if VT delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks' gestation. METHODS A flow-sensor was placed between the mask and the ventilation device. VT values were compared with recently described reference ranges for VT in spontaneously breathing preterm infants at birth. Infants were divided into two groups: VT<6 mL/kg or VT>6 mL/kg (normal and high VT, respectively). Brain injury (eg, intraventricular haemorrhage (IVH)) was assessed using routine ultrasound imaging within the first days after birth. RESULTS A total of 165 preterm infants were included, 124 (75%) had high VT and 41 (25%) normal VT. The mean (SD) gestational age and birth weight in high and normal VT group was similar, 26 (2) and 26 (1) weeks, 858 (251) g and 915 (250) g, respectively. IVH in the high VT group was diagnosed in 63 (51%) infants compared with 5 (13%) infants in the normal VT group (P=0.008).Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the high VT group and 2/41 (6%) in the normal VT group (P=0.01). CONCLUSIONS High VT delivery during mask PPV at birth was associated with brain injury. Strategies to limit VT delivery during mask PPV should be used to prevent high VT delivery.
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Affiliation(s)
- Qaasim Mian
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Po-Yin Cheung
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Megan O'Reilly
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Georg M Schmölzer
- Centre for the Studies of Asphyxia and Resuscitation, Royal Alexandra Hospital, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
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Takatori F, Inoue S, Togo S, Yamamori S. Development of respiratory function monitor for neonates. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:3719-3722. [PMID: 29060706 DOI: 10.1109/embc.2017.8037665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Approximately, 10 million babies do not breathe immediately at birth and some of them require positive pressure ventilation. However, inappropriate and excessive tidal volume delivery could lead to lung injury in neonatal patients. We developed a respiratory function monitor which can monitor mask leak, expiratory tidal volume, respiratory rate, peak inspiratory pressure, and end-tidal CO2 on a real-time basis. A neonatal flow sensor was specially designed and was integrated with a small mainstream capnometer, cap-ONE. Usability was enhanced by using a tablet for the display of the monitored parameters. The basic performance evaluation using a neonatal training test lung shows that the respiratory function monitor effectively detects mask leak. The system may help healthcare providers to efficiently support neonatal patients start breathing.
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Morini F, Capolupo I, van Weteringen W, Reiss I. Ventilation modalities in infants with congenital diaphragmatic hernia. Semin Pediatr Surg 2017. [PMID: 28641754 DOI: 10.1053/j.sempedsurg.2017.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neonates with congenital diaphragmatic hernia are among the more complex patients to support with mechanical ventilation. They have particular features that add to the difficulties already present in the neonatal patient. A ventilation strategy tailored to the patient's underlying physiology rather than mode of ventilation is a crucial issue for clinicians treating these delicate patients.
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Affiliation(s)
- Francesco Morini
- Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - Irma Capolupo
- Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Willem van Weteringen
- Department of Pediatric Surgery, Erasmus Medical Centre-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Irwin Reiss
- Division of Neonatology, Department of Pediatrics, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
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Ricci F, Catozzi C, Murgia X, Rosa B, Amidani D, Lorenzini L, Bianco F, Rivetti C, Catinella S, Villetti G, Civelli M, Pioselli B, Dani C, Salomone F. Physiological, Biochemical, and Biophysical Characterization of the Lung-Lavaged Spontaneously-Breathing Rabbit as a Model for Respiratory Distress Syndrome. PLoS One 2017; 12:e0169190. [PMID: 28060859 PMCID: PMC5217971 DOI: 10.1371/journal.pone.0169190] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 12/13/2016] [Indexed: 12/01/2022] Open
Abstract
Nasal continuous positive airway pressure (nCPAP) is a widely accepted technique of non-invasive respiratory support in spontaneously-breathing premature infants with respiratory distress syndrome (RDS). Surfactant administration techniques compatible with nCPAP ventilation strategy are actively investigated. Our aim is to set up and validate a respiratory distress animal model that can be managed on nCPAP suitable for surfactant administration techniques studies. Surfactant depletion was induced by bronchoalveolar lavages (BALs) on 18 adult rabbits. Full depletion was assessed by surfactant component analysis on the BALs samples. Animals were randomized into two groups: Control group (nCPAP only) and InSurE group, consisting of a bolus of surfactant (Poractant alfa, 200 mg/kg) followed by nCPAP. Arterial blood gases were monitored until animal sacrifice, 3 hours post treatment. Lung mechanics were evaluated just before and after BALs, at the time of treatment, and at the end of the procedure. Surfactant phospholipids and protein analysis as well as surface tension measurements on sequential BALs confirmed the efficacy of the surfactant depletion procedure. The InSurE group showed a significant improvement of blood oxygenation and lung mechanics. On the contrary, no signs of recovery were appreciated in animals treated with just nCPAP. The surfactant-depleted adult rabbit RDS model proved to be a valuable and efficient preclinical tool for mimicking the clinical scenario of preterm infants affected by mild/moderate RDS who spontaneously breathe and do not require mechanical ventilation. This population is of particular interest as potential target for the non-invasive administration of surfactant.
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Affiliation(s)
| | | | - Xabier Murgia
- Department of Drug Delivery, Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken, Germany
| | - Brenda Rosa
- Chiesi Farmaceutici, R&D Department, Parma, Italy
| | - Davide Amidani
- Department of Life Sciences, University of Parma, Parma, Italy
| | | | | | - Claudio Rivetti
- Department of Life Sciences, University of Parma, Parma, Italy
| | | | | | | | | | - Carlo Dani
- Department of Neurosciences, Psychology, Drug Research and Child Health, Careggi University Hospital of Florence, Florence, Italy
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Allison BJ, Hooper SB, Coia E, Zahra VA, Jenkin G, Malhotra A, Sehgal A, Kluckow M, Gill AW, Sozo F, Miller SL, Polglase GR. Ventilation-induced lung injury is not exacerbated by growth restriction in preterm lambs. Am J Physiol Lung Cell Mol Physiol 2016; 310:L213-23. [DOI: 10.1152/ajplung.00328.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022] Open
Abstract
Intrauterine growth restriction (IUGR) and preterm birth are frequent comorbidities and, combined, increase the risk of adverse respiratory outcomes compared with that in appropriately grown (AG) infants. Potential underlying reasons for this increased respiratory morbidity in IUGR infants compared with AG infants include altered fetal lung development, fetal lung inflammation, increased respiratory requirements, and/or increased ventilation-induced lung injury. IUGR was surgically induced in preterm fetal sheep (0.7 gestation) by ligation of a single umbilical artery. Four weeks later, preterm lambs were euthanized at delivery or delivered and ventilated for 2 h before euthanasia. Ventilator requirements, lung inflammation, early markers of lung injury, and morphological changes in lung parenchymal and vascular structure and surfactant composition were analyzed. IUGR preterm lambs weighed 30% less than AG preterm lambs, with increased brain-to-body weight ratio, indicating brain sparing. IUGR did not induce lung inflammation or injury or alter lung parenchymal and vascular structure compared with AG fetuses. IUGR and AG lambs had similar oxygenation and respiratory requirements after birth and had significant, but similar, increases in proinflammatory cytokine expression, lung injury markers, gene expression, and surfactant phosphatidylcholine species compared with unventilated controls. IUGR does not induce pulmonary structural changes in our model. Furthermore, IUGR and AG preterm lambs have similar ventilator requirements in the immediate postnatal period. This study suggests that increased morbidity and mortality in IUGR infants is not due to altered lung tissue or vascular structure, or to an altered response to early ventilation.
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Affiliation(s)
- Beth J. Allison
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Stuart B. Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Elise Coia
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Valerie A. Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Graham Jenkin
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Atul Malhotra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Monash Newborn, Monash Medical Centre, and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
| | - Arvind Sehgal
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Monash Newborn, Monash Medical Centre, and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
| | - Martin Kluckow
- Department of Neonatology, Royal North Shore Hospital and University of Sydney, Sydney, New South Wales, Australia
| | - Andrew W. Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Western Australia, Australia; and
| | - Foula Sozo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Suzanne L. Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria, Australia
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15
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Jobe AH. Animal Models, Learning Lessons to Prevent and Treat Neonatal Chronic Lung Disease. Front Med (Lausanne) 2015; 2:49. [PMID: 26301222 PMCID: PMC4528292 DOI: 10.3389/fmed.2015.00049] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/14/2015] [Indexed: 11/23/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a unique injury syndrome caused by prolonged injury and repair imposed on an immature and developing lung. The decreased septation and decreased microvascular development phenotype of BPD can be reproduced in newborn rodents with increased chronic oxygen exposure and in premature primates and sheep with oxygen and/or mechanical ventilation. The inflammation caused by oxidants, inflammatory agonists, and/or stretch injury from mechanical ventilation seems to promote the anatomic abnormalities. Multiple interventions targeted to specific inflammatory cells or pathways or targeted to decreasing ventilation-mediated injury can substantially prevent the anatomic changes associated with BPD in term rodents and in preterm sheep or primate models. Most of the anti-inflammatory therapies with benefit in animal models have not been tested clinically. None of the interventions that have been tested clinically are as effective as anticipated from the animal models. These inconsistencies in responses likely are explained by the antenatal differences in lung exposures of the developing animals relative to very preterm humans. The animals generally have normal lungs while the lungs of preterm infants are exposed variably to intrauterine inflammation, growth abnormalities, antenatal corticosteroids, and poorly understood effects from the causes of preterm delivery. The animal models have been essential for the definition of the mediators that can cause a BPD phenotype. These models will be necessary to develop and test future-targeted interventions to prevent and treat BPD.
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Affiliation(s)
- Alan H Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati , Cincinnati, OH , USA
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16
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Evaluation of respiratory function monitoring at the resuscitation of prematurely born infants. Eur J Pediatr 2015; 174:205-8. [PMID: 25029987 DOI: 10.1007/s00431-014-2379-2] [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: 05/15/2014] [Revised: 07/01/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED Our aim was to determine whether neonatal trainees found respiratory function monitoring (RFM) helpful during the resuscitation of prematurely born infants, what decisions they made on the basis of RFM and whether those decisions were evidence based. Fifty one trainees completed an electronic questionnaire. Eighty-three percent found the tidal volume display useful, 59 % altered the inflation pressure based on the tidal volume: 52 % considered 5 ml/kg adequate; 33 % 4 ml/kg; 13 % 6 ml/kg; and 2 % 7 ml/kg, despite no evidence on which to decide was the optimum tidal volume. If there was no detectable expired carbon dioxide (CO2), 30 trainees said they would reintubate, yet the absence of expired CO2 can indicate inadequate vasodilation of the pulmonary circulation rather than inappropriate placement of the endotracheal tube. If there was no chest wall expansion, but expired CO2, a third of junior trainees would reintubate which is inappropriate. If the oxygen saturation (SaO2) was <85 % at 1 min, no senior trainee, but 50 % of junior trainees would increase the inspired oxygen. The majority of healthy babies have an SaO2 > 85 % by 1 min. CONCLUSIONS The usefulness of respiratory function monitoring for trainees during neonatal resuscitation is often not evidence based.
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17
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Rimensberger PC. Surfactant. PEDIATRIC AND NEONATAL MECHANICAL VENTILATION 2015. [PMCID: PMC7175631 DOI: 10.1007/978-3-642-01219-8_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Exogenous pulmonary surfactant, widely used in neonatal care, is one of the best-studied treatments in neonatology, and its introduction in the 1990s led to a significant improvement in neonatal outcomes in preterm infants, including a decrease in mortality. This chapter provides an overview of surfactant composition and function in health and disease and summarizes the evidence for its clinical use.
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Affiliation(s)
- Peter C. Rimensberger
- Service of Neonatology and Pediatric Intensive Care, Department of Pediatrics, University Hospital of Geneva, Geneve, Switzerland
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18
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Setting the Ventilator in the NICU. PEDIATRIC AND NEONATAL MECHANICAL VENTILATION 2015. [PMCID: PMC7122498 DOI: 10.1007/978-3-642-01219-8_42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Success in providing respiratory support to the neonate requires a clear understanding of the context in which it is being applied. Perhaps more than for any other age group, the array of different situations in which ventilation is applied to the newborn infant is extremely broad, with in each case different pathophysiological disturbances and often the need to use a specific approach to apply ventilation optimally. Table 42.1 provides a list of the more common situations in which conventional ventilation is used in the neonate and includes some considerations regarding ventilator settings for each situation. For each situation, a suggested mode of ventilation is indicated, along with target ranges for positive end-expiratory pressure (PEEP) and tidal volume (VT). Further discussion of the physiological rationale and available evidence for ventilator settings is set out below.
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19
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Barton SK, Tolcos M, Miller SL, Roehr CC, Schmölzer GM, Davis PG, Moss TJM, LaRosa DA, Hooper SB, Polglase GR. Unraveling the Links Between the Initiation of Ventilation and Brain Injury in Preterm Infants. Front Pediatr 2015; 3:97. [PMID: 26618148 PMCID: PMC4639621 DOI: 10.3389/fped.2015.00097] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/26/2015] [Indexed: 11/13/2022] Open
Abstract
The initiation of ventilation in the delivery room is one of the most important but least controlled interventions a preterm infant will face. Tidal volumes (V T) used in the neonatal intensive care unit are carefully measured and adjusted. However, the V Ts that an infant receives during resuscitation are usually unmonitored and highly variable. Inappropriate V Ts delivered to preterm infants during respiratory support substantially increase the risk of injury and inflammation to the lungs and brain. These may cause cerebral blood flow instability and initiate a cerebral inflammatory cascade. The two pathways increase the risk of brain injury and potential life-long adverse neurodevelopmental outcomes. The employment of new technologies, including respiratory function monitors, can improve and guide the optimal delivery of V Ts and reduce confounders, such as leak. Better respiratory support in the delivery room has the potential to improve both respiratory and neurological outcomes in this vulnerable population.
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Affiliation(s)
- Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia
| | - Mary Tolcos
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Suzie L Miller
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Charles C Roehr
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Newborn Services, John Radcliffe Hospital, Oxford University Hospitals , Oxford , UK
| | - Georg M Schmölzer
- Department of Pediatrics, University of Alberta , Edmonton, AB , Canada ; Centre for the Study of Asphyxia and Resuscitation, Neonatal Research Unit, Royal Alexandra Hospital, Alberta Health Services , Edmonton, AB , Canada
| | - Peter G Davis
- Neonatal Services, Newborn Research Centre, The Royal Women's Hospital , Melbourne, VIC , Australia
| | - Timothy J M Moss
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Domenic A LaRosa
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research , Melbourne, VIC , Australia ; Department of Obstetrics and Gynecology, Monash University , Melbourne, VIC , Australia
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20
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Hillman NH, Kemp MW, Miura Y, Kallapur SG, Jobe AH. Sustained inflation at birth did not alter lung injury from mechanical ventilation in surfactant-treated fetal lambs. PLoS One 2014; 9:e113473. [PMID: 25419969 PMCID: PMC4242618 DOI: 10.1371/journal.pone.0113473] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/23/2014] [Indexed: 01/10/2023] Open
Abstract
Background Sustained inflations (SI) are used with the initiation of ventilation at birth to rapidly recruit functional residual capacity and may decrease lung injury and the need for mechanical ventilation in preterm infants. However, a 20 second SI in surfactant-deficient preterm lambs caused an acute phase injury response without decreasing lung injury from subsequent mechanical ventilation. Hypothesis A 20 second SI at birth will decrease lung injury from mechanical ventilation in surfactant-treated preterm fetal lambs. Methods The head and chest of fetal sheep at 126±1 day GA were exteriorized, with tracheostomy and removal of fetal lung fluid prior to treatment with surfactant (300 mg in 15 ml saline). Fetal lambs were randomized to one of four 15 minute interventions: 1) PEEP 8 cmH2O; 2) 20 sec SI at 40 cmH2O, then PEEP 8 cmH2O; 3) mechanical ventilation with 7 ml/kg tidal volume; or 4) 20 sec SI then mechanical ventilation at 7 ml/kg. Fetal lambs remained on placental support for the intervention and for 30 min after the intervention. Results SI recruited a mean volume of 6.8±0.8 mL/kg. SI did not alter respiratory physiology during mechanical ventilation. Heat shock protein (HSP) 70, HSP60, and total protein in lung fluid similarly increased in both ventilation groups. Modest pro-inflammatory cytokine and acute phase responses, with or without SI, were similar with ventilation. SI alone did not increase markers of injury. Conclusion In surfactant treated fetal lambs, a 20 sec SI did not alter ventilation physiology or markers of lung injury from mechanical ventilation.
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Affiliation(s)
- Noah H. Hillman
- Division of Neonatology, Cardinal Glennon Children's Medical Center, Saint Louis University, Saint Louis, Missouri, United States of America
- * E-mail:
| | - Matthew W. Kemp
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
| | - Yuichiro Miura
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
| | - Suhas G. Kallapur
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
| | - Alan H. Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
- School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia
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21
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Polglase GR, Barton SK, Melville JM, Zahra V, Wallace MJ, Siew ML, Tolcos M, Moss TJM. Prophylactic erythropoietin exacerbates ventilation-induced lung inflammation and injury in preterm lambs. J Physiol 2014; 592:1993-2002. [PMID: 24591575 DOI: 10.1113/jphysiol.2013.270348] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Ventilation-induced lung injury (VILI) of preterm neonates probably contributes to the pathogenesis of bronchopulmonary dysplasia (BPD). Erythropoietin (EPO) has been suggested as a therapy for BPD. The aim of this study was to determine whether prophylactic administration of EPO reduces VILI in preterm newborn lambs. Lambs at 126 days of gestation (term is 147 days) were delivered and ventilated with a high tidal volume strategy for 15 min to cause lung injury, then received gentle ventilation until 2 h of age. Lambs were randomized to receive intravenous EPO (5000 IU kg(-1): Vent+EPO; n = 6) or phosphate-buffered saline (Vent; n = 7) soon after birth: unventilated controls (UVC; n = 8) did not receive ventilation or any treatment. Physiological parameters were recorded throughout the experimental procedure. Samples of lung were collected for histological and molecular assessment of inflammation and injury. Samples of liver were collected to assess the systemic acute phase response. Vent+EPO lambs received higher F IO 2, P aO 2 and oxygenation during the first 10 min than Vent lambs. There were no differences in physiological indices beyond this time. Total lung injury score, airway wall thickness, inflammation and haemorrhage were higher in Vent+EPO lambs than in Vent lambs. Lung inflammation and early markers of lung and systemic injury were elevated in ventilated lambs relative to unventilated lambs; EPO administration further increased lung inflammation and markers of lung and systemic injury. Prophylactic EPO exacerbates VILI, which may increase the incidence and severity of long-term respiratory disease. More studies are required before EPO can be used for lung protection in preterm infants.
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Affiliation(s)
- Graeme R Polglase
- Ritchie Centre, Monash Institute of Medical Research, PO Box 5418, Clayton, Victoria, 3168, Australia.
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22
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Lall A, Prendergast M, Greenough A. Risk factors for the development of bronchopulmonary dysplasia: the role of antenatal infection and inflammation. Expert Rev Respir Med 2014; 1:247-54. [DOI: 10.1586/17476348.1.2.247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Abstract
This article describes the gas exchange abnormalities occurring in the acute respiratory distress syndrome seen in adults and children and in the respiratory distress syndrome that occurs in neonates. Evidence is presented indicating that the major gas exchange abnormality accounting for the hypoxemia in both conditions is shunt, and that approximately 50% of patients also have lungs regions in which low ventilation-to-perfusion ratios contribute to the venous admixture. The various mechanisms by which hypercarbia may develop and by which positive end-expiratory pressure improves gas exchange are reviewed, as are the effects of vascular tone and airway narrowing. The mechanisms by which surfactant abnormalities occur in the two conditions are described, as are the histological findings that have been associated with shunt and low ventilation-to-perfusion.
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Affiliation(s)
- Richard K Albert
- Chief of Medicine, Denver Health, Professor of Medicine, University of Colorado, Adjunct Professor of Engineering and Computer Science, University of Denver, Denver, Colorado, USA.
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24
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van Zyl JM, Smith J. Surfactant treatment before first breath for respiratory distress syndrome in preterm lambs: comparison of a peptide-containing synthetic lung surfactant with porcine-derived surfactant. Drug Des Devel Ther 2013; 7:905-16. [PMID: 24039400 PMCID: PMC3769412 DOI: 10.2147/dddt.s47270] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND In a recent study utilizing a saline-lavaged adult rabbit model, we described a significant improvement in systemic oxygenation and pulmonary shunt after the instillation of a novel synthetic peptide-containing surfactant, Synsurf. Respiratory distress syndrome in the preterm lamb more closely resembles that of the human infant, as their blood gas, pH values, and lung mechanics deteriorate dramatically from birth despite ventilator support. Moreover, premature lambs have lungs which are mechanically unstable, with the advantage of being able to measure multiple variables over extended periods. Our objective in this study was to investigate if Synsurf leads to improved systemic oxygenation, lung mechanics, and histology in comparison to the commercially available porcine-derived lung surfactant Curosurf® when administered before first breath in a preterm lamb model. MATERIALS AND METHODS A Cesarean section was performed under general anesthesia on 18 time-dated pregnant Dohne Merino ewes at 129-130 days gestation. The premature lambs were delivered and ventilated with an expiratory tidal volume of 6-8 mL/kg for the first 30 minutes and thereafter at 8-10 mL/kg. In a randomized controlled trial, the two surfactants tested were Synsurf and Curosurf®, both at a dose of 100 mg/kg phospholipids (1,2-dipalmitoyl-L-α-phosphatidylcholine; 90% in Synsurf, 40% in Curosurf®). A control group of animals was treated with normal saline. Measurements of physiological variables, blood gases, and lung mechanics were made before and after surfactant and saline replacement and at 15, 30, 45, 60, 90, 120, 180, 240 and 300 minutes after treatment. The study continued for 5 hours. RESULTS Surfactant treatment led to a significant improvement in oxygenation within 30 minutes, with the Synsurf group and the Curosurf® group having significantly higher ratios between arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2; P = 0.021) compared to that of the control (saline-treated) animals. Dynamic compliance improved in the three groups over time, with no intergroup differences. All of the surfactant-treated animals survived, and one in the saline group died before the study ended. Histology between groups was not different, showing mild-moderate injury patterns. DISCUSSION Treatment with surfactants before first breath clearly resulted in improved systemic oxygenation within 30 minutes of instillation. Both Synsurf- and Curosurf®-treated animals experienced similar and more sustained improvement in oxygenation and decreased calculated shunt compared to saline-treated animals.
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Affiliation(s)
- Johann M van Zyl
- Division of Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
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25
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Wheeler K, Wallace M, Kitchen M, Te Pas A, Fouras A, Islam M, Siew M, Lewis R, Morley C, Davis P, Hooper S. Establishing lung gas volumes at birth: interaction between positive end-expiratory pressures and tidal volumes in preterm rabbits. Pediatr Res 2013; 73:734-41. [PMID: 23478642 DOI: 10.1038/pr.2013.48] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND We investigated the effects of positive end-expiratory pressure (PEEP) and tidal volume (VT) on lung aeration, pulmonary mechanics, and the distribution of ventilation immediately after birth using a preterm rabbit model. METHODS Sixty preterm rabbits (27 d) received volume-targeted positive pressure ventilation from birth, with one of the 12 combinations of PEEP (0, 5, 8, or 10 cm H2O) and VT (4, 8, or 12 ml/kg). Outcomes included functional residual capacity (FRC), peak inflating pressure (PIP), dynamic compliance (Cd), and distribution of ventilation. RESULTS Increasing PEEP from 0 to 10 cm H2O increased FRC by 4 ml/kg, increased Cd by 0.2 ml/kg/cm H2O, and reduced PIP by 5 cm H2O. Increasing VT from 4 to 12 ml/kg increased FRC by 2 ml/kg, increased Cd by 0.3 ml/kg/cm H2O, and increased PIP by 4 cmH2O. No effect of VT on FRC occurred at 0 or 5 PEEP, and no effect of PEEP occurred at VT = 4 ml/kg. At 0 PEEP, increasing VT increased the proportion of gas entering the smaller apical regions, whereas at 10 PEEP, increasing VT increased the proportion of gas entering basal regions, from 47% to 63%. CONCLUSION Both PEEP and VT have independent, additive effects on FRC, lung mechanics, and the distribution of ventilation during the immediate newborn period.
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Affiliation(s)
- Kevin Wheeler
- The Ritchie Centre, Monash Institute for Medical Research, Monash University, Melbourne, Australia.
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26
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Failure of early nasal continuous positive airway pressure in preterm infants of 26 to 30 weeks gestation. J Perinatol 2013; 33:297-301. [PMID: 22935774 DOI: 10.1038/jp.2012.110] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To identify variables associated with early nasal continuous positive airway pressure (ENCPAP) failure in preterm neonates less than 30 weeks gestational age. STUDY DESIGN Multicenter prospective study including 131 preterm newborns, over a period of 2 years. Patients and respiratory variables were assessed using univariate analysis. RESULT Variables associated with ENCPAP failure were: the need of resuscitation with a FiO(2)>0.30; a CPAP pressure of 6.4±1.2 cm H(2)O; the need of a FiO(2) of 0.40 in the first 4 h of life; male gender maintaining the need of a FiO(2)>0.25 in the first 4 h of life; and respiratory distress syndrome with criteria for surfactant administration. CONCLUSION The need for oxygen in resuscitation and maintained in first hours of life, male gender, a CPAP pressure over 5 cm H(2)O and surfactant need are predictors of ENCPAP failure in preterm neonates 26 to 30 weeks gestational age.
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Bronchopulmonary dysplasia: a review. Arch Gynecol Obstet 2013; 288:325-33. [DOI: 10.1007/s00404-013-2753-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 02/04/2013] [Indexed: 10/27/2022]
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Abstract
BACKGROUND Preterm infants often receive mechanical ventilation and oxygen at birth. Exposure to large tidal volumes (V(T)s) at birth causes lung inflammation, and oxygen may amplify the injury. We hypothesized that normal V(T) ventilation at birth causes lung injury that is exacerbated by 95% oxygen. METHODS The head and chest of anesthetized preterm fetal sheep (129 ± 1 d gestation) were surgically exteriorized while maintaining the placental circulation. Fetuses were randomized to four groups with either V(T) ventilation to 6 ml/kg or continuous positive airway pressure of 5 cm H2O, and either 95%O2/5%CO2 or 95%N2/5%CO2. Age-matched fetuses were used as controls. After a 15-min intervention, the fetal lamb was returned to the uterus for 1 h 45 min. RESULTS In ventilated lambs, V(T) was 6.2 ± 0.4 ml/kg at 15 min. Ventilation increased proinflammatory cytokines as compared with controls and lambs on continuous positive airway pressure, with recruitment of primarily monocytes to bronchoalveolar lavage fluid. Early response protein 1 was activated around the bronchioles in V(T)-ventilated animals. The 15-min oxygen exposure did not change inflammatory mediators or other markers of lung and oxidative stress. CONCLUSION A V(T) of 6-7 ml/kg at birth increased early markers of injury and lung inflammation. Brief exposure to 95% oxygen did not alter lung inflammation.
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29
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O'Donnell CPF, Schmölzer GM. Resuscitation of preterm infants: delivery room interventions and their effect on outcomes. Clin Perinatol 2012; 39:857-69. [PMID: 23164183 DOI: 10.1016/j.clp.2012.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Despite advances in neonatal care, the rate of oxygen dependence at 36 weeks' postmenstrual age or bronchopulmonary dysplasia has not fallen. Neonatologists are increasingly careful to apply ventilation strategies that are gentle to the lung in the neonatal intensive care unit. However, there has not been the same emphasis applying gentle ventilation strategies immediately after birth. A lung-protective strategy should start immediately after birth to establish a functional residual capacity, reduce volutrauma and atelectotrauma, facilitate gas exchange, and improve oxygenation during neonatal transition. This article discusses techniques and equipment recommended by international resuscitation guidelines during breathing assistance in the delivery room.
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Affiliation(s)
- Colm P F O'Donnell
- Department of Neonatology, The National Maternity Hospital, Holles Street, Dublin 2, Ireland
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30
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Sato A, Ikegami M. SP-B and SP-C containing new synthetic surfactant for treatment of extremely immature lamb lung. PLoS One 2012; 7:e39392. [PMID: 22808033 PMCID: PMC3396642 DOI: 10.1371/journal.pone.0039392] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/23/2012] [Indexed: 11/19/2022] Open
Abstract
Although superiority of synthetic surfactant over animal-driven surfactant has been known, there is no synthetic surfactant commercially available at present. Many trials have been made to develop synthetic surfactant comparable in function to animal-driven surfactant. The efficacy of treatment with a new synthetic surfactant (CHF5633) containing dipalmitoylphosphatidylcholine, phosphatidylglycerol, SP-B analog, and SP-C analog was evaluated using immature newborn lamb model and compared with animal lung tissue-based surfactant Survanta. Lambs were treated with a clinical dose of 200 mg/kg CHF5633, 100 mg/kg Survanta, or air after 15 min initial ventilation. All the lambs treated with air died of respiratory distress within 90 min of age. During a 5 h study period, Pco(2) was maintained at 55 mmHg with 24 cmH(2)O peak inspiratory pressure for both groups. The preterm newborn lamb lung functions were dramatically improved by CHF5633 treatment. Slight, but significant superiority of CHF5633 over Survanta was demonstrated in tidal volume at 20 min and dynamic lung compliance at 20 and 300 min. The ultrastructure of CHF5633 was large with uniquely aggregated lipid particles. Increased uptake of CHF5633 by alveolar monocytes for catabolism was demonstrated by microphotograph, which might be associated with the higher treatment dose of CHF5633. The higher catabolism of CHF5633 was also suggested by the similar amount of surfactant lipid in bronchoalveolar lavage fluid (BALF) between CHF5633 and Survanta groups, despite the 2-fold higher treatment dose of CHF5633. Under the present ventilation protocol, lung inflammation was minimal for both groups, evaluated by inflammatory cell numbers in BALF and expression of IL-1β, IL-6, IL-8, and TNFα mRNA in the lung tissue. In conclusion, the new synthetic surfactant CHF5633 was effective in treating extremely immature newborn lambs with surfactant deficiency during the 5 h study period.
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Affiliation(s)
- Atsuyasu Sato
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Machiko Ikegami
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
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Schmölzer GM, Morley CJ, Wong C, Dawson JA, Kamlin COF, Donath SM, Hooper SB, Davis PG. Respiratory function monitor guidance of mask ventilation in the delivery room: a feasibility study. J Pediatr 2012; 160:377-381.e2. [PMID: 22056350 DOI: 10.1016/j.jpeds.2011.09.017] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/01/2011] [Accepted: 09/06/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE To investigate whether using a respiratory function monitor (RFM) during mask resuscitation of preterm infants reduces face mask leak and improves tidal volume (V(T)). STUDY DESIGN Infants receiving mask resuscitation were randomized to have the display of an RFM (airway pressure, flow, and V(T) waves) either visible or masked. RESULT Twenty-six infants had the RFM visible, and 23 had the RFM masked. The median mask leak was 37% (IQR, 21%-54%) in the visible RFM group and 54% (IQR, 37%-82%) in the masked RFM group (P = .01). Mask repositioning was done in 19 infants (73%) of the visible group and in 6 infants (26%) of the masked group (P = .001). The median expired V(T) was similar in the 2 groups. Oxygen was provided to 61% of the visible RFM group and 87% of the RFM masked group (P = .044). Continuous positive airway pressure use was greater in the visible RFM group (73% vs 43%; P = .035). Intubation in the delivery room was done in 21% of the visible group and in 57% of the masked group (P = .035). CONCLUSION Using an RFM was associated with significantly less mask leak, more mask adjustments, and a lower rate of excessive V(T).
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Affiliation(s)
- Georg M Schmölzer
- Neonatal Services, The Royal Women's Hospital, Melbourne, Australia.
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Schmölzer GM, Kamlin COF, Dawson JA, Morley CJ, Davis PG. Tidal volume delivery during surfactant administration in the delivery room. Intensive Care Med 2011; 37:1833-9. [DOI: 10.1007/s00134-011-2366-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 07/04/2011] [Indexed: 11/24/2022]
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Hillman NH, Nitsos I, Berry C, Pillow JJ, Kallapur SG, Jobe AH. Positive end-expiratory pressure and surfactant decrease lung injury during initiation of ventilation in fetal sheep. Am J Physiol Lung Cell Mol Physiol 2011; 301:L712-20. [PMID: 21856815 DOI: 10.1152/ajplung.00157.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The initiation of ventilation in preterm, surfactant-deficient sheep without positive end-expiratory pressure (PEEP) causes airway injury and lung inflammation. We hypothesized that PEEP and surfactant treatment would decrease the lung injury from initiation of ventilation with high tidal volumes. Fetal sheep at 128-day gestational age were randomized to ventilation with: 1) no PEEP, no surfactant; 2) 8-cmH(2)O PEEP, no surfactant; 3) no PEEP + surfactant; 4) 8-cmH(2)O PEEP + surfactant; or 5) control (2-cmH(2)O continuous positive airway pressure) (n = 6-7/group). After maternal anesthesia and hysterotomy, the head and chest were exteriorized, and the fetus was intubated. While maintaining placental circulation, the fetus was ventilated for 15 min with a tidal volume escalating to 15 ml/kg using heated, humidified, 100% nitrogen. The fetus then was returned to the uterus, and tissue was collected after 30 min for evaluation of early markers of lung injury. Lambs receiving both surfactant and PEEP had increased dynamic compliance, increased static lung volumes, and decreased total protein and heat shock proteins 70 and 60 in bronchoalveolar lavage fluid compared with other groups. Ventilation, independent of PEEP or surfactant, increased mRNA expression of acute phase response genes and proinflammatory cytokine mRNA in the lung tissue compared with controls. PEEP decreased mRNA for cytokines (2-fold) compared with groups receiving no PEEP. Surfactant administration further decreased some cytokine mRNAs and changed the distribution of early growth response protein-1 expression. The use of PEEP during initiation of ventilation at birth decreased early mediators of lung injury. Surfactant administration changed the distribution of injury and had a moderate additive protective effect.
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Affiliation(s)
- Noah H Hillman
- Cincinnati Children's Hospital Medical Center, Division of Pulmonary Biology, 3333 Burnet Ave., Cincinnati, OH 45229-3039, USA.
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de Caen A, Singhal N. A summary of the changes in paediatric and neonatal resuscitation guidelines from the International Liaison Committee on Resuscitation document. Paediatr Child Health 2011; 11:11-3. [PMID: 19030234 DOI: 10.1093/pch/11.1.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Allan de Caen
- Division of Pediatric Critical Care, Department of Pediatrics, University of Alberta, Edmonton
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Abstract
Fetal to neonatal transition poses an extraordinary challenge for the extremely low birth weight (ELBW) neonate. Indeed a significant number of ELBW neonates will need proactive resuscitation to achieve postnatal stabilization. Positive pressure ventilation and oxygenation are the most relevant interventions in the delivery room (DR). Oxygen needs during resuscitation still represent a conundrum for neonatologists. While hyperoxemia favors oxidative stress and subsequent organ injury, hypoxemia is associated with long-term neurodevelopmental impairment. It has been shown that ELBW neonates can be successfully resuscitated with lower concentrations of oxygen as had been done traditionally. Moreover, reducing oxygen load has resulted in achievement of arterial partial pressures of oxygen at admission closer to the physiologic range, less oxidative stress and less inflammation. The availability of reference ranges for arterial oxygen saturation (SpO(2)) for ELBW neonates in the first 10 min after birth has been an extraordinary step forward in our ability to individually titrate oxygen needs thus avoiding the risks of both hypo- and hyperoxemia. The optimal fraction of inspired oxygen (FiO(2)) to initiate resuscitation and the safest SpO(2) percentiles for ELBW neonates during the first minutes of life are still unknown and will need further research in the future. Until then, optimal ventilation at birth and individually tailoring FiO(2) according to the nomogram seem to be the most reasonable and safe approach.
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Affiliation(s)
- Máximo Vento
- Health Research Institute, Hospital La Fe, Division of Neonatology, University and Polytechnic Hospital La Fe, Valencia, Spain.
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Abstract
Ventilator-induced lung injury (VILI) is considered an important risk factor in the development of bronchopulmonary dysplasia (BPD) and is primarily caused by overdistension (volutrauma) and repetitive opening and collapse (atelectrauma) of terminal lung units. Lung-protective ventilation should therefore aim to reduce tidal volumes, and recruit and stabilize atelectatic lung units (open lung ventilation strategy). This review will summarize the available evidence on lung-protective ventilation in neonatology, discussing both high-frequency ventilation (HFV) and positive pressure ventilation (PPV). It shows that HFV does not appear to have a clear benefit over PPV, although most studies failed to apply a true open lung ventilation strategy during HFV. The evidence on the optimal tidal volume, positive end-expiratory pressure and the role for lung recruitment during lung-protective PPV is extremely limited. Volume-targeted ventilation seems to be a promising mode in terms of lung protection, but more studies are needed. Due to the lack of convincing evidence, lung-protective ventilation and modes seem to be implemented in daily clinical practice at a slow pace.
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Affiliation(s)
- Anton van Kaam
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
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van Kaam AH, Rimensberger PC, Borensztajn D, De Jaegere AP. Ventilation practices in the neonatal intensive care unit: a cross-sectional study. J Pediatr 2010; 157:767-71.e1-3. [PMID: 20619854 DOI: 10.1016/j.jpeds.2010.05.043] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 04/30/2010] [Accepted: 05/25/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To assess current ventilation practices in newborn infants. STUDY DESIGN We conducted a 2-point cross-sectional study in 173 European neonatal intensive care units, including 535 infants (mean gestational age 28 weeks and birth weight 1024 g). Patient characteristics, ventilator settings, and measurements were collected bedside from endotracheally ventilated infants. RESULTS A total of 457 (85%) patients were conventionally ventilated. Time cycled pressure-limited ventilation was used in 59% of these patients, most often combined with synchronized intermittent mandatory ventilation (51%). Newer conventional ventilation modes like volume targeted and pressure support ventilation were used in, respectively, 9% and 7% of the patients. The mean tidal volume, measured in 84% of the conventionally ventilated patients, was 5.7 ± 2.3 ml/kg. The mean positive end-expiratory pressure was 4.5 ± 1.1 cmH(2)O and rarely exceeded 7 cmH(2)O. CONCLUSIONS Time cycled pressure-limited ventilation is the most commonly used mode in neonatal ventilation. Tidal volumes are usually targeted between 4 to 7 mL/kg and positive end-expiratory pressure between 4 to 6 cmH(2)O. Newer ventilation modes are only used in a minority of patients.
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Affiliation(s)
- Anton H van Kaam
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, the Netherlands
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Hillman NH, Kallapur SG, Pillow JJ, Nitsos I, Polglase GR, Ikegami M, Jobe AH. Inhibitors of inflammation and endogenous surfactant pool size as modulators of lung injury with initiation of ventilation in preterm sheep. Respir Res 2010; 11:151. [PMID: 21034485 PMCID: PMC2978154 DOI: 10.1186/1465-9921-11-151] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 10/29/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increased pro-inflammatory cytokines in tracheal aspirates correlate with the development of BPD in preterm infants. Ventilation of preterm lambs increases pro-inflammatory cytokines and causes lung inflammation. OBJECTIVE We tested the hypothesis that selective inhibitors of pro-inflammatory signaling would decrease lung inflammation induced by ventilation in preterm newborn lambs. We also examined if the variability in injury response was explained by variations in the endogenous surfactant pool size. METHODS Date-mated preterm lambs (n = 28) were operatively delivered and mechanically ventilated to cause lung injury (tidal volume escalation to 15 mL/kg by 15 min at age). The lambs then were ventilated with 8 mL/kg tidal volume for 1 h 45 min. Groups of animals randomly received specific inhibitors for IL-8, IL-1, or NF-κB. Unventilated lambs (n = 7) were the controls. Bronchoalveolar lavage fluid (BALF) and lung samples were used to quantify inflammation. Saturated phosphatidylcholine (Sat PC) was measured in BALF fluid and the data were stratified based on a level of 5 μmol/kg (~8 mg/kg surfactant). RESULTS The inhibitors did not decrease the cytokine levels or inflammatory response. The inflammation increased as Sat PC pool size in BALF decreased. Ventilated lambs with a Sat PC level > 5 μmol/kg had significantly decreased markers of injury and lung inflammation compared with those lambs with < 5 μmol/kg. CONCLUSION Lung injury caused by high tidal volumes at birth were decreased when endogenous surfactant pool sizes were larger. Attempts to decrease inflammation by blocking IL-8, IL-1 or NF-κB were unsuccessful.
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Affiliation(s)
- Noah H Hillman
- Cincinnati Children's Hospital Medical Center, Division of Pulmonary Biology, Cincinnati, OH 45236, USA.
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Establishing gas exchange and improving oxygenation in the delivery room management of the lung. Adv Neonatal Care 2010; 10:256-60. [PMID: 20838076 DOI: 10.1097/anc.0b013e3181f0836d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
One of the components of promoting good outcomes in high-risk neonates is supporting normal gas exchange while avoiding lung injury. Respiratory care in the first hour following birth plays an important role in stabilizing the infant with respiratory problems. The goal of this article is to review the causes of lung injury that can occur in the first hour and that could be prevented with careful respiratory support.
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Schmölzer GM, Morley CJ, Davis PG. Respiratory function monitoring to reduce mortality and morbidity in newborn infants receiving resuscitation. Cochrane Database Syst Rev 2010:CD008437. [PMID: 20824878 DOI: 10.1002/14651858.cd008437.pub2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND A respiratory function monitor is routinely used in neonatal intensive care units to continuously measure and display airway pressures, tidal volume and leak during ventilation. During positive pressure ventilation in the delivery room, clinical signs are used to monitor the effectiveness of ventilation. The additional use of a respiratory function monitor during positive pressure ventilation in the delivery room might help to improve the effectiveness of ventilation. OBJECTIVES To determine whether the use of a respiratory function monitor in addition to clinical assessment compared to clinical assessment alone in newborn infants resuscitated with positive pressure ventilation reduces mortality and morbidity. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2010), MEDLINE (January 1996 to March 2010), EMBASE (January 1980 to March 2010) and CINAHL (January 1982 to March 2010). Clinical trials registers and the abstracts of the Society for Pediatric Research and the European Society for Pediatric Research were searched from 2004 to 2009. No language restrictions were applied. SELECTION CRITERIA We planned to include randomised and quasi-randomised controlled trials and cluster trials that compared the use of a respiratory function monitor in addition to clinical assessment, compared to clinical assessment alone, in newborn infants resuscitated with positive pressure ventilation. DATA COLLECTION AND ANALYSIS Two review authors independently evaluated the search results against the selection criteria. Data extraction and risk of bias assessment were not performed because there were no studies that met our inclusion criteria. MAIN RESULTS No studies were found meeting the criteria for inclusion in this review AUTHORS' CONCLUSIONS There is insufficient evidence to determine the efficacy and safety of a respiratory function monitor in addition to clinical assessment during positive pressure ventilation at neonatal resuscitation. Randomised clinical trials comparing positive pressure ventilation with and without a respiratory function monitor in addition to clinical assessment at neonatal resuscitation are warranted.
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Affiliation(s)
- Georg M Schmölzer
- Department of Newborn Research, The Royal Women's Hospital, 20 Flemington Road, Parkville, Victoria, Australia, 3052
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Ball MK, Hillman NH, Kallapur SG, Polglase GR, Jobe AH, Pillow JJ. Body temperature effects on lung injury in ventilated preterm lambs. Resuscitation 2010; 81:749-54. [PMID: 20299144 DOI: 10.1016/j.resuscitation.2009.12.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 11/30/2009] [Accepted: 12/03/2009] [Indexed: 10/19/2022]
Abstract
AIMS Mechanical ventilation causes lung injury in premature infants. Hypothermia may protect against and hyperthermia may augment lung injury. We tested the effects of hypo- and hyperthermia on ventilation induced acute lung injury in preterm lambs. METHODS Twin sheep fetuses at 128 d GA (term 150 d) were surgically delivered and randomized to unventilated control (UVC), normothermia (38-39 degrees C) without lung injury (NTNI), or to 1 of 3 injurious ventilation groups: hypothermic (33-34 degrees C, LT), normothermic (38-39 degrees C, NT) or hyperthermic (40-41 degrees C, HT). NT, LT and HT groups had 15 min of injurious ventilation (PEEP 0 cmH(2)O, V(T) escalation to 15 mL/kg) following delivery and prior to surfactant. The animals were then gently ventilated (PEEP 5cmH(2)O, V(T) 7.5 mL/kg) for 2h 45 min. NTNI lambs received surfactant at birth prior to gentle ventilation. The lambs were then euthanized, and bronchoalveolar lavage (BAL) fluid and lung tissue were used to evaluate lung injury, inflammatory cell counts, inflammatory markers and cytokine mRNA. RESULTS Target temperatures were achieved by 15 min of age and maintained for 3h. All ventilated groups had increased BAL protein, lung inflammation and increased cytokine mRNA. HT animals developed acidosis, premature death, pneumothoraces, impaired lung function and increased inflammatory mRNA expression. LT animals remained clinically stable without pneumothoraces or death, had improved ventilatory efficiency and trended toward lower inflammatory mRNA expression than NT animals. CONCLUSION Hyperthermia exacerbated ventilator induced lung injury, while hypothermia may protect against lung injury in the preterm lamb.
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Affiliation(s)
- Molly K Ball
- Division of Perinatal Medicine, Northwestern University, Chicago, IL 60611, USA.
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Schmölzer GM, Morley CJ, Davis PG. Respiratory function monitoring to reduce mortality and morbidity in newborn infants receiving resuscitation. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2010. [DOI: 10.1002/14651858.cd008437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Sato A, Whitsett JA, Scheule RK, Ikegami M. Surfactant protein-d inhibits lung inflammation caused by ventilation in premature newborn lambs. Am J Respir Crit Care Med 2010; 181:1098-105. [PMID: 20133924 DOI: 10.1164/rccm.200912-1818oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Premature newborns frequently require manual ventilation for resuscitation during which lung injury occurs. Although surfactant protein (SP)-D regulates pulmonary inflammation, SP-D levels are low in the preterm lung. Commercial surfactants for treatment of respiratory distress syndrome do not contain SP-D. OBJECTIVES To determine whether addition of recombinant human SP-D (rhSP-D) to commercial surfactant influences lung inflammation in ventilated premature newborn lambs. METHODS Prematurely delivered lambs (130 d gestation age) were resuscitated with 100% O(2) and peak inspiratory pressure 40 cm H(2)O for 20 minutes and then treated with Survanta or Survanta containing rhSP-D. Ventilation was then changed to regulate tidal volume at 8 to 9 ml/kg. At 5 hours of age lambs were killed for sample collection. MEASUREMENTS AND MAIN RESULTS Sequential blood gas and tidal volume were similar in lambs treated with or without rhSP-D, indicating that lung immaturity and ventilatory stress used to support premature lambs were comparable between the two groups. Ventilation caused pulmonary inflammation in lambs treated with surfactant alone. In contrast, surfactant containing rhSP-D decreased neutrophil numbers in bronchoalveolar lavage fluid and decreased neutrophil elastase activity in lung tissue. IL-8 mRNA and IL-8 protein were significantly decreased in the +rhSP-D group lamb lungs, to 20% of those in controls. The addition of rhSP-D also rendered Survanta more resistant to plasma protein inhibition of surfactant function. CONCLUSIONS Treatment with rhSP-D-containing surfactant inhibited lung inflammation and enhanced the resistance of surfactant to inhibition, supporting its potential usefulness for prevention of lung injury in the preterm newborn.
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Affiliation(s)
- Atsuyasu Sato
- Cincinnati Children's Hospital Medical Center, Division of Pulmonary Biology, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA
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Ventre K, Haroon M, Davison C. WITHDRAWN. Surfactant therapy for bronchiolitis in critically ill infants. Cochrane Database Syst Rev 2010; 2010:CD005150. [PMID: 20091572 PMCID: PMC10641642 DOI: 10.1002/14651858.cd005150.pub3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Viral bronchiolitis is a common cause of respiratory failure in infants and children, and accounts for a significant portion of intensive care unit (ICU) admissions during seasonal epidemics. Currently there is no evidence to support the use of anything but supportive care for this disease. Surfactant is a potentially promising therapy; alterations in its composition have been described in bronchiolitis, and it may play a role in the host immunity for this disease. OBJECTIVES To assess the efficacy of exogenous surfactant for the treatment of bronchiolitis in mechanically ventilated infants and children. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2006, issue 1) which contains the Acute Respiratory Infections Group's Specialized Register; MEDLINE (1966 to Week 1, February 2006); and EMBASE (1990 to September 2005). SELECTION CRITERIA Randomised controlled trials (RCTs) comparing surfactant with placebo or surfactant with no surfactant in mechanically ventilated infants and children with viral bronchiolitis. DATA COLLECTION AND ANALYSIS Two authors independently extracted data and assessed trial quality. Unpublished data were requested from trial authors when necessary. MAIN RESULTS Three trials containing a total of 79 patients met the inclusion criteria. No mortality or adverse effects associated with surfactant administration were reported in any of these trials. In the three trials, use of surfactant was associated with a decrease in duration of mechanical ventilation by 2.6 days (95% confidence interval (CI) -5.34 to 0.18 days; P value 0.07) and a decrease in ICU length of stay by 3.3 days (95% CI -6.38 to -0.23 days; P value 0.04). In two studies with 59 patients, in which duration of mechanical ventilation in the control groups was more comparable, surfactant was associated with a decrease in ventilator days by 1.21 days (95% CI 0.75 to 1.67 days) and a decrease in ICU stay by 1.81 days (95% CI 1.19 days to 2.42 days). Individually the studies reported some short term benefit of surfactant on pulmonary mechanics and gas exchange. AUTHORS' CONCLUSIONS Available data on surfactant were not sufficient to provide reliable estimates of its effects in mechanically ventilated infants and children with bronchiolitis. Future studies should be adequately powered and will need to address unresolved questions regarding which surfactant preparation may be best suited for the treatment of bronchiolitis, the appropriate dose and administration interval, and how the choice of ventilator strategy may modify its effects.
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Affiliation(s)
- Kathleen Ventre
- Primary Children's Medical CenterDivision of Critical Care Medicine100 N. Medical DriveSalt Lake CityUtahUSA84113
| | - Munib Haroon
- NHS Leicester CityChildrens ServicesBridgepark PlazaBridgepark RoadThurmastonLeicesterUKLE4 8PQ
| | - Caroline Davison
- St George's HospitalDepartment of AnaestheticsTootingLondonUKSW17 0QT
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Schulzke SM, Polglase GR, Sozo F, Pillow JJ. Feasibility and short-term effects of biphasic positive airway pressure versus assist-control ventilation in preterm lambs. Pediatr Res 2009; 66:665-70. [PMID: 19690512 DOI: 10.1203/pdr.0b013e3181bc309d] [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] [Indexed: 11/06/2022]
Abstract
Biphasic positive airway pressure (BiLevel) ventilation allows utilization of two alternating positive end-expiratory pressures (PEEP) while permitting unrestricted spontaneous breathing with superimposed synchronized pressure support. We aimed to compare whether BiLevel versus assist-control (A-C) ventilation provides effective gas exchange and reduces severity of early lung injury in preterm lambs. Preterm lambs delivered at 134 d (term = 150 d) were quasirandomized to BiLevel (PEEP low/high 5/20 cm H2O) or A-C5 (PEEP 5 cm H2O) ventilation. Ventilation parameters and arterial blood gases were recorded at regular intervals. Postmortem measurements included pressure-volume relationship, lung inflammatory score, wet/dry body weight ratio, and messenger RNA (mRNA) expression of early markers of lung injury. There were no significant differences between groups in baseline characteristics, oxygenation index (p = 0.49), or partial pressure of carbon dioxide (Paco2) (p = 0.08). BiLevel group lambs showed improved pressure-volume relationship (p = 0.006), lower lung inflammatory score (p = 0.013), and trend toward lower messenger RNA expression of markers of lung injury compared with A-C5 group lambs. In unsedated preterm lambs, BiLevel ventilation provides gas exchange equivalent to A-C ventilation and potentially results in reduced lung injury.
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Affiliation(s)
- Sven M Schulzke
- School of Women's and Infant's Health, University of Western Australia, Crawley, Western Australia 6009, Australia.
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te Pas AB, Siew M, Wallace MJ, Kitchen MJ, Fouras A, Lewis RA, Yagi N, Uesugi K, Donath S, Davis PG, Morley CJ, Hooper SB. Establishing functional residual capacity at birth: the effect of sustained inflation and positive end-expiratory pressure in a preterm rabbit model. Pediatr Res 2009; 65:537-41. [PMID: 19190537 DOI: 10.1203/pdr.0b013e31819da21b] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effect of a 20 s sustained inflation (SI) and positive end-expiratory pressure (PEEP) on functional residual capacity (FRC) formation at birth were investigated. Preterm rabbit pups (28 d) were randomized at birth into four groups (n = 6 for each): 1) SI, PEEP 5 cm H2O, 2) no SI, PEEP 5 cm H2O, 3) no SI + no PEEP, 4) SI + no PEEP. FRC and tidal volume (Vt) were measured by plethysmography and uniformity of lung aeration by phase contrast x-ray imaging. Ventilation with a SI and PEEP uniformly aerated the lung and Vt and FRC were recruited by the first tidal inflation. Ventilation without a SI, with PEEP, gradually recruited Vt and FRC with each inflation but aeration was not uniform. Ventilation without a SI or PEEP, gradually recruited Vt, but no FRC. Ventilation with a SI, without PEEP, uniformly aerated the lung and recruited Vt but no FRC. FRC was greater with SI (p = 0.006) during the first minute, but was larger with PEEP than without PEEP throughout the first 7 min (p < 0.0005). Effects of PEEP and SI were additive. In ventilated preterm rabbits at birth, combining a SI and PEEP improved FRC formation and uniformity of lung aeration, but PEEP had the greatest influence.
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Affiliation(s)
- Arjan B te Pas
- Neonatal Services, Royal Women's Hospital, Melbourne, Victoria 3052, Australia.
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Wallace MJ, Probyn ME, Zahra VA, Crossley K, Cole TJ, Davis PG, Morley CJ, Hooper SB. Early biomarkers and potential mediators of ventilation-induced lung injury in very preterm lambs. Respir Res 2009; 10:19. [PMID: 19284536 PMCID: PMC2662809 DOI: 10.1186/1465-9921-10-19] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 03/10/2009] [Indexed: 12/24/2022] Open
Abstract
Background Bronchopulmonary dysplasia (BPD) is closely associated with ventilator-induced lung injury (VILI) in very preterm infants. The greatest risk of VILI may be in the immediate period after birth, when the lungs are surfactant deficient, still partially filled with liquid and not uniformly aerated. However, there have been very few studies that have examined this immediate post-birth period and identified the initial injury-related pathways that are activated. We aimed to determine if the early response genes; connective tissue growth factor (CTGF), cysteine rich-61 (CYR61) and early growth response 1 (EGR1), were rapidly induced by VILI in preterm lambs and whether ventilation with different tidal volumes caused different inflammatory cytokine and early response gene expression. Methods To identify early markers of VILI, preterm lambs (132 d gestational age; GA, term ~147 d) were resuscitated with an injurious ventilation strategy (VT 20 mL/kg for 15 min) then gently ventilated (5 mL/kg) for 15, 30, 60 or 120 min (n = 4 in each). To determine if early response genes and inflammatory cytokines were differentially regulated by different ventilation strategies, separate groups of preterm lambs (125 d GA; n = 5 in each) were ventilated from birth with a VT of 5 (VG5) or 10 mL/kg (VG10) for 135 minutes. Lung gene expression levels were compared to levels prior to ventilation in age-matched control fetuses. Results CTGF, CYR61 and EGR1 lung mRNA levels were increased ~25, 50 and 120-fold respectively (p < 0.05), within 30 minutes of injurious ventilation. VG5 and VG10 caused significant increases in CTGF, CYR61, EGR1, IL1-β, IL-6 and IL-8 mRNA levels compared to control levels. CTGF, CYR61, IL-6 and IL-8 expression levels were higher in VG10 than VG5 lambs; although only the IL-6 and CYR61 mRNA levels reached significance. Conclusion CTGF, CYR61 and EGR1 may be novel early markers of lung injury and mechanical ventilation from birth using relatively low tidal volumes may be less injurious than using higher tidal volumes.
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Affiliation(s)
- Megan J Wallace
- Department of Physiology, Monash University, Victoria, Australia.
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Polglase GR, Hillman NH, Ball MK, Kramer BW, Kallapur SG, Jobe AH, Pillow JJ. Lung and systemic inflammation in preterm lambs on continuous positive airway pressure or conventional ventilation. Pediatr Res 2009; 65:67-71. [PMID: 18704000 DOI: 10.1203/pdr.0b013e318189487e] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intratracheal lipopolysaccharide (LPS) causes acute inflammation and injurious mechanical ventilation results in pulmonary and systemic inflammation. We aimed to determine in preterm lungs if continuous positive airway pressure (CPAP) protects against pulmonary and systemic inflammation, compared with conventional mechanical ventilation (CMV) after intratracheal LPS. Preterm fetuses were exposed to maternal betamethasone and Epostane 36 h before delivery at 133 d gestational age (term = 150 d). Lambs were intubated and randomized to receive gentle CMV (tidal volume 8 mL/kg) or CPAP with 8 cm H2O pressure. Surfactant (10 mg/kg) mixed with 1 mg LPS or saline was instilled into the trachea at 15 min. Blood gas status, ventilation variables, and arterial pressures were recorded for 3 h. Static pressure-volume curves and lung and systemic inflammation were assessed postmortem. CPAP lambs had elevated Paco2 and minute ventilation compared with the CMV lambs. Cytokine mRNA was increased in the lungs and liver of CPAP and CMV lambs relative to unventilated controls. Intratracheal LPS amplified the cytokine mRNA responses of IL-1beta, IL-6, and IL-8 in the lung and liver. Blood neutrophils decreased similarly after LPS in CPAP and CMV groups. Cytokine markers of lung injury or the systemic response to intratracheal LPS were not decreased by CPAP relative to CMV, in preterm lambs
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Affiliation(s)
- Graeme R Polglase
- School of Women's and Infants' Health, The University of Western Australia, Perth, Western Australia 6009, Australia.
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O'Donnell CPF, Stenson BJ. Respiratory strategies for preterm infants at birth. Semin Fetal Neonatal Med 2008; 13:401-9. [PMID: 18515200 DOI: 10.1016/j.siny.2008.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Neonatologists treating extremely premature infants in the delivery room are faced with many dilemmas, not least how best to support their breathing. A balance must be struck between helping those infants who need it and not applying potentially harmful treatments to infants who might not need them. Crucial to this process is being able to identify infants who might benefit.
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