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Lim K, Cramer SJE, Te Pas AB, Gale TJ, Dargaville PA. Sensory stimulation for apnoea mitigation in preterm infants. Pediatr Res 2022; 92:637-646. [PMID: 34819656 DOI: 10.1038/s41390-021-01828-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/14/2021] [Accepted: 10/20/2021] [Indexed: 11/09/2022]
Abstract
Apnoea, a pause in respiration, is ubiquitous in preterm infants and are often associated with physiological instability, which may lead to longer-term adverse neurodevelopmental consequences. Despite current therapies aimed at reducing the apnoea burden, preterm infants continue to exhibit apnoeic events throughout their hospital admission. Bedside staff are frequently required to manually intervene with different forms of stimuli, with the aim of re-establishing respiratory cadence and minimizing the physiological impact of each apnoeic event. Such a reactive approach makes apnoea and its associated adverse consequences inevitable and places a heavy reliance on human intervention. Different approaches to improving apnoea management in preterm infants have been investigated, including the use of various sensory stimuli. Despite studies reporting sensory stimuli of various forms to have potential in reducing apnoea frequency, non-invasive intermittent positive pressure ventilation is the only automated stimulus currently used in the clinical setting for infants with persistent apnoeic events. We find that the development of automated closed-looped sensory stimulation systems for apnoea mitigation in preterm infants receiving non-invasive respiratory support is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form. IMPACT: This review examines the effects of various forms of sensory stimulation on apnoea mitigation in preterm infants, namely localized tactile, generalized kinesthetic, airway pressure, auditory, and olfactory stimulations. Amongst the 31 studies reviewed, each form of sensory stimulation showed some positive effects, although the findings were not definitive and comparative studies were lacking. We find that the development of automated closed-loop sensory stimulation systems for apnoea mitigation is warranted, including the possibility of stimulation being applied preventatively, and in a multi-modal form.
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Affiliation(s)
- Kathleen Lim
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Sophie J E Cramer
- Willem-Alexander Children's Hospital, Division of Neonatolog, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Arjan B Te Pas
- Willem-Alexander Children's Hospital, Division of Neonatolog, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Timothy J Gale
- School of Engineering, College of Science, Engineering and Technology, University of Tasmania, Hobart, TAS, Australia
| | - Peter A Dargaville
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia. .,Neonatal and Pediatric Intensive Care Unit, Department of Pediatrics, Royal Hobart Hospital, Hobart, TAS, Australia.
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2
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Gilfillan M, Bhandari V. Moving Bronchopulmonary Dysplasia Research from the Bedside to the Bench. Am J Physiol Lung Cell Mol Physiol 2022; 322:L804-L821. [PMID: 35437999 DOI: 10.1152/ajplung.00452.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although advances in the respiratory management of extremely preterm infants have led to improvements in survival, this progress has not yet extended to a reduction in the incidence of bronchopulmonary dysplasia (BPD). BPD is a complex multifactorial condition that primarily occurs due to disturbances in the regulation of normal pulmonary airspace and vascular development. Preterm birth and exposure to invasive mechanical ventilation also compromises large airway development, leading to significant morbidity and mortality. Although both predisposing and protective genetic and environmental factors have been frequently described in the clinical literature, these findings have had limited impact on the development of effective therapeutic strategies. This gap is likely because the molecular pathways that underlie these observations are yet not fully understood, limiting the ability of researchers to identify novel treatments that can preserve normal lung development and/or enhance cellular repair mechanisms. In this review article, we will outline various well-established clinical observations whilst identifying key knowledge gaps that need to be filled with carefully designed pre-clinical experiments. We will address these issues by discussing controversial topics in the pathophysiology, the pathology and the treatment of BPD, including an evaluation of existing animal models that have been used to answer important questions.
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Affiliation(s)
- Margaret Gilfillan
- Division of Neonatology, St. Christopher's Hospital for Children/Drexel University College of Medicine, Philadelphia, PA
| | - Vineet Bhandari
- Division of Neonatology, The Children's Regional Hospital at Cooper/Cooper Medical School of Rowan University, Camden, NJ
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3
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Walther FJ, Waring AJ, Otieno M, DiBlasi RM. Efficacy, dose-response, and aerosol delivery of dry powder synthetic lung surfactant treatment in surfactant-deficient rabbits and premature lambs. Respir Res 2022; 23:78. [PMID: 35379243 PMCID: PMC8978426 DOI: 10.1186/s12931-022-02007-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/21/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Dry powder (DP) synthetic lung surfactant may be an effective means of noninvasive delivery of surfactant therapy to premature infants supported with nasal continuous positive airway pressure (nCPAP) in low-resource settings. METHODS Four experimental DP surfactant formulations consisting of 70% of phospholipids (DPPC:POPG 7:3), 3% Super Mini-B (SMB) or its sulfur-free derivate B-YL as SP-B peptide mimic, 25% of lactose or trehalose as excipient, and 2% of NaCl were formulated using spray drying. In vitro surface activity was confirmed with captive bubble surfactometry. Surfactant particle size was determined with a cascade impactor and inhaled dose was quantified using a spontaneously breathing premature lamb lung model supported with CPAP. In vivo surfactant efficacy was demonstrated in three studies. First, oxygenation and lung compliance were monitored after intratracheal instillation of resuspended DP surfactant in intubated, ventilated, lavaged, surfactant-deficient juvenile rabbits. In dose-response studies, ventilated, lavaged, surfactant-deficient rabbits received 30, 60, 120 or 240 mg/kg of DP B-YL:Lactose or B-YL:Trehalose surfactant by aerosol delivery with a low flow aerosol chamber via their endotracheal tube. Noninvasive aerosolization of DP B-YL:Trehalose surfactant via nasal prongs was tested in spontaneous breathing premature lambs supported with nCPAP. Intratracheal administration of 200 mg/kg of Curosurf®, a liquid porcine surfactant, was used as a positive control. RESULTS Mass median aerosol diameter was 3.6 μm with a geometric standard deviation of 1.8. All four experimental surfactants demonstrated high surface efficacy of intratracheal instillation of a bolus of ~ 100 mg/kg of surfactant with improvement of oxygenation and lung compliance. In the dose-response studies, rabbits received incremental doses of DP B-YL:Lactose or B-YL:Trehalose surfactant intratracheally and showed an optimal response in oxygenation and lung function at a dose of 120-240 mg/kg. Aerosol delivery via nasal prongs of 1 or 2 doses of ~ 100 mg/kg of B-YL:Trehalose surfactant to premature lambs supported with nCPAP resulted in stabilization of spontaneous breathing and oxygenation and lung volumes comparable to the positive control. CONCLUSION These studies confirm the clinical potential of DP synthetic lung surfactant with B-YL peptide as a SP-B mimic to alleviate surfactant deficiency when delivered as a liquid bolus or as an aerosol.
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Affiliation(s)
- 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, 1124 W Carson Street, Torrance, CA, 90502-2006, USA.
| | - Alan J Waring
- Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, 1124 W Carson Street, Torrance, CA, 90502-2006, USA
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Monicah Otieno
- Department of Translational Discovery, Nonclinical Development, Bill & Melinda Gates Medical Research Institute, Cambridge, MA, 02139, USA
| | - Robert M DiBlasi
- Respiratory Therapy Department, Seattle Children's Hospital, Seattle, WA, 98105, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98101, USA
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4
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Bianco F, Salomone F, Milesi I, Murgia X, Bonelli S, Pasini E, Dellacà R, Ventura ML, Pillow J. Aerosol drug delivery to spontaneously-breathing preterm neonates: lessons learned. Respir Res 2021; 22:71. [PMID: 33637075 PMCID: PMC7908012 DOI: 10.1186/s12931-020-01585-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023] Open
Abstract
Delivery of medications to preterm neonates receiving non-invasive ventilation (NIV) represents one of the most challenging scenarios for aerosol medicine. This challenge is highlighted by the undersized anatomy and the complex (patho)physiological characteristics of the lungs in such infants. Key physiological restraints include low lung volumes, low compliance, and irregular respiratory rates, which significantly reduce lung deposition. Such factors are inherent to premature birth and thus can be regarded to as the intrinsic factors that affect lung deposition. However, there are a number of extrinsic factors that also impact lung deposition: such factors include the choice of aerosol generator and its configuration within the ventilation circuit, the drug formulation, the aerosol particle size distribution, the choice of NIV type, and the patient interface between the delivery system and the patient. Together, these extrinsic factors provide an opportunity to optimize the lung deposition of therapeutic aerosols and, ultimately, the efficacy of the therapy.In this review, we first provide a comprehensive characterization of both the intrinsic and extrinsic factors affecting lung deposition in premature infants, followed by a revision of the clinical attempts to deliver therapeutic aerosols to premature neonates during NIV, which are almost exclusively related to the non-invasive delivery of surfactant aerosols. In this review, we provide clues to the interpretation of existing experimental and clinical data on neonatal aerosol delivery and we also describe a frame of measurable variables and available tools, including in vitro and in vivo models, that should be considered when developing a drug for inhalation in this important but under-served patient population.
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Affiliation(s)
- Federico Bianco
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.P.A., 43122 Parma, Italy
| | - Fabrizio Salomone
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.P.A., 43122 Parma, Italy
| | - Ilaria Milesi
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.P.A., 43122 Parma, Italy
| | | | - Sauro Bonelli
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.P.A., 43122 Parma, Italy
| | - Elena Pasini
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.P.A., 43122 Parma, Italy
| | - Raffaele Dellacà
- TechRes Lab, Dipartimento Di Elettronica, Informazione E Bioingegneria (DEIB), Politecnico Di Milano University, Milano, Italy
| | | | - Jane Pillow
- School of Human Sciences, University of Western Australia, Perth, Australia
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5
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Gie AG, Hubble TR, Regin Y, Salaets T, Zamora M, Deprest J, Toelen J. A Systematic Review of the Influence of Continuous Positive Airway Pressure on Fetal and Newborn Animal Models: Suggestions to Improve Neonatal Respiratory Care. Neonatology 2021; 118:5-14. [PMID: 33091899 DOI: 10.1159/000511086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/23/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Prematurely born infants regularly develop respiratory distress syndrome and require assisted ventilation. Ventilation may injure the premature lung and increase the risk of bronchopulmonary dysplasia. Continuous positive airway pressure (CPAP), a form of noninvasive ventilation, is commonly used in modern neonatology. Limited clinical data are available on the acute and long-term effect of neonatal exposure to CPAP on the lung. Given the restricted clinical data, newborn animal models have been used to study the influence of CPAP on lung structure and function. The findings of animal studies can guide neonatal care and improve the use of CPAP. METHODS A systematic review of electronic databases (Medline, Embase, and Cinahl) was performed using the medical subject heading terms, "CPAP" or "continuous positive airway pressure" and "animals" and "newborn." Abstracts were screened for inclusion using predetermined eligibility criteria. RESULTS In total, 235 abstracts were identified and screened for inclusion. Of these, 21 papers were included. Large (N = 18) and small (N = 3) animal models investigated the effects of CPAP. Pulmonary outcomes included gas exchange, lung structure and function, surfactant metabolism, lung inflammation and injury, and the effect of intrapulmonary therapy. Compared to mechanical ventilation, CPAP improves lung function, evokes less lung injury, and does not disrupt alveolar development. Surfactant administration combined with CPAP further improves respiratory outcomes. Of concern are findings that CPAP may increase airway reactivity. DISCUSSION/CONCLUSION CPAP offers numerous advantages over mechanical ventilation for the immature lung. The combination of CPAP and exogenous surfactant administration offers further pulmonary benefit.
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Affiliation(s)
- Andre George Gie
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Talia Rose Hubble
- Medical Science Division, University of Oxford, Oxford, United Kingdom
| | - Yannick Regin
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Thomas Salaets
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Monica Zamora
- BCNatal, Fetal Medicine Research Center, Hospital Clinic and Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Jan Deprest
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium.,Institute for Woman's Health, University College London Hospital, London, United Kingdom
| | - Jaan Toelen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium,
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6
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Salaets T, Aertgeerts M, Gie A, Vignero J, de Winter D, Regin Y, Jimenez J, Vande Velde G, Allegaert K, Deprest J, Toelen J. Preterm birth impairs postnatal lung development in the neonatal rabbit model. Respir Res 2020; 21:59. [PMID: 32085773 PMCID: PMC7035772 DOI: 10.1186/s12931-020-1321-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 02/13/2020] [Indexed: 01/10/2023] Open
Abstract
Background Bronchopulmonary dysplasia continues to cause important respiratory morbidity throughout life, and new therapies are needed. The common denominator of all BPD cases is preterm birth, however most preclinical research in this area focusses on the effect of hyperoxia or mechanical ventilation. In this study we investigated if and how prematurity affects lung structure and function in neonatal rabbits. Methods Pups were delivered on either day 28 or day 31. For each gestational age a group of pups was harvested immediately after birth for lung morphometry and surfactant protein B and C quantification. All other pups were hand raised and harvested on day 4 for the term pups and day 7 for the preterm pups (same corrected age) for lung morphometry, lung function testing and qPCR. A subset of pups underwent microCT and dark field imaging on day 0, 2 and 4 for terms and on day 0, 3, 5 and 7 for preterms. Results Preterm pups assessed at birth depicted a more rudimentary lung structure (larger alveoli and thicker septations) and a lower expression of surfactant proteins in comparison to term pups. MicroCT and dark field imaging revealed delayed lung aeration in preterm pups, in comparison to term pups. Preterm birth led to smaller pups, with smaller lungs with a lower alveolar surface area on day 7/day 4. Furthermore, preterm birth affected lung function with increased tissue damping, tissue elastance and resistance and decreased dynamic compliance. Expression of vascular endothelial growth factor (VEGFA) was significantly decreased in preterm pups, however in the absence of structural vascular differences. Conclusions Preterm birth affects lung structure and function at birth, but also has persistent effects on the developing lung. This supports the use of a preterm animal model, such as the preterm rabbit, for preclinical research on BPD. Future research that focuses on the identification of pathways that are involved in in-utero lung development and disrupted by pre-term birth, could lead to novel therapeutic strategies for BPD.
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Affiliation(s)
- Thomas Salaets
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium.
| | - Margo Aertgeerts
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium
| | - André Gie
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium
| | - Janne Vignero
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Derek de Winter
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium
| | - Yannick Regin
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium
| | - Julio Jimenez
- Facultad de Medicina, Universidad del Desarollo, Clínica Alemana, Santiago de Chile, Chile
| | | | - Karel Allegaert
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Clinical Pharmacy, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Jan Deprest
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium.,Institute for Women's Health, University College London Hospital, London, UK
| | - Jaan Toelen
- Department of Development and Regeneration, KULeuven, Herestraat 49, 3000, Leuven, Belgium
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7
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Veneroni C, Dahl MJ, Lavizzari A, Dawson E, Rebentisch A, Studstill S, Bowen S, Albertine KH, Dellaca RL. Non-invasive measurements of respiratory system mechanical properties by the forced oscillation technique in spontaneously breathing, mixed-breed, normal term lambs from birth to five months of age. Physiol Meas 2019; 40:105007. [PMID: 31341100 DOI: 10.1088/1361-6579/ab3493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To provide a non-invasive approach to monitoring lung function in spontaneously breathing lambs, from birth to five months of life, by the forced oscillation technique (FOT). This report describes the experimental set-up, data processing, and identification of normal predicted values of resistance (Rrs) and reactance (Xrs) of the respiratory system, along with normal bronchodilator response for bronchial reversibility testing. APPROACH Rrs and Xrs at 5, 11, and 19 Hz were measured monthly for five months in 20 normal term lambs that breathed spontaneously. In seven lambs, repeated measurements also were made within the first month of life (at 3, 7, 14, and 21 d of life). We determined the repeatability and reproducibility of the measurements and characterized the relationship between lung mechanics and age, sex, and body dimensions, using regression analysis, and measured changes in lung mechanics in response to inhaled bronchodilator. MAIN RESULTS The measurements provided repeatable and reproducible data. Rrs decreased, whereas Xrs increased, with growth from birth through the first two months of life, after which no statistically significant differences were detected. We identified normal value equations for Rrs and Xrs and for each of the measured anthropometric variables. Respiratory system mechanics were not affected by the bronchodilator. SIGNIFICANCE The FOT provides reliable non-invasive measurement of respiratory system mechanics in spontaneously breathing term lambs from birth to five months of age. The methods and normal reference values defined in this study will facilitate testing of the pathophysiological consequences of preterm birth and prolonged respiratory support on respiratory system mechanics.
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Affiliation(s)
- Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milano, Italy. Co-first and co-last authors. Author to whom any correspondence should be addressed
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8
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Walther FJ, Gupta M, Lipp MM, Chan H, Krzewick J, Gordon LM, Waring AJ. Aerosol delivery of dry powder synthetic lung surfactant to surfactant-deficient rabbits and preterm lambs on non-invasive respiratory support. Gates Open Res 2019; 3:6. [PMID: 31131369 PMCID: PMC6480449 DOI: 10.12688/gatesopenres.12899.2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2019] [Indexed: 11/20/2022] Open
Abstract
Background: The development of synthetic lung surfactant for preterm infants has focused on peptide analogues of native surfactant proteins B and C (SP-B and SP-C). Non-invasive respiratory support with nasal continuous positive airway pressure (nCPAP) may benefit from synthetic surfactant for aerosol delivery. Methods: A total of three dry powder (DP) surfactants, consisting of phospholipids and the SP-B analogue Super Mini-B (SMB), and one negative control DP surfactant without SMB, were produced with the Acorda Therapeutics ARCUS® Pulmonary Dry Powder Technology. Structure of the DP surfactants was compared with FTIR spectroscopy, in vitro surface activity with captive bubble surfactometry, and in vivo activity in surfactant-deficient adult rabbits and preterm lambs. In the animal experiments, intratracheal (IT) aerosol delivery was compared with surfactant aerosolization during nCPAP support. Surfactant dosage was 100 mg/kg of lipids and aerosolization was performed using a low flow inhaler. Results: FTIR spectra of the three DP surfactants each showed secondary structures compatible with peptide folding as an α-helix hairpin, similar to that previously noted for surface-active SMB in other lipids. The DP surfactants with SMB demonstrated in vitro surface activity <1 mN/m. Oxygenation and lung function increased quickly after IT aerosolization of DP surfactant in both surfactant-deficient rabbits and preterm lambs, similar to improvements seen with clinical surfactant. The response to nCPAP aerosol delivery of DP surfactant was about 50% of IT aerosol delivery, but could be boosted with a second dose in the preterm lambs. Conclusions: Aerosol delivery of DP synthetic surfactant during non-invasive respiratory support with nCPAP significantly improved oxygenation and lung function in surfactant-deficient animals and this response could be enhanced by giving a second dose. Aerosol delivery of DP synthetic lung surfactant has potential for clinical applications.
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Affiliation(s)
- Frans J Walther
- Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, 90502, USA
| | - Monik Gupta
- Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, 90502, USA
| | - Michael M Lipp
- Acorda Therapeutics Inc., Chelsea, Massachusetts, 02150, USA
| | - Holly Chan
- Acorda Therapeutics Inc., Chelsea, Massachusetts, 02150, USA
| | - John Krzewick
- Acorda Therapeutics Inc., Chelsea, Massachusetts, 02150, USA
| | - Larry M Gordon
- Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, 90502, USA
| | - Alan J Waring
- Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, 90502, USA
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9
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Walther FJ, Gupta M, Lipp MM, Chan H, Krzewick J, Gordon LM, Waring AJ. Aerosol delivery of dry powder synthetic lung surfactant to surfactant-deficient rabbits and preterm lambs on non-invasive respiratory support. Gates Open Res 2019. [DOI: 10.12688/gatesopenres.12899.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: The development of synthetic lung surfactant for preterm infants has focused on peptide analogues of native surfactant proteins B and C (SP-B and SP-C). Non-invasive respiratory support with nasal continuous positive airway pressure (nCPAP) may benefit from synthetic surfactant for aerosol delivery. Methods: A total of three dry powder (DP) surfactants, consisting of phospholipids and the SP-B analogue Super Mini-B (SMB), and one negative control DP surfactant without SMB, were produced with the Acorda Therapeutics ARCUS® Pulmonary Dry Powder Technology. Structure of the DP surfactants was compared with FTIR spectroscopy, in vitro surface activity with captive bubble surfactometry, and in vivo activity in surfactant-deficient adult rabbits and preterm lambs. In the animal experiments, intratracheal (IT) aerosol delivery was compared with surfactant aerosolization during nCPAP support. Surfactant dosage was 100 mg/kg of lipids and aerosolization was performed using a low flow inhaler. Results: FTIR spectra of the three DP surfactants each showed secondary structures compatible with peptide folding as an α-helix hairpin, similar to that previously noted for surface-active SMB in other lipids. The DP surfactants with SMB demonstrated in vitro surface activity <1 mN/m. Oxygenation and lung function increased quickly after IT aerosolization of DP surfactant in both surfactant-deficient rabbits and preterm lambs, similar to improvements seen with clinical surfactant. The response to nCPAP aerosol delivery of DP surfactant was about 50% of IT aerosol delivery, but could be boosted with a second dose in the preterm lambs. Conclusions: Aerosol delivery of active DP synthetic surfactant during non-invasive respiratory support with nCPAP significantly improved oxygenation and lung function in surfactant-deficient animals and this response could be enhanced by giving a second dose. Aerosol delivery of DP synthetic lung surfactant has potential for clinical applications.
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10
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Chest Compressions in the Delivery Room. CHILDREN-BASEL 2019; 6:children6010004. [PMID: 30609872 PMCID: PMC6352088 DOI: 10.3390/children6010004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/18/2018] [Accepted: 12/26/2018] [Indexed: 12/23/2022]
Abstract
Annually, an estimated 13–26 million newborns need respiratory support and 2–3 million newborns need extensive resuscitation, defined as chest compression and 100% oxygen with or without epinephrine in the delivery room. Despite such care, there is a high incidence of mortality and neurologic morbidity. The poor prognosis associated with receiving chest compression alone or with medications in the delivery room raises questions as to whether improved cardiopulmonary resuscitation methods specifically tailored to the newborn could improve outcomes. This review discusses the current recommendations, mode of action, different compression to ventilation ratios, continuous chest compression with asynchronous ventilations, chest compression and sustained inflation optimal depth, and oxygen concentration during cardiopulmonary resuscitation.
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11
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Abstract
Bronchopulmonary dysplasia (BPD) continues to be one of the most common complications of preterm birth and is characterized histopathologically by impaired lung alveolarization. Extremely preterm born infants remain at high risk for the development of BPD, highlighting a pressing need for continued efforts to understand the pathomechanisms at play in affected infants. This brief review summarizes recent progress in our understanding of the how the development of the newborn lung is stunted, highlighting recent reports on roles for growth factor signaling, oxidative stress, inflammation, the extracellular matrix and proteolysis, non-coding RNA, and fibroblast and epithelial cell plasticity. Additionally, some concerns about modeling BPD in experimental animals are reviewed, as are new developments in the in vitro modeling of pathophysiological processes relevant to impaired lung alveolarization in BPD.
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Affiliation(s)
- Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.
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12
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Surate Solaligue DE, Rodríguez-Castillo JA, Ahlbrecht K, Morty RE. Recent advances in our understanding of the mechanisms of late lung development and bronchopulmonary dysplasia. Am J Physiol Lung Cell Mol Physiol 2017; 313:L1101-L1153. [PMID: 28971976 DOI: 10.1152/ajplung.00343.2017] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/21/2017] [Accepted: 09/23/2017] [Indexed: 02/08/2023] Open
Abstract
The objective of lung development is to generate an organ of gas exchange that provides both a thin gas diffusion barrier and a large gas diffusion surface area, which concomitantly generates a steep gas diffusion concentration gradient. As such, the lung is perfectly structured to undertake the function of gas exchange: a large number of small alveoli provide extensive surface area within the limited volume of the lung, and a delicate alveolo-capillary barrier brings circulating blood into close proximity to the inspired air. Efficient movement of inspired air and circulating blood through the conducting airways and conducting vessels, respectively, generates steep oxygen and carbon dioxide concentration gradients across the alveolo-capillary barrier, providing ideal conditions for effective diffusion of both gases during breathing. The development of the gas exchange apparatus of the lung occurs during the second phase of lung development-namely, late lung development-which includes the canalicular, saccular, and alveolar stages of lung development. It is during these stages of lung development that preterm-born infants are delivered, when the lung is not yet competent for effective gas exchange. These infants may develop bronchopulmonary dysplasia (BPD), a syndrome complicated by disturbances to the development of the alveoli and the pulmonary vasculature. It is the objective of this review to update the reader about recent developments that further our understanding of the mechanisms of lung alveolarization and vascularization and the pathogenesis of BPD and other neonatal lung diseases that feature lung hypoplasia.
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Affiliation(s)
- David E Surate Solaligue
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - José Alberto Rodríguez-Castillo
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Katrin Ahlbrecht
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and.,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Rory E Morty
- Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany; and .,Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
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Supraglottic Atomization of Surfactant in Spontaneously Breathing Lambs Receiving Continuous Positive Airway Pressure. Pediatr Crit Care Med 2017; 18:e428-e434. [PMID: 28742723 DOI: 10.1097/pcc.0000000000001267] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To determine the short-term tolerance, efficacy, and lung deposition of supraglottic atomized surfactant in spontaneously breathing lambs receiving continuous positive airway pressure. DESIGN Prospective, randomized animal study. SETTING Animal research laboratory. SUBJECTS Twenty-two preterm lambs on continuous positive airway pressure (132 ± 1 d gestational age). INTERVENTIONS Animals receiving continuous positive airway pressure via binasal prongs at 8 cm H2O were randomized to receive atomized surfactant at approximately 60-minute of life (atom; n = 15) or not (control; n = 7). The atom group received 200 mg/kg of poractant alfa (Curosurf; Chiesi Farmaceutici SpA, Parma, Italy) over 45 minutes via a novel atomizer located in the upper pharynx that synchronized surfactant delivery with the inspiratory phase. MEASUREMENTS AND MAIN RESULTS Arterial blood gas, regional distribution of tidal ventilation (electrical impedance tomography), and carotid blood flow were recorded every 15 minutes until 90 minutes after stabilizing on continuous positive airway pressure. Gas exchange, respiratory rate, and hemodynamic variables, including carotid blood flow, remained stable during surfactant treatment. There was a significant improvement in arterial alveolar ratio after surfactant delivery in the atom group (p < 0.05; Sidak posttests), while there was no difference in PaCO2. Electrical impedance tomography data showed a more uniform pattern of ventilation in the atom group. In the atom group, the median (interquartile range) deposition of surfactant in the lung was 32% (22-43%) of the delivered dose, with an even distribution between the right and the left lungs. CONCLUSIONS In our model of spontaneously breathing lambs receiving CPAP, supraglottic atomization of Curosurf via a novel device was safe, improved oxygenation and ventilation homogeneity compared with CPAP only, and provided a relatively large lung deposition suggesting clinical utility.
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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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