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Aladwani G, Momin MAM, Spence B, Farkas DR, Bonasera S, Hassan A, Hindle M, Longest W. Effects of different mesh nebulizer sources on the dispersion of powder formulations produced with a new small-particle spray dryer. Int J Pharm 2023; 642:123138. [PMID: 37307962 PMCID: PMC10527815 DOI: 10.1016/j.ijpharm.2023.123138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/14/2023]
Abstract
The objective of this study was to explore the aerosolization performance of powders produced with different mesh nebulizer sources in the initial design of a new small-particle spray dryer system. An aqueous excipient enhanced growth (EEG) model formulation was spray dried using different mesh sources and the resulting powders were characterized based on (i) laser diffraction, (ii) aerosolization with a new infant air-jet dry powder inhaler, and (iii) aerosol transport through an infant nose-throat (NT) model ending with a tracheal filter. While few differences were observed among the powders, the medical-grade Aerogen Solo (with custom holder) and Aerogen Pro mesh sources were selected as lead candidates that produced mean fine particle fractions <5 µm and <1 µm in ranges of 80.6-77.4% and 13.1-16.0%, respectively. Improved aerosolization performance was achieved at a lower spray drying temperature. Lung delivery efficiencies through the NT model were in the range of 42.5-45.8% for powders from the Aerogen mesh sources, which were very similar to previous results with a commercial spray dryer. Ultimately, a custom spray dryer that can accept meshes with different characteristics (e.g., pore sizes and liquid flow rates) will provide particle engineers greater flexibility in producing highly dispersible powders with unique characteristics.
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Affiliation(s)
- Ghali Aladwani
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Mohammad A M Momin
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Benjamin Spence
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Amr Hassan
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States; Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States.
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Poletto S, Trevisanuto D, Ramaswamy VV, Seni AHA, Ouedraogo P, Dellacà RL, Zannin E. Bubble CPAP respiratory support devices for infants in low-resource settings. Pediatr Pulmonol 2023; 58:643-652. [PMID: 36484311 DOI: 10.1002/ppul.26258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/18/2022] [Accepted: 11/25/2022] [Indexed: 12/14/2022]
Abstract
Approximately 46% of the 5.2 million annual under-5 deaths derive from neonatal conditions commonly associated with hypoxemia or acute respiratory distress. It has been estimated that 98% of these deaths occur in low- and middle-income countries (LMICs). Effective implementation of noninvasive respiratory support at all levels of healthcare could significantly reduce neonatal mortality. Several factors limit the widespread and effective implementation of noninvasive respiratory support in LMICs, including inadequate infrastructure, lack of proper instrumentation, shortage of skilled staff, costly disposables, and difficulties in the supply of consumables and spare parts. The aim of this state-of-the-art paper is to provide a detailed evaluation of the commercially available devices providing noninvasive respiratory support in LMICs, focusing on bubblecontinuous positive airway pressure (bCPAP). bCPAP might be administrated using a variety of different commercial devices, including devices specifically designed for LMICs, as well as using self-made systems. We described all the equipment required for safe and effective implementation of bCPAP, including air and oxygen sourced, pressure-reducing valves and flowmeters, air-oxygen blending systems, humidifiers, respiratory support devices, patient circuits, and airway interfaces. Specifically, we critically evaluated the advantages and disadvantages of various existing solutions within the context of low-resource settings.
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Affiliation(s)
- Sofia Poletto
- Technologies for Respiration Laboratory, Electronics, Information and Bioengineering Department (DEIB), Politecnico di Milano, Milan, Italy
| | | | | | | | | | - Raffaele L Dellacà
- Technologies for Respiration Laboratory, Electronics, Information and Bioengineering Department (DEIB), Politecnico di Milano, Milan, Italy
| | - Emanuela Zannin
- Neonatal Intesive Care Unit at Fondazione Monza e Brianza per il Bambino e la sua Mamma (MBBM), Monza, Italy
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Higher CPAP levels improve functional residual capacity at birth in preterm rabbits. Pediatr Res 2022; 91:1686-1694. [PMID: 34294868 DOI: 10.1038/s41390-021-01647-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/03/2021] [Accepted: 06/17/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Preterm infants are commonly supported with 4-8 cm H2O continuous positive airway pressures (CPAP), although higher CPAP levels may improve functional residual capacity (FRC). METHODS Preterm rabbits delivered at 29/32 days (~26-28 weeks human) gestation received 0, 5, 8, 12, 15 cm H2O of CPAP or variable CPAP of 15 to 5 or 15 to 8 cm H2O (decreasing ~2 cm H2O/min) for up to 10 min after birth. RESULTS FRC was lower in the 0 (6.8 (1.0-11.2) mL/kg) and 5 (10.1 (1.1-16.8) mL/kg) compared to the 15 (18.8 (10.9-22.4) mL/kg) cm H2O groups (p = 0.003). Fewer kittens achieved FRC > 15 mL/kg in the 0 (20%), compared to 8 (36%), 12 (60%) and 15 (73%) cm H2O groups (p = 0.008). While breathing rates were not different (p = 0.096), apnoea tended to occur more often with CPAP < 8 cm H2O (p = 0.185). CPAP belly and lung bulging rates were similar whereas pneumothoraces were rare. Lowering CPAP from 15 to 5, but not 15 to 8 cm H2O, decreased FRC and breathing rates. CONCLUSION In all, 15 cm H2O of CPAP improved lung aeration and reduced apnoea, but did not increase the risk of lung over-expansion, pneumothorax or CPAP belly immediately after birth. FRC and breathing rates were maintained when CPAP was decreased to 8 cm H2O. IMPACT Although preterm infants are commonly supported with 4-8 cm H2O CPAP at birth, preclinical studies have shown that higher PEEP levels improve lung aeration. In this study, CPAP levels of 15 cm H2O improved lung aeration and reduced apnoea in preterm rabbit kittens immediately after birth. In all, 15 cm H2O CPAP did not increase the risk of lung over-expansion (indicated by bulging between the ribs), pneumothorax, or CPAP belly. These results can be used when designing future studies on CPAP strategies for preterm infants in the delivery room.
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Bamat N, Fierro J, Mukerji A, Wright CJ, Millar D, Kirpalani H. Nasal continuous positive airway pressure levels for the prevention of morbidity and mortality in preterm infants. Cochrane Database Syst Rev 2021; 11:CD012778. [PMID: 34847243 PMCID: PMC8631577 DOI: 10.1002/14651858.cd012778.pub2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Preterm infants are at risk of lung atelectasis due to various anatomical and physiological immaturities, placing them at high risk of respiratory failure and associated harms. Nasal continuous positive airway pressure (CPAP) is a positive pressure applied to the airways via the nares. It helps prevent atelectasis and supports adequate gas exchange in spontaneously breathing infants. Nasal CPAP is used in the care of preterm infants around the world. Despite its common use, the appropriate pressure levels to apply during nasal CPAP use remain uncertain. OBJECTIVES To assess the effects of 'low' (≤ 5 cm H2O) versus 'moderate-high' (> 5 cm H2O) initial nasal CPAP pressure levels in preterm infants receiving CPAP either: 1) for initial respiratory support after birth and neonatal resuscitation or 2) following mechanical ventilation and endotracheal extubation. SEARCH METHODS We ran a comprehensive search on 6 November 2020 in the following databases: CENTRAL via CRS Web and MEDLINE via Ovid. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-randomized trials. SELECTION CRITERIA We included RCTs, quasi-RCTs, cluster-RCTs and cross-over RCTs randomizing preterm infants of gestational age < 37 weeks or birth weight < 2500 grams within the first 28 days of life to different nasal CPAP levels. DATA COLLECTION AND ANALYSIS We used the standard methods of Cochrane Neonatal to collect and analyze data. We used the GRADE approach to assess the certainty of the evidence for the prespecified primary outcomes. MAIN RESULTS Eleven trials met inclusion criteria of the review. Four trials were parallel-group RCTs reporting our prespecified primary or secondary outcomes. Two trials randomized 316 infants to low versus moderate-high nasal CPAP for initial respiratory support, and two trials randomized 117 infants to low versus moderate-high nasal CPAP following endotracheal extubation. The remaining seven studies were cross-over trials reporting short-term physiological outcomes. The most common potential sources of bias were absent or unclear blinding of personnel and assessors and uncertain selective reporting. Nasal CPAP for initial respiratory support after birth and neonatal resuscitation None of the six primary outcomes prespecified for inclusion in the summary of findings was eligible for meta-analysis. No trials reported on moderate-severe neurodevelopmental impairment at 18 to 26 months. The remaining five outcomes were reported in a single trial. On the basis of this trial, we are uncertain whether low or moderate-high nasal CPAP levels improve the outcomes of: death or bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (PMA) (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.56 to 1.85; 1 trial, 271 participants); mortality by hospital discharge (RR 1.04, 95% CI 0.51 to 2.12; 1 trial, 271 participants); BPD at 28 days of age (RR 1.10, 95% CI 0.56 to 2.17; 1 trial, 271 participants); BPD at 36 weeks' PMA (RR 0.80, 95% CI 0.25 to 2.57; 1 trial, 271 participants), and treatment failure or need for mechanical ventilation (RR 1.00, 95% CI 0.63 to 1.57; 1 trial, 271 participants). We assessed the certainty of the evidence as very low for all five outcomes due to risk of bias, a lack of consistency across multiple studies, and imprecise effect estimates. Nasal CPAP following mechanical ventilation and endotracheal extubation One of the six primary outcomes prespecified for inclusion in the summary of findings was eligible for meta-analysis. On the basis of these data, we are uncertain whether low or moderate-high nasal CPAP levels improve the outcome of treatment failure or need for mechanical ventilation (RR 1.52, 95% CI 0.92 to 2.50; 2 trials, 117 participants; I2 = 17%; risk difference 0.15, 95% CI -0.02 to 0.32; number needed to treat for an additional beneficial outcome 7, 95% CI -50 to 3). We assessed the certainty of the evidence as very low due to risk of bias, inconsistency across the studies, and imprecise effect estimates. No trials reported on moderate-severe neurodevelopmental impairment at 18 to 26 months or BPD at 28 days of age. The remaining three outcomes were reported in a single trial. On the basis of this trial, we are uncertain whether low or moderate-high nasal CPAP levels improve the outcomes of: death or BPD at 36 weeks' PMA (RR 0.87, 95% CI 0.51 to 1.49; 1 trial, 93 participants); mortality by hospital discharge (RR 2.94, 95% CI 0.12 to 70.30; 1 trial, 93 participants), and BPD at 36 weeks' PMA (RR 0.87, 95% CI 0.51 to 1.49; 1 trial, 93 participants). We assessed the certainty of the evidence as very low for all three outcomes due to risk of bias, a lack of consistency across multiple studies, and imprecise effect estimates. AUTHORS' CONCLUSIONS: There are insufficient data from randomized trials to guide nasal CPAP level selection in preterm infants, whether provided as initial respiratory support or following extubation from invasive mechanical ventilation. We are uncertain as to whether low or moderate-high nasal CPAP levels improve morbidity and mortality in preterm infants. Well-designed trials evaluating this important aspect of a commonly used neonatal therapy are needed.
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Affiliation(s)
- Nicolas Bamat
- Division of Neonatology and Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Julie Fierro
- Division of Pulmonary Medicine, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Amit Mukerji
- Paediatrics, McMaster University, Hamilton, Canada
| | - Clyde J Wright
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, Colorado, USA
| | - David Millar
- Regional Neonatal Intensive Care Unit, Royal Jubilee Maternity Service, Belfast, UK
| | - Haresh Kirpalani
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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Zannin E, Veneroni C, Dellacà RL, Corbetta R, Suki B, Tagliabue PE, Ventura ML. Effect of continuous positive airway pressure on breathing variability in early preterm lung disease. Pediatr Pulmonol 2018; 53:755-761. [PMID: 29687665 DOI: 10.1002/ppul.24017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/03/2018] [Indexed: 11/11/2022]
Abstract
OBJECTIVES In preterm infants, the application of nasal Continuous Positive Airway Pressure (nCPAP) improves lung function through several mechanisms and may interact with the control of breathing. Our aim was to evaluate the effect of increasing/decreasing nCPAP on gas exchange, breathing pattern, and its variability in preterm infants. METHODS Fifeteen infants with mild to moderate respiratory distress syndrome (RDS) were studied on the first day of life. Infants had a mean (SD) gestational age of 30 + 4 (3 + 4) weeks + day and body weight of 1405 (606) g. nCPAP was increased every 10 min stepwise (0-4-8-10 cmH2 O) and then decreased every 20 min (8-6-4-2 cmH2 O). At each step, vital parameters, oxygenation, and chest wall volume changes (optoelectronic plethysmography) were evaluated. Tidal volume (VT ), inter-breath interval (IBI), end-expiratory lung volume (EELV) changes, and other breathing pattern parameters were computed breath-by-breath. The correlation properties of VT , IBI, and EELV were quantified by detrended fluctuation analysis, computing the scaling exponent α. RESULTS During nCPAP, oxygenation improved and VT decreased significantly compared with no nCPAP. No significant changes in breathing pattern were observed between nCPAP levels. α of EELV was significantly higher off nCPAP than during nCPAP, suggesting that nCPAP helps stabilize EELV control mechanisms. CONCLUSIONS In our population of preterm infants with mild to moderate RDS, in the first day of life, nCPAP improved gas exchange, VT , and EELV stability independent of nCPAP level.
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Affiliation(s)
- Emanuela Zannin
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Chiara Veneroni
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | - Raffaele L Dellacà
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy
| | | | - Bela Suki
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
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Bhatia R, Davis PG, Tingay DG. Regional Volume Characteristics of the Preterm Infant Receiving First Intention Continuous Positive Airway Pressure. J Pediatr 2017; 187:80-88.e2. [PMID: 28545875 DOI: 10.1016/j.jpeds.2017.04.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/27/2017] [Accepted: 04/21/2017] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To determine whether applying nasal continuous positive airway pressure (CPAP) using systematic changes in continuous distending pressure (CDP) results in a quasi-static pressure-volume relationship in very preterm infants receiving first intention CPAP in the first 12-18 hours of life. STUDY DESIGN Twenty infants at <32 weeks' gestation with mild respiratory distress syndrome (RDS) managed exclusively with nasal CPAP had CDP increased from 5 to 8 to 10 cmH2O, and then decreased to 8 cmH2O and returned to baseline CDP. Each CDP was maintained for 20 min. At each CDP, relative impedance change in end-expiratory thoracic volume (ΔZEEV) and tidal volume (ΔZVT) were measured using electrical impedance tomography. Esophageal pressure (Poes) was measured as a proxy for intrapleural pressure to determine transpulmonary pressure (Ptp). RESULTS Overall, there was a relationship between Ptp and global ΔZEEV representing the pressure-volume relationship in the lungs. There were regional variations in ΔZEEV, with 13 infants exhibiting hysteresis with the greatest gains in EEV and tidal volume in the dependent lung with no hemodynamic compromise. Seven infants did not demonstrate hysteresis during decremental CDP changes. CONCLUSION It was possible to define a pressure-volume relationship of the lung and demonstrate reversal of atelectasis by systematically manipulating CDP in most very preterm infants with mild RDS. This suggests that CDP manipulation can be used to optimize the volume state of the preterm lung.
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Affiliation(s)
- Risha Bhatia
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia; Monash Newborn, Monash Children's Hospital, Melbourne, Australia.
| | - Peter G Davis
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia
| | - David G Tingay
- Newborn Research, The Royal Women's Hospital, Melbourne, Australia; Neonatal Research, Murdoch Childrens Research Institute, Melbourne, Australia; The University of Melbourne, Melbourne, Australia; Department of Neonatology, The Royal Children's Hospital, Melbourne, Australia
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Effect of time and body position on ventilation in premature infants. Pediatr Res 2016; 80:499-504. [PMID: 27331352 DOI: 10.1038/pr.2016.116] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 04/05/2016] [Indexed: 11/08/2022]
Abstract
BACKGROUND Infants with respiratory dysfunction undergo regular position changes to improve lung function however it is not known how often a position change should occur. This study measured changes in lung function occurring over time after repositioning in preterm infants. METHODS Changes in end-expiratory level (EEL) and ventilation distribution were measured 30 mins, 2 h, and 4 h after repositioning into either prone, quarter turn from prone, or supine using Electrical Impedance Tomography (EIT). Physiological measurements were also taken. RESULTS Sixty preterm infants were included in the study. Infants receiving respiratory support (mechanical ventilation or continuous positive airway pressure (CPAP)) had improved ventilation homogeneity after 2 h (P < 0.01), maintained at 4 h. Spontaneously breathing infants had improved homogeneity at 2 h (P < 0.01) and improved global EEL after 4 h (P < 0.01) whereas infants receiving CPAP demonstrated an improved global EEL at 2 h (P < 0.01). CONCLUSION Regional ventilation distribution is influenced by time independent of changes due to body position. Differences exist between infants on ventilatory support compared with those who are spontaneously breathing. Infants receiving ventilatory support have a physiological peak in lung function after 2 h which remains above baseline at 4 h. A change in body position facilitates an improvement in lung function in infants on ventilatory support.
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Abstract
Nasal continuous positive airway pressure (CPAP) is increasingly used for respiratory support in preterm babies at birth and after extubation from mechanical ventilation. Various CPAP devices are available for use that can be broadly grouped into continuous flow and variable flow. There are potential physiologic differences between these CPAP systems and the choice of a CPAP device is too often guided by individual expertise and experience rather than by evidence. When interpreting the evidence clinicians should take into account the pressure generation sources, nasal interface, and the factors affecting the delivery of pressure, such as mouth position and respiratory drive. With increasing use of these devices, better monitoring techniques are required to assess the efficacy and early recognition of babies who are failing and in need of escalated support.
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Liu L, Takahashi D, Qui H, Slutsky AS, Sinderby C, Beck J. Feasibility of neurally adjusted positive end-expiratory pressure in rabbits with early experimental lung injury. BMC Anesthesiol 2015; 15:124. [PMID: 26369672 PMCID: PMC4570554 DOI: 10.1186/s12871-015-0103-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 09/07/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During conventional Neurally Adjusted Ventilatory Assist (NAVA), the electrical activity of the diaphragm (EAdi) is used for triggering and cycling-off inspiratory assist, with a fixed PEEP (so called "Triggered Neurally Adjusted Ventilatory Assist" or "tNAVA"). However, significant post-inspiratory activity of the diaphragm can occur, believed to play a role in maintaining end-expiratory lung volume. Adjusting pressure continuously, in proportion to both inspiratory and expiratory EAdi (Continuous NAVA, or cNAVA), would not only offer inspiratory assist for tidal breathing, but also may aid in delivering a "neurally adjusted PEEP", and more specific breath-by-breath unloading. METHODS Nine adult New Zealand white rabbits were ventilated during independent conditions of: resistive loading (RES(1) or RES(2)), CO2 load (CO2) and acute lung injury (ALI), either via tracheotomy (INV) or non-invasively (NIV). There were a total of six conditions, applied in a non-randomized fashion: INV-RES(1), INV-CO2, NIV-CO2, NIV-RES(2), NIV-ALI, INV-ALI. For each condition, tNAVA was applied first (3 min), followed by 3 min of cNAVA. This comparison was repeated 3 times (repeated cross-over design). The NAVA level was always the same for both modes, but was newly titrated for each condition. PEEP was manually set to zero during tNAVA. During cNAVA, the assist during expiration was proportional to the EAdi. During all runs and conditions, ventilator-delivered pressure (Pvent), esophageal pressure (Pes), and diaphragm electrical activity (EAdi) were measured continuously. The tracings were analyzed breath-by-breath to obtain peak inspiratory and mean expiratory values. RESULTS For the same peak Pvent, the distribution of inspiratory and expiratory pressure differed between tNAVA and cNAVA. For each condition, the mean expiratory Pvent was always higher (for all conditions 4.0 ± 1.1 vs. 1.1 ± 0.5 cmH2O, P < 0.01) in cNAVA than in tNAVA. Relative to tNAVA, mean inspiratory EAdi was reduced on average (for all conditions) by 19 % (range 14 %-25 %), p < 0.05. Mean expiratory EAdi was also lower during cNAVA (during INV-RES(1), INV-CO2, INV-ALI, NIV-CO2 and NIV-ALI respectively, P < 0.05). The inspiratory Pes was reduced during cNAVA all 6 conditions (p < 0.05). Unlike tNAVA, during cNAVA the expiratory pressure was comparable with that predicted mathematically (mean difference of 0.2 ± 0.8 cmH2O). CONCLUSION Continuous NAVA was able to apply neurally adjusted PEEP, which led to a reduction in inspiratory effort compared to triggered NAVA.
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Affiliation(s)
- Ling Liu
- Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Daijiro Takahashi
- Division of Pediatrics, Fukuda Hospital, 2-2-6, Shinmachi, Chuou-ku, Kumamoto city, 860-0004, Japan.
| | - Haibo Qui
- Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, 87 Dingjiaqiao Street, Nanjing, 210009, China.
| | - Arthur S Slutsky
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada.
| | - Christer Sinderby
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Medicine and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
| | - Jennifer Beck
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital; Department of Critical Care, St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B1W8. .,Department of Pediatrics, University of Toronto, Toronto, Canada. .,Institute for Biomedical Engineering and Science Technology (iBEST) at Ryerson University and St-Michael's Hospital, Toronto, Canada.
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Cross-Sectional Changes in Lung Volume Measured by Electrical Impedance Tomography Are Representative for the Whole Lung in Ventilated Preterm Infants. Crit Care Med 2014; 42:1524-30. [DOI: 10.1097/ccm.0000000000000230] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pickerd N, Williams EM, Watkins WJ, Kotecha S. Tidal breathing in preterm infants receiving and weaning from continuous positive airway pressure. J Pediatr 2014; 164:1058-1063.e1. [PMID: 24518163 DOI: 10.1016/j.jpeds.2013.12.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 12/02/2013] [Accepted: 12/26/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To compare tidal breathing on different continuous positive airway pressure (CPAP) devices and pressures and to serially measure tidal breathing during weaning off CPAP using electromagnetic inductive plethysmography. STUDY DESIGN Using electromagnetic inductive plethysmography, tidal breathing was measured in 29 preterm infants receiving CPAP, gestational age 28 ± 2 weeks. Variable-flow nasal CPAP (nCPAP), bubble CPAP (bCPAP) at pressures of 5, 7, and 9 cmH2O, nasal bi-level positive airway pressure (nBiPAP) system at pressures of 5, 7/5, and 9/5 cmH2O, and unsupported breathing were studied. Twenty-one infants had weekly tidal breathing measurements on and off nCPAP. RESULTS Minute volume (MV/kg) was similar between all devices (0.30-0.33 L/kg/min). On bCPAP, weight corrected tidal volume (VT/kg) was the least, changing little with increasing pressures. On nCPAP and nBiPAP, VT/kg increased with increasing pressure and the respiratory rate (fR) decreased. The delivered pressure varied slightly from the set pressure being most dissimilar on nBiPAP and similar on bCPAP. Compared with unsupported breathing, all devices decreased VT/kg, MV/kg, and phase angle, but did not alter fR. Serial tidal breathing measurements showed decreasing difference for VT/kg over time on and off nCPAP. CONCLUSIONS At different pressure settings, on all CPAP devices the measured MV/kg was similar either through increasing VT/kg and decreasing fR (nCPAP and nBiPAP) or maintaining both (bCPAP). Serial tidal breathing measurements may aid weaning from CPAP.
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Affiliation(s)
- Nicole Pickerd
- Department of Child Health, Cardiff University, Cardiff, United Kingdom
| | - Edgar Mark Williams
- Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | | | - Sailesh Kotecha
- Department of Child Health, Cardiff University, Cardiff, United Kingdom.
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Mirabella L, Grasselli G, Haitsma JJ, Zhang H, Slutsky AS, Sinderby C, Beck J. Lung protection during non-invasive synchronized assist versus volume control in rabbits. Crit Care 2014; 18:R22. [PMID: 24456613 PMCID: PMC4057206 DOI: 10.1186/cc13706] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 01/14/2014] [Indexed: 11/10/2022] Open
Abstract
Introduction Experimental work provides insight into potential lung protective strategies. The objective of this study was to evaluate markers of ventilator-induced lung injury after two different ventilation approaches: (1) a “conventional” lung-protective strategy (volume control (VC) with low tidal volume, positive end-expiratory pressure (PEEP) and paralysis), (2) a physiological approach with spontaneous breathing, permitting synchrony, variability and a liberated airway. For this, we used non-invasive Neurally Adjusted Ventilatory Assist (NIV-NAVA), with the hypothesis that liberation of upper airways and the ventilator’s integration with lung protective reflexes would be equally lung protective. Methods In this controlled and randomized in vivo laboratory study, 25 adult White New Zealand rabbits were studied, including five non-ventilated control animals. The twenty animals with aspiration-induced lung injury were randomized to ventilation with either VC (6 mL/kg, PEEP 5 cm H2O, and paralysis) or NIV-NAVA for six hours (PEEP = zero because of leaks). Markers of lung function, lung injury, vital signs and ventilator parameters were assessed. Results At the end of six hours of ventilation (n = 20), there were no significant differences between VC and NIV-NAVA for vital signs, PaO2/FiO2 ratio, lung wet-to-dry ratio and broncho-alveolar Interleukin 8 (Il-8). Plasma IL-8 was higher in VC (P <0.05). Lung injury score was lower for NIV-NAVA (P = 0.03). Dynamic lung compliance recovered after six hours in NIV-NAVA but not in VC (P <0.05). During VC, peak pressures increased from 9.2 ± 2.4 cm H2O (hour 1) to 12.3 ± 12.3 cm H2O (hour 6) (P <0.05). During NIV-NAVA, the tracheal end-expiratory pressure was similar to the end-expiratory pressure during VC. Two animals regurgitated during NIV-NAVA, without clinical consequences, and survived the protocol. Conclusions In experimental acute lung injury, NIV-NAVA is as lung-protective as VC 6 ml/kg with PEEP. Electronic supplementary material The online version of this article (doi:10.1186/cc13706) contains supplementary material, which is available to authorized users.
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Abstract
Managing pulmonary issues faced by both term and preterm infants remains a challenge to the practicing pediatric surgeon. An understanding of normal fetal and neonatal pulmonary development and physiology is the cornerstone for understanding the pathophysiology and treatment of many congenital and acquired problems in the neonate. Progression through the phases of lung development and the transition to postnatal life requires a symphony of complex and overlapping events to work in concert for smooth and successful transition to occur. Pulmonary physiology and oxygen transport in the neonate are similar to older children; however, there are critical differences that are important to take into consideration when treating the youngest of patients. Our understanding of fetal and neonatal pulmonary physiology continues to evolve as the molecular and cellular events governing these processes are better understood. This deeper understanding has helped to facilitate groundbreaking research, leading to improved technology and treatment of term and preterm infants. As therapeutics and research continue to advance, a review of neonatal pulmonary physiology is essential to assist the clinician with his/her management of the wide variety of challenging congenital and acquired pulmonary disease.
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Affiliation(s)
- Ryan P Davis
- Section of Pediatric Surgery, C.S. Mott Children's Hospital, University of Michigan Health Systems, Ann Arbor, Michigan
| | - George B Mychaliska
- Section of Pediatric Surgery, C.S. Mott Children's Hospital, University of Michigan Health Systems, Ann Arbor, Michigan.
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Gouna G, Rakza T, Kuissi E, Pennaforte T, Mur S, Storme L. Positioning effects on lung function and breathing pattern in premature newborns. J Pediatr 2013; 162:1133-7, 1137.e1. [PMID: 23312684 DOI: 10.1016/j.jpeds.2012.11.036] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 10/22/2012] [Accepted: 11/08/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To compare breathing patterns and lung function in the supine, lateral, and prone positions in oxygen-dependent preterm infants. STUDY DESIGN Respiratory function in preterm infants receiving nasal continous positive airway pressure therapy for mild respiratory failure was evaluated by respiratory inductive plethysmography. Infants were randomized to supine, left lateral, and prone positions for 3 hours. A nest provided a semiflexed posture for the infants placed in the left lateral position, similar to the in utero position. Tidal volume (Vt), phase angle between abdominal and thoracic movements, rib cage contribution to Vt, and dynamic elevation of end-expiratory lung volume were measured. RESULTS Fraction of inspired O2 was similar in the 3 positions for 19 infants (mean gestational age, 27±2 weeks; mean birth weight, 950±150 g; mean postnatal age, 17±5 days). However, arterial O2 saturation and Vt were higher in the left lateral and prone positions than in the supine position (P<.05). The phase angle between abdominal and thoracic movements was lower and rib cage contribution to Vt was higher in the left lateral and prone positions than in the supine position (P<.05). Dynamic elevation of end-expiratory lung volume was greater in the supine position than in the left lateral and prone positions (P<.05). CONCLUSION In oxygen-dependent preterm infants, both the left lateral and prone positions improve lung function by optimizing breathing strategy. In the neonatal intensive care unit, the left lateral position can be used as an alternative to the prone position for mild respiratory failure.
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Affiliation(s)
- Georgette Gouna
- Department of Perinatology, Jeanne de Flandre Hospital, University Hospital of Lille, and EA4489 Perinatal Environment and Growth, School of Medicine, Université Lille 2, Lille, France
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15
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Miedema M, van der Burg PS, Beuger S, de Jongh FH, Frerichs I, van Kaam AH. Effect of nasal continuous and biphasic positive airway pressure on lung volume in preterm infants. J Pediatr 2013; 162:691-7. [PMID: 23102792 DOI: 10.1016/j.jpeds.2012.09.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 07/19/2012] [Accepted: 09/17/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE To monitor regional changes in end-expiratory lung volume (EELV), tidal volumes, and their ventilation distribution during different levels of nasal continuous positive airway pressure (nCPAP) and nasal biphasic positive airway pressure (BiPAP) in stable preterm infants. STUDY DESIGN By using electrical impedance tomography and respiratory inductive plethysmography, we measured changes in EELV and tidal volumes in 22 preterm infants (gestational age 29.7 ± 1.5 weeks) during 3 nCPAP levels (2, 4, and 6 cmH2O) and unsynchronized BiPAP (nCPAP = 6 cmH2O; pressure amplitude = 3 cmH2O; frequency = 50/min; inspiration time = 0.5 seconds) at 10-minute intervals. We assessed the distribution of these volumes in ventral and dorsal chest regions by using electrical impedance tomography. RESULTS EELV increased with increasing nCPAP with no difference between the ventral and dorsal lung regions. Tidal volume also increased, and a decrease in phase angle and respiratory rate was noted by respiratory induction plethysmography. At the regional level, electrical impedance tomography data showed a more dorsally oriented ventilation distribution. BiPAP resulted in a small increase in EELV but without changes in tidal volume or its regional distribution. CONCLUSION Increasing nCPAP in the range of 2 to 6 cmH2O results in a homogeneous increase in EELV and an increase in tidal volume in preterm infants with a more physiologic ventilation distribution. Unsynchronized BiPAP does not improve tidal volume compared with nCPAP.
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Affiliation(s)
- Martijn Miedema
- Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
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16
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Hough JL, Johnston L, Brauer S, Woodgate P, Schibler A. Effect of body position on ventilation distribution in ventilated preterm infants. Pediatr Crit Care Med 2013; 14:171-7. [PMID: 23314179 DOI: 10.1097/pcc.0b013e31826e708a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE Positioning is considered vital to the maintenance of good lung ventilation by optimizing oxygen transport and gas exchange in ventilated premature infants. Previous studies suggest that the prone position is advantageous; however, no data exist on regional ventilation distribution for this age group. OBJECTIVES To investigate the effect of body position on regional ventilation distribution in ventilated and nonventilated preterm infants using electrical impedance tomography. DESIGN Randomized crossover study design. SETTING Neonatal ICU. PATIENTS A total of 24 ventilated preterm infants were compared with six spontaneously breathing preterm infants. INTERVENTIONS Random assignment of the order of the positions supine, prone, and quarter prone. MEASUREMENTS AND MAIN RESULTS Ventilation distribution was measured with regional impedance amplitudes and global inhomogeneity indices using electrical impedance tomography. In the spontaneously breathing infants, regional impedance amplitudes were increased in the posterior compared with the anterior lung (p < 0.01) and in the right compared with the left lung (p = 0.03). No differences were found in the ventilated infants. Ventilation was more inhomogeneous in the ventilated compared with the healthy infants (p < 0.01). Assessment of temporal regional lung filling showed that the posterior lung filled earlier than the anterior lung in the spontaneously breathing infants (p < 0.02) whereas in the in the ventilated infants the right lung filled before the left lung (p < 0.01). CONCLUSIONS In contrast to previous studies showing that ventilation is distributed to the nondependent lung in infants and children, this study shows that gravity has little effect on regional ventilation distribution.
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Affiliation(s)
- Judith L Hough
- Critical Care of the Newborn Program, Mater Medical Research Institute, South Brisbane, QLD, Australia.
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17
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Effect of body position on ventilation distribution in preterm infants on continuous positive airway pressure. Pediatr Crit Care Med 2012; 13:446-51. [PMID: 21926660 DOI: 10.1097/pcc.0b013e31822f18d9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE Although continuous positive airway pressure is used extensively in neonatal intensive care units, and despite the belief that positioning is considered vital to the maintenance of good lung ventilation, no data exist on regional ventilation distribution in infants on continuous positive airway pressure ventilatory support. OBJECTIVES To investigate the effect of body position on regional ventilation in preterm infants on continuous positive airway pressure ventilatory support using electrical impedance tomography. DESIGN Randomized crossover study design. SETTING Neonatal intensive care unit. PATIENTS Twenty-four preterm infants on continuous positive airway pressure were compared to six spontaneously breathing preterm infants. INTERVENTIONS Random assignment of the order of the positions supine, prone, and quarter prone. MEASUREMENTS AND RESULTS Changes in global and regional lung volume were measured with electrical impedance tomography. Although there were no differences between positions, regional tidal volume was increased in the posterior compared with the anterior lung (p < .01) and in the right compared with the left lung (p < .03) in both the spontaneously breathing infants and in the infants on continuous positive airway pressure. The posterior lung filled earlier than the anterior lung in the spontaneously breathing infants (p < .02), whereas in the infants on continuous positive airway pressure the right lung filled before the left lung (p < .01). There was more ventilation inhomogeneity in the infants on continuous positive airway pressure than in the healthy infants (p < .01). CONCLUSIONS This study presents the first results on regional ventilation distribution in preterm infants on continuous positive airway pressure using electrical impedance tomography. Gravity had little impact on regional ventilation distribution in preterm infants on continuous positive airway pressure or in spontaneously breathing infants in the supine or prone position, indicating that ventilation distribution in preterm infants is not gravity-dependent but follows an anatomical pattern. AUSTRALIA NEW ZEALAND CLINICAL TRIALS REGISTRY:: ACTRN12606000210572.
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Sandberg KL, Hjalmarson O. CPAP of 4 cm H(2)O Has no short-term benefit at term in infants with BPD. Neonatology 2012; 102:282-6. [PMID: 22922725 DOI: 10.1159/000341765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 07/10/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Lung development and function is compromised at term in infants with bronchopulmonary dysplasia (BPD), characterized by reduced functional residual capacity (FRC) and impaired gas-mixing efficiency in distal airways. OBJECTIVE To determine whether continuous positive airway pressure (CPAP) improves FRC, ventilation, distal airway function, and gas exchange in spontaneously breathing infants with BPD. DESIGN/METHODS Twenty-one infants with BPD (median birth weight 0.72 kg (range 0.50-1.27) and median gestational age 26 weeks (range 23-28)) were studied before and after CPAP of 4 cm H(2)O was applied by a facemask system. A multiple-breath nitrogen washout method was used to assess FRC, ventilation, and gas-mixing efficiency. Moment analysis and lung clearance index was calculated from the nitrogen-decay curve for assessment of gas-mixing efficiency. Transcutaneous (Tc) PO(2)/PCO(2) was monitored during stable infant conditions before each washout test. RESULTS When CPAP was raised from 0 to 4 cm H(2)O, FRC increased significantly together with a significant increase in moment ratios (M(1)/M(0) and M(2)/M(0)). Tc PO(2) decreased significantly and the breathing pattern changed, with significantly reduced respiratory rate, minute ventilation, and alveolar ventilation. There was also an increase in tidal volume and dead space. CONCLUSIONS CPAP of 4 cm H(2)O applied with a facemask at term to infants with BPD did not improve ventilation, gas-mixing efficiency in distal airways, or oxygenation despite an increase in FRC. We speculate that instead of promoting recruitment of unventilated lung volumes, increasing the end-expiratory pressure in infants with BPD may lead to an overexpansion of already ventilated parts of the lung, causing further compromise of lung function.
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Affiliation(s)
- Kenneth L Sandberg
- Department of Paediatrics, Queen Silvia Children's Hospital, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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19
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Morris MG. A novel physiological investigation of the functional residual capacity by the bias flow nitrogen washout technique in infants. Pediatr Pulmonol 2009; 44:683-92. [PMID: 19499588 PMCID: PMC3032594 DOI: 10.1002/ppul.21040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The dynamic functional residual capacity (FRC(dyn)), the lung volume most routinely measured in infants, is an unreliable volume landmark. In addition to the FRC(dyn), we measured the (passive) static FRC (FRC(st)) by inducing a brief post-hyperventilation apnea (PHA) in 33 healthy infants aged 7.4-127.2 weeks. A commercial system for nitrogen (N2) washout to measure FRC, and a custom made system to monitor and record flow and airway opening pressure signals in real-time were used in unison. Infants were manually hyperventilated to induce a PHA. After the last passive expiration, FRC(st) was estimated by measuring the volume of N2 expired after end-passive expiratory switching of the inspired gas from room air to 100% oxygen during the post-expiratory apneic pause. Repeatable intrasubject FRC(st) and FRC(dyn) measurements overlapped in most infants including the younger ones (P = 0.2839). Mean (95% confidence interval [CI]) FRC(st) was 21.1 (20.0-22.3), and error-corrected FRC(dyn) was 21.4 (20.4-22.4) ml/kg. Mean (washout time [t]) tFRC(st) was longer than tFRC(dyn) 60 sec (95% CI 55-65) versus 47 sec (95% CI 43-51) (P < 0.0001). The FRC and washout time were dependent on body length, weight and age. We conclude that the FRC(st) is not different from the FRC(dyn) in infants. The FRC(st) is a reliable volume landmark because the PHA stabilizes the end-expiratory level by potentially abolishing the sedated infant's breathing strategies. The FRC(st) lacks potential sources of errors and disadvantages associated with measuring the FRC(dyn). The findings cast significant doubt on the traditional physiology of air trapping in healthy infants' lungs.
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Affiliation(s)
- Mohy G Morris
- Department of Pediatrics, Pulmonary Medicine Section, College of Medicine, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, 1 Children's Way, Slot 512-17, Little Rock, AR 72202, USA.
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Emeriaud G, Eberhard A, Benchetrit G, Debillon T, Baconnier P. Calibration of respiratory inductance plethysmograph in preterm infants with different respiratory conditions. Pediatr Pulmonol 2008; 43:1135-1141. [PMID: 18846561 DOI: 10.1002/ppul.20923] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Respiratory inductance plethysmography (RIP) is a method for respiratory measurements particularly attractive in infants because it is noninvasive and it does not interfere with the airway. RIP calibration remains controversial in neonates, and is particularly difficult in infants with thoraco-abdominal asynchrony or with ventilatory assist. The objective of this study was to evaluate a new RIP calibration method in preterm infants either without respiratory disease, with thoraco-abdominal asynchrony, or with ventilatory support. This method is based on (i) a specifically adapted RIP jacket, (ii) the least squares method to estimate the volume/motion ribcage and abdominal coefficients, and (iii) an individualized filtering method that takes into account individual breathing pattern. The reference flow was recorded with a pneumotachograph. The accuracy of flow reconstruction using the new method was compared to the accuracy of three other calibration methods, with arbitrary fixed RIP coefficients or with coefficients determined according to qualitative diagnostic calibration method principle. Fifteen preterm neonates have been studied; gestational age was (mean +/- SD) 31.7 +/- 0.8 weeks; birth weight was 1,470 +/- 250 g. The respiratory flow determined with the new method had a goodness of fit at least equivalent to the other three methods in the entire group. Moreover, in unfavorable conditions--breathing asynchrony or ventilatory assist--the quality of fit was significantly higher than with the three other methods (P < 0.05, repeated measures ANOVA). Accuracy of tidal volume measurements was at least equivalent to the other methods, and the breath-by-breath differences with reference volumes were lower, although not significantly, than with the other methods. The goodness of fit of the reconstructed RIP flow with this new method--even in unfavorable respiratory conditions--provides a prerequisite for the study of flow pattern during the neonatal period.
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Affiliation(s)
- Guillaume Emeriaud
- Laboratoire TIMC-UMR 5525 CNRS-Université Joseph Fourier IPG, La Tronche, France.,Réanimation Pédiatrique et Néonatale, CHU de Grenoble, Grenoble, France
| | - André Eberhard
- Laboratoire TIMC-UMR 5525 CNRS-Université Joseph Fourier IPG, La Tronche, France
| | - Gila Benchetrit
- Laboratoire TIMC-UMR 5525 CNRS-Université Joseph Fourier IPG, La Tronche, France
| | - Thierry Debillon
- Réanimation Pédiatrique et Néonatale, CHU de Grenoble, Grenoble, France
| | - Pierre Baconnier
- Laboratoire TIMC-UMR 5525 CNRS-Université Joseph Fourier IPG, La Tronche, France
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Kugelman A, Bar A, Riskin A, Chistyakov I, Mor F, Bader D. Nasal respiratory support in premature infants: short-term physiological effects and comfort assessment. Acta Paediatr 2008; 97:557-61. [PMID: 18394099 DOI: 10.1111/j.1651-2227.2008.00732.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To evaluate the effects of nasal respiratory support on physiologic parameters and comfort of premature infants, when compared to spontaneous breathing without nasal respiratory support. METHODS This was a prospective, randomized, controlled, cross-over clinical study. Infants were enrolled into the study when in 'stable' condition (when discontinuation of nasal respiratory support was considered appropriate). Infants were randomized to receive first 3 h of nasal respiratory support (nasal continuous positive airway pressure or nasal intermittent mandatory ventilation) or to spontaneous breathing, and then were crossed-over to the other assignment. Each infant served as his own control. RESULTS Fifty-four infants were included in the study (birth-weight: 1528 +/- 545 g; gestational age: 30.5 +/- 2.7 weeks). Average values of systolic, diastolic and mean blood pressure and discomfort score were significantly higher while respiratory rate was significantly slower on nasal respiratory support compared to spontaneous breathing. Heart rate was comparable on both modes. CONCLUSIONS Nasal respiratory support in 'stable' premature infants is associated with increased blood pressure and increased discomfort, despite a decreased respiratory rate. The clinical importance of these effects is modest. Medical teams should consider these effects and balance its need with its adverse effects according to the clinical condition.
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Affiliation(s)
- A Kugelman
- Department of Neonatology, Bnai Zion Medical Center, The B. Rappaport Faculty of Medicine, Technion, Haifa, Israel.
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Boumecid H, Rakza T, Abazine A, Klosowski S, Matran R, Storme L. Influence of three nasal continuous positive airway pressure devices on breathing pattern in preterm infants. Arch Dis Child Fetal Neonatal Ed 2007; 92:F298-300. [PMID: 17088340 PMCID: PMC2675435 DOI: 10.1136/adc.2006.103762] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The pattern of breathing was studied in 13 premature newborns treated by variable-flow Nasal Continuous Positive Airway Pressure (NCPAP), conventional NCPAP, and nasal cannulae. Compared to constant-flow NCPAP and nasal cannulae, the variable-flow NCPAP increases tidal volume and improves thoraco-abdominal synchrony, suggesting that variable-flow NCPAP provides more effective ventilatory support than conventional NCPAP or nasal cannulae.
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Emeriaud G, Beck J, Tucci M, Lacroix J, Sinderby C. Diaphragm electrical activity during expiration in mechanically ventilated infants. Pediatr Res 2006; 59:705-10. [PMID: 16627886 DOI: 10.1203/01.pdr.0000214986.82862.57] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The presence of diaphragm electrical activity (EAdi) during expiration is believed to be involved in the maintenance of end-expiratory lung volume (EELV) and has never been studied in intubated and mechanically ventilated infants. The aim of this study was to quantify the amplitude of diaphragm electrical activity present during expiration in mechanically ventilated infants and to measure the impact of removing positive end-expiratory pressure (PEEP) on this activity. We studied the EAdi in 16 ready-to-be weaned intubated infants who were breathing on their prescribed ventilator and PEEP settings. In all 16 patients, 5 min of data were collected on the prescribed ventilator settings. In a subset of eight patients, the PEEP was briefly reduced to zero PEEP (ZEEP). EAdi was recorded with miniaturized sensors placed on a conventional nasogastric feeding tube. Airway pressure (Paw) was also measured. For each spontaneous breath, we identified the neural inspiration and neural expiration. Neural expiration was divided into quartiles (Q1, Q2, Q3, and Q4), and the amplitude of EAdi calculated for each Q1-Q4 represented 95 +/- 29%, 31 +/- 15%, 15 +/- 8%, and 12 +/- 7%, respectively, of the inspiratory EAdi amplitude. EAdi for Q3-Q4 significantly increased during ZEEP, and decreased after reapplication of PEEP. These findings confirm that the diaphragm remains partially active during expiration in intubated and mechanically ventilated infants and that removal of PEEP affects this tonic activity. This could have potential implications on the management of PEEP in intubated infants.
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Affiliation(s)
- Guillaume Emeriaud
- Department of Pediatrics, Hôpital Sainte-Justine, Quebec, Canada, H3T 1C5
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