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van Dijk J, Koopman AA, Blokpoel RG, Dijkstra S, Markhorst DG, Burgerhof JG, Kneyber MC. Global and Regional Tidal Volume Distribution in Spontaneously Breathing Mechanically Ventilated Children. Respir Care 2022; 67:383-393. [PMID: 34934009 PMCID: PMC9994001 DOI: 10.4187/respcare.09190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Allowing the ventilated adult patient to breathe spontaneously may improve tidal volume (VT) distribution toward the dependent lung regions, reduce shunt fraction, and decrease dead space. It has not been studied if these effects under various levels of ventilatory support also occur in children. We sought to explore the effect of level of ventilatory support on VT distribution and end-expiratory lung volume (EELV) in spontaneously breathing ventilated children in the recovery phase of their acute respiratory failure. METHODS This is a secondary analysis of data from a prospective clinical trial comparing 2 different ventilator modes during weaning in mechanically ventilated children < 5 y: CPAP + pressure support ventilation (PSV) and pressure control (PC)/intermittent mandatory ventilation (IMV) + PSV with the mandatory breath rate set at 25% of baseline. Using electrical impedance tomography (EIT), we assessed VT distribution by calculating the center of ventilation. Polynomial functions of the second degree were plotted to evaluate regional lung filling characteristics. Changes in end-expiratory impedance were calculated to assess changes in EELV. Baseline measurements were compared with measurements during CPAP/PSV, PC/IMV + PSV, and during a downward titration of the level of pressure support. RESULTS Thirty-five subjects with a median age 4.5 (2.1-12.9) months and a median ventilation time of 4.9 (3.3-6.9) d were studied. The overall median coefficient of variation was 50.1% and not different between CPAP/PSV or PC/synchronized IMV + PSV. Regional filling characteristics of the lung identified a homogeneous VT distribution under all study conditions. Downtapering of the level of PSV resulted in a significant shift of the coefficient of variation toward the dependent lung regions. CONCLUSIONS Our data showed that allowing ventilated children in the recovery phase of respiratory failure to breathe spontaneously in a continuous spontaneous ventilation mode did not negatively affect VT distribution or EELV.
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Affiliation(s)
- Jefta van Dijk
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Alette A Koopman
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Robert Gt Blokpoel
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Sandra Dijkstra
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Dick G Markhorst
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - Johannes Gm Burgerhof
- Department of Epidemiology, University Medical Center Groningen, The University of Groningen, Groningen, the Netherlands
| | - Martin Cj Kneyber
- Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands and Critical Care, Anaesthesiology, Peri-operative and Emergency Medicine, University of Groningen, Groningen, the Netherlands
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Szczapa T, Kwapień P, Merritt TA. Neonatal Applications of Heliox: A Practical Review. Front Pediatr 2022; 10:855050. [PMID: 35359907 PMCID: PMC8960277 DOI: 10.3389/fped.2022.855050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/09/2022] [Indexed: 11/21/2022] Open
Abstract
Heliox is a mixture of helium and oxygen that may be utilized as an alternative to air-oxygen during the ventilatory support in the neonate. Special physical properties of Heliox, particularly low density, allow for improved gas flow and diffusion. First reports of Heliox use in the pediatric population were published in 1930s; however, this therapy has never gained widespread popularity despite its described beneficial effects. Historically, this was largely due to technical challenges associated with Heliox ventilation that significantly limited its use and realization of large-scale clinical trials. However, nowadays several commercially available ventilators allow easy and safe ventilation with both conventional and non-invasive modes. In the era of minimally invasive respiratory interventions in the newborn Heliox could be seen as a therapy that may potentially decrease the risk of non-invasive ventilation failure. This review presents pathophysiologic rationale for the use of Heliox in the newborn, and summarizes available data regarding applications of Heliox in the setting of neonatal intensive care unit based on clinical studies and findings from animal models. Mechanisms of action and practical aspects of Heliox delivery are thoroughly discussed. Finally, future research directions for neonatal use of Heliox are proposed.
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Affiliation(s)
- Tomasz Szczapa
- Department of Newborns' Infectious Diseases, Chair of Neonatology, Poznan University of Medical Sciences, Poznan, Poland
| | - Patryk Kwapień
- Department of Neonatology, Chair of Neonatology, Poznan University of Medical Sciences, Poznan, Poland
| | - T. Allen Merritt
- Division of Neonatology, Loma Linda University School of Medicine, Loma Linda, CA, United States
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Liu W, Guan WJ, Zhong NS. Strategies and Advances in Combating COVID-19 in China. ENGINEERING (BEIJING, CHINA) 2020; 6:1076-1084. [PMID: 33078078 PMCID: PMC7558233 DOI: 10.1016/j.eng.2020.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 05/02/2023]
Abstract
Coronavirus disease 2019 (COVID-19)-the third in a series of coronavirus infections-has caused a global public health event in the 21st century, resulting in substantial global morbidity and mortality. Building on its legacy of managing severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), China has played a key role in the scientific community by revealing the viral transmission routes and clinical characteristics of COVID-19 and developing novel therapeutic interventions and vaccines. Despite these rapid scientific and technological advances, uncertainties remain in tracing the original sources of infection, determining the routes of transmission and pathogenesis, and addressing the lack of targeted clinical management of COVID-19. Here, we summarize the major COVID-19 research advances in China in order to provide useful information for global pandemic control.
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Affiliation(s)
- Wei Liu
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Wei-Jie Guan
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Nan-Shan Zhong
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
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MART ÖÖ, YILDIZDAŞ D, ÖZGÜR HOROZ Ö, EKİNCİ F, MISIRLIOĞLU M. Solunum sinsityal virüsü ile ilişkili bronşiyolite bağlı solunum sıkıntısı gelişen trakeostomili bir çocuk olguda Heliox tedavisi kullanımı. CUKUROVA MEDICAL JOURNAL 2020. [DOI: 10.17826/cumj.740316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Seliem W, Sultan AM. Does heliox administered by low-flow nasal cannula improve respiratory distress in infants with respiratory syncytial virus acute bronchiolitis? A randomised controlled trial. ANALES DE PEDIATRÍA (ENGLISH EDITION) 2019. [DOI: 10.1016/j.anpede.2018.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Mueller JL, Muller P, Mellenthin M, Murthy R, Capps M, Alsaker M, Deterding R, Sagel SD, DeBoer E. Estimating regions of air trapping from electrical impedance tomography data. Physiol Meas 2018; 39:05NT01. [PMID: 29726838 PMCID: PMC6015736 DOI: 10.1088/1361-6579/aac295] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Electrical impedance tomography (EIT) has been shown to be a viable non-invasive, bedside imaging modality to monitor lung function. This paper introduces a method for identifying regions of air trapping from EIT data collected during tidal breathing and breath-holding maneuvers. APPROACH Ventilation-perfusion index maps are computed from dynamic EIT images. These maps are then used to identify regions of air trapping in the area of the lung as regions that are poorly ventilated but well perfused throughout the breathing and cardiac cycles. These EIT-identified regions are then compared with independently identified regions of low attenuation, or air trapping, on chest CT. Results of this method are demonstrated in two children with cystic fibrosis and on a healthy control subject. MAIN RESULTS In both CF children, the EIT-identified regions of air trapping matched the regions indicated from the chest CT. The EIT-based method is only validated with CT scans within 4 cm of the chest cross-section defined by the electrode plane. SIGNIFICANCE The results indicate the potential use of EIT-derived ventilation-perfusion index maps as a non-invasive method for identifying regions of air trapping.
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Affiliation(s)
- Jennifer L Mueller
- Department of Mathematics, Colorado State University, Fort Collins, CO, United States of America. School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States of America
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Seliem W, Sultan AM. [Does heliox administered by low-flow nasal cannula improve respiratory distress in infants with respiratory syncytial virus acute bronchiolitis? A randomized controlled trial]. An Pediatr (Barc) 2018; 90:3-9. [PMID: 29627312 DOI: 10.1016/j.anpedi.2018.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES The aim of our study is to evaluate whether the use of heliox (79:21) delivered through a low flow nasal cannula would improve respiratory distress in infants with acute bronchiolitis caused by respiratory syncytial virus. METHODS We have conducted a prospective randomized controlled study. All patients fulfilled inclusion criteria were randomized to either heliox (79:21) or air via NC at 2 L/min for a continuous 24hours. Measurements were taken at baseline, after 2hours and at the end of the 24hours. RESULTS We have included 104 patients into our study. The MCA-S did not show any significant difference between the two groups after 2hours 4.3 vs. 4.1 (P =.78), or at 24hours after 4.2 vs. 4.3 (P =.89). No difference was found in the proportion of participants progressed to MV, n-CPAP or oxygen via nasal cannula (RR 1.0, 0.86 and 0.89) (P= 1.0, .77 and .73). There was no notable reduction in length of treatment in Heliox group 2.42 days vs. 2.79 days in air group P =.65. The in oxygen saturation, PaO2, and PaCO2 did not to have any statistical difference between the two studied groups after 2hours and 24hours of treatment. CONCLUSION Our data showed absence of any beneficial effect of heliox in a concentration (79:21) delivered through low flow nasal cannula in terms of respiratory distress improvement in infants with RSV acute bronchiolitis.
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Affiliation(s)
- Wael Seliem
- Facultad de Medicina, Universidad de El Mansura, El Mansura, Egipto; Departamento de Pediatría, Hospital Infantil Universitario de El Mansura, El Mansura, Egipto.
| | - Amira M Sultan
- Facultad de Medicina, Universidad de El Mansura, El Mansura, Egipto; Departamento de Microbiología Clínica e Inmunología, Hospital Infantil Universitario de El Mansura, El Mansura, Egipto
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Heliox delivered by high flow nasal cannula improves oxygenation in infants with respiratory syncytial virus acute bronchiolitis. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2018. [DOI: 10.1016/j.jpedp.2017.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Heliox delivered by high flow nasal cannula improves oxygenation in infants with respiratory syncytial virus acute bronchiolitis. J Pediatr (Rio J) 2018; 94:56-61. [PMID: 28506664 DOI: 10.1016/j.jped.2017.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE The objective of this study is to evaluate the hypothesis that use of heliox would result in improvement of gas exchange when used with high flow nasal cannula in infants with RSV acute bronchiolitis. METHODS All patients that met the inclusion criteria were randomized to either heliox (70:30) or air-oxygen mixture 30% via high flow nasal cannula at 8L/min for a continuous 24h. Measurements were taken at baseline, after 2h, and at the end of the 24h. RESULTS This prospective study included 48 patients. After 2h of treatment with heliox, the oxygen saturation and PaO2 significantly improved when compared with the air-oxygen group, 98.3% vs. 92.9%, 62.0mmHg vs. 43.6mmHg (p=0.04 and 0.01), respectively. Furthermore, PaO2/FiO2 ratio was significantly higher in the heliox group when compared with the air-oxygen group, 206.7 vs. 145.3. Nevertheless, CO2 showed better elimination when heliox was used, without significance. MWCA score dropped significantly in the heliox group, 2.2 points vs. 4.0 points in air-oxygen (p=0.04), 2h after starting the therapy. CONCLUSION Transient improvement of oxygenation in infants with RSV acute bronchiolitis during the initial phase of the therapy is associated with heliox when provided with HFNC, may provide a precious time for other therapeutic agents to work or for the disease to resolve naturally, avoiding other aggressive interventions.
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Wilsterman MEF, de Jager P, Blokpoel R, Frerichs I, Dijkstra SK, Albers MJIJ, Burgerhof JGM, Markhorst DG, Kneyber MCJ. Short-term effects of neuromuscular blockade on global and regional lung mechanics, oxygenation and ventilation in pediatric acute hypoxemic respiratory failure. Ann Intensive Care 2016; 6:103. [PMID: 27783382 PMCID: PMC5081313 DOI: 10.1186/s13613-016-0206-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/17/2016] [Indexed: 01/10/2023] Open
Abstract
Background Neuromuscular blockade (NMB) has been shown to improve outcome in acute respiratory distress syndrome (ARDS) in adults, challenging maintaining spontaneous breathing when there is severe lung injury. We tested in a prospective physiological study the hypothesis that continuous administration of NMB agents in mechanically ventilated children with severe acute hypoxemic respiratory failure (AHRF) improves the oxygenation index without a redistribution of tidal volume VT toward non-dependent lung zones. Methods Oxygenation index, PaO2/FiO2 ratio, lung mechanics (plateau pressure, mean airway pressure, respiratory system compliance and resistance), hemodynamics (heart rate, central venous and arterial blood pressures), oxygenation [oxygenation index (OI), PaO2/FiO2 and SpO2/FiO2], ventilation (physiological dead space-to-VT ratio) and electrical impedance tomography measured changes in end-expiratory lung volume (EELV), and VT distribution was measured before and 15 min after the start of continuous infusion of rocuronium 1 mg/kg. Patients were ventilated in a time-cycled, pressure-limited mode with pre-set VT. All ventilator settings were not changed during the study. Results Twenty-two patients were studied (N = 18 met the criteria for pediatric ARDS). Median age (25–75 interquartile range) was 15 (7.8–77.5) weeks. Pulmonary pathology was present in 77.3%. The median lung injury score was 9 (8–10). The overall median CoV and regional lung filling characteristics were not affected by NMB, indicating no ventilation shift toward the non-dependent lung zones. Regional analysis showed a homogeneous time course of lung inflation during inspiration, indicating no tendency to atelectasis after the introduction of NMB. NMB decreased the mean airway pressure (p = 0.039) and OI (p = 0.039) in all patients. There were no significant changes in lung mechanics, hemodynamics and EELV. Subgroup analysis showed that OI decreased (p = 0.01) and PaO2/FiO2 increased (p = 0.02) in patients with moderate or severe PARDS. Conclusions NMB resulted in an improved oxygenation index in pediatric patients with AHRF. Distribution of VT and regional lung filling characteristics were not affected.
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Affiliation(s)
- Marlon E F Wilsterman
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.,Department of Paediatrics, Nij Smellinghe Hospital, Drachten, The Netherlands
| | - Pauline de Jager
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Robert Blokpoel
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Inez Frerichs
- Department of Anaesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Sandra K Dijkstra
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Marcel J I J Albers
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Johannes G M Burgerhof
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Dick G Markhorst
- Division of Paediatric Intensive Care, Department of Paediatrics, VU University Medical Center, Amsterdam, The Netherlands
| | - Martin C J Kneyber
- Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. .,Critical Care, Anaesthesia, Peri-operative Medicine and Emergency Medicine (CAPE), University of Groningen, Groningen, The Netherlands.
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Abstract
BACKGROUND Bronchiolitis is the leading cause of hospitalisation among infants in high-income countries. Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing. In this review, we selected trials that objectively assessed the effect of the addition of heliox to standard medical care for acute bronchiolitis. OBJECTIVES To assess heliox inhalation therapy in addition to standard medical care for acute bronchiolitis in infants with respiratory distress, as measured by clinical endpoints (in particular the rate of endotracheal intubation, the rate of emergency department discharge, the length of treatment for respiratory distress) and pulmonary function testing (mainly clinical respiratory scores). SEARCH METHODS We searched CENTRAL (2015, Issue 2), MEDLINE (1966 to March week 3, 2015), EMBASE (1974 to March 2015), LILACS (1982 to March 2015) and the National Institutes of Health (NIH) website (May 2009). SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data and assessed trial quality. MAIN RESULTS We included seven trials involving 447 infants younger than two years with respiratory distress secondary to viral bronchiolitis. All children were recruited from a paediatric intensive care unit (PICU; 378 infants), except in one trial (emergency department; 69 infants). All children were younger than two (under nine months in two trials and under three months in one trial). Positive tests for respiratory syncytial virus (RSV) were required for inclusion in five trials. The two other trials were carried out in the bronchiolitis seasons. Seven different protocols were used for inhalation therapy with heliox.When heliox was used in the PICU, we observed no significant reduction in the rate of intubation: risk ratio (RR) 2.73 (95% confidence interval (CI) 0.96 to 7.75, four trials, 408 infants, low quality evidence). When heliox inhalation was used in the emergency department, we observed no increase in the rate of discharge: RR 0.51 (95% CI 0.17 to 1.55, one trial, 69 infants, moderate quality evidence).There was no decrease in the length of treatment for respiratory distress: mean difference (MD) -0.19 days (95% CI -0.56 to 0.19, two trials, 320 infants, moderate quality evidence). However, in the subgroup of infants who were started on nasal continuous positive airway pressure (nCPAP) right from the start, because of severe respiratory distress, heliox therapy reduced the length of treatment: MD -0.76 days (95% CI -1.45 to -0.08, one trial, 21 infants, low quality evidence). No adverse events related to heliox inhalation were reported.We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation: MD -1.04 (95% CI -1.60 to -0.48, four trials, 138 infants, moderate quality evidence). This outcome had statistical heterogeneity, which remained even after removing the study using a standard high-concentration reservoir mask. Several factors may explain this heterogeneity, including first the limited number of patients in each trial, and the wide differences in the baseline severity of disease between studies, with the modified Wood Clinical Asthma Score (m-WCAS) in infants treated with heliox ranging from less than two to more than seven. AUTHORS' CONCLUSIONS Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. We noticed this beneficial effect regardless of which heliox inhalation protocol was used. Nevertheless, there was no reduction in the rate of intubation, in the rate of emergency department discharge, or in the length of treatment for respiratory distress. Heliox could reduce the length of treatment in infants requiring CPAP for severe respiratory distress. Further studies with homogeneous logistics in their heliox application are needed. Inclusion criteria must include a clinical severity score that reflects severe respiratory distress to avoid inclusion of children with mild bronchiolitis who may not benefit from heliox inhalation. Such studies would provide the necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.
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Affiliation(s)
- Jean‐Michel Liet
- Hôpital Mère‐Enfant, CHU de NantesPediatric Intensive Care Unit38 Boulevard Jean‐MonnetFaïencerieNantesFrance44093
| | | | - Vineet Gupta
- Moses Cone HospitalPediatric Critical Care Medicine1200 N. Elm StreetGreensboroNCUSA27401
| | - Gilles Cambonie
- Hôpital Arnaud de VilleneuveService de Réanimation Pédiatrique et Néonatale, Pédiatrie II371 av du Doyen Gaston GiraudMontpellier CEDEX 5France34295
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Beurskens CJP, Wösten-van Asperen RM, Preckel B, Juffermans NP. The potential of heliox as a therapy for acute respiratory distress syndrome in adults and children: a descriptive review. Respiration 2015; 89:166-74. [PMID: 25662070 DOI: 10.1159/000369472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/28/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In neonatal respiratory distress syndrome (RDS) and acute RDS (ARDS) mechanical ventilation is often necessary to manage hypoxia, whilst protecting the lungs through lower volume ventilation and permissive hypercapnia. Mechanical ventilation can, however, induce or aggravate the lung injury caused by the respiratory distress. Helium, in a gas mixture with oxygen (heliox), has a low density and can reduce the flow in narrow airways and allow for lower driving pressures. OBJECTIVES The aim of this study was to review preclinical and clinical studies of the use of heliox ventilation in acute lung injury associated with respiratory failure. METHODS A systematic search was executed in the PubMed and EMBASE databases, with search terms referring to ARDS or an acute lung injury condition associated with respiratory failure and the corresponding intervention. RESULTS A total of 576 papers were retrieved. After the majority had been excluded 20 papers remained, of which 6 articles described animal models (3 paediatric; 3 adult animal models) and 14 were clinical studies, of which 12 described paediatric patient populations and 2 adult patient populations. In both paediatric and adult animal models, heliox improved gas exchange while allowing for less invasive ventilation in a wide variety of models using different ventilation modes. Clinical studies show a reduction in the work of breathing during heliox ventilation, with a concomitant increase in pH and decrease in PaCO2 levels compared to oxygen ventilation. CONCLUSIONS Although evidence so far is limited, there may be a rationale for heliox ventilation in ARDS as an intervention to improve ventilation and reduce the work of breathing.
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Affiliation(s)
- Charlotte J P Beurskens
- Laboratory of Experimental Intensive Care and Anaesthesiology, University of Amsterdam, Amsterdam, The Netherlands
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Monitoring Lung Volumes During Mechanical Ventilation. PEDIATRIC AND NEONATAL MECHANICAL VENTILATION 2015. [PMCID: PMC7193716 DOI: 10.1007/978-3-642-01219-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Respiratory inductive plethysmography (RIP) is a non-invasive method of measuring change in lung volume which is well-established as a monitor of tidal ventilation and thus respiratory patterns in sleep medicine. As RIP is leak independent, can measure end-expiratory lung volume as well as tidal volume and is applicable to both the ventilated and spontaneously breathing patient, there has been a recent interest in its use as a bedside tool in the intensive care unit.
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Bronchiolitis. PEDIATRIC AND NEONATAL MECHANICAL VENTILATION 2015. [PMCID: PMC7122073 DOI: 10.1007/978-3-642-01219-8_50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Everyone on the planet is exposed to respiratory syncytial virus (RSV) infection by the age of 2 years. Most infants admitted to the pediatric intensive care unit (PICU) for respiratory support during this infection are previously healthy, but their principal risk for needing PICU treatment is young age. That is, if you are born in October/November in the northern hemisphere, then your first winter exposure to RSV is likely to be when you are less than 4 months of age and vulnerable because of poor respiratory mechanical reserve (Alonso et al. 2007). However, if you are born in May/June, then you will be 7–8 months during your first winter exposure to RSV, much bigger and stronger and have more efficient thoracic and diaphragmatic mechanics. In the PICU, the main predictors of severe outcome in previously well infants appear to be young age, presence of apnea, and pulmonary consolidation on admission chest radiograph (Tasker et al. 2000; Lopez Guinea et al. 2007). Taken together, we can say that more severe RSV bronchiolitis in PICU practice is typically a problem of pulmonary consolidation, poor respiratory mechanics, and poor reserve, in the younger infant.
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Beurskens CJ, Aslami H, de Beer FM, Roelofs JJTH, Vroom MB, Juffermans NP. Mechanical ventilation with heliox in an animal model of acute respiratory distress syndrome. Intensive Care Med Exp 2014; 2:8. [PMID: 26266912 PMCID: PMC4513042 DOI: 10.1186/2197-425x-2-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heliox has a lower density and higher diffusion capacity compared to oxygen-in-air. We hypothesized that heliox ventilation allows for a reduction in minute volume ventilation and inspiratory pressures needed for adequate gas exchange in an animal model of an acute lung injury. METHODS After intratracheal instillation of lipopolysaccharide (10 mg/kg), adult rats were randomized to ventilation with either a gas mixture of helium/oxygen (50:50%) or oxygen/air (50:50%). They were mechanically ventilated according to the ARDSnet recommendations with tidal volumes of 6 ml/kg and monitored with a pneumotachometer. Bronchoalveolar lavage fluid was analyzed for markers of lung injury, and embedded lung sections were histologically scored for lung injury. RESULTS Heliox limited the increase in driving pressures needed to achieve preset tidal volumes, with a concomitant decrease in loss of compliance. Heliox did neither allow for reduced minute volume ventilation in this model nor improve gas exchange. Also, heliox did not reduce lung injury. CONCLUSIONS Heliox modestly improved respiratory mechanics but did not improve lung injury in this rat model of acute respiratory distress syndrome.
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Affiliation(s)
- Charlotte J Beurskens
- />Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
- />Department of Intensive Care, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
| | - Hamid Aslami
- />Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
| | - Friso M de Beer
- />Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
- />Department of Intensive Care, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
| | - Joris JTH Roelofs
- />Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, 1012 WX the Netherlands
| | - Margreeth B Vroom
- />Department of Intensive Care, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
| | - Nicole P Juffermans
- />Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
- />Department of Intensive Care, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ the Netherlands
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16
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Abstract
This paper reviews the medical use of helium oxygen mixture in obstructive airway disease in patients with croup, narrow endotracheal tubes (ETTs), respiratory distress syndrome, asthma, bronchiolitis, as well as patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) and acute lung injury. In addition, some other indications of heliox use and some innovative methods of ventilation applied in pediatrics and adults are presented through review of the literature of current decade. Yet, to recommend heliox use seems to require more research based on clinical practice and observation through vaster and more robust investigations.
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Affiliation(s)
- Seyed Mohammadreza Hashemian
- Chronic Respiratory Disease Research Center, National Research Institute of Tuberculosis and Lung Disease, Masih Daneshvari Hospital, Tehran, Iran
| | - Farahnaz Fallahian
- Shohada Hospital Critical Care Unit, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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17
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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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18
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Szczapa T, Gadzinowski J, Moczko J, Merritt TA. Heliox for mechanically ventilated newborns with bronchopulmonary dysplasia. Arch Dis Child Fetal Neonatal Ed 2014; 99:F128-33. [PMID: 24239984 DOI: 10.1136/archdischild-2013-303988] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE We assessed the safety and studied the influence of short-term helium-oxygen (heliox) mechanical ventilation (MV) on respiratory function, gas exchange and oxygenation in infants with bronchopulmonary dysplasia (BPD) or at high risk for BPD. DESIGN A pilot, time-series study. SETTING Neonatal intensive care unit. PATIENTS Infants with severe BPD who required MV. INTERVENTIONS MV with helium-oxygen and air-oxygen mixtures. MAIN OUTCOME MEASURES Respiratory parameters, acid-base balance, oxygenation and vital signs were recorded at five time points: initially during MV with air-oxygen, after 15 and 60 min of helium-oxygen MV, and 15 and 60 min after return to air-oxygen MV. RESULTS 15 infants with BPD were enrolled. Helium-oxygen MV was well tolerated and was associated with a statistically significant increase in tidal volume, dynamic compliance and peak expiratory flow rate. An improvement in oxygenation and a decrease in fraction of inspired oxygen was also observed. During helium-oxygen MV there was a significant decrease in the oxygenation index and alveolar-arterial oxygen tension difference. The PaO2/fraction of inspired oxygen (FiO2) ratio increased significantly during helium-oxygen ventilation. A decrease in PaCO2 and an increase in pH were also observed during helium-oxygen administration, however this was not statistically significant. After ventilation with helium-oxygen was discontinued, the infants' respiratory function and oxygenation deteriorated and supplemental oxygen requirements increased accordingly. CONCLUSIONS Helium-oxygen MV is safe and resulted in improvement of respiratory function and oxygenation in infants with severe BPD requiring MV.
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Affiliation(s)
- Tomasz Szczapa
- Department of Neonatology, Poznań University of Medical Sciences, , Poznań, Poland
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19
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Beurskens CJ, Aslami H, de Beer FM, Vroom MB, Preckel B, Horn J, Juffermans NP. Heliox allows for lower minute volume ventilation in an animal model of ventilator-induced lung injury. PLoS One 2013; 8:e78159. [PMID: 24205139 PMCID: PMC3799754 DOI: 10.1371/journal.pone.0078159] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/13/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2) diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator-induced lung injury. METHODS Sprague-Dawley rats (N=8 per group) were mechanically ventilated with heliox (50% oxygen; 50% helium). Controls received a standard gas mixture (50% oxygen; 50% air). VILI was induced by application of tidal volumes of 15 mL kg(-1); lung protective ventilated animals were ventilated with 6 mL kg(-1). Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO2 within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF) was obtained. Data are mean (SD). RESULTS VILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324) vs. 290 (181) μg mL(-1); p<0.05) and IL-6 levels (640 (8.7) vs. 206 (8.7) pg mL(-1); p<0.05), whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123 ± 0.6 vs. 146 ± 8.9 mL min(-1), P<0.001), due to a decrease in respiratory rate (22 (0.4) vs. 25 (2.1) breaths per minute; p<0.05), while pCO2 levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects. CONCLUSIONS Heliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of severe acidosis.
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Affiliation(s)
- Charlotte J. Beurskens
- Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Hamid Aslami
- Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands
| | - Friso M. de Beer
- Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Margreeth B. Vroom
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Benedikt Preckel
- Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands
- Department of Anaesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Janneke Horn
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Nicole P. Juffermans
- Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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20
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Chowdhury MM, McKenzie SA, Pearson CC, Carr S, Pao C, Shah AR, Reus E, Eliahoo J, Gordon F, Bland H, Habibi P. Heliox therapy in bronchiolitis: phase III multicenter double-blind randomized controlled trial. Pediatrics 2013; 131:661-9. [PMID: 23509160 DOI: 10.1542/peds.2012-1317] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Supportive care remains the mainstay of therapy in bronchiolitis. Earlier studies suggest that helium-oxygen therapy may be beneficial, but evidence is limited. We aimed to compare efficacy of 2 treatment gases, Heliox and Airox (21% oxygen + 79% helium or nitrogen, respectively), on length of hospital treatment for bronchiolitis. METHODS This was a multicenter randomized blinded controlled trial of 319 bronchiolitic infant subjects randomly assigned to either gas; 281 subjects completed the study (140 Heliox, 141 Airox), whose data was analyzed. Treatment was delivered via facemask (nasal cannula, if the facemask intolerant) ± continuous positive airway pressure (CPAP). Severe bronchiolitics received CPAP from the start. Primary end point was length of treatment (LoT) required to alleviate hypoxia and respiratory distress. Secondary end-points were proportion of subjects needing CPAP; CPAP (LoT); and change in respiratory distress score. RESULTS Analysis by intention to treat (all subjects); median LoT (inter-quartile range, days): Heliox 1.90 (1.08-3.17), Airox 1.87 (1.11-3.34), P = .41. Facemask tolerant subgroup: Heliox 1.46 (0.85-1.95), Airox 2.01 (0.93-2.86), P = .03. Nasal cannula subgroup: Heliox 2.51 (1.21-4.32), Airox 2.81 (1.45-4.78), P = .53. Subgroup started on CPAP: Heliox 1.55 (1.38-2.01), Airox 2.26 (1.84-2.73), P = .02. Proportion of subjects needing CPAP: Heliox 17%, Airox 19%, O.R. 0.87 (0.47-1.60), P = .76. Heliox reduced respiratory distress score after 8 hours (mixed models estimate, -0.1298; P < .001). The effect was greater for facemask compared with nasal cannula (mixed models estimate, 0.093; P = .04). CONCLUSIONS Heliox therapy does not reduce LoT unless given via a tight-fitting facemask or CPAP. Nasal cannula heliox therapy is ineffective.
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Affiliation(s)
- Mina M Chowdhury
- Department of Pediatrics, Wright Fleming Institute, Imperial College, London, United Kingdom
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21
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Colnaghi M, Pierro M, Migliori C, Ciralli F, Matassa PG, Vendettuoli V, Mercadante D, Consonni D, Mosca F. Nasal continuous positive airway pressure with heliox in preterm infants with respiratory distress syndrome. Pediatrics 2012; 129:e333-8. [PMID: 22291116 DOI: 10.1542/peds.2011-0532] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To assess the therapeutic effects of breathing a low-density helium and oxygen mixture (heliox, 80% helium and 20% oxygen) in premature infants with respiratory distress syndrome (RDS) treated with nasal continuous positive airway pressure (NCPAP). METHODS Infants born between 28 and 32 weeks of gestational age with radiologic findings and clinical symptoms of RDS and requiring respiratory support with NCPAP within the first hour of life were included. These infants were randomly assigned to receive either standard medical air (control group) or a 4:1 helium and oxygen mixture (heliox group) during the first 12 hours of enrollment, followed by medical air until NCPAP was no longer needed. RESULTS From February 2008 to September 2010, 51 newborn infants were randomly assigned to two groups, 24 in the control group and 27 in the heliox group. NCPAP with heliox significantly decreased the risk of mechanical ventilation in comparison with NCPAP with medical air (14.8% vs 45.8%). CONCLUSIONS Heliox increases the effectiveness of NCPAP in the treatment of RDS in premature infants.
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Affiliation(s)
- Mariarosa Colnaghi
- NICU, Fondazione IRCCS Cà Granda - Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy.
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22
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Abstract
PURPOSE OF REVIEW Electrical impedance tomography (EIT) is an attractive method of monitoring patients during mechanical ventilation because it can provide a noninvasive continuous image of pulmonary impedance, which indicates the distribution of ventilation. This article will discuss ongoing research on EIT, with a focus on methodological aspects and limitations and novel approaches in terms of pathophysiology, diagnosis and therapeutic advancements. RECENT FINDINGS EIT enables the detection of regional distribution of alveolar ventilation and, thus, the quantification of local inhomogeneities in lung mechanics. By detecting recruitment and derecruitment, a positive end-expiratory pressure level at which tidal ventilation is relatively homogeneous in all lung regions can be defined. Additionally, different approaches to characterize the temporal local behaviour of lung tissue during ventilation have been proposed, which adds important information. SUMMARY There is growing evidence that supports EIT usage as a bedside measure to individually optimize ventilator settings in critically ill patients in order to prevent ventilator-induced lung injury. A standardization of current approaches to analyse and interpret EIT data is required in order to facilitate the clinical implementation.
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23
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Szczapa T, Gadzinowski J. Use of heliox in the management of neonates with meconium aspiration syndrome. Neonatology 2011; 100:265-70. [PMID: 21701217 DOI: 10.1159/000327531] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 03/08/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND Helium-oxygen mixture (heliox) ventilation has been known as an alternative treatment in patients with airway obstruction. Because of the physical properties of heliox, mechanical ventilation with this gas mixture may offer advantages in the management of respiratory failure associated with meconium aspiration syndrome (MAS). OBJECTIVES The purpose of this pilot study was to assess the effect of short-term mechanical ventilation with heliox in newborns with MAS on vital signs, oxygenation, acid-base balance and respiratory function parameters. METHODS The study was carried out in newborns with respiratory failure requiring mechanical ventilation due to MAS. Eight patients were ventilated using pressure-controlled synchronized intermittent mandatory ventilation. Parameters of respiratory function, oxygenation, acid-base balance and vital signs were recorded at baseline, then twice during 1 h of heliox ventilation and finally twice during 1 h after switching back to air-oxygen ventilation. RESULTS Mechanical ventilation with heliox did not affect vital signs and the infants' clinical condition remained stable during the study. Heliox ventilation was associated with a nonsignificant increase in tidal volume, minute ventilation and peak expiratory flow rate values. Mechanical ventilation with heliox allowed the use of significantly lower FiO(2), with a significant decrease in alveolar-arterial oxygen tension difference and a decrease in the oxygenation index which was not statistically significant. There was also a significant increase in the PaO(2)/FiO(2) ratio during heliox ventilation. CONCLUSIONS Ventilation with a helium and oxygen mixture had a positive effect on the selected parameters of oxygenation, while its effects on other respiratory parameters were relatively small.
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Affiliation(s)
- Tomasz Szczapa
- Department of Neonatology, Poznań University of Medical Sciences, Poznań, Poland.
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24
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Bueno SM, González PA, Riedel CA, Carreño LJ, Vásquez AE, Kalergis AM. Local cytokine response upon respiratory syncytial virus infection. Immunol Lett 2010; 136:122-9. [PMID: 21195729 DOI: 10.1016/j.imlet.2010.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 11/01/2010] [Accepted: 12/06/2010] [Indexed: 11/28/2022]
Abstract
Respiratory syncytial virus (RSV) is the leading cause of childhood hospitalization and respiratory distress and has been recognized for several decades as a major health and economic burden worldwide. This virus has developed several virulence mechanisms to impair the establishment of a protective immune response to re-infection. Accordingly, inefficient immunological memory is usually generated after exposure to this pathogen. Furthermore, it has been shown that RSV can actively promote the induction of an inadequate cellular immune response at the site of infection that causes exacerbated inflammation in the respiratory tract. Such an inflammatory response is both inefficient for clearing the virus and can be responsible for detrimental symptoms, such as asthma and wheezing. Recent data suggest that RSV possesses molecular mechanisms to induce the secretion of pro-inflammatory cytokines that modulate the immune response and impair viral clearance by reducing IFN-γ production. Here, we discuss recent research leading to the identification of RSV virulence factors that are responsible of promoting a pro-inflammatory environment at the airways and their implications on pathogenicity.
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Affiliation(s)
- Susan M Bueno
- Millennium Nucleus on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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25
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Abstract
BACKGROUND Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing. OBJECTIVES To assess heliox in addition to standard medical care for acute bronchiolitis in infants. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2), which includes the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, MEDLINE (1966 to June 2009), EMBASE (June 2009), LILACS (May 2009) and the NIH web site (May 2009). SELECTION CRITERIA Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data and assessed trial quality. We pooled data from individual trials. MAIN RESULTS We included four trials involving 84 infants under two years of age with respiratory distress secondary to bronchiolitis caused by respiratory syncytial virus (RSV) and requiring paediatric intensive care unit (PICU) hospitalisation. We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation (mean difference (MD) -1.15, 95% confidence interval (CI) -1.98 to -0.33, P = 0.006, n = 69). There was no clinically significant reduction in the rate of intubation (risk ratio (RR) 1.38, 95% CI 0.41 to 4.56, P = 0.60, n = 58), in the need for mechanical ventilation (RR 1.11, 95% CI 0.36 to 3.38, P = 0.86, n = 58), or in the length of stay in a PICU (MD = -0.15 days, 95% CI -0.92 to 0.61, P = 0.69, n = 58). No adverse events related to heliox inhalation were reported. AUTHORS' CONCLUSIONS Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. Nevertheless, there was no reduction in the rate of intubation, in the need for mechanical ventilation, or in the length of PICU stay. Further studies with homogeneous logistics in their heliox application are needed. Such studies would provide necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.
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Affiliation(s)
- Jean-Michel Liet
- Pediatric Intensive Care Unit, Hôpital Mère-Enfant, CHU de Nantes, 38 Boulevard Jean-Monnet, Faïencerie, Nantes, France, 44093
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26
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Eastwood PR, Maher TM, Wells AU, Lam B. Year in review 2009: Interstitial lung diseases, acute injury, sleep, physiology, imaging and bronchoscopic intervention. Respirology 2010; 15:172-81. [PMID: 20199638 DOI: 10.1111/j.1440-1843.2009.01696.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter R Eastwood
- West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Perth, Western Australia 6009, Australia.
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