title: Heliox inhalation therapy for bronchiolitis in infants.
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.
  
  
  OBJECTIVE
  To assess heliox in addition to standard medical care for acute bronchiolitis in infants.
  
  
  METHODS
  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).
  
  
  METHODS
  Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis.
  
  
  METHODS
  Two review authors independently extracted data and assessed trial quality. We pooled data from individual trials.
  
  
  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.
  
  
  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.
authors.affiliation: Pediatric Intensive Care Unit, Hôpital Mère-Enfant, CHU de Nantes, 38 Boulevard Jean-Monnet, Faïencerie, Nantes, France, 44093.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Liet
authors.forename: Thierry
authors.initials: T
authors.lastname: Ducruet
authors.forename: Vineet
authors.initials: V
authors.lastname: Gupta
authors.forename: Gilles
authors.initials: G
authors.lastname: Cambonie
mesh_terms: D000208:Acute Disease; D000280:Administration, Inhalation; D001990:Bronchiolitis, Viral / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D015278:Intensive Care Units, Pediatric / Q000706:statistics & numerical data; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data; D007902:Length of Stay; D010100:Oxygen / Q000008:administration & dosage*; D016032:Randomized Controlled Trials as Topic; D018357:Respiratory Syncytial Virus Infections / Q000150:complications*
chemical_list: D001993:Bronchodilator Agents; D006371:Helium; C038949:heliox; D010100:Oxygen