Clinical effects of heliox administration for acute bronchiolitis in young infants

Chest. 2006 Mar;129(3):676-82. doi: 10.1378/chest.129.3.676.


Objective: To assess the effect of heliox, a helium-oxygen mixture, on respiratory distress symptoms in young infants.

Design: Prospective, randomized, double-blind study.

Setting: Pediatric ICU (PICU) of a university hospital.

Patients: Twenty infants, all < 3 months old, admitted to the PICU with moderate-to-severe acute respiratory syncytial virus bronchiolitis.

Interventions: All infants were randomly and blindly assigned to inhale either heliox or an air-oxygen mixture (airox) for 1 h under an oxyhood.

Measurements and results: After 1 h, the respiratory distress score was significantly lower in the heliox group compared with the airox group (3.05 vs 5.5, p < 0.01), with a significant reduction in accessory muscles use (p < 0.05) and expiratory wheezing (p < 0.01). In contrast, inspiratory breath sounds and cyanosis did not significantly differ between groups. The ex-premature infants of the heliox group had a higher respiratory distress score at baseline compared with the term infants of this group (5.8 vs 5.2, p < 0.05) and a comparable decrease in the score at 60 min.

Conclusions: In young infants, even those born prematurely, heliox breathing induced a rapid reduction in accessory muscles use and expiratory wheezing. Further studies are needed to confirm the decreased respiratory muscle work of breathing during heliox inhalation in this population.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acute Disease
  • Bronchiolitis / drug therapy*
  • Bronchiolitis / physiopathology
  • Bronchiolitis / virology
  • Double-Blind Method
  • Helium / pharmacology
  • Helium / therapeutic use*
  • Humans
  • Hypoxia / physiopathology*
  • Infant
  • Oxygen / pharmacology
  • Oxygen / therapeutic use*
  • Prospective Studies
  • Respiratory Muscles / drug effects*
  • Respiratory Syncytial Virus Infections / drug therapy*
  • Treatment Outcome


  • Helium
  • heliox
  • Oxygen