Heliox delivered by high flow nasal cannula improves oxygenation in infants with respiratory syncytial virus acute bronchiolitis^☆

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 8 L/min for a continuous 24 h. Measurements were taken at baseline, after 2 h, and at the end of the 24 h.

Results:

This prospective study included 48 patients. After 2 h of treatment with heliox, the oxygen saturation and PaO₂ significantly improved when compared with the air-oxygen group, 98.3% vs. 92.9%, 62.0 mmHg vs. 43.6 mmHg (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), 2 h 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.

KEYWORDS
Heliox; High flow nasal cannula; RSV; Bronchiolitis