Heliox and forward-leaning posture improve the efficacy of nebulized bronchodilator in acute asthma: a randomized trial.

Background: Heliox and forward-leaning posture (torso inclined forward at 50-60° with the elbows resting on the thighs) are adjuncts in the administration of nebulized bronchodilator to patients with acute asthma.

Methods: We randomized 59 patients who presented to the emergency department in severe asthma crisis, into 4 treatment groups: nebulized bronchodilator + oxygen; nebulized bronchodilator + oxygen + forward-leaning posture; nebulized bronchodilator + heliox; and nebulized bronchodilator + heliox + forward-leaning posture. Before and after the bronchodilator treatments the subjects were seated with torso erect, breathing room air. Each subject received 2 doses, 20 min apart, of nebulized fenoterol (2.5 mg) plus ipratropium bromide (0.25 mg) in 3 mL of 0.9% saline, delivered with a semi-closed valved aerosol reservoir. The nebulizer was run with oxygen or 80:20 heliox. The post-treatment pulmonary function tests were performed 15 min after the second nebulization. The group's mean age was 35.1 ± 13.6 y, and there were 20 men and 39 women.

Results: The oxygen + forward-leaning-posture group had a greater FEV(1) improvement than the oxygen group (59% vs 38%, P = .02). The heliox + forward-leaning-posture group had a greater FEV(1) improvement than the oxygen group (103% vs 38%, P = .001) and the heliox group (103% vs 42%, P = .03). The heliox group had greater reduction in respiratory rate than the oxygen group (P = .03). The heliox + forward-leaning-posture group had significantly greater peak expiratory flow improvement than any of the other groups.

Conclusions: Heliox plus forward-leaning posture during bronchodilator nebulization improves bronchodilator efficacy in patients with severe acute asthma. (ClinicalTrials.gov registration NCT00922350).