Beneficial Effects of Albuterol Therapy Driven by Heliox versus by Oxygen in Severe Asthma Exacerbation

Objectives: To determine and define the beneficial effects of heliox‐driven albuterol therapy on severe asthma exacerbation and clinical factors that affect greater response. Methods: The authors conducted two randomized, double‐blinded, controlled trials in patients with severe asthma exacerbation. The first trial recruited 80 patients in the emergency department (ED). They received three consecutive doses of albuterol delivered by a nebulizer powered by either O₂ (O₂ group) or heliox (He/O₂= 80:20; heliox group). Changes in peak expiratory flow rate (PEF) were compared, and factors influencing the response to heliox‐driven albuterol therapy were identified. The second trial of 80 patients was conducted in older patients, a subpopulation associated with greater response in the first trial. Results: In the first trial, the heliox group had more rapid and greater improvement in PEF compared with the O₂ group. There tended to be more patients in the heliox group reaching the predetermined dischargeable PEF (>60% predicted) after three albuterol treatments (odds ratio, 2.58; 95% confidence interval = 1.03 to 6.46; p = 0.069). For patients eventually discharged from the ED, the ED stay was shorter by 10 minutes per patient in the heliox group compared with the O₂ group (p = 0.007). Logistic regression showed older age and lower pretreatment PEF to be associated with favorable heliox responses. The second trial, which recruited older patients (older than 40 years), showed greater improvement in PEF and dyspnea score with heliox‐driven albuterol therapy in patients with lower pretreatment PEF. Conclusions: Heliox‐driven albuterol may be a useful adjunct therapy for older asthmatic patients with severe asthma exacerbation.