title: Beneficial effects of albuterol therapy driven by heliox versus by oxygen in severe asthma exacerbation.
abstract: OBJECTIVE
  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 O(2) (O(2) group) or heliox (He/O(2) = 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 O(2) 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 O(2) 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.
authors.affiliation: Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung City, Taiwan 813, Republic of China. leelin.s0996@msa.hinet.net
authors.forename: David Lin
authors.initials: DL
authors.lastname: Lee
authors.forename: Chien-Wei
authors.initials: CW
authors.lastname: Hsu
authors.forename: Huan
authors.initials: H
authors.lastname: Lee
authors.forename: Hsueh-Wen
authors.initials: HW
authors.lastname: Chang
authors.forename: Yuh-Chin T
authors.initials: YC
authors.lastname: Huang
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D004311:Double-Blind Method; D004417:Dyspnea / Q000188:drug therapy / Q000209:etiology; D005260:Female; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D016015:Logistic Models; D008297:Male; D009330:Nebulizers and Vaporizers; D010100:Oxygen / Q000008:administration & dosage*; D012129:Respiratory Function Tests; D016896:Treatment Outcome
chemical_list: D001993:Bronchodilator Agents; D006371:Helium; C038949:heliox; D000420:Albuterol; D010100:Oxygen