Study objective: To compare continuous nebulization with the use of a metered-dose inhaler (MDI) with spacer device for delivery of albuterol in acute bronchospastic episodes in the emergency department. Design: Prospective, randomized, double-blinded, placebo-controlled clinical trial. Setting: Urban ED with a 28,000 annual census. Participants: Patients older than 18 years of age presenting to the ED with an acute bronchospastic episode. Intervention: After conducting evaluation and collecting baseline data, we treated each patient with a continuous-flow nebulizer set to deliver 15 mg/hour of albuterol or a placebo by face mask. Subsequently, each patient received four puffs (albuterol or placebo) from an MDI with a spacer device. The four MDI puffs were followed by 5 minutes on nebulization, and this sequence was continued until predetermined therapeutic end points were reached or side effects developed. The optimal MDI dose was then determined and repeated each hour for the 3-hour time period of the study. Results: Repeated-measures ANOVA testing revealed statistically and clinically significant improvements over time within each treatment group in peak flow (F=3.864, P =.0057), Borg score (F=14.77, P =.0001), pulse (F=9.642, P =.0001), and respiratory rate (F=3.081, P =.0093). However, no significant differences could be detected between treatment groups over time except for systolic blood pressure (F=8.231, P =.0141), and this change was not considered clinically significant. Conclusion: On the basis of the findings of this study, we conclude that continuous nebulization is equally effective as MDI with spacer device for delivery of albuterol to treat acute bronchospastic episodes in the ED. Each method of delivery offers advantages. Each ED should decide which modality to use on the basis of its own resources. [Levitt MA, Gambrioli EF, Fink JB: Comparative trial of continuous nebulization versus metered-dose inhaler in the treatment of acute bronchospasm. Ann Emerg Med September 1995;26:273-277.]