EFFICACY AND SAFETY OF A RAPID-SEQUENCE METAPROTERENOL PROTOCOL IN THE TREATMENT OF ACUTE ADULT ASTHMA

A 6-month prospective study was performed to examine the efficacy and safety of a rapid-sequence nebulized metaproterenol regimen for the tr eatment of acute asthma in adults. Patients 18 years of age or older w ho were not pregnant and who had not received beta(2)-agonist therapy were identified and started on a rapid-sequence metaproterenol regimen (15 mg) by the triage nurse. Pretreatment and posttreatment peak flow , respiratory rate, pulse rate, and blood pressure were documented. Pa tients also gave a pretreatment and posttreatment rating of the clinic al severity of their attack using a 1-to-10 visual analogue scale. Fif ty patients were entered into the study, with an average age of 38 yea rs (range, 19 to 87 years). Data were analyzed using the Wilcoxon matc hed-pairs signed rank test. Patients showed statistically significant increases in peak flow (193 to 328 L/min, P < .00001) and systolic blo od pressure (136 to 143 mm Hg, P < .0054). Statistically significant d ecreases were shown for respiratory rate (25 to 22 beats/min, P < .000 1) and clinical severity (6.2 to 3.2, P < .00001). Thirty-three patien ts (71%) who completed the protocol experienced an increase in pulse r ate. Ten (21%) had a pulse rate increase of more than 30 beats/min. Tw o (4.2%) had pulse rate increases of more than 40 beats/min. Four pati ents were removed after one or two nebulizers because of severe side e ffects. One patient's pulse rate increased to more than 200 beats/min. Although effective in reversing bronchospasm, the side effects of met aproterenol when used in rapid sequence are of major concern. (C) 1995 by W.B. Saunders Company