A predictive score for unfavorable outcome of acute asthma in the emergency room

Abstract

Background: It is sometimes difficult to decide on a safe discharge of an acute asthmatic patient from the emergency room (ER). Objective: To develop a predictive score for safe discharge of an acute asthmatic patient from the ER. Material and Method: All adult asthmatic patients who visited the ER at Ramathibodi Hospital from January 2004 to August 2005 were recruited. Vital signs, oxygen saturation, and severity factors were recorded. Salbutamol was nebulized initially and repeatedly if the peak expiratory flow rates (PEFR) were < 70% predicted or if unfavorable physical signs were seen. Systemic steroids were administered to those patients whose severity factors had been identified. Patients were admitted if further treatments were needed after the 4 th nebulization. An unfavorable outcome was defined as either hospital admission or relapse within 48 hours of the ER discharge. Univariate analysis of each variable was performed, followed by multivariate analysis of those with statistical significance. Predictive scores were derived from statistically significant factors at the cutoff point of receiver-operating curve that yielded the best area under the curve. Results: There were 905 visits from 568 patients. Predictive factors included inability to lie down on presentation and wheezing or low PEFR after the last dose of bronchodilator. A comparison of score sensitivity, specificity, and predictive values, across different cutoffs indicated that a score of ≥ 2 predicted an unfavorable outcome. Conclusion: A predictive score based on three bedside parameters might be used for a safe discharge of asthma patients from the ER.