Predicting recovery from acute asthma in an emergency diagnostic and treatment unit

Objective: Optimal use of emergency di agnostic and treatment unit (EDTU) r esources for treatment of acute asthma should be facilitated by the selecti on of patients with a high probability of discharge from the EDTU. The stud y goal was to identify characteristics of the patient or exacerbation that could be used to predict recovery of pulmonary function within 12 hours. Me thods: Comprehensive cohort design in an urban public hospital. The subject s were 269 patients with moderately severe asthma exacerbations. Data were collected for historical and presenting features and response to treatment over 12 hours. Two outcomes were examined: 1) discharge from the EDTU and 2 ) achieving 50% predicted peak expiratory flow rate (PEFR) within 12 hours. Results: The two outcomes showed good concordance. The third-treatment PEE R was found to be predictive of both discharge and reaching 50% predicted P EER within 12 hours. Since the objective measure of reaching 50% predicted PEFR is more readily defined and thus more generalizable, the authors focus ed on this outcome when describing prediction zones. Patients with 40% or h igher PEER after third treatment had an 89% probability of reaching 50% pre dicted in 12 hours, while those with a third-treatment PEER lower than 32% predicted had only a 22% probability. Conclusions: A simple objective measu re of pulmonary function early in treatment discriminated among those with high, low, and intermediate probabilities of achieving a specified level of PEER within 12 hours. Awareness of this probability could assist clinician s attempting to predict discharge from the EDTU and facilitate decision mak ing regarding utilization of EDTU resources.