A Prospective Evaluation of the 1-Hour Decision Point for Admission Versus Discharge in Acute Asthma

Abstract

Study objectives were to evaluate the 1-hour decision point for discharge or admission for acute asthma; to compare this decision point to the admission recommendations of the Expert Panel Report 2 (EPR-2) guidelines; to develop a model for predicting need for admission in acute asthma. The design used was a prospective preinterventional and postinterventional comparison. The setting was a university hospital emergency department. Participants included 50 patients seeking care for acute asthma. Patients received standard therapy and were randomized to receive albuterol by nebulizer or metered-dose inhaler with spacer every 20 minutes up to 2 hours. Symptoms, physical examination, spirometry, pulsus paradoxus, medication use, and outcome were evaluated. Based on clinical judgment, the attending physician decided to admit or discharge after 1 hour of therapy. Outcome was compared to the EPR-2 guidelines. Post hoc statistical analyses examined predictors of the need for admission from which a prediction model was developed. Maximal accuracy of the admit versus discharge decision occurred at 1 hour of therapy. Using FEV(1) alone as an outcome predictor yielded suboptimal performance. FEV(1) at 1 hour plus ability to lie flat without dyspnea were the best indicators of response and outcome. A model predictive of the need for admission was developed. It performed better (P =.0054) than the admission algorithm of the EPR-2 guidelines. The decision to admit or discharge acute asthmatics from the ED can be made at 1 hour of therapy. No absolute value of peak flow or FEV(1) reliably predicts need for hospital admission. The EPR-2 guideline thresholds for admission are barely adequate as outcome predictors. A clinical model is proposed that may allow more accurate outcome prediction.

Compliance with guidelines in the treatment of asthma exacerbations in primary care

“…In our study an attempt was made to measure PEF in every patient, but a valid measurement was obtained in little more than half of the episodes (because of inappropriate technique by the patient). Similarly, other studies have reported the measurement of PEF in 30-76% of episodes [Global Initiative for Asthma, 2007;Wilson et al 2003;Neville et al 1997]. Nonetheless, our results are better than those reported by Á lvarez and colleagues (2004), who observed that only 18% of patients had undergone PEF measurement in the primary care setting in Spain.…”

Pediatric Dyspnea Scale for use in hospitalized patients with asthma

“…These measurements have shown reproducibility in adolescents12 but cost, time, effort and difficulty in obtaining these measurements during acute asthma and their questionable utility in guiding management have limited their use 13, 30. FEV1 and PEFR did not correlate with the PDS in our study showing that spirometry measurements and perception of dyspnea are at times unrelated, consistent with previous findings by other investigators 31, 32.…”

Prediction of unsuccessful treatment in patients with severe acute asthma

“…We found that oxygen flow rate predicted need for critical care, presumably reflecting that flow rate is a better predictor than saturation when treatment involves titration of oxygen flow rate to achieve target oxygen saturation. Mallmann et al 9 and Rodrigo and Rodrigo15 reported that accessory muscle use predicted need for hospital admission, while Boonsarngsuk et al 8 and Wilson et al 10 reported that the inability to lie flat were predictive of hospital admission or relapse. We did not test these variables in our analysis.…”

“…Wilson et al 10 developed a predictive score for hospital admission or relapse based on FEV1 and inability to lie flat after 1 h of bronchodilator therapy that was better than FEV1 alone (AUROC 0.88 vs 0.74). Statistical validation with bootstrap sampling generated an AUROC of 0.86.…”