Objective: Asthma is one of the most common childhood illnesses and accounts for a substantial amount of pediatric emergency department visits. Historically, acute exacerbations are treated with a beta agonist via nebulizer therapy (NEB). However, with the advent of the spacer, the medication can be delivered via a metered dose inhaler (MDI+S) with the same efficacy for mild-to-moderate asthma exacerbations. To date, no study has been done to evaluate emergency department (ED) length of stay (LOS) and opportunity cost between nebulized vs MDI+S. The objective of this study was to compare ED LOS and associated opportunity cost among children who present with a mild asthma exacerbation according to the delivery mode of albuterol: MDI+S vs NEB.
Methods: A structured, retrospective cross-sectional study was conducted. Medical records were reviewed from children aged 1-18 years treated at an urban pediatric ED from July 2007 to June 2008 with a discharge diagnosis International Classification of Disease-9 of asthma. Length of stay was defined: time from initial triage until the time of the guardian signature on the discharge instructions. An operational definition was used to define a mild asthma exacerbation; those patients requiring only one standard weight based albuterol treatment. Emergency department throughput time points, demographic data, treatment course, and delivery method of albuterol were recorded.
Results: Three hundred and four patients were analyzed: 94 in the MDI+S group and 209 in the NEB group. Mean age in years for the MDI+S group was 9.57 vs 5.07 for the NEB group (p<0.001). The percentage of patients that received oral corticosteroids was 39.4% in the MDI+S group vs 61.7% in the NEB group (p<0.001). There was no difference between groups in: race, insurance status, gender, or chest radiographs. The mean ED LOS for patients in the MDI+S group was 170 minutes compared to 205 minutes in the NEB group. On average, there was a 25.1 minute time savings per patient in ED treatment time (p<0.001; 95% CI=3.8-31.7). Significant predictors of outcome for treatment time were chest radiograph, steroids, and treatment mode. Opportunity cost analysis estimated a potential cost savings of $213,532 annually using MDI+S vs NEB.
Conclusion: In mild asthma exacerbations, administering albuterol via MDI+S decreases ED treatment time when compared to administering nebulized albuterol. A metered dose inhaler with spacer utilization may enhance opportunity cost savings and decrease the left without being seen population with improved throughput.
Limitations: The key limitations of this study include its retrospective design, the proxy non-standard definition of mild asthma exacerbation, and the opportunity cost calculation, which may over-estimate the value of ED time saved based on ED volume.