ABSTRACT & COMMENTARY

Inhaled steroids in the ED treatment of asthma

Source: Sung L, et al. Randomized controlled trial of inhaled budesonide as an adjunct to oral prednisone in acute asthma. Acad Emerg Med 1998; 5:209-213.

The clinical benefit of systemic glucocorticoids for patients in the emergency department (ED) with acute asthma has been clearly demonstrated, but would the addition of an inhaled steroid in the acute setting provide any further benefit? This is the question that Sung and colleagues asked in their randomized, controlled, double-blind trial comparing inhaled budesonide to placebo, as an adjunct to oral prednisone in acute pediatric asthma.

A total of 44 patients age 6 months to 18 years with moderate-to-severe asthma were randomized to receive 2 mg of either nebulized budesonide or normal saline in a single dose. All patients received nebulized salbutamol in a standard dosing schedule, 1 mg/kg of oral prednisone, and supplemental oxygen.

There was no significant difference between the two groups in the primary outcome measure, the pulmonary index score (PIS). Although based on bedside clinical measures, the PIS has been found to significantly correlate with FEV1/FVC and hospitalization rates in a prior study. A power calculation showed that the study size was large enough to detect a previously determined minimally clinically important difference in the PIS.

There was no statistically significant difference in admission rates between the two groups. However, Sung, et al. point out that there was a "trend" toward improved PIS at one hour in the budesonide group (median=5) as compared with the placebo group (median=6; P=0.07). In addition, the children who received budesonide were released from the ED or discharged from the hospital significantly more rapidly than those who had received placebo (P=0.02). No adverse effects were seen.

Comment by Staphanie Abbuhl, MD

Even a double-blind, randomized, placebo-controlled trial, including a power calculation to determine sample size, does not always give us a straight answer. It is probably reasonable to conclude that if there is a benefit to inhaled budesonide as an adjunct to oral prednisone, it is likely a small effect or an effect that will only be understood when a large enough study is done to allow subgroup analysis.

If there is a possible additional benefit of inhaled budesonide to systemic steroids, it begs the question "why?" Is this a systemic effect, a topical effect, or both? It is possible that giving inhaled steroids is just another way of delivering systemic doses of steroids. However, it seems unlikely that a single dose of inhaled budesonide would significantly change the serum level of glucocorticoids, and, furthermore, there is no evidence that differences in dosages in the moderate to high range make a difference. In a recent study in the critical care literature, inhaled flunisolide in multiple doses was compared to placebo in severe adult asthmatics in the ED who did not receive systemic steroids initially.1

The authors found beneficial effects in the inhaled flunisolide group at 90 to 180 minutes and a lower admission rate for those patients who had symptoms greater than 24 hours. Our understanding of the glucocorticoid effect in asthma is based on anti-inflammatory action that requires six to 12 hours to occur.

As noted by the authors, the explanation for this early effect of inhaled steroids may be due to a potent topical vasoconstrictive action that could potentially reduce airway edema. In the meantime, I would favor the standard practice of PO or IV glucocorticoids while hoping for a large study that directly compares inhaled and systemic steroids.

Reference

1. Rodrigo G, Rodrigo C. Am J Respir Crit Care Med 1998; 157:698-703.