The bronchodilator effect of intravenous glucagon in asthma exacerbation: A randomized, controlled trial

Study objective: Glucagon is a rapid-acting smooth muscle relaxant with a s hort half-life. Previous studies suggested glucagon may have bronchodilator effects. We sought to determine whether intravenous glucagon produces clin ically important immediate bronchodilation in emergency department patients with asthma exacerbation. Methods: We conducted a randomized, double-blind, placebo-controlled study at 2 university-affiliated community teaching hospital EDs (annual census 9 0,000). ED patients 18 to 50 years old with asthma exacerbation and peak ex piratory flow rate (PEFR) less than 350 L/min were eligible. Exclusion crit eria were need for intubation, chronic obstructive pulmonary disease, diabe tes mellitus, insulinoma, pheochromocytoma, pregnancy, lactation, or curren t oral steroid treatment. Patients were randomly assigned to receive glucag on 0.03 mg/kg or an equivalent volume of saline solution intravenously. At 10 minutes, PEFR was measured and all patients began standardized albuterol therapy. Successful bronchodilation was a PEFR increase of 66 L/min at 10 minutes. Results: Success occurred in 2 (9.5%) of 21 glucagon-treated patients and 3 (12%) of 25 placebo-treated patients (95% confidence interval [CI] for dif ference of -2.5% [-20.4% to 15.4%]). Mean PEFR improvement for glucagon was 2 L/min versus 9 L/min for placebo (95% CI for difference of -7 L/min [-36 L/min to 23 L/min]). Conclusion: Glucagon alone provided no clinically important immediate bronc hodilation in ED patients with asthma exacerbation.