Improvement in clinical asthma score and Paco 2 in children with severe asthma treated with continuously nebulized terbutaline

Abstract

We analyzed continuous nebulized terbutaline (CNT) therapy in 19 patients with 27 admissions for severe asthma and impending respiratory failure who failed to respond to our standard asthma protocol of methylprednisolone, aminophylline, and intermittently nebulized terbutaline. Terbutaline was administered by continuous face mask nebulization at a dose equaling the most frequent previous intermittent dose per hour (4 mg per hour). No patient with frank respiratory failure (i.e., Paco 2 ⩾60 torr, exhaustion, or coma) was studied. All patients improved, and therapy was stopped in a mean of 15.4 hours (range 3 to 37 hours). The average heart rate did not increase over baseline measurements through 24 hours of CNT. The mean clinical asthma score improved significantly during 8 hours, falling from 6.9 to 3.2 ( p > 0.001). In 14 patients whose Paco 2 was ⩾39 torr (range 39 to 58 torr) and clinical asthma score was 6 or greater, Paco 2 decreased a mean of 11.7 torr during a mean of 8.1 hours. In six patients whose Paco 2 was 45 torr or greater at the start of CNT (mean 49, range 45 to 58 torr) and in whom we would have previously treated with intravenous isoproterenol, Paco 2 decreased a mean of 15 torr in an average of 8.7 hours. This preliminary study suggests that CNT is an effective therapy for severe asthma in children.