Background: The mainstay of treatment for acute asthma in children is nebulised beta 2-adrenergic agents such as salbutamol, given with corticosteroids. However, penetration of the drug to the small airways is impeded by obstruction so intravenous salbutamol may be more effective. We assessed the use of intravenous salbutamol in the management of children with acute severe asthma in a double-blind randomised study.
Methods: Children who presented to the Emergency Department of Westmead Hospital, Sydney, Australia with asthma were assessed with a clinical assessment scale, and those with severe acute asthma were given nebulised salbutamol at a dose of 2.5 mg (age < or = 2 years) or 5.0 mg (age > 2 years), made up to 4 mL with saline. Children who did not improve were eligible to enter phase one of the study. In this phase (0 h-2 h) treatment was by a standard protocol: nebulised salbutamol at the above dose: 4 L/min or 6 L/min continuous oxygen until oxygen saturation reached 93% in room air for at least 30 min; a bolus of intravenous hydrocortisone 5 mg/kg given over 3 min; and then 15 micrograms/kg intravenous salbutamol or saline, depending on randomised allocation. In phase two (2 h-24 h) the children were given nebulised salbutamol continuously then at 30 min, 1 h, 2 h, 3 h, and 4 h, according to need. All children were transferred to the ward once they were ready to start hourly nebulisation. All patients were followed up until discharge. The primary endpoints were recovery time (no longer requiring inhaled salbutamol) and persistent moderate to severe asthma 2 h after randomisation. Analyses were by intention-to-treat although no withdrawals occurred.
Findings: The recovery time (time to cessation of nebulised salbutamol every 30 min) was 4 h in the 14 children allocated intravenous salbutamol compared with 11.5 h for the 15 children in the control group. 2 (14%) of the intravenous salbutamol group compared with 8 (53%) of the control group needed oxygen to maintain oxygen saturation at 93% room air. The intravenous salbutamol group were ready for discharge from the emergency department 9.7 h earlier than the control group. No clinically significant side-effects were found in either group.
Interpretation: Addition of a 10 min infusion of salbutamol in the early treatment of children with acute severe asthma has the potential to curtail the clinical progression of asthma, reduce demand placed on hospital resources, and improve the quality of health care provided to the acutely sick child with asthma.