Hypokalaemia following nebulized salbutamol in children with acute attack of bronchial asthma

Objective: To determine whether use of nebulized salbutamol therapy for treatment of an acute attack of asthma in children is associated with hypokalaemia and if so what is its frequency, severity and effect on recovery. Methodology: Forty-six children, aged 10 months to 12 years (mean 7.9 +/- 1.5 years) with acute attack of bronchial asthma, treated initially with three doses of nebulized salbutamol 0.15-0.3 mg/kg, every 30 min participated in the study. Blood for serum potassium was obtained at the beginning and after three doses of nebulized salbutamol therapy, before administering other drugs. Results: The mean +/-SD serum potassium level decreased marginally from 3.9 +/- 0.5 mEq/L to 3.71 +/- 0.5 mEq/L (P<0.05). A decrease in serum potassium concentration was noted in 26 (56.5%) and hypokalaemia (serum potassium <3.5 mg/L) in 17 (39%) patients. It was more frequent in patients who had received oral salbutamol for the preceding 7 days. The average time taken for recovery was longer in patients who had hypokalaemia than those who had normal serum potassium concentration (8.6 +/- 2.7 h vs 6.5 +/- 2.7 h; P<0.005). Conclusions: Hypokalaemia may occur in about one-third of patients treated with three doses of nebulized salbutamol therapy, especially those on prior oral salbutamol therapy. The monitoring of serum potassium concentration may be warranted in such patients.