Therapy of acute asthma: I. Evaluation of successive bronchodilator treatments.

Ninety-one children with acute asthma were studied to determine the extent of incremental improvement in pulmonary function afforded by successive doses of subcutaneous epinephrine, and by a bronchodilator aerosol in those patients refractory to epinephrine. A significant proportion of patients (69%), as expected, responded to the first injection. Among those who did not respond to the first injection a significant proportion (30%) responded to the second injection. Markedly fewer patients responded to subsequent bronchodilator treatments, including aerosols, if they did not improve significantly after the first two treatments. Patients with higher initial peak flow rates (PEFR) generally required fewer epinephrine injections, and achieved higher maximal PEFR than those with lower initial PEFR. Most asthmatic patients who required hospital admission had lower initial peak flow rates, were less responsive to epinephrine injections, and achieved lower maximal rates than those who could be discharged home.