THE EFFECTS OF CONTINUOUS INHALATION THERAPY WITH LOW CONCENTRATION OF ISOPROTERENOL IN STATUS ASTHMATICUS

1-isoproterenol hydrochloride is a strong bronchodilator acting on the β-adrenergic receptors. Efficacy of continuous inhalation therapy with isoproterenol has been approved but the optimal concentration of the drug for inhalation is not standardized. We studied the efficacy and safty of continuous inhalation therapy with low-dose isoproterenol for patients with status asthmaticus. The results were as follows;(1) Remarkable improvement of clinical symptoms was seen in 9 of 14 patients (64.3%). Significant adverse effects of the drug, which led prompt discontinuation of the thrapy, were recognized in 2 patients but these adverse effects disappeared promptly after stopping the drug.(2) Significant improvement in heart rate, respiratory rate, PaCo2, O2 saturation and pH was seen within 1 hour after initiation of the therapy.(3) The therapy prevented respiratory failure in most patients at the early stage of the inhalation therapy.(4) There was no difference in improvement in any of the tested concentrations of 7.5-12.5μg/kg/hr.Those results suggested that continuous inhalation therapy with low-dose isoproterenol for the treatment of status asthmaticus is effective and safe.