Acute asthma. Part II. The effects of therapy on heart rate and blood pressure.

This study evaluated cardiovascular effects of epinephrine in the treatment of asthma. Heart rates, systolic and diastolic blood pressures were monitored in 64 patients treated for acute asthma. Treatment regimens included subcutaneous epinephrine in doses of 0.1 to 0.5 mg. Pretreatment heart rates ranged from 64 to 136 beats per minute and systolic and diastolic blood pressures from 80 to 190 and 50 to 108 mm Hg respectively. Epinephrine in all doses and repeated as often as three times did not raise blood pressure or heart rates, and in the highest dose or in patients with pressures in the hypertensive range exerted a hypotensive effect. Adverse cardiovascular effects of epinephrine observed in normal subjects are significantly modified in acute asthma and its use should be considered in light of these findings.