[Comparing studies on the influence of dopamine and orciprenaline on cardiac and renal function of patients after cardiac surgery (author's transl)].

Cardiac and circulatory function (cardiac output, stroke volume, heart rate, mean arterial pressure = MAP, total peripheral resistance = TPR), further renal function (PAH- and inulin clearance, filtration fraction, urinary excretion, renal sodium- and potassium excretion) were measured on 15 patients undergoing cardiac surgery to whom Dopamine and Orciprenaline were administered in increasing doses of 100 mug - up to 500 mug/min (Dopamine) and 10 mug - to 20 mug/min (Orciprenaline). An infusion of Dopamine up to 250 mug/min caused a dosis-related increase of the cardiac output up to 31% (2P less than 0.001) without essential increasing of the MAP and of the heart rate. Dopamine caused a decrease of the TPR up to 24%. Doses of Dopamine over 250 mug/min cause an increase of the MAP and of the heart rate without a real increase of the cardiac output. Renal function improved under increasing doses of Dopamine, effective renal plasma flow (ERPF) up to 74%, urinary excretion up to 130%, sodium and potassium excretion up to 60% respectively. After administering Orciprenaline in a dosis of 20 mug/min cardiac output increases up to 28%, MAP and heart rate up to 12% and 17% respectively. After the administration of Orciprenaline (20 mug/min) and Dopamine (500 mug/min) frequent extra systoles were observed without any increase of the cardiac output; MAP increased by 12%, TPR decreased by 16% after 20 mug/min of Orciprenaline. ERPF decreased slightly after Orciprenaline. Urinary excretion was reduced by a half.