[Extrarenal effects of potassium-canrenoate. Haemodynamic investigations during neuroleptanalgesia in cardiosurgical patients (author's transl)].

Direct cardiac and vascular effects of the antikaliuretic diuretic potassium-canrenoate were measured in cardio-surgical patients during extracorporal circulation and immediatly after operations, each time in neuroleptanalgesia. During "steady state" extracorporeal circulation (aorta cross-clamped, constant flow rate of heart-lung-machine, constant hypothermia), in 13 patients no significant influence on peripheral circulation was found after i.v.-injection of 800 mg potassium-canrenoate. Neither arterial perfusion pressure (representing an arterial vascular reaction) nor changes in oxygenator-volume (indicating venous vasodilation or contraction) demonstrated significant differences in comparison to a control group. After cardiac surgery haemodynamic measurements were performed for a period of 60 minutes in 10 patients given 800 mg potassium-canrenoate. In comparison with a control group (n = 6), no significant differences in arterial pressure, heart rate, cardiac index and pulmonary arterial pressure were found. Left ventricular measurements, using a catheter tip manometer, revealed no direct positive inotropic effect of a single i.v.-injection of potassium-canrenoate. In acute myocardial failure during anaesthesia or in "low cardiac ouptut" following open heart surgery no improvement in myocardial contractility is obtained by i.v.-application of potassium-canrenoate; at the present there seems no alternative to other positive inotropic agents such as calcium, glucagon, dopamine, orciprenaline and epinephrine.