[Alfentanil, a new, short-acting opioid. Hemodynamic and respiratory aspects].

The haemodynamic and respiratory-depressive effects of 20 micrograms/kg and 40 micrograms/kg of alfentanil in 54 patients with coronary bypass operation were compared with a control group (n = 36). The measurements were carried out at 3 different times, each lasting over a 10 min period: 1. Before induction of anaesthesia but after premedication with flunitrazepam. 2. During anaesthesia and 3. during extracorporeal circulation (standardized conditions).--The preoperative as well as the intraoperative investigations showed a reduction in pulse rate, mean arterial pressure, left ventricular pressure and arterial perfusion pressure during extracorporeal circulation. As cardiac output remained constant in the awake patient, peripheral vasodilatation was predominant. Aside from this during anaesthesia reduction in cardiac output may have been responsible for the decrease in pressure although the cause of this could be the nitrous oxide as well. During the preoperative period a clear increase in wedge pressure, mean pulmonary artery pressure, right atrial pressure and pulmonary vascular resistance occurred from the 3rd minute after the injection. The cause is a vasoconstriction during apnoea. In the intraoperative period this did not occur. The respiratory depression(paO2: -34%, paCO2: +29%) resembles that after fentanyl, except that it starts earlier and lasts for a shorter time. In summary, it can be stated that all effects after alfentanil are similar to those of fentanyl.