THE INFLUENCE OF DRUGS USED IN NEUROLEPTANALGESIA ON CARDIOVASCULAR AND VENTILATORY FUNCTION

The circulatory and ventilatory influences of various combinations of the narcotic analgesics phenoperidine and fentanyl, and the neuroleptics haloperidol and dehydrobenzperidol, were investigated during nitrous oxide anaesthesia in 230 patients. Measurements of cardiac output and other haemodynamic variables in nine patients supported the general findings that the cardiovascular effects of the analgesics were modified by alterations of ventilation, in particular the haemodynamic effects of concurrent hypercapnia. Serious circulatory disturbances were not found following premedication with neuroleptic drugs. Mechanisms of ventilatory depression following the use of the analgesics have been evaluated, and indices of ventilation and arterial oxygenation show that postoperative values after neuroleptanalgesia are comparable to those after other methods of anaesthesia. The rationale of neuroleptanalgesia combined with light general anaesthesia is explored and the pharmacology of the drugs is reviewed.