[Experiences with combined catheter-peridural anesthesia and nitrous oxide-oxygen ventilation in patients at risk in gynecology and obstetrics].

In 271 gynaecological or obstetrical patients a "combined anaesthesia method" was applied, consisting of lumbar catheter epidural analgesia and controlled ventilation with nitrous oxide/oxygen. We aim to show that by mere interaction of the local anaesthetic, with nitrous oxide, and the drugs used for premedication and during induction of anaesthesia a stage of sleep can be achieved, which, on the patient's behalf is identical with his idea of "full anaesthesia", while at the same time the use of centrally acting agents can be kept at a minimum. In incidents of sympatho-adrenergic-stimulation due to insufficient cephalad spread of the blockade and not amenable to additional doses of local anaesthetic, i.v. fentanyl or low concentrations of volatile anaesthetics were added. In the postoperative phase the patients showed a high degree of vigilance. Epidural morphine offered best pain relief with full mobility maintained. In cases with postoperative hypertensive crises, morphine was combined with bupivacaine injections. Even marked obesity or senile degenerative changes in the vertebral column proved not to constitute contraindications for this method.