Naloxone does not influence breathing during isoflurane anaesthesia

Abstract

Naloxone influences ventilation, probably by an action on endogenous opioids, in several conditions in which ventilation is reduced or impaired. Ventilatory depression is a feature of anaesthesia; some of the actions of anaesthetic drugs have been attributed to endogenous opioids. Naloxone was given to two groups of patients to investigate the possibility that ventilatory depression might be reversed. Patients breathed iso-flurane in oxygen (1.5% end-tidal) or isoflurane in 67% nitrous oxide in oxygen (0.75% end tidal) which are approximately equivalent MAC values. Naloxone 2 mg, i. v. given during surgery had no influence on ventilation or ventilatory timing in either group. © 1987 British Journal of Anaesthesia.