Article

Canadian Anaesthetists’ Society Journal

, Volume 27, Issue 6, pp 531-534

The effect of halothane with nitrous oxide on baroreflex control of heart rate in man

  • P. C. DukeAffiliated withDepartment of Anaesthesia, Health Sciences Centre, University of Manitoba
  • , S. TroskyAffiliated withDepartment of Anaesthesia, Health Sciences Centre, University of Manitoba

Abstract

To assess the effect of halothane with 70 percent nitrous oxide on the human baroreflex, we observed the heart rate response to pharmacological elevation of blood pressure in subjects anaesthetized to the 1 MAC and 1.25 MAC levels. We observed, in comparison to the awake control, that at I MAC halothane with 70 per cent nitrous oxide and oxygen, the baroreflex was depressed and this became more significant at 1.25 MAC anaesthesia. In comparison to previous similar studies on the effect of halothane-oxygen anaesthesia, there was significantly less baroreflex depression at equianaesthetic doses with halothane with 70 per cent nitrous oxide.

Ré SUMé

Pour é valuer l’ action de 1’ halothane sur le systè me barorecepteur ré flexe de l’ humain, on a é tudié le comportement de la fré quence cardiaque aprè s l’ é lé vation de la tension arté rielle induite pharmacologiquement chez des sujets anesthé sies aux niveaux MAC 1 et MAC 1. 25. Lorsqu’ on a comparé avec les contrô les obtenus au pré alable chez les sujets é veillé s, on a observé une dé pression du systè me baroré cepteur ré flexe à MAC 1 par 1’ halothane dans un mé lange protoxyde d’ azote (70 pour cent) oxygè ne dé pression qui s’ accentuait lorsque le MAC atteignait 1.25. Cette dé pression du systè me ré flexe a é té moindre à des concentrations é quivalentes d’ halothane dans le mvlange protoxyde à 70 pour cent que celle rapporté e lors d’ é tudes similaires anté rieures.