The independent metabolic effects of halothane and isoflurane anaesthesia.
Twelve healthy, unpremedicated women scheduled for total abdominal hysterectomy were given either isoflurane (n = 6) or halothane (n = 6) anaesthesia. They all received general anaesthesia for a period of 3 h, with surgery being carried out only in the last hour. The anaesthesia consisted of thiopentone, pancuronium and a mixture of oxygen-enriched air (FiO2 = 34%) supplemented with 1 MAC of either isoflurane or halothane. The patients were maintained normothermic, and with an arterial SaO2 above 95% throughout the period of the study. The following measurements were made before, during and after anaesthesia (with and without surgery): oxygen consumption (VO2), carbon dioxide production (VCO2); circulating concentrations of various hormones (insulin, growth hormone and cortisol); various metabolites; selected amino acids and albumin; forearm arterio-venous concentration difference of glucose, lactate, free fatty-acids and selected amino acids (four patients in each group). Whole body VO2 decreased significantly by over 20% during anaesthesia (with or without surgery), P < 0.05). Although the circulating concentration of most amino acids showed little or no change during anaesthesia alone, there was a tendency for the flux of most metabolites to decrease, and this persisted during surgery (P < 0.05). During anaesthesia alone there was a twofold reduction in the plasma cortisol concentration (P < 0.05), and a decrease in albumin concentration (P < 0.01). With the onset of surgery, plasma cortisol concentration increased rapidly (in association with several other hormones and metabolites) but hypoalbuminemia persisted.
Carli
F
F
Department of Anaesthesia, Northwick Park Hospital, Harrow, United Kingdom.
Ronzoni
G
G
Webster
J
J
Khan
K
K
Elia
M
M
D000328:Adult; D000769:Anesthesia, Inhalation; D017558:Elective Surgical Procedures; D005260:Female; D006221:Halothane; D006801:Humans; D007044:Hysterectomy; D007530:Isoflurane; D008660:Metabolism / Q000187:drug effects*; D008875:Middle Aged
D007530:Isoflurane; D006221:Halothane