Effect of extradural analgesia on glucose metabolism and gluconeogenesis. Studies in association with upper abdominal surgery.

Concentrations of glucose and gluconeogenic substrates across the splanchnic circulation were studied in 20 patients undergoing cholecystectomy with general anaesthesia. In 10 patients, general anaesthesia was administered alone, and in 10 general anaesthesia was combined with thoracic extradural analgesia. All patients received a constant i.v. infusion of glucose. Blood glucose concentration increased markedly in the general anaesthesia group in contrast to a moderate and shortlived increase in the patients given extradural analgesia, in whom the splanchnic release of glucose tended to be lower. The splanchnic uptake of glycerol was lower in the patients given extradural analgesia, while the uptake of lactate and the increase in alanine uptake was similar in both groups. Plasma catecholamine and serum cortisol concentrations were higher in the group receiving general anaesthesia alone, while serum growth hormone concentration was higher after surgery in the extradural group. The addition of extradural blockade to general anaesthesia suppresses the increase in blood glucose concentration--and this may be related to a reduced splanchnic release of glucose combined with an increased peripheral uptake.