EFFECTS OF GENERAL ANAESTHESIA WITH HALOTHANE ON ANTRODUODENAL MOTILITY, pH AND GASTRIC EMPTYING RATE IN MAN

Abstract

Antroduodenal motility, pH and gastric emptying rate were measured in 11 patients undergoing orthopaedic or plastic surgery with general anaesthesia. Motility was measured by manometry and gastric emptying rate by the rate of paracetamol absorption. During anaesthesia, gastric emptying was delayed in eight patients. General anaesthesia with halothane reduced the duration of the interdigestive motility complex (P < 0.01), mainly by a shortening of phase II (P < 0.01) which correlated with the inhaled concentrations of halothane (P < 0.01). Anaesthesia impeded the occurrence of antral contractions during phase II (P < 0.01); the frequency of contractions was unchanged during anaesthesia, but decreased during the recovery period (P < 0.01). The amplitudes of antral contractions diminished with anaesthesia (P < 0.01), but increased after operation. The frequency of contractions in the duodenum was unchanged during phase II and reduced during phase III (P < 0.01). Gastric pH increased during and after operation (P < 0.01). General anaesthesia with halothane affects gastroduodenal motility especially during phase II, increases gastric pH and delays gastric emptying rate.