Effects of general anaesthesia with enflurane on antroduodenal motility, pH and gastric emptying rate in man.

Antroduodenal motility, pH and gastric emptying rate were investigated before, during and after general anaesthesia with enflurane in 11 patients undergoing elective surgery not involving the abdomen. Motility was measured by manometry and the gastric emptying rate by the rate of paracetamol absorption. During anaesthesia gastric emptying rate was delayed in nine patients. General anaesthesia with enflurane nearly abolished the motility in the antrum. The duration of successive interdigestive motor complexes was reduced (P less than 0.001) mainly be a reduction in Phase II (P less than 0.01). The frequency of contractions was unchanged in the duodenum during Phase II and decreased during Phase III (P less than 0.01). The amplitudes of contractions were unchanged in the proximal part of the duodenum and decreased in the distal part (P less than 0.01). General anaesthesia with enflurane increased the gastric pH per- and post-operatively (P less than 0.01). Motility in the antrum was rapidly regained in the recovery period. General anaesthesia with enflurane seems to delay gastric emptying rate by affecting the motility in the gastric antrum. The acidity of the stomach contents is reduced.