Gastric emptying following caesarean section and the effect of epidural fentanyl.

The rate of absorption of paracetamol following oral administration was used as an indirect measure of the rate of gastric emptying. This was to determine the effect on gastric motility of the addition of fentanyl to a solution of local anaesthetic given into the epidural space to provide pain relief following Caesarean section. Thirty subjects were randomly allocated to receive either bupivacaine plus fentanyl or bupivacaine alone. The area under the curve of the graph of plasma paracetamol concentration versus time was calculated for each subject at 45 and 90 minutes after administration of the epidural injection, and this value was used as an index of the rate of gastric emptying. This study demonstrated that gastric emptying may be normal immediately following Caesarean section under epidural anaesthesia, but that if fentanyl is added to the epidural solution, gastric emptying is significantly slower in the first 45 minutes following surgery (p less than 0.05).