The effect of spinal analgesia and surgery on peroperative drug absorption and gastric emptying in man.

Paracetamol 20 mg kg-1 dissolved in 200 ml of water was given by mouth to seven patients undergoing minor orthopaedic surgery in spinal analgesia, and again 2 weeks later. The rate of paracetamol absorption was significantly delayed by spinal analgesia and surgery, indicating an inhibition of peroperative drug absorption and gastric emptying. The effect of spinal analgesia on gastric emptying was not able to normalize the delayed peroperative gastric emptying produced by surgery, and suggests that surgery is an important factor in peroperatively delayed gastric emptying.