Inter-ethnic differences in postoperative pethidine requirements.

A preliminary study of 24 hours' postoperative analgesia using a patient-controlled analgesia technique was undertaken in eight European and fourteen Asian adult patients. All patients had upper abdominal surgery and received weight-related doses of pethidine postoperatively via a Cardiff Palliator. Both groups had a similar degree of analgesia as assessed by visual analogue score but the Asian patients were more sedated in the postoperative period. The Asian patients made 24% fewer demands for analgesia and had a smaller mean (SD) pethidine consumption, 7.62 (2.04) mg.kg-1, compared with the European patients, 9.97 (2.14) mg.kg-1, (P less than 0.05) during the first 24 hours. Further research is necessary to determine whether the smaller requirement for analgesia in Asian patients is a result of pharmacokinetic or pharmacodynamic differences.