[Intravenous patient-controlled analgesia with pethidine for the treatment of postoperative pain in patients undergoing upper abdominal surgery].

Intravenous patient-controlled analgesia (PCA) with pethidine (standard technique of self-administration of pethidine) for the treatment of postoperative pain in 10 patients who had undergone abdominal surgery was evaluated. Serum pethidine concentration also was measured in order to evaluate the suitability of dose of pethidine. After an operation, intravenous PCA pump (CADD-PCA, Model 5200 PXC, Pharma Deltec) was attached to intravenous line with a basal infusion rate of 50 mg.12 h-1 of pethidine, and set to administer pethidine 5 mg intravenously by rapid bolus no more frequently than once every 20 min until 72 hours postoperatively. Verbal descriptor score, doses of pethidine, serum level of pethidine and side effect were evaluated each 12 hour period until 72 postoperative hours. Pain scores within 36 postoperative hours were comparable and stable analgesia was obtained throughout 72 postoperative hours. In only two cases out of 9 pain score improved according to the elevation of serum pethidine concentration. We conclude PCA with pethidine is effective for postoperative pain in patients after upper abdominal surgery, but administered doses in this study is not enough to achieve complete relief of postoperative pain in view of the serum level of pethidine.