Background. To provide postoperative analgesia by spinal anesthesia, we compared the quality of analgesia and side effects of two doses of morphine added to ropivacaine in kidney donors. 

Materials and Methods. Thirty renal donors underwent nephrectomy under standard general anesthesia. After the operation, the patients were randomly allocated into two groups of intrathecal doses for spinal anesthesia: the 0.5 group (n = 15) received a total volume of 4 mL including 0.5 mg morphine, 10 mg ropivacaine, and 0.9% NaCl, and the 0.3 group (n = 15), a total volume of 4 mL including 0.3 mg morphine, 10 mg ropivacaine, and 0.9% NaCl. After extubation, an intravenous (IV) morphine protocol was initiated by a patient-controlled analgesia pump to provide sufficient spinal analgesia. 

Results. In the 0.3 group, the IV morphine consumption was significantly higher, namely, 14.60 +/- 7.57 times versus 4.60 +/- 10.14 times for the 0.5 group (P = .005). The total amount of morphine was 7.80 +/- 5.40 mg in the 0.5 group and 13.53 +/- 5.30 mg in the 0.3 group (P < .05). Postoperative side effects of nausea and vomiting were higher among the 0.3 group (P < .05). 

Conclusions. In the 0.5 group, the quality of analgesia was better than in the 0.3 group. The need for IV morphine was less in the 0.5 group. Also, side effects like nausea and vomiting were less, so better analgesia in the postoperative period was obtained with the 0.5 mg morphine solution.