Comparison of Pain-relieving Effects of Fentanyl versus Ketorolac after Eye Amputation Surgery

PURPOSE To investigate the analgesic effect and incidence of postoperative nausea and vomiting (PONV) between the opioid fentanyl and the non-steroidal anti-inflammatory drug ketorolac in patients who underwent eye amputation surgery. METHODS Retrospective observational case series. Eighty-two patients underwent evisceration or enucleation surgery by one surgeon over a 2-year period. Fentanyl by intravenous patient-controlled analgesia (IV-PCA) at 20 µg/kg with 12 mg/kg ondansetron or intravenous ketorolac at 2 mg/kg/day was administered to patients at postoperative days 0, 1, and 2. The pain score was measured using an 11-point visual analog scale (VAS). The incidence of severe nausea requiring anti-emetics and the incidence of vomiting were reviewed. RESULTS The mean postoperative VAS in the fentanyl group was significantly lower than that in the ketorolac group on the day of operation for both types of surgery (p = 0.001 and p = 0.004, respectively). At postoperative days 1 and 2, the mean VAS was not different between the two groups for either surgical type (p > 0.05 for both days). The mean VAS was significantly higher in eviscerated patients than in enucleated patients at postoperative days 0 and 1 in the fentanyl group (p = 0.023 and p = 0.016, respectively). However, this was not observed in the ketorolac group. The incidence of PONV was higher in the fentanyl group than in the ketorolac group, although this was not statistically significant for either surgical type (p > 0.05 for both groups). CONCLUSIONS Fentanyl was more effective as an analgesic than was ketorolac on the day of operation for both surgical types. There was no difference between the two analgesics on postoperative day 1. The analgesic effect of fentanyl in enucleated patients was significantly higher than in eviscerated patients at postoperative days 0 and 1. The use of fentanyl by IV-PCA was associated with greater PONV despite co-administration with anti-emetics, although this finding was not significant.