Does ketorolac have a preemptive analgesic effect? A randomized, double-blind, control study

To examine the effect of ketorolac used as preemptive analgesia on the intensity of pain and analgesic requirements in the postoperative period.

The present study was a randomized, double-blind, control study involving human subjects who underwent extraction of the mandibular third molars under intravenous anesthesia. The study group received 30 mg of intravenous ketorolac preoperatively, and the control group received a placebo. The pain intensity was measured using a visual analog scale. The decrease in postoperative pain was measured as the primary outcome variable. The interval to the first dose of analgesic, total analgesic requirements, and the global assessment were measured as secondary outcomes. The data were analyzed using the Student t test, Wilcoxon rank sum test, and χ(2) test.

A total of 85 adult subjects, American Society of Anesthesiologists class I and II, participated in the present study. Randomization was effective, as shown by the absence of differences in the study variables between the 2 groups. Of the 85 patients, 29 were men and 56 were women. The average patient age was 22.6 years in the study group and 24 years in the control group. Those in the ketorolac group recorded lower visual analog scale pain scores at all intervals. However, the difference was statistically significant at the 4-hour interval (P = .01). The median interval to the use of rescue medication in the ketorolac group was 9.5 hours compared with 7 hours in the control group. However, no statistically significant difference was found in the interval to the rescue analgesic between the 2 groups (P = .39). No statistically significant difference was noted in the total amount of postoperative analgesics required in the first 72 hours between the 2 groups (P = .54). Also, no difference was seen in the global assessment between the 2 groups (P = .22).

Those who received 30 mg of intravenous ketorolac preoperatively had less pain in the early (8-hour) postoperative period. The median interval to rescue medication was 2 hours longer in the ketorolac group. However, the difference in the total narcotic consumption was clinically and statistically insignificant between the ketorolac and control groups.