No preemptive analgesic effect of preoperative ketorolac administration following total abdominal hysterectomy: A randomized study

Abstract

Background: Experimental models using short-duration noxious stimuli have led to the concept of preemptive analgesia. Ketorolac, a nonsteroidal anti-inflammatory drug, has been shown to have a postoperative narcotic-sparing effect when given preoperatively and alternatively to not have this effect. This study was undertaken to determine whether a single intravenous (IV) dose of ketorolac would result in decreased postoperative pain and narcotic requirements.

Methods: In a double-blind, randomized controlled trial, 48 women undergoing abdominal hysterectomy were studied. Patients in the ketorolac group received 30 mg of IV ketorolac 30 min before surgical incision, while the control group received normal saline. The postoperative analgesia was performed with a continuous infusion of tramadol at 12 mg/h with the possibility of a 10 mg bolus for every 10 min. Pain was assessed using the visual analog scale (VAS), tramadol consumption, and hemodynamic parameters at 0, 1, 2, 4, 8, 12, 16, and 24 h postoperatively. We quantified times to rescue analgesic (morphine), adverse effects, and patient satisfaction.

Results: There were neither significant differences in VAS scores between groups (P > 0.05) nor in the cumulative or incremental consumption of tramadol at any time point (P > 0.05). The time to first requested rescue analgesia was 66.25 ± 38.61 min in the ketorolac group and 65 ± 28.86 min in the control group (P = 0.765). There were no significant differences in systolic blood pressure (BP) between both groups, except at 2 h (P = 0.02) and 4 h (P = 0.045). There were no significant differences in diastolic BP between both groups, except at 4 h (P = 0.013). The respiratory rate showed no differences between groups, except at 8 h (P = 0.017), 16 h (P = 0.011), and 24 h (P = 0.049). These differences were not clinically significant. There were no statistically significant differences between groups in heart rate (P > 0.05).

Conclusions: Preoperative ketorolac neither showed a preemptive analgesic effect nor was it effective as an adjuvant for decreasing opioid requirements or postoperative pain in patients receiving IV analgesia with tramadol after abdominal hysterectomy.

Keywords: Abdominal hysterectomy; ketorolac; nonsteroidal anti-inflammatory drugs; postoperative pain; preemptive analgesia.

Figure 1

Visual analog scale scores in the two groups during the 24 h after surgery (mean ± standard deviation). There were no statistically significant differences between groups (P > 0.05). There was a significant effect of time in pain scores for each group separately (P < 0.001)

Figure 2

Cumulative patient-controlled analgesia tramadol consumption in both groups during the 24 h after surgery (mean ± standard deviation). There were no significant differences between the two groups (P > 0.05). The effect of time on total tramadol consumption in the postoperative period was statistically significant (P < 0.001)

Figure 3

Incremental patient-controlled analgesia tramadol consumption in bolus in both groups during the 24 h after surgery (mean ± standard deviation). There were no statistically significant differences among groups (P > 0.05). The effect of time on tramadol consumption in the postoperative period was statistically significant (P < 0.001)