Evaluation of intravenous ketorolac administered by bolus or infusion for treatment of postoperative pain. A double-blind, placebo-controlled, multicenter study.

Background: Ketorolac is a nonsteroidal analgesic that may provide postoperative analgesia without opioid-related side effects. This double-blind, randomized, multicenter study evaluated the analgesic efficacy and safety of intravenous ketorolac in 207 patients during the first 24 h after major surgery.

Methods: Subjects were assigned to receive one of three analgesic regimens: a ketorolac infusion, ketorolac boluses, or placebo. All subjects had access to intravenous morphine via patient-controlled analgesia (PCA). Evaluations included PCA morphine used, pain assessment (categorical pain intensity scores and visual analogue pain scores), pain relief (categorical pain relief scores), sedation, presence of adverse events, and overall rating of regimens by study observers and patients.

Results: Patients in the ketorolac infusion group (but not the ketorolac bolus group) used less morphine (average 33 mg) than did the placebo group (44 mg) (P = 0.009). Significant differences favoring both ketorolac groups were seen in the pain intensity and the categorical pain relief scores at various time points during the study. At the termination of the study, compared with the placebo group, categorical pain intensity scores were lower in the ketorolac bolus group; visual analogue pain scores were lower in both ketorolac groups; and pain relief scores were higher in the ketorolac bolus group. The incidence of vomiting was significantly greater in the placebo group (27%) than in the ketorolac infusion group (12%) or bolus group (9%) (P = 0.032 and P = 0.005, respectively). The incidence of postoperative fever was 10% in the ketorolac bolus group and 25% in the placebo group (P = 0.013). Study observers noted less nursing difficulty while caring for patients in the ketorolac infusion group (P = 0.015). Study observers and patients in both ketorolac groups reported statistically significant overall drug superiority compared with placebo.

Conclusions: It is concluded that intravenous boluses or infusions of ketorolac in conjunction with PCA morphine provide effective, safe analgesia after major surgery and improve on the response to PCA morphine alone.