Impact of Ketorolac on Opioid Consumption after Knee Arthroscopy

The objective of this study was to examine postoperative opioid consumption in outpatients undergoing knee arthroscopy after a single dose of intravenous ketorolac.

Patients ages 18-65 years old, weighing over 50kg and scheduled for knee arthroscopy were randomized to one of the four groups of preoperative ketorolac (0mg, 7.5mg, 15mg, 30mg). The primary outcome measured was postoperative opioid consumption. Secondary outcomes included visual analog scale pain scores, patient satisfaction scores, side effects and total postoperative anesthesia care unit time. Equivalency between ketorolac groups in opioid reduction relative to placebo was evaluated for each dose pair (7.5 vs. 15mg, 7.5 vs. 30mg, and 15 vs. 30mg). Linear regression models were used to examine associations between ketorolac dose with postoperative length of stay and patient satisfaction. A linear mixed model was used to evalaute the association between ketorolac dose and pain scores over time.

A total of 112 patients with comparable patient and procedural characteristics were enrolled. Equivalency in opioid reduction relative to placebo was not demonstrated between any examined ketorlac doses (7.5 vs. 15mg, P = 0.167; 7.5 vs. 30mg, P = 0.451; 15 vs. 30mg, P = 0.515). Compared to placebo, all ketorlac doses decreased postoperative pain scores (global P=0.012). Patient satisfaction and postoperative duration did not vary with ketorolac dose.

Although all ketorolac doses decreased PACU pain scores, equivalency in PACU opioid reduction between ketorolac doses was not demonstrated.