Influence of timing on the analgesic effect of intravenous ketorolac after orthopedic surgery

Abstract

This study evaluated the pre-emptive analgesic effect of intravenous (i.v.) ketorolac (KET) for total hip replacement (THR). Sixty patients who underwent surgery for THR under general anesthesia were randomly allocated to 3 groups. Two i.v. injections were administered: one before induction and one after surgery. The patients were studied prospectively in a double-blind manner. The control group (CONT; n = 20) received 2 ml of normal saline (NS) for both injections. The pre-operative KET group (PRE; n = 20) received 60 mg of KET and then 2 ml of NS. The postoperative KET group (POST; n = 20) received 2 ml of NS and then 60 mg of KET. General anesthesia was standardized with a intra-operative cumulated dose of fentanyl limited to 4 micrograms/kg. In the recovery room (RR), pain was controlled with an i.v. tritration of morphine; thereafter, on the surgical ward, patients used a patient-controlled analgesia (PCA) pump (Abbott). Pain was evaluated with a visual analogue scale (VAS) at rest and movement in the RR, then every hour for 6 h and every 6 h for 5 days. The side effects monitored were: sedation, respiratory depression, nausea, perioperative bleeding. The patients and surgery were similar for the 3 groups. Upon arrival in the RR, VAS scores taken at rest and at movement were lower for the PRE group than for the CONT and POST groups. Otherwise, VAS scores were similar in all 3 groups. The cumulative dose of morphine in the PRE group was lower than that for the CONT and POST groups from 0 to 6 h.(ABSTRACT TRUNCATED AT 250 WORDS)