This study was done to evaluate the effect on pain relief when acetaminophen was added to lidocaine for intravenous regional anesthesia (IVRA).

Sixty patients undergoing hand or forearm surgery received IVRA were assigned to three groups: Group C received 0.5% lidocaine diluted with 0.9% normal saline to a total volume of 40 ml (n = 20), Group P received 0.5% lidocaine diluted with intravenous acetaminophen 300 mg to a total volume of 40 ml (n = 20) and Group K received 0.5% lidocaine diluted with 0.9% normal saline plus ketorolac 10 mg made up to a total volume of 40 ml (n = 20). Sensory block onset time, tourniquet pain onset time, which was defined as the time from tourniquet application to fentanyl administration for relieving tourniquet pain and amount of analgesic consumption during surgery were recorded. Following deflation of tourniquet sensory recovery time, postoperative pain and quantity of analgesic uses in post-anesthesia care unit were assessed.

Sensory block onset time was shorter in Group P compared to Group C (P < 0.05). Tourniquet pain onset time was delayed in Group P when compared with group C (P < 0.05). Postoperative pain and analgesic consumption were reduced in Group P and Group K compared to Group C (P < 0.001).

The addition of acetaminophen to lidocaine for IVRA shortens the onset time of sensory block and delays tourniquet pain onset time, but not with ketorolac. Both acetaminophen and ketorolac reduce postoperative pain and analgesic consumption.