Anesthesia and postoperative analgesia after intra-articular injection of warmed versus room-temperature levobupivacaine: a double-blind randomized trial.

ABSTRACT

PURPOSE: This prospective, randomized, blinded study was designed to compare the effects of warmed versus room-temperature levobupivacaine in patients undergoing knee arthroscopy and partial meniscectomy. METHODS: Patients were randomly allocated into 2 groups of 16 patients each. In all patients the 2 portal sites were infiltrated with 10 mL of room-temperature mepivacaine (20 mg/mL). In the first group, patients underwent intra-articular injection of 20 mL of levobupivacaine (5 mg/mL) and 0.005-mg/mL epinephrine (1200,000) at a temperature of 40 degrees C +/- 0.2 degrees C, whereas in the second group the levobupivacaine and epinephrine were at room temperature (25 degrees C +/- 0.5 degrees C). Pain was graded and recorded intraoperatively and postoperatively by use of a visual analog scale (VAS). Analgesia was supplemented if the VAS score was 4 cm or greater with morphine intraoperatively or ketorolac postoperatively. RESULTS: There were no significant differences between groups in intraoperative and postoperative VAS values. There was no need for morphine as a rescue dose in any patient during surgery. Eight patients treated with warmed levobupivacaine and seven patients treated with room-temperature levobupivacaine requested a single rescue dose of ketorolac (30 mg) postoperatively. CONCLUSIONS: No compelling evidence exists to suggest that intra-articular injection of warmed levobupivacaine is more effective than room-temperature levobupivacaine for intraoperative anesthesia and postoperative analgesia in patients undergoing partial meniscectomy during knee arthroscopy. LEVEL OF EVIDENCE Level I, randomized controlled trial.