RESUMEN
BACKGROUND: A low dose of ketamine can be an effective preemptive analgesic by preventing central sensitization when administered before surgical trauma. In this study, we assessed the preemptive analgesic effect of low-dose ketamine administered intravenously to patients undergoing arthroscopic rotator cuff repair with intra articular ropivacaine injection. METHODS: This randomized, double-blinded study included fifty-six patients scheduled for elective arthroscopic rotator cuff repair. Normal saline (group C) or 0.5 mg/kg of ketamine (group K) was injected intravenously before the skin incision. An intra articular injection using 20 ml of 0.75% ropivacaine was performed in both groups just before wound closure by the surgeon at the end of the surgery. Postoperative pain was assessed by the numeric rating scale (NRS) in the post-anesthesia care unit (PACU) and at 12, 24, and 48 hours postoperatively. The total dose of fentanyl consumption and side effects were recorded. RESULTS: There were no significant differences between the C and K groups for the NRS of pain in the PACU and at 12, 24, and 48 hours after the surgery. In addition, there was also no significant difference in total fentanyl consumption between the two groups. CONCLUSIONS: Preemptive ketamine did not reduce preemptive pain scores and fentanyl consumption in patients who underwent arthroscopic rotator cuff repair with intra articular local anesthetic injection. Therefore, more aggressive and multimodal pain control is required in patients undergoing arthroscopic shoulder surgery regardless of the use of preemptive intravenous ketamine injection.