Evaluating the analgesic efficacy of two anesthetic techniques during arthroscopic knee surgery

Background and Purpose: The aim of the study was to compare unilateral spinal and local anesthesia with respect to intraoperative and postoperative pain control, safety and complications for knee arthroscopies in outpatients. Methods: We studied 70 ASA I or II patients scheduled for outpatient knee arthroscopic surgery. The patients were allocated into two groups to receive either local (LA group = 35) or unilateral spinal (SA group = 35) anesthesia during a year period. The unilateral SA group received hyperbaric bupivacaine 7.5 mg (1.5 mL). The LA group received portal injection (5 mL lidocaine 2% with adrenaline) and intra-articular injection into the knee (10 mL lidocaine 2% with adrenaline). The following parameters were assessed: perioperative pain (10 cm VAS: 0 = no pain, 10 = extreme pain), surgical operating conditions, patient satisfaction score (1 = very satisfied, 4 = very unsatisfied), postoperative analgesia, and time to discharge. Results: In the LA group, 94.3% (33/35) of patients experienced no pain throughout the procedure. Only two (5.7%) patients required conversion to general anesthesia. In the unilateral SA group, one patient required conversion to general anesthesia. The need for postoperative analgesics was higher in the unilateral SA group compared with the LA group (p<0.01). The mean postoperative stay was significantly shorter in the LA than the unilateral SA group (p<0.05). The rate of complications differed significantly between the LA and unilateral SA groups (p<0.05). Conclusion: LA provides good pain relief following arthroscopic knee surgery compared to conventional unilateral spinal anesthesia. Major LA advantages are hemodynamic stability, patient satisfaction and faster anesthetic recovery.