[Effect of a 3-in-1 block in arthroscopic knee surgery. Comparative study with subarachnoid block]. / Eficacia del bloqueo "tres en uno" en la cirugía artroscópica de la rodilla. Estudio comparativo con el bloqueo subaracnoideo.

HYPOTHESIS AND OBJECTIVES: Trunk blockades in arthroscopic knee surgery are rarely performed because combined blockade of the sciatic and lumbar plexus nerves are required, particularly if ischemia is required. We aimed to assess the efficacy of the "3-in-1 block" combined with intraarticular infiltration of local anesthetic for arthroscopic meniscectomy. The results were compared with our standard technique, subarachnoid anesthesia. PATIENTS AND METHODS: Forty ASA I-II patients undergoing arthroscopic meniscectomy without ischemia. The patients were randomly assigned to receive "3-in-1 block" with 40 mL of 1.5% mepivacaine (T group, n = 20), or the standard technique of subarachnoid puncture with 3 mL of 2% lidocaine (S group, n = 20). Twenty minutes after puncture patients in both groups received intraarticular injections of 20 ml of bupivacaine 0.25% with 1:200,000 adrenaline in the knee. Surgery began 10 minutes later. We assessed requirements for sedation during surgery, degree of satisfaction during surgery according to the surgeon and the patient, hemodynamic variables at predetermined times, postoperative pain (on a verbal scale and related to consumption of analgesics in the first 48 hours after surgery), and the appearance of side effects attributable to anesthetic technique. RESULTS: Demographic variables were comparable in the two groups and no surgical events were recorded. Eighteen patients in the T group and one in the S group required sedation during surgery (p < 0.05). Blood pressure was significantly lower in the S group than in the T group (p < 0.05). No patient in the T group required atropine and/or ephedrine during surgery, whereas 5 patients in the S group did (p < 0.05). Postoperative evolution was similar in the two groups. No postoperative complications attributable to the techniques were recorded. CONCLUSIONS: The "3-in-1 block" combined with joint infiltration of local anesthetics may be an effective alternative when subarachnoid anesthesia is contraindicated in patients undergoing arthroscopic meniscectomy.