Introduction: TKA is usually performed under general or spinal anaesthesia (SA). Most of the patients who undergo this procedure are old and their postoperative rehabilitation could be compromised due to the adverse effects of the relevant anaesthesia. Lumbar Plexus and Sciatic nerve Block (LPSB) have been increasingly applied for intraoperative and postoperative analgesia. The aim of this study is to compare the time required for the performance of the anaesthesia technique, the quality of intraoperative anaesthesia and postoperative analgesia, the incidence of intraoperative or postoperative complications, the blood loss at the recovery room and the required intraoperative intravenous (IV) administration of fluid volume.

Material & Methods: Fifty (50) patients, mean age 70± 5years, ASA I-III were randomly divided into two groups to receive spinal anaesthesia (group A) or LPSB (group B). Patients in group A (n=25) received hyperbaric Bupi-vacaine 0.5% plus 15mcq Fentanyl through atraumatic 25g needle. Lumbar plexus and sciatic nerve block were performed with a 15cm insulated needle (Brown) and nerves were identified by a peripheral electric nerve stimulator. 30 and 15 ml of Ropivacaine (0.5%) were used for each block respectively. All patients received 0.2mg/ Kg of Midazolam and 50μg of Fentanyl IV. The success of the technique was defined as a complete sensory and motor block. All patients received postoperatively Patient-Controlled Anaesthesia (PCA) with morphine intravenously. Time to perform blockade, sensory and complete motor block, hemodynamic parameters, blood loss, IV fluid volume, postoperative analgesic requirements and satisfaction score were recorded. Results were analyzed with Chi Square test and Student’s t-test (level of significance: p< 0.05).

Results: Demographic data, operating time and hemo-dynamic parameters were similar in both groups. Three patients (group B) had insufficient blocks and were converted to general anaesthesia. Although SA is performed and accomplishes complete motor and sensory blockade faster (p< 0,05), LPSB leaded to decreased necessity of intraoperative fluid loading and blood loss at the recovery room (p< 0,05). Overall patient’s satisfaction till leaving the recovery room, Visual Analogue Score (VAS) intraoperatively, 4 and 8hours postoperatively and analgesic counts (recorded through the PCA) in the first 24hours were statistically significant between two groups, in favor of patients with LPSB.

Conclusion: PLSB is an effective alternative to spinal anesthesia taking into account basic clinical and anaesthesiological parameters intraoperatively and immediate postoperatively. Concerning postoperative pain and required administration of analgesics during the first 24hours, LPSB is more efficient compared to SA, underlining the importance of overall patient’s satisfaction during the first postoperative day.