COMPARISON OF THE EFFECT OF LUMBAR/SCIATIC BLOCK AND SPINAL ANAESTHESIA ON THE FRONTAL QRS-T ANGLE AND INFLAMMATORY VALUES IN ARTHROSCOPIC KNEE SURGERIES

The study was designed as a randomised controlled double-blind trial. Eighty patients aged 18-65 years with ASA I-II status who were scheduled for arthroscopic knee surgery were divided into two groups of 40 patients each using a sealed envelope method. Group 1 (n=40) received spinal anaesthesia, and Group 2 (n=40) received a lumbar/sciatic block. Patients under 18 years of age, over 65 years of age, those for whom regional anaesthesia is contraindicated, those with known cardiac disease, arrhythmia, electrolyte imbalance, liver and/or renal failure, and those who do not wish to participate in the study will be excluded. After obtaining informed consent from the patients, they will be taken to the operating theatre and a venous access will be established using an 18 G peripheral venous cannula. Patients undergoing surgery will undergo routine ASA monitoring (ECG, non-invasive arterial blood pressure, pulse oximetry). Group 1 patients will receive 2 mg midazolam and 50 mcg fentanyl, followed by spinal anaesthesia. The patient will be placed in a sitting position, and a spinal block will be administered by injecting 15 mg of 0.5% bupivacaine (Marcain® spinal heavy, 0.5%, 4 mL ampoule, AstraZeneca) through a 26 G spinal needle into the L3-4 intervertebral space. Sensory block will be assessed with a pinprick test, and the operation will commence once sensory block at the T10 level is achieved. Group 2 patients will receive 2 mg midazolam and 50 mcg fentanyl, and a lumbar/sciatic block will be performed under ultrasound guidance.A combined sciatic-lumbar nerve block with a total of 40 cc of 0.5% bupivacaine will be administered. The sciatic block will be performed first. For this, patients will be placed in the lateral decubitus 8 position, with the leg to be blocked on top, in the 'Sim's' position. Under ultrasound guidance, 20 cc of 0.5% bupivacaine will be injected with a 10 cm regional nerve block needle (B Braun, Melsungen, Germany) following negative aspiration. In the same position, the entry point for the lumbar block will be determined under ultrasound guidance, and 20 cc of 0.5% bupivacaine will be administered following a negative aspiration test. For surgical anaesthesia, both the sciatic and lumbar nerve distribution areas will be tested with the pinprick test to assess complete sensory block and complete motor block in the knee, ankle, and toes. Patients with adequate block quality (no need for sedoanalgesia during the operation) will be included in the study. In both groups, heart rate and mean arterial pressure will be recorded preoperatively (T1), after anaesthesia administration (T2), during surgery at 5 (T3), 15 (T4), and 30 (T5) minutes, and postoperatively (T6). ECG recordings will be obtained preoperatively, 5 minutes after anaesthesia administration, at the end of surgery, and 6 hours postoperatively. The duration of the first postoperative analgesia will be recorded for all patients. Haemogram and biochemical parameters will be assessed preoperatively, at the end of surgery, and 6 hours postoperatively.