Circumflex Nerve Blocks Versus Posterior Cord Nerve Blocks in Shoulder Arthroscopy

The patient will be put in sitting down position with upper limbs pending beside the body then a high-frequency linear ultrasound probe will be positioned transversely above the spine of the scapula. The suprascapular nerve often appears as hypereccoic structure at the suprascapular notch. A 20-gauge spinal needle will be advanced in-plane from medial to lateral 10mL of bupivacaine 0.25% into the suprascapular notch deep to the superior transverse scapular ligament (STSL) and adjacent to the suprascapular artery (SSA) .

Patient will be put in sitting position, with the shoulder in full adduction. linear transducer (8-14 MHz) will be positioned in the short axis orientation at the neck of humerous to identify the axillary artery about 1 to 3 cm from the skin surface.The artery is the most reliable landmark, then a 21-gauge 90 mm needle will be advanced in-plane and 10 mL of bupivacaine 0.25% will be injected adjacent to the artery.

Patient will be put in supine position with head turned away from side that will be blocked with the arm abducted 90 and flexed at the elbow then linear transducer (8-14 MHz) will be positioned in short-axis just medial to coracoid process.Once the artery will be identified, an attempt will be made to identify the hyperechoic cords of the brachial plexus and their corresponding positions relative to the artery, although these may not always be identifiable. The needle will be inserted in plane from the cephalad end of the probe. 10 mL bupivacaine 0.25% will be injected at the posterior cord.

General anaesthesia will be induced after giving nerve block in a standardized way with propofol 1.5-2.5mg/kg, fentanyl 2-3 µ/kg and atracurium 0.5mg/kg. maintenance of anaesthesia with isoflurane and atracurium 0.1mg/kg/20min.