Lateral Trendelenburg with the injected side down after the block improves the efficacy of the axillary approach to brachial plexus block

Abstract

Purpose: We hypothesized that, after axillary block, positioning the patient in a lateral position with the injected side down and simultaneously in a 20° Trendelenburg position will increase the success rate and quality of the block.

Methods: Fifty patients with chronic renal failure (ASA 2-3) scheduled for arteriovenous fistula surgery were included in this study. In all patients, 30-40 ml of 0.25 % levobupivacaine were injected into the axillary sheath. The block was performed as three injections (multiple injection technique) with the arm in 90° abduction and 90° flexion in the supine position. Patients were randomly allocated to two groups. Group I (n = 25) patients were kept in the supine position after the block. Group II (n = 25) patients were positioned laterally after the block with the injected arm down and in a 20° Trendelenburg position. Sensory and motor block were evaluated at 2, 4, 6, 8, 10, 15, 20, and 25 min after the administration of the block. Thus, the patients in group II were evaluated in a lateral position during the first 30 min. Throughout the surgery and the recovery period, sensory and motor block were evaluated at 30-min intervals.

Results: There were no significant intergroup differences in the effects on radial, ulnar, median, and musculoskeletal nerve blockade. Thirty minutes after the injection, the patients in group II had higher levels of sensory axillary nerve blockade. Subscapular and thoracodorsal nerve motor block were not detected in group I, while 84 % of the patients in group II experienced blockade of both of these nerves (p < 0.01).

Conclusion: We conclude that, for patients undergoing an axillary block, positioning the patient laterally with the injected side down and in a 20° Trendelenburg position increases the success rate and quality of the block.