Short term outcome of brachial plexus block in vascular access surgery

ABSTRACT

To present short term outcome of brachial plexus block for upper limb vascular access procedures performed for renal dialysis. This is a retrospective review of all cases that had a brachial plexus block for a renal dialysis vascular access procedure at the vascular surgery unit in King Hussein Medical Center, Amman, Jordan, between January 2009 and September 2011. Two hundred eighty- eight patients [172 males, 116 females] with a mean age of 41 [19-68] years had the block. In 183 [63.5%] patients the procedure was primary and in 75 [26.0%] patients it was native access. Procedures performed included 27 [9.4%] brachio-cephalic arteriovenous fistula, 48 [16.7%] basilic vein transposition, 96 [33.3%] forearm prosthetic loop graft, 67 [23.3%] upper arm prosthetic loop graft, 25 [8.7%] salvage procedures with interposition prosthetic grafts, 14 [4.9%] removal of infected prosthetic grafts, and 11 [3.8%] repairs of false aneurysms and disrupted anastomoses. All blocks were guided by a nerve stimulator at strength of 0.2-0.5MHZ and Bupivacaine 0.375 [25-35 ml] used for the block. Supraclavicular block was used in 132 [45.8%] patients while combined supraclavicular and axillary blocks were used in 156 [54.2%] patients. When local anesthetic infiltration was needed for supplementation of the block, Lignocaine 1% [10-15 ml] was used. Data regarding the procedure, adequacy of the block, time of onset, duration of block, and immediate complications was retrospectively collected from anesthetic charts and operative records. All patients had an adequate block with no conversions to general anesthesia or cancellation of the procedure. A successful block was achieved in 232 [80.6%] patients while a partially successful block was achieved in 56 [19.4%] patients. The median time for onset of the block was 10 [5-20] minutes for motor block and 15 [10-35] minutes for sensory block. The mean duration of the block was 5.6 [2.2-48.0] hours. Prolonged blocks beyond 24 hours occurred in 5 patients [48 hours in 1 patient, 36 hours in 1 patient, and 24 hours in 3 patients]. Injection related complications included discomfort during injection in 100 [34.7%] patients and local hematomas relieved by compression in 8 [2.8%] patients]. Transient nerve paralysis complicated 82 [28.5%] cases [phrenic nerve in 57 [19.8%] patients, sympathetic chain resulting in Horner's syndrome in 20 [6.9%] patients and vagus nerve resulting in hoarseness of voice in 5 [1.7%] patients]. No clinically detectable pneumothorax or drug toxicity occurred. No peri-operative mortality was reported during the study period. Brachial plexus block is an effective and safe mode of anesthesia for upper limb renal dialysis vascular access procedures. It offers major advantages over general anesthesia and enjoys low rate of failure and complications. Its use as a main mode of anesthesia for such procedures is advisable