Ultrasound Guidance Enhances the Efficiency of Brachial Plexus Block and Ameliorates the Vascular Injury Compared with Nerve Stimulator Guidance in Hand Surgery Patients.

Background: Nerve stimulation guidance and ultrasound guidance are two major methods that have been widely accepted and applied in axillary brachial plexus block. However, the differences between the effects of these two types of guidance still need to be further elucidated for clinical usage. Materials and Methods: Overall, 208 patients undergoing elective upper limb surgeries and receiving axillary brachial plexus block were recruited in our study. The patients were randomly assigned to receive either ultrasound guidance (group U, n = 112) or nerve stimulation (group N, n = 96). Pinprick test was performed for assessing the sensory blockades. The pain was evaluated by visual analog scale (VAS). Reactive oxygen species (ROS) levels were measured by dichloro-dihydro-fluorescein diacetate staining and serum levels of nitric oxide (NO), nitric oxide synthases (NOS), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein 1 (MCP1) were evaluated by ELISA. Results: Ultrasound guidance significantly enhanced the quality of the sensory blockade and reduced the VAS scores when compared with the nerve stimulator guidance. In addition, the production of ROS, NO, NOS, TNF-α, and MCP-1 were significantly alleviated by ultrasound guidance. Conclusion: Ultrasound-guided brachial plexus block relieves pain during operation, provides higher success rates in the nerve block, causes less vascular damage and results in lower levels of inflammatory cytokines secretion when compared with neurostimulator-directed brachial plexus blockage.