[Influence of stimulating different cords on the efficacy of infraclavicular brachial plexus block].

Objective: Stimulating lateral or posterior cord may produce different anesthesia extent because of different anatomical position of the two plexus at the infraclavicular region. We To explore the difference in the efficacy of infraclavicular brachial plexus block by stimulating different cords of the infraclavicular brachial plexus.
Methods: 70 patients of the ASA physical status class I - II, aged 14 - 64, scheduled for elective surgical procedures below elbow underwent infraclavicular brachial plexus block with the Wilson's approach via the point 2 cm medial and caudal to the coracoid process guided by nerve stimulator, to simulate the lateral cord (n = 32) or posterior cord (n = 38). 30 ml of 0.5% ropivacaine was injected after the stimulation of the lateral or posterior cords. Anesthesia was assessed 5, 10, 20, and 30 min after the local anesthetic injection. A successful blockade was defined as analgesia in all dermatomes of the five nerves (median nerve, musculocutaneous nerve, radial nerve, ulnar nerve, and medial antebrachial cutaneous nerve).
Results: Stimulating the posterior cord provided complete blockade in 30 patients (78.9%) and stimulating the lateral cord provided complete blockade in 17 patients (53.1%).
Conclusion: Stimulating the posterior cord guided by nerve stimulator increases the efficacy of infraclavicular brachial plexus block compared with stimulating the lateral cord.