The Effects of 0.3 mA and 0.5 mA Threshold Currents on Axillary Brachial Plexus Block

Aim:The nerve block success by peripheral nerve stimulator may be increased byoptimal nerve localization. However, it is not clear which current threshold is more suitable for this. Material and Methods: Forty patients between 18-60 years of age were included in this randomized, double blind study. In group 1 (n=20) and group 2 (n=20), the thresholds of current were 0.3 mA and 0.5 mA respectively. The mixture of 150 mg oflevobupivacaine (0.5%) and 200 mg of lidocaine (2%) in a total volume of 40 ml was injected around the radial nerve. The duration of postoperative sensory and motor block and the first analgesic requirement were measured. Results; The onset of sensory and motor block of the musculocutaneus (p=0.01 and p=0.004 respectively) and the onset of motor block of the median and ulnar nerve (p=0.009 and p=0.02 respectively) were significantly shorter in group 1 than in group 2. The duration of postoperative sensory and motor block and the time to first analgesic requirement were significantly longer in group 1 than in group 2 (p=0.0001). Conclusions; The 0.3 mA current is more beneficial than 0.5 mA current in shortening the onset of sensory and motor block, lengthening the postoperative sensory and motor block and the duration of first analgesic requirement