Objective: In this study, we aimed to compare axillary brachial plexus block using the two-injection and four-injection techniques assisted with ultrasonography (USG) and nerve stimulator in patients operated for carpal tunnel syndrome with articaine. To evaluate which technique is more effective, we compared the onset time, effectiveness, and duration of block procedures, patient satisfaction, adverse effect of the drug, and complication rates of the motor and sensory blocks.
Methods: Sixty patients were randomly divided into two groups. A mixture of physiologic serum added to articain with NaHCO3 (30 mL) was injected into the patients' axilla in both the groups. After the blockage of the musculocutaneous nerve in both the groups, the median nerve in the two-injection group and the median nerve, ulnar nerve, and radial nerve in the four-injection group were blocked. In brachial plexus nerves, sensorial blockage was evaluated with pinprick test, and motor block was evaluated by contraction of the muscles innervated by each nerve. The adverse effects and complications, visual analog scale (VAS) values during the operation, and post-operative patient satisfaction were recorded.
Results: Sufficient analgesia and anaesthesia were achieved with no need for an additional local anaesthetics in both the groups. Furthermore, additional sedation requirements were found to be similar in both the groups. A faster rate and a more effective complete block were achieved in more patients from the four-injection group. In the two-injection group, the block could not be achieved for N. radialis in one patient. All other nerves were successfully blocked. Whereas the blockage procedure lasted longer in the four-injection group, the VAS values recorded during the blockage procedure were higher in the four-injection group. No statistical difference was found with regard to patient satisfaction, and no adverse effects and complications were observed in any group.
Conclusion: Although the multi-injection method takes more time, it provides faster anaesthesia and more complete blockage than the two-injection method used with articain. The two-injection method can also be used in specific surgery such as for carpal tunnel syndrome, as an alternative to multi-injection method.
Keywords: Brachial block; articain; four-injection technique; neurostimulator; ultrasonography.