Lateral infraclavicular plexus block vs. axillary block for hand and forearm surgery

In the last few years infraclavicular plexus block has become a method of increasing interest. However, this block has been associated with high complication incidences and without advantage in the quality of blockade over the axillary approach. We prospectively studied 40 patients (ASA I-III) undergoing surgery of the forearm and hand, and investigated the performance of the lateral infraclavicular plexus block against an axillary paravascular block to evaluate the success rate as well as the extent and quality of blockade.

Patients were randomized into two groups: group I (lateral infraclavicular approach; n=20) and group A (axillary approach; n=20). The lateral infraclavicular approach is a technique with the coracoid process (CP) as landmark. Alone the sagittal plane, the needle is inserted until contact with the CP. The needle is then withdrawn 2-3 mm and reinserted directly under the CP, until it contacts the brachial plexus sheath. Plexus blockade was performed using 40 ml of mepivacaine 1%. Quality of sensory and motor block was recorded selectively for each nerve distribution at close intervals for 6 h.

Successful block according to Vester-Andersen's criteria was achieved in 100% of group I and 85% of group A. In group I, a pronounced sensory and motor blockade of the musculocutaneous nerve was observed, while patients of group A had a weak block of this nerve. In group I, an additional spectrum of nerves (thoracodorsal, axillary and medial brachial cutaneous nerves) was involved compared to group A. There was no difference among groups in onset and duration of block.

Based on the safe landmark and feasibility of this procedure and the additional spectrum of nerve block achieved, the application of lateral infraclavicular technique has to be reconsidered in clinical practice.