[Low minimal stimulating current improves infraclavicular brachial plexus block efficacy]

Area of Science:

• Anesthesiology
• Regional Anesthesia
• Nerve Stimulation Techniques

Background:

• Nerve stimulator-guided regional anesthesia is crucial for surgical procedures.
• Optimizing parameters like minimal stimulating current (MSC) can enhance block efficacy.
• The infraclavicular brachial plexus block is a common technique for upper limb surgery.

Purpose of the Study:

• To determine if a lower minimal stimulating current (MSC) during nerve stimulation increases the success rate of infraclavicular brachial plexus blocks.
• To compare the efficacy of a low MSC (0.1-0.3 mA) versus a regular MSC (0.3-0.5 mA) for this block.

Main Methods:

• A prospective study involving 188 patients undergoing below-elbow surgery.
• Patients were randomized into a low current group (Group A, <0.3 mA) or a regular current group (Group B, 0.3-0.5 mA).
• Infraclavicular block was performed using the Wilson's approach with 0.5% ropivacaine, guided by nerve stimulation.

Main Results:

• The overall success rate was significantly higher in the low current group (84.7%) compared to the regular current group (67.1%).
• In the posterior cord subgroup, the success rate for the low current group (96.5%) was significantly higher than the regular current group (78.9%).

Conclusions:

• A minimal stimulating current below 0.3 mA improves the efficacy of infraclavicular brachial plexus blocks.
• This lower current is particularly beneficial when targeting the posterior cord of the brachial plexus.
• The findings suggest a revised optimal current for nerve stimulator-guided blocks.