Infraclavicular brachial plexus block: Comparison of posterior cord stimulation with lateral or medial cord stimulation, a prospective double blinded study

Abstract

Background:Infraclavicular approach to the brachial plexus sheath provides anesthesia for surgery on the distal arm, elbow, forearm, wrist, and hand. It has been found that evoked distal motor response or radial nerve-type motor response has influenced the success rate of single-injection infraclavicular brachial plexus block.Aim:We conducted this study to compare the extent and effectiveness of infraclavicular brachial plexus block achieved by injecting a local anesthetic drug after finding specific muscle action due to neural stimulator guided posterior cord stimulation and lateral cord/medial cord stimulation.Methods:After ethical committee approval, patients were randomly assigned to one of the two study groups of 30 patients each. In group 1, posterior cord stimulation was used and in group 2 lateral/medial cord stimulation was used for infraclavicular brachial plexus block. The extent of motor block and effectiveness of sensory block were assessed.Results:All four motor nerves that were selected for the extent of block were blocked in 23 cases (76.7%) in group 1 and in 15 cases (50.0%) in group 2 (P:0.032). The two groups did not differ significantly in the number of cases in which 0, 1, 2, and 3 nerves were blocked (P>0.05). In group 1, significantly lesser number of patients had pain on surgical manipulation compared with patients of group 2 (P:0.037).Conclusion:Stimulating the posterior cord guided by a nerve stimulator before local anesthetic injection is associated with greater extent of block (in the number of motor nerves blocked) and effectiveness of block (in reporting no pain during the surgery) than stimulation of either the lateral or medial cord.

Role of positioning posterior cord on coracoid approach brachial plexus block guided by nerve stimulator

“…It is consistent with the result that motor response evoked from lateral cord is more than from medial cord (61.5% vs 38.5%). This is similar to the conclusion by Sharma et al [ 16 ] Maybe it is because lateral cord is easy to position. And the onset time may decrease further if dextrose is used as a diluent instead of saline.…”

“…Among the 3 cords, posterior cord was associated with greater effectiveness. [ 5 , 16 ] But no significant difference was found between dual motor responses and triple motor responses. [ 15 ] So, we selected posterior cord motor response combined with another motor response as our stimulation target.…”

Infraclavicular block in children: Is blocking lateral or posterior cord equally successful?

“…One such example is the study conducted by Sharma et al . [ 14 ] They compared efficacy of all three cords against posterior cord and demonstrated that success rate and onset of complete sensory block after injection of the LA posterior to the axillary artery is comparable to triple injection targeting each cord. However, this study was performed in adult population.…”

Modified vertical infraclavicular block: An evaluation of two methods

“…The vertical infraclavicular block (VIB) of the brachial plexus is commonly used to provide local anesthesia (LA) or analgesia of the upper limb; because it is relatively simple, reliable, and safe. [ 1 2 ] It has clearly defined anatomic landmarks and low risk of complications. [ 1 2 ] The original method involved LA injection at the mid-point of an infraclavicular line between the acromion and jugular fossa.…”

“…[ 1 2 ] It has clearly defined anatomic landmarks and low risk of complications. [ 1 2 ] The original method involved LA injection at the mid-point of an infraclavicular line between the acromion and jugular fossa. However, this method was problematic in adult patients with small stature, extreme tallness, or variant anatomy.…”