Background: Supraclavicular (SC) and infraclavicular (IC) brachial plexus block (BPB) are commonly used for upper extremity surgery. Recent clinical studies have compared the effect of SC- and IC-BPB, but there have been controversies over spread of sensory blockade in each of the 4 peripheral nerve branches of brachial plexus.
Methods: This study included a systemic review, using the Medline and EMBASE database from their inceptions through March 2016. Randomized controlled trials (RCTs) comparing SC- and IC-BPB were included. The prespecified primary outcome was the incidences of incomplete sensory blockade in each of the 4 terminal nerve branches of brachial plexus. Secondary outcome included the incidence of successful blockade, performance time, onset of sensory block, duration of analgesia, and complication rates.
Results: Ten RCTs involving 676 patients were included. Pooled analyses showed the incidence of incomplete block at 30 minutes in radial nerve territory was significantly higher in IC-BPB, favoring SC-BPB (risk ratio 0.39; 95% confidence interval [0.17-0.88], P = .02, I = 0%). However, subgroup analysis according to the number of injections of IC-BPB showed that double or triple injections IC-BPB yielded no difference in the incomplete radial block. Furthermore, the incidence of incomplete ulnar block at 30 minutes was significantly lower in IC-BPB when using double or triple injection IC-BPB. There was no difference in the secondary outcomes between SC- and IC-BPB groups, with the exception of complication rates. The incidence of paresthesia/pain on local anesthetic injection, phrenic nerve palsy, and Horner syndrome was significantly higher in the SC group, favoring IC-BPB.
Conclusions: This meta-analysis demonstrated that IC-BPB showed a significantly high incidence of incomplete radial nerve sensory block at 30 minutes, which may be avoided by double or triple injection. Furthermore, IC-BPB with multiple injection technique showed significantly lower incidence of incomplete ulnar block than SC-BPB. There were no differences in the incidence of successful blockade, block onset, and duration of analgesia between SC- and IC-BPB. Procedure-related paresthesia/pain and adjacent nerve-related complications were more frequent in SC-BPB. However, because of the small sample size, publication bias remains a concern when interpreting our results. Further studies with sufficient sample size and reporting large number of outcomes are required.