Appropriate Digital Nerve Block Technique: The Single-Injection Subcutaneous Volar Block Versus the Two-Injection Dorsal Digital Block

摘要

Background: Finger injuries are a common chief complaint in the emergency department (ED) and primary care setting. Repair of these injuries often require digital anesthesia through performing a digital nerve block (DNB). The two-injection subcutaneous volar block (SVB) and a two-injection dorsal digital block (DDB) are two of the most prevalently performed digital blocks in practice today. This systematic review examines which DNB technique is most appropriate and attempts to offer a recommendation for a standardized level of care.Methods: An extensive literature search was performed using Medline-OVID, Medline-PubMed, CINAHL, and Google Scholar. The following keywords were searched individually and in combination: digital anesthesia, digital block, and finger block. Inclusion criteria consisted of trials comparing the SVB and the DDB from 2007 to present. All articles were assessed for quality using GRADE.Results: The search resulted in 114 articles that were narrowed down to 32 by limiting articles to human studies written in English and published after 2007. The abstracts and titles were then hand searched for trials comparing the SVB and the DDB. Final articles meeting all inclusion criteria were three studies, two RCTs and one quasi-experimental. The primary outcome of successful anesthesia was measured and the quasi-experimental showed the SVB being more effective than the DDB and the two RCTs provided data with no significant difference between the two digital blocks. A secondary outcome of the patients’ pain score of the injection was also measured by two of the studies and no statistical significance was found.Conclusion: The SVB is equally effective in delivering anesthesia as the DDB but is only a single injection making it less invasive, easier to perform and teach, and avoids the risk of damaging the finger nerves. For these reasons a safe recommendation come be made for the use of the SVB when repairing a finger injury that is not located on the dorsal aspect of the proximal phalanx in which case is the only clinical scenario that the DDB should be utilized.