Comparable Incidence, Intensity of Tourniquet Pain With Infraclavicular, Axillary Brachial Plexus Blocks

Axillary and infraclavicular brachial plexus blocks (ABPB and ICB, respectively) may have comparable efficacy in preventing and alleviating tourniquet pain associated with moderate-duration repair of fractures distal to the elbow, according to a study published in the European Journal of Anaesthesiology.

Upper limb surgery is often conducted with the use of ABPB or ICB, a choice based on the specific patient and the specific procedure being performed.

For this single-center randomized prospective single-blinded clinical trial (ClinicalTrials.gov identifier: NCT02714738), 82 participants undergoing plastic or orthopedic surgery in Ireland between April 2016 and May 2017 were recruited. Patients were randomly assigned to receive ABPB (n=40; mean age, 51.87 years; 57.5% women) or ICB (n=42; mean age, 54.47 years; 61.9% women). 

All patients were >18 years of age and were classified as I through III according to the American Society of Anesthesiologists classification, with an expected tourniquet duration >45 minutes. Lidocaine 2% plus epinephrine (1:200,000) was used in both blocking regimens. Incidence of tourniquet pain was the study’s primary outcome. Secondary outcomes were time to tourniquet pain onset and severity of tourniquet pain. A straight pneumatic tourniquet was used around the upper arm. Beginning 30 minutes postinflation, patients were asked to evaluate pain level every 10 minutes (ie, mild, moderate, or severe).

A total of 71 participants (n=36 receiving ABPB; n=35 receiving ICB). Intraoperative tourniquet pain was reported by 13.8% and 8.5% of patients receiving ABPB and ICB, respectively (P =.71), with comparable levels of severity (mild: 4 vs 1, respectively; moderate, 1 vs 2, respectively; P =.51), timing of onset (73.0 vs 86.6 minutes, respectively; P =.18), and tourniquet duration (55.4 vs 60.9 minutes; P =.23).

A higher percentage of participants given ABPB vs ICB reported paresthesias during the block (P =.0054), and block performance time was greater with ABPB vs ICB (P =.012). Although patients given ICB vs ABPB required more total anesthetic, they also experienced higher levels of sensory block (P <.01 for both). Vascular punctures occurred in 3 and 4 patients in the ABPB and ICB groups, respectively.

Study strengths include use of a single expert to apply all pain blocks, removing interoperator differences. Study limitations include the possibility that tourniquet times differed from other studies and possible lack of external validity.

“The challenge for the clinician is to individualise the selection of technique based on patient and procedural factors as well as his/her own expertise and experience,” noted the authors.

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Reference

Brenner D, Iohom G, Mahon P, Shorten G. Efficacy of axillary versus infraclavicular brachial plexus block in preventing tourniquet pain: a randomized trial [published online November 19, 2018]. Eur J Anaesthesiol. doi:10.1097/EJA.0000000000000928