Comparison of USG-Guided Supraclavicular Brachial Plexus Block by Single-Point Versus Multiple-Point Injection Technique: A Prospective Randomized Trial

Abstract

Background This study investigated the success rate of ultrasonography (USG)-guided supraclavicular block using a single-point injection technique comparing it with multiple-point injection technique, in terms of nerve sparing, time taken to perform the procedure, time taken to onset of sensory and motor block. Materials and methods A total of 204 patients of American Society of Anesthesiologists (ASA) Status I and II, aged 18-60 years, with body mass index (BMI) ≤30 kg/m 2 , posted for upper limb surgeries were given USG-guided supraclavicular brachial plexus block with 15 mL of 0.5% Ropivacaine. The patients were randomly divided into group A (single-point injection) and group B (multiple-point injection), using an out-of-plane technique. Sensory and motor block was assessed for onset and maximum grade achieved, by using pinprick, cold, touch, and movement respectively. The efficacy of the block was tested by assessment in the territories of musculocutaneous, ulnar, radial, median, axillary, and intercostobrachial nerves. Procedural time was calculated from the insertion of the needle till the complete injection of the drug. Results Patients in both groups were comparable in terms of demography and ASA status. The success rate for group A was 60.8%, compared to 98% in group B. In group B, the intercostobrachial nerve was most commonly spared (7.84%), followed by ulnar (1.96%), and radial (0.98%). On the other hand, in group A, the most frequently spared nerves were ulnar and intercostobrachial (23.5% each), followed by radial (12.7%), axillary (10.8%), musculocutaneous (7.8%), and median nerves (6.9%). The onset of sensory and motor block was similar in both groups. The procedure time was longer in the multiple-point group. Conclusion Our observations suggest that nerve sparing is much lesser in the multiple-point injection technique used for USG-guided supraclavicular block. In a good number of patients using this technique, the intercostobrachial nerve gets blocked.