For superficial surgery of anteromedial and posteromedial surfaces of the upper arm, the medial brachial cutaneous nerve (MBCN) and the intercostobrachial nerve (ICBN) must be selectively blocked, in addition to an axillary brachial plexus block. We compared efficacy of ultrasound-guided (USG) versus conventional block of the MBCN and the ICBN.
Eighty-four patients, undergoing upper limb surgery, were randomized to receive either USG (n = 42) or conventional (n = 42) block of the MBCN and the ICBN with 1% mepivacaine. Sensory block was evaluated using light-touch on the upper and lower half of the anteromedial and posteromedial surfaces of the upper arm at 5, 10, 15, 20 minutes after nerve blocks. The primary outcome was the proportion of patients who had no sensation in all 4 regions innervated by the MBCN and the ICBN at 20 minutes. Secondary outcomes were onset time of complete anesthesia, volume of local anesthetic, tourniquet tolerance, and quality of ultrasound images.
In the USG group, 37 patients (88%) had no sensation at 20 minutes in any of the 4 areas tested versus 8 patients (19%) in the conventional group (P < 0.001). When complete anesthesia was obtained, it occurred within 10 minutes in more than 90% of patients, in both groups. Mean total volumes of local anesthetic used for blocking the MBCN and the ICBN were similar in the 2 groups. Ultrasound images were of good quality in only 20 (47.6%) of 42 patients. Forty-one patients (97.6%) who received USG block were comfortable with the tourniquet versus 16 patients (38.1%) in the conventional group (P < 0.001).
Ultrasound guidance improved the efficacy of the MBCN and ICBN blocks.
This study was registered at ClinicalTrials.gov, identifier NCT02940847.
From the *Department of Anesthesiology, Hôpital Central, CHRU Nancy; and
†Department of Anesthesiology, Hôpital Albert Schweitzer, Colmar, France;
‡Department of Anaesthesia, Intensive Care and Pain Medicine/University College Cork, Cork University Hospital, Wilton, Cork, Ireland; and
§Unit of Methodology, Data Management, Statistic, CHRU Nancy, France.
Accepted for publication February 12, 2018.
Address correspondence to: Hervé Bouaziz, MD, PhD, Service d'Anesthésie-Réanimation Chirurgicale, Hôpital Central, CHRU Nancy, 29 Avenue du Maréchal De Lattre de Tassigny, 54000 Nancy, France (e-mail: firstname.lastname@example.org).
The authors declare no conflict of interest.