Ultrasound-guided block of the brachial plexus at the humeral canal.
OBJECTIVE
Conduction block of the brachial plexus block at the humeral canal, as described by Dupre, has certain clinical indications. The aim of this preliminary study was to assess the feasibility of this technique under ultrasound guidance.


METHODS
After ultrasound evaluation of the brachial plexus at the humeral canal in 61 adult volunteers, we performed ultrasound-guided blocks in another 20 adult patients. A linear 38 mm probe, 13-6 MHz, and a 50-mm insulated block needle were used to guide injection of lidocaine 1.5% with epinephrine.


RESULTS
Ulnar and median nerves are superficial and located at similar depths. Ultrasound imaging showed the musculocutaneous nerve to be located dorsally. The radial nerve is dorsal to the plane of the musculocutaneous nerve. Relative to the brachial artery, the median nerve is situated between 12 and 1 o'clock in 66% of the cases. Relative to the basilic vein, the ulnar nerve is situated at 3 o'clock in 46% of the cases. The evaluated block sequence was radial, ulnar, musculocutaneous and median nerve; two points of puncture were mandatory, and 6.85 +/- 0.37 min were required to perform the blocks. Sensory onset times were similar for the four nerves. Injectate volume was lower for the musculocutaneous nerve compared to other nerves (P < 0.05). All 20 patients experienced complete sensory and motor blocks.


CONCLUSIONS
We describe an approach to, and the feasibility of ultrasound-guided block of the brachial plexus at the humeral canal. Further study will be required to establish the effectiveness and the safety of this technique.
Guntz
Emmanuel
E
Department of Anesthesiology, Hôpital Universitaire Saint-Pierre, Université Libre de Bruxelles, Rue Haute, 322, 1000, Brussels, Belgium. eguntz@ulb.ac.be
Van den Broeck
Vanessa
V
Dereeper
Etienne
E
El Founas
Walid
W
Sosnowski
Maurice
M
D000322:Adrenergic Agonists / Q000008:administration & dosage; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage; D001917:Brachial Plexus / Q000000981:diagnostic imaging; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D006811:Humerus; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D013997:Time Factors; D014463:Ultrasonography
D000322:Adrenergic Agonists; D000779:Anesthetics, Local; D008012:Lidocaine; D004837:Epinephrine