The radial nerve should be blocked before the ulnar nerve during a brachial plexus block at the humeral canal.
OBJECTIVE
The brachial plexus block through the humeral canal as described by Dupré is indicated in hand and forearm surgery. This block requires a multi-stimulation technique that emphasizes the necessity of a rigorous and safe technique. Nerve injury associated with regional anesthesia can entail significant morbidity for patients. Thus, we investigated the brachial block sequence in terms of unintended nerve stimulation as a surrogate of potential nerve injury.


METHODS
Sixty patients were randomly allocated in two groups of 30. In Group I the radial nerve was blocked before the ulnar nerve. In Group II the ulnar nerve was blocked before the radial nerve. During the radial nerve approach we recorded, if present, an ulnar nerve response. During the ulnar nerve approach we recorded, if present, a radial nerve response.


RESULTS
In Group I while looking for the radial nerve, in 50% of the cases, an ulnar motor response was recorded. In Group II while looking for the ulnar nerve, a radial motor response was recorded in 10% of the cases.


CONCLUSIONS
Our results indicate that the radial nerve should be blocked before the ulnar nerve when performing a brachial plexus block at the humeral canal.
Guntz
Emmanuel
E
Department of Anesthesiology, Université Libre de Bruxelles, Hôpital Universitaire Saint-Pierre, Brussels, Belgium. eguntz@ulb.ac.be
Herman
Pierre
P
Delbos
Alain
A
Sosnowski
Maurice
M
D000293:Adolescent; D000322:Adrenergic Agonists / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage; D001917:Brachial Plexus / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D004837:Epinephrine / Q000008:administration & dosage; D005542:Forearm / Q000294:innervation / Q000601:surgery; D006225:Hand / Q000294:innervation / Q000601:surgery; D006801:Humans; D006811:Humerus; D008012:Lidocaine / Q000008:administration & dosage; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D011826:Radial Nerve / Q000187:drug effects / Q000502:physiology*; D014459:Ulnar Nerve / Q000187:drug effects / Q000502:physiology*
D000322:Adrenergic Agonists; D000779:Anesthetics, Local; D008012:Lidocaine; D004837:Epinephrine