Ultrasound examination of peripheral nerves in the forearm.
OBJECTIVE
We examined in a volunteer population whether nerves in the forearm could be seen consistently using ultrasound imaging and whether this new information could have implications for the way we perform regional anesthesia of the median, radial, and ulnar nerves.


METHODS
Eleven volunteers underwent ultrasound examination of both forearms. The median, ulnar, and radial nerves were followed and images were obtained at the elbow, proximal forearm, mid forearm, distal forearm and wrist levels. In addition the radial nerve was followed proximally to a point 5 cm above the elbow. Images were compared for consistency of location of the nerves and depth from skin and width was calculated for each nerve at each level.


RESULTS
Anatomy of each nerve was consistent except for one forearm where the median nerve was lateral to the brachial artery at the elbow and one forearm where a superficial ulnar artery only joined the ulnar nerve at the wrist. A convenient location for blockade of both median and ulnar nerves is the midforearm combining ease of visualization, ability to block all terminal branches and minimal potential for vascular injury. The radial nerve is seen most easily at the elbow although blockade of the superficial radial nerve may spare radial motor function.


CONCLUSIONS
Nerves in the forearm are consistently located using ultrasound. Further confirmation in clinical practice is required.
McCartney
Colin J L
CJ
Department of Anesthesia, Sunnybrook Health Sciences Centre and University of Toronto, Toronto, Ontario, Canada. colin.mccartney@utoronto.ca
Xu
Daquan
D
Constantinescu
Corina
C
Abbas
Sherif
S
Chan
Vincent W S
VW
D000328:Adult; D005542:Forearm / Q000000981:diagnostic imaging* / Q000294:innervation*; D006801:Humans; D008475:Median Nerve / Q000000981:diagnostic imaging; D009407:Nerve Block / Q000379:methods; D010525:Peripheral Nerves / Q000000981:diagnostic imaging*; D011826:Radial Nerve / Q000000981:diagnostic imaging; D012016:Reference Values; D012867:Skin / Q000000981:diagnostic imaging; D014459:Ulnar Nerve / Q000000981:diagnostic imaging; D014463:Ultrasonography; D014953:Wrist / Q000000981:diagnostic imaging