Forearm ultrasound-guided nerve blocks vs landmark-based wrist blocks for hand anesthesia in healthy volunteers

Am J Emerg Med. 2016 Apr;34(4):730-4. doi: 10.1016/j.ajem.2016.01.020. Epub 2016 Jan 21.


Objective: Although ultrasound-guided regional nerve blocks have become more commonplace in the emergency department, there is no evidence to suggest that they are more effective than traditional landmark-based wrist blocks for hand anesthesia. We hypothesized that ultrasound-guided forearm nerve blocks would provide superior analgesia as compared with conventional landmark-based wrist blocks.

Methods: Eighteen paired nerve injections were performed by an experienced operator on 12 healthy volunteers. Each subject's right arm was assigned to receive either an ultrasound-guided forearm block with a saline placebo wrist block or a traditional landmark-based wrist block with a saline placebo ultrasound-guided forearm block. The subject's left arm then received the alternate approach. All blocks were performed with 3 mL of 1% lidocaine. We evaluated sensory block to pinprick. Secondary outcome variables included pain associated with injection, participant's subjective assessment of block effectiveness, and presence of any complications.

Results: At 15 minutes postinjection, 14 of 18 (78%; 95% confidence interval [CI], 59%-97%) ultrasound-guided forearm blocks were successful, as opposed to 10 of 18 (56%; 95% CI, 33%-79%) anatomic wrist blocks. The ultrasound-guided forearm blocks had a 22% (95% CI, 2%-42%; P=.032) higher rate of success than the wrist blocks. The ultrasound-guided forearm block was subjectively felt to be denser by 12 of 18 (67%) subjects (P=.0034)).

Conclusions: Ultrasound-guided forearm nerve blocks performed by an experienced operator result in more effective hand anesthesia than traditional anatomic landmark-based wrist blocks.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anesthetics, Local / administration & dosage
  • Double-Blind Method
  • Emergency Service, Hospital
  • Forearm / diagnostic imaging*
  • Forearm / innervation*
  • Humans
  • Injections / adverse effects
  • Lidocaine / administration & dosage
  • Nerve Block / methods*
  • Pain / etiology
  • Ultrasonography
  • Wrist / diagnostic imaging*
  • Wrist / innervation*


  • Anesthetics, Local
  • Lidocaine