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Three Part Question

[In patients requiring a median nerve block] is [ultrasound guided local anaesthetic infiltration better than landmark technique] at [improving success rate as defined by procedure adequate analgesia and/or reducing need for multiple attempts at infiltration]

Clinical Scenario

A 27 year old man presents to the ED after being bitten by a dog on his right palm. The wound is contaminated and needs a good clean before referral on to plastics for more formal repair. It is very painful and you elect to use a median nerve block to facilitate good wound toilet. You use a landmark technique and infiltrate a mixture of lignocaine and bupivicaine. However, you are dissapointed to find that it has not worked. You ask a colleague to help and they suggest getting the Ultrasound machine out to help localise the nerve more precisely. You are familiar with this technique for other nerve blocks but have not seen it done at the wrist before.

Search Strategy

Medline 1950 - August 2007 via OVID interface
median nerve.mp. or exp Median Nerve/ or exp Wrist Injuries/ or wrist.mp. or exp Wrist/] and [ultrasound.mp. or exp Ultrasonography/] and [exp Anesthesia/ or anaesthesia.mp. or exp Anesthetics, Local/ or regional anaesthesia.mp. or nerve block.mp. or exp Nerve Block/]

Search Outcome

5 papers were found. None were relevant to the three part question

Comment(s)

In the authors opinion regional anaesthesia is underused in the ED, and in part this may be due to a lack of confidence in the location of nerves from surface anatomy and landmark techniques. Ultrasound offers the potential to teach, reinforce and learn the landmarks for nerve blocks and this has been shown to be successful for other regional blocks (e.g. femoral). With the increasing use of ED ultrasound more data may follow on this potential indication.

Clinical Bottom Line

There is no published comparative evidence on USS guided vs landmark technique for median nerve blocks.