Your next ED chart: Finger injury
The finger needs to be anesthetized.
Patient: "I have had this freezing before. The needles really hurt! Is there anything else less painful? "
Trick of the Trade:
A single, subcutaneous, volar-approach digital block
The traditional ring block involves two injections at the base of the finger (and a third injection if anesthetizing the thumbs and toes). A recent article adds to the literature on a non-traditional approach to the digital block - the single subcutaneous method.
Where do we inject?
Midpoint of the crease where the finger joins the palm, on the volar side.How deep is the injection?
Subcutaneously. The anesthetic will deposit on top of the tendon sheath and infiltrate to where the digital nerves are.
How much volume?
About 2-3 cc.
Study results
How effective is this volar subcutaneous approach?
It is just as good as the traditional multiple-stick, dorsal approach. In this study at 5 minutes, 76% (28/37) patients in the single injection group were adequately anesthetised compared to 65% (22/34) patients in the traditional block (p=0.436, no statistically significant difference).
Also there were no differences in anesthesia at 10 minutes.
Is this less painful?
The self reported pain score was less, but again the difference was NOT statistically significant.
Do clinicians like this better?
Yes, the difference in Clinician Satisfaction score WAS statistically significant. In fact, many study clinicians adopted the single injection method, making recruitment of the trial subjects difficult.
What is my experience?
I really like this method since patients seem to tolerate this better. However, it does not work as well for the thumb, probably due to the dorsal branches of its digital nerves.
Other techniques described involve infiltrating the area 1-2 cm proximal to the digital-palmar crease similarly. I find they all work well for me.
What are others' experiences?
Converts swear by this. Some even use this to anesthetise toes!
Bottom line:
A single volar subcutaneous injection is efficacious and may be less painful for finger anesthesia.
Reference:
Cannon B, Chan L, Rowlinson JS, Baker M, Clancy M (2010). Digital anaesthesia: one injection or two? Emergency medicine journal: EMJ, 27 (7), 533-6 PMID: 20360491
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Hey Stella - Great find and tip. I haven't used this personally and will have to remember to wait a good 5-10 minutes as the study results suggest. Thanks!
ReplyDeleteI really like this technique! Sometimes if I'm not confident that I've gotten into the tendon sheath and that the anesthetic will spread I might use the same puncture site to reach both sides of the digit.
ReplyDeleteDoes anyone have any experience using this technique in the lower extremities?
Wait, so is this a subcutaneous or a tendon sheath block? Haven't used to for fingers or toes. Thanks for clarifying!
ReplyDeleteDemian: Thanks for the comment. I think your tendon sheath technique (the transthecal technique - which has the same landmark) is technically more difficult than the subcutaneous one. I really only go subcutaneously.
ReplyDeleteI haven't tried it, but colleagues have used it on toes.
tried it on a finger injury today. great trick!
ReplyDeleteAwesome. I'm still waiting to try it myself. Thanks for the feedback!
ReplyDelete