Admission: I have taught and preached, and practiced this dogma for my whole career.
This is a great example of medical dogma, without any firm evidence becoming part of the axiom of pretty much every doctor on the planet! There are other notable axioms of medicine which have a massive impact on the health care and budgets of whole health systems. However, this is a simple blog – so I am just gonna tackle the “evil adrenaline in the digital block” axiom today. If you are interested in this kinda of dogma busting, commonsense approach or just want some enlightenment about the way we think – I strongly advise reading Dr David Newman’s book – Hippocrate’s Shadow. It is one of those books you read and feel like you are going to turn up to your next shift with a whole new way of thinking.
Anyway, back to the old finger block dogma. Here is what the evidence shows: it is completely safe to inject dilute (1:100,000) adrenaline into a digit. Actually, it might even reduce the bleeding and augment the duration of analgesia gained by doing the block – these are good things!
So you can believe me, or go look at these recent trials and see for yourself:
Clinical Hemorheology and Microcirculation 2008 (is this on your regular reading list?)
PLastic & Reconstructive Surgery 2010
European Journal of Hand Surgery 2008
Now, I ahve seen one incident of nasty vasoconstriction post adrenaline – this occured during a training drill for anaphylaxis when a nurse accidentally fired an Epipen into her finger (OUCH!). Of course, this was neat (1:1000 adrenaline) so a different scenario to the lignocain mix we use in ED! This resulted in a pale, painful fingertip, but ultimately a normal finger the next day. So what should you do if this happens well the short answer is pnentolamine, you can inject it right into the finger – see this case study from Mathez et al. Once again – no long term sequelae.
So are you feeling brave, can you overcome your entrenched, well-ingrained belief system and inject some “local with” into a pinky?