Jacobs IG, Finn JC, Jelinek GA, Oxer HF, Thompson PL. Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. Resuscitation 2011 Sep.;82(9):1138–1143. PMID 21745533
This paper got a lot of attention in the podcasting/blogging world but now I’ve read it I’m not sure what to make of it.
I really doubt we should be giving adrenaline in cardiac arrest (and I haven’t got round to listening to the SmartEM folks on this yet so that might change things…) but I expected this trial to confirm that and instead it leaves it an open question.
- planned as a big 5000 person RCT in Western Australia (where the LITFL guys work) but because of difficulties getting others on board it ended up as a 500 person RCT. That must have big implications for the statistical powering of the trial and what we can say about it.
- Randomised standard ALS adrenaline v placebo
- placebo and blinded and all the rest
- Primary outcome was survival to hospital discharge
- 500 pts
- ROSC in the field was 23.5% vs 8.4% favouring adrenaline
- survival to hospital discharge was 4.0% vs 1.9% favouring adrenaline but this didn’t reach the magic p number
- if you work that out that means 16 survivors overall.
And that’s where the problem comes. When your primary outcome occurs that infrequently it’s hard to know whether it’s all by chance. It could be that adrenaline is entirely useless in cardiac arrest (which I suspect) but it could also be that adrenaline is really important – double the number of survivors… well…
I’m off to listen to the SMARTEM folks cover this, so I’ll likely have to retract most of it…