Craig M, Jeavons R, Probert J, Benger J. Randomised comparison of intravenous paracetamol and intravenous morphine for acute traumatic limb pain in the emergency department. Emergency Medicine Journal 10.1136/emj.2010.104687 PMID 21362724
I confess I have a bias against this stuff. Putting paracetamol in a bottle and charging massive amounts for it is quite the marketing move but I have yet to be convinced. It used to always annoy me when I saw docs prescribing this as some sort of placebo for proper pain meds (ie opiates) beacuse the nurses would hang it and the doc wouldn’t have to go to the patient’s bedside themselves and give it. (in the place I sued to work the docs had to give IV morphine, crazy I know…)
One of the bosses even tried to put a kind of ban on it for being overused and overpriced.
But now there’s stuff coming out to try and point me the other way. Like this trial.
METHODS
- RCT, blinded, non-pharma funded
- pain >7/10 with isolated limb trauma were eligible
- radomised to 1g IV paracetamol over 15 mins or 10mg IV morphine (a reasonable dose) over 15 mins.
- morphine was rescue for both groups if needed
- outcome was pain on a VAS
RESULTS
- n = 55 so tiny numbers which is the single biggest problem
- paracetamol group had consistently higher pain (about 6mm) but it decreased in the same manner as the morophine group and they were of comparable efficacy
- neither group did that well (pain went from 75 to 55 over an hr) and 1/3 in each group wanted resuce meds
- they state a statistically significant increase in AEs in the morphine group but this was 8 vs 2 pts and they don’t tell us specifically what those AEs were
- more pts were satisfied in the morphine group
They conclude that a large trial is needed to answer this, and it seems that it probably does. This one is two small to change practice over. Especially when it involves something almost 10 times the price.
My bias is that I’ll want morphine when I break my arm, and that remains unchanged for now, but as always I’m willing to be persuaded!
The thing I get concerned with, is that people would read this and feel justified in giving paracetmol as appropriate analgesia and forget the more important part of going back and reassessing and offereing more if they need it
NB EM Lit of Note had a similar post a few weeks back on the same topic. Go read it.
I would have added a third arm to this study – a placebo group….
and what do you think it would have showed
- placebo as good as both?
We’d know for sure if they had studied it
I suspect in the same way, both placebo and paracetamol would have higher pain scores than morphine. I suspect a larger trial would also highlight morphines superior pain killing profile…
Withholding analgesia when someone needs it. Ethically dodgy, no?
Good point jim! Though looking at their pain scores (ie still 50mm or so even after treatment) then one could arge that they were still witholding treatment.
really the best thing for your “broken arm” is regional anesthesia, in most cases…but i realize EM is there yet
if the price were better and it was available to me, i would be using BOTH morphine and paracetamol in traumatic injuries.
however, i agree with you: a repeat trial with huge numbers would be nice
and one that includes subset analysis pulling out fractures
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btw, i am new to this blog recently – great stuff – i am adding it to my list of frequent reads, which includes the biggies like LITFL and EM Crit, and SMART EM, etc.
keep going (i especially like the anatomy reviews with clinical references)
HH
Hi Hamhock, thanks for the comments. Totally agree, no need to have just one agent when we can have two (though not if we cripple the bank account) and it would have been particularly appropriate in this study where neither group got especially good pain relief
Personally I also have a huge bias against iv paracetemol. Everywhere I have read it is recommended for mild to moderate pain only. The use in severe pain makes no sense to me. Thats why we have morphine which in my hospital is about 25% of the cost of iv paracetemol (1g vs10mg) not to mention the cost of the giving set to infuse it ( not sure how that compares to the total cost of a needle / syringe and 10ml normal saline vial to give the morphine but assume a little more)
The big issue is most of the juniors using the drug have no idea of relative cost or bioavailability. Sure iv paracetemol has peak effects in 15 minutes but oral its only an hour to reach therapeutic levels to no major difference there. The only thing I would say is I would be loathe to use pr paracetemol in isolation due to its erratic absorption taking many hours to achieve peak concentration.
For those who don’t know iv paracetemol costs about 6 euro per 1g vial while pr is about 1.5 euro. Oral paracetemol however is only about 3 cents for 1g and also avoids the expensive giving set so probably the cost diffence between oral and iv paracetemol is at least 200 if not 300 times that of the oral dose.
For the record my preference is morphine titrated to presentation, not always a lover of the pain score but can at least titrate to comfort and often I’ll give pr diclofenac (obviously not in all patients) +/- paracetemol po or pr ( though less of a fan of pr nowadays) about the same time as the iv is given for maximum effect.
Thanks for the comments adrian
I’ve rarely given PR dicolfenac but it does have a reputation for being an excellent analgesic. I definitely like the idea of giving more than one analgesic and giving it till the patients comfortable
I’m a fan of Ed Gentile’s morphine protocol myself (as described on EMRAP and EMCRIT) http://emcrit.org/podcasts/gentile-pain/
Particularly for things like renal colic or fractures.
I actually blogged on that one before. Best thing I’ve heard on acute pain management
http://emergencymedicineireland.com/2011/05/21/an-appeal-to-do-one-thing-well/
Andy