Should POPs be mixed with Heparin?

We published an interesting BET in the EMJ earlier (open access version here) this year about the use of low molecular weight heparin for patients placed in below knee POPs in the ED. This is particularly pertinent to me as I have been unlucky enough to deal with several really nasty cases in the last few years.

Standby phone goes…….Young cardiac arrest on the way in…….as the doors to resus open you see the POP on the leg….and you know this is going to end badly.

Some of the conversations with the spouses and children of patients who have died young are memorable for all the wrong reasons.

So, there is no great surprise that the cause of death is inevitably massive PE, and this is where it gets interesting as we assume that this is a preventable death. If only they had been given prophylaxis then surely this would not have happened. Well, perhaps not as the event rate is low and heparin is not without it’s own complications, so what is the evidence?

Well, my colleagues Dan Horner and Cath Roberts found a pretty good systematic review on the subject that came to an interesting conclusion. The NNT for prevention of DVT is 14. Crikey, 14 people treated to prevent one DVT is a shocker to me as that reduction is a result of a big change on a very high event rate (>18% incidence of DVT in the placebo group)….but it’s one that I don’t see coming through the door of the ED. Considering the rate of POP applications in the fracture clinic next door if the rate was that high then why am I not swamped with fracture clinic patients with DVTs? A tricky question and I can only surmise, but arguably this is a different patient group to the spontaneous patients and as the BET states, the incidence of PE and fatality as a result of these rather common DVTs is low.

So, should we routinely treat? Do you routinely treat? Would this change your practice??

I must admit to having changed practice. I am much more likely to prescribe LMWH if there is even a sniff of a risk factor and no contra-indications and up until recently I’ve been using POPs much less frequently.

I’d also say that if I turn up in your ED with a broken leg that requires a POP I will be asking for the LMWH. I don’t think I want to risk a 1:5 – 1:6 chance of getting a DVT.

What about you? Would you, should you, could you, do you??

Simon Carley

Cite this article as: Simon Carley, "Should POPs be mixed with Heparin?," in St.Emlyn's, July 13, 2012,

5 thoughts on “Should POPs be mixed with Heparin?”

  1. thegreathornero

    This is another one we are on the cusp of. Should be a guideline coming out in the EMJ within the next year surmising all the recent evidence.
    Also very interested to see the results of PROTECT ( and FONDACAST ( which should be out shortly.

    VTE rules! Unless you get it yourself in which case of course I am terribly sympathetic………..

    Another issue we are about to flesh out a funding bid for. Any takers for a multi centre RCT? Get involved and EM research within your department can take off like a rocket. You just need enthusiasm, a bit of time and a lot of patience……


  2. it we can get the services in place and pt self-administration (something that’s not as always as easy as it should be) then it seems fairly reasonable. Presumably it’s 4-6 week course. And is there any difference for above knee and below knee POPs? The DVTs i’ve seen in POP (and I agree they’re not as common as that study said) are mainly above knee.

  3. Could oral anticoagulants be the future here then as I agree that self administration of LMWH is of variable success.

    As for above knee DVTs….is that because you can only access the thigh ‘cos the lower leg is in plaster????


    1. Sean MCGovern

      Oral anti-coagulants are the future but only when we recognise that they require the same due diligence as warfarin in terms of potential other medication interaction. I agree more and more will start prophylaxis but there needs to be education re calf muscle exercise as well and the fact that DVT will occur on anti-coagulants not 100% guarantee

  4. We at the Urgent Care Centre in Rochdale do prescribe LMWH for below knee POP’S. We cover them for 7 days until their fracture clinic appt. We actively encourage self administration but district nurses will do it. The decision to continue with the LMWH or not is made by the doctors in fracture clinic as some POP’s may be changed for walking boots. Long live prophylaxis!!

Thanks so much for following. Viva la #FOAMed

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