Episode 11 - Should We Delay Hip Fracture Surgery for DOACs?

Listen to Tim Coughlin and Iain Moppett discuss the paper 'Reversal of direct oral anticoagulants in adult hip fracture patients: a systematic review and meta analysis'.

Paper discussed: Alcock HMF, Nayar SK, Moppett IK. Reversal of direct oral anticoagulants in adult hip fracture patients: a systematic review and meta analysis. Injury. 2021;52(11):3206-3216.

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Transcript

[00:00:00] Hello and welcome to this month's Bone and Joint 360 podcast. I'm Tim Coughlin and I'm joined today by Iain Moppett who's Professor of Anesthesia and Perioperative Medicine at the University of Nottingham. So he's kindly joined us today to discuss the paper 'Reversal of direct oral anticoagulants in adult hip fracture patients: a systematic review and meta analysis', which is available now in the November 21 issue of Injury. So, and I thought this was a really interesting study looking at the problem of direct oral anticoagulants or DOACs, which those of us see frequently treat hip fracture.

Patients often face, particularly in terms of the delay they often cause and getting the patient to theatre. So how big do you think the problem is of DOACs in the hip fracture population? Is this affecting a lot of people? Yeah, it's affecting quite a few. The, the data that we have, our. A bit scanty overall, [00:01:00] we think a rough estimate is around 10% of people with hip fracture are on an anticoagulant of some sorts in the UK that is still predominantly Warfarin.

But if you go across the world, for instance, in Australia they move, they seem to have moved much more towards DOACs. So some is reckon at the moment around 2% of patients with some, with a hip fracture on a DOAC. And that's gut feeling is likely to increase off the ICs primary care use DOACs more often. So even at the moment, it's quite a lot it's going to become more, I think.

Okay. That's interesting. And obviously our issue with DOACs is that anticoagulant effect from a surgical perspective. So how long, roughly speaking, and I appreciate it may be different to DOACs tend to last in terms of that anticoagulant effect. After that. It's a slightly trickier question than it might appear.

The half-life of most of the structure of Rivaroxaban and the put span are around 12 hours. It's a little bit longer for Dabigatran. But bear in mind first, the half-life so the, the, the time to sort of [00:02:00] to lose most of the antiplatelet activity is for most of the drugs it's around 24 hours, but that does happen.

There are some caveats to that, essentially largely around renal function and also around the fact that a lot of the studies that are done on essentially healthier people, not older people with, with hip fractures. And then I hit the last heart. So in terms of sort of a pragmatic view, about 24 hours.

If you're going to the elective situation, then as I'm sure lots of your listeners will know they, their elective guidance is basically to get rid of that effect completely as to that's the guidance person for, for operating. To the the 48 hours, 72 hour mark, but that's different process for perhaps for hip fractures.

Yeah, that's interesting because obviously we are keen to get hip fractures to theatre quickly. So are there any options for reversing the action of DOACs that we commonly use at the moment? Essentially there's in theory, if there are three options which what we looked at in the paper there's waiting, that is one, one option. That's just what we refer to as time. There's there's the option to use things like some of the the clotting [00:03:00] products or PTCs and prothrombin complex concentrates. And there are a couple of specific antidotes and I'm going to struggle here. I always get these pronounced wrong.

So there's, there's Idarucizumab, close anyway. It's for navigation and there's and next to that, Alpha for Rivaroxaban. But not widely used and not recommended, which we might come onto in a minute. So there are some antidotes, but basically it's essentially it's wait or not wait. That's the common decision.

Okay. Now just taking a step back from the DOACs for a second, I was interested to see that you've used the concept of a network meta analysis in this paper, and that wasn't something I was particularly familiar with. Could you explain a little bit about what type of meta analysis this is before we go on to talk about the results?

So obviously it falls within, within the whole the framework and nationalities. So there's a whole concept of making sure that the studies are reasonable and so forth, but just coming to the network, but essentially if you can visualize a triangle if we've got most [00:04:00] studies are done in head to head studies, A versus B studies.

So a trial, you know, and orthopaedic trial of, of implant A versus implant B. We might have some data on that. We might also then have another trial of implant B versus implant C, which is not a direct head-to-head comparison, but the question you might be interested in is about how does implant A compare to implant C when there's no direct comparison. So we have the indirect comparison and that's what that's where network network mesh analysis comes in, especially saying. With all the caveats of mesh analysis and making sure the groups are, are similar and that consistent. Even if we haven't got a direct comparison between between one group and the other can we essentially go around the triangle or sometimes it's more complex than just the triangle to try and do you try and recreate that that's that comparison, but just doing it indefinitely.

So that's where that's essentially what it, what it's doing. Very interesting. Now for me, one of the headline findings in this study was that there was a quite significant fall in time to theatre from about 46 to [00:05:00] 25 hours in the non-time reversed group. And this seems like a strong reason not to wait for the DOACs to wear off.

Yeah. I mean, I certainly be in that camp and that's what we found was that. Within the limitations of the data and the data aren't great, these aren't randomised controlled trials. Within the limitations of the data, we couldn't find any evidence of harm from from going to to theatre more quickly or, or benefit from going to theatre more quickly.

So I can't say conclusively, it's a better strategy or worse strategy, however, If you look in the wider context, lots of observational studies, the the suggestion is that getting to theatre more quickly is associated with with better outcomes for patients. Now, clearly we have to unpack why people got delayed to theatre, but the general feeling is that if it's a purely organisational delay, you're going to theatre, it's associated with worse outcomes for patients.

The, and, you know, when we talk, we talk about those outcomes. Some [00:06:00] evidence suggesting that delirium rates are reduced by getting to theatre. Length of stay, you mentioned probably goes down with with getting to theatre and the fundamentally, we're just taking a humanitarian view. We think about why are we fixing people's hip, hip fracture in the first place?

There are painful distressing injuries. Getting people fixed on that road to recovery, which you know, both know from our clinical practice that we're doing our bit is, and this is the surgeon. This is to let the rest of the team getting these people, these people up and about, and anything we can do to delay, to reduce that delay I think is going to be a good thing. So there's no evidence to suggest that waiting makes things better. And the system generally works. Why don't we try and get people through that as promptly and efficiently as possible. 

Did you not think it was reasonable to assume that there is some additional benefit with the fall in length of stay? Because it seems to fall from a median of six to four days. And although I appreciate the data's difficult that's that does seem like quite a striking finding. Yeah, I think we have to take that in the context of smaller studies. And actually that is [00:07:00] at least some of that is deliberate is directly built in to take a simplistic view of it.

The length of stay of someone with an operation, you're largely determined by, like we say, after their operations. So we're just, we're waiting for them to go to theatre, we're just delaying when they go home. There may be other stuff as well, in terms of, of actually linked from the recovery time.

So it's more smaller studies suggesting that, but that's the evidence that we have. And I say, if we take a purely humanitarian point of view or we take a resource point resource resourcing view of it, then from a vast majority of people going home. So, you know, it's going to be better. So without evidence of harm from a delay, it's hard to say.

And it's interesting. One of the things that I suspect people are always very conscious about the bleeding complications. And you mentioned no harm, but you specifically found that there was no evidence of increased bleeding complications or otherwise. The, again, I, you know, I would cover everything with caution around the quality of the data that are there.

And the, and also on the fact that we know that measured blood loss in [00:08:00] theatre is is not a great metric of, of blood loss. But within the things that we looked at transfusion rates didn't seem to be different. So the worry which was there when the DOACs came out, first of all, was, it was uncontrolled bleeding.

Which is completely unmanageable in theatre. And so far the evidence seemed to say that that is, that that is borne out. Say that those complications seem to be those metrics appear to be much the same between between the groups. I think that seems quite reassuring. I mean, I think certainly from the perspective of the patient and the surgery watch and wait, doesn't seem to be the way to go, but are there not some anaesthetic reasons why DOACs are of concern particularly thinking around anaesthetic techniques, because I'm sure that's been quoted before as a reason to delay things.

So Tim you're straying into sort of anaesthetic controversy here. So I got to be careful what I say before I put my foot in it, but so and I wonder whether you're hinting at the, there's a couple of large trials which have just come [00:09:00] out. I'm looking at and I'm going to encourage your listeners to go and look at those and talk to the anaesthetic colleagues about them.

But obviously the, the worry we have with anti-coagulated patients already saw is that we we have two worries as anaethetists. One is, are you the surgeon going to cause blood loss, which is unhelpful for them. And then there's the small, but an largely unquantifiable, very small risk of vertical cloud haematoma from us delivering spinal anaesthesia.

And that is the, what, that's one of the worries around, around the DOACs and that's where, sort of the pragmatic recommendations which are around. So for instance the, if you really want to go and look at the Association of Anaethetists guidance on hip fractures. There's some supplementary information there about essentially a pragmatic view saying broadly speaking, wait 24 hours.

And generally, if there isn't a good reason to give a spinal general anaesthetic, perfectly reasonable thing to do no evidence at the moment that it's, that it's a worse outcome. Colleagues might criticise me for saying that, but that's the evidence as I interpret it at the moment. So and then the issues around [00:10:00] making sure that the surgery itself doesn't make people bleed more.

But I think the evidence so far is that they don't, if it's safe for surgery, it's probably safer anaesthesia.

No, that's a, that's very interesting. And actually, I think there was a large randomised control trial in New England Journal of Medicine late last year, which was one of the ones I think you're alluding to, that was looking at spinal versus general anaesthesia.

So, Ian, do you think we should consider changing our practice now? Or do you think it is changing and it's just changing slowly? Or do you think we need some more evidence before we make any decisions as to what we should do? I suppose the question of whether we, whether it should be changing, our practice is difficult.

I can describe, or what's what we, what you and I currently do, where we are. Which I say is that pragmatic approach of by large for for surgery at 24 hours, don't delay them beyond that. We like most units rarely get people before that time anyway. So that's not really making, you know, we're not likely to suddenly change our practice. Other, other units are more cautious.

If they're going to be [00:11:00] a large randomised controlled trial of waiting versus getting on. I don't think so. Is there ever going to be a trial of either of the the direct reversal agents in this population? I'm don't think there will be partly because the, there's never going to be an indication for assisting a patient who is bleeding that needs the anticoagulation reversed.

This is a patient where they might bleed when we get to them. So I think a lot of places have just taken a pragmatic view based on the evidence that's out there. Around 24 hours seems a sensible approach. But as a clinician, I would very, very strongly advocate that is a unit wide decision. So a unit has a consistent approach or a consistent policy on who gets blood, what blood tests are done when they're done, and that the humans are involved with that conversation in that conversation. So you've got geriatricians, the haematologist, all involved in drawing up an agree, agreed view, rather than I think what's the least helpful thing is patient by patient decision making, becomes, it becomes inconsistent.

And of course there will always be [00:12:00] times when a particular patient should be delayed for a particular reason. We should, we shouldn't be high bound by the, by those decisions, but I think most people would move sort of broadly to sort of 24 hours. But I say make a considered decision, don't basis it on me, nd you sat in on a podcast.

Professor Moppett, thank you very much. That was really interesting. Thank you very much for your time. Thank you very much, Tim.