VTE Unplugged Episode 2: Exploring Thrombocytopenia Risks and Optimal Platelet Count Cutoffs in Prophylactic Thromboprophylaxis
Welcome back to the second episode of VTE unplugged on thrombosis versus bleeding risk, making the right choice. In this episode, Dr. Shari Brosnahan and Dr. Abhe Bave will discuss the risks of thrombocytopenia and the optimal cutoff value for platelet count during prophylactic thromboprophylaxis. They also discuss anticoagulation in patients who bleed as well as the role of different mechanical prophylactic measures in patients with thrombotic risk. Let's listen to this interesting conversation. I think when we deal with malignancies and we give chemotherapy to our patients, more than the derangement of liver and renal parameters is a thrombocytopenia. We've already alluded to this and just as a ballpark figure, when you want to give a therapeutic intention of anticoagulation versus a prophylactic intention of anticoagulation, what is your platelet cutoff value? Actually, it seems a little bit counterintuitive, but I tend to be a little bit more aggressive wanting to give the treatment, right? And this could be that do no harm. So I know that when I know someone has a thrombosis, I know I have to treat that. They're already have proven to me that they are definitely hypercoagulable and that they are definitely likely to have a night is for improved infection. So those are patients that I'll actually even start thromboprophylaxis around 50. I might even go to 40 and then increase to treatment when they get above 50 to 75. And then I'll get treatment dose again with a heparin based therapy because those have reversibility, I'll usually use a heparin drip in those patients initially for treatment so that that can be turned off and that person can be given, you know, reversal agents. But in terms of prophylaxis, I usually will do that around 50. I'll give them a heparin. Thank you, Dr. Shari for that. You did mention about GI luminal bleeding. So let me direct my next question towards that. Suppose I've got a patient who needs thromboprophylaxis in the water in the ICU. But there is two scenarios that I'll mention to you. One, there is some kind of GI bleeding maybe because there's a rhyl stubin certain, there's an active gastric ulcer. How will I give anticoagulation at that point of time because the intensive care will not let me give anticoagulation. And the second situation where the bleeding in the GI has occurred a while ago, but there's always the fear that it might reactivate, but I've still got to give the anticoagulation. So in these two scenarios where there is either a history or an evidence of bleeding, how will I give anticoagulation to them? Yeah, I think those are great scenarios and there are things we come across all the time in the real world. The biggest thing that I would think of is stability. So how stable has this patient been? And how comfortable I am that I can fix the problem that's happening. So if someone has had a horrible, very field lead or a spurting recent ulcer, that's different than if someone has a slowed down trend in their hemoglobin over months, that I assume is GI luminal. So I think that these rather dramatic bleed are a little bit more of a stressful situation. And in general, I would say I wait, and this is all kind of expert opinion. There's no clear guidelines on this. But I would say for stability of the blood counts for 24, definitely 48 hours, definitely 24 hours. So I usually wait for two days. I definitely need it beef for at least a day. And at that point, I could start a couple of different strategies. I could just start with sub-cue heparin if I feel like there's a little bit of stability. The other thing I can do is start with a very, very low dose heparin drip, non-bollus, where I start maybe 5 milligrams per kilogram, very low, very low. And make sure that there's no bleeding with that. And then I am comfortable because I know exactly how much the patient got. I can turn it off. I can reverse it very quickly. And then I'll run hemoglobin in those patients much more frequently, maybe every 4 hours, or maybe after the initiation I'll run one after 2 hours. And while the hemoglobin might not change that quickly, if you have the ability to do a lactate or if you have an A line or if you have something to manage your an output, that can be actually the first indicator that the patient is bleeding rather than the hemoglobin going down. That means the patient's kind of clamping down. So an A line or definitely a catheter to make sure that the urine output is staying stable would be important with reintroduction there. Right. That's a detailed discussion. Thank you very much for that. You know, what I face in situations when someone has had a bleed and I tend to use a therapeutic or prophylactic anti-crylation. Either the intensive care, intensivist or the physician who has referred the case to me quickly asked me a question. Instead of a pharmaceutical method, can I use something which is mechanical? So commonly the discussion comes up for sequential compression device or intermittent neuromatics compression. So in today's world, are these obsolete or are we still using it? Is there a situation where you prefer it to be used? Yeah. So I only use these sequential compression devices as CDs when I feel like I can do nothing else. I don't think they have some efficacy, right? But they don't have the same efficacy as thromboprophylaxis. And I think basically the only time I use them is if someone's briefly bleeding or if someone has a contraindication for anti-crylation with platelets under 50 or patient has been found to be coagulopathic for other reasons. With that being said, if someone's coagulopathic for other reasons, meaning that I did a tech and I know that the INR actually means they're therapeutically anti-cragulate, anti-cragulate, I'm not as worried about them bleeding. They have an elevated INR, but the tech didn't show that they had thinned blood. In general, I'm still giving them thromboprophylaxis even with the elevated INR. And again, renal failure for me is not a cutoff to give anti-cragulation, not give prophylaxis. It might be a thought to decrease the dose a little bit, but it's never renal failure in my mind is just changes my drug of choice to more of a short and half-life drug rather than a longer half-life drug. Right. Thank you. So let's just take this a little bit further about the IPC and SCD. We are not routinely doing ultrasound, color-doplex ammunition of the lower extremities prior to applying the IPC or SCD. Is there a risk that they might have been a silent thrombus or a small thrombus and then apply the IPC or SCD, am I at a risk of the patient dislodging your clot? And despite the application, if they continue to have thrombosis, how do I add, when do I add the anti-cragulant, the therapeutic or the pharmaceutical anti-cragulant? Yeah. So I would say that's a great question. So I'm not sure some institutions develop policies and why you actually have a policy that if a patient has been hospitalized for more than 48 hours, SCDs cannot be placed without formal, below our extremity dapplers for the exact reason you're speaking about. I think now with how many ultrasounds there are access to with butterflies, and I'm not sure what devices you have, but there are a lot more handheld devices throughout the United States that I will not put them on without scanning the patient myself and looking. It is a very quick exam to learn. Anyone can learn it, how to look for lower extremity dbt's. And I think that that is extremely important to do prior to placement for the exact risk you're talking about. The times when if a patient cannot tolerate anti-cragulant for an extended period of time, meaning more than 48 hours, the SCDs might be something that I'm doing while I'm waiting for the GI scope to see where the bleeding is or to treat the bleeding. But if a patient cannot receive anti-cragulant for a long time, meaning more than 48 hours, and they're having thrombosis, that patient needs an IVC filter. I don't like putting IVC filters in, but I also don't like watching clot grow. And SCDs do nothing to do very little. They do maybe treat like activate this thrombo activating pathway, which could increase TPA theoretically, but they don't actually treat clot. And so those patients need to be on anti-cragulant as soon as possible, and if they cannot do that, they need to be treated with magnesium filter. Lovely. So while you've brought up the issue of IVC filters, let's talk a little bit more about where you would consider IVC filter placement as appropriate in today's practice when we have got such a plethora of anti-cragulants available to us. Yeah. So I would not put an IVC filter in any, at this point, I think the guidelines have changed so much. I don't put IVC filters in anyone that does not have an active thrombosis or is not still in the active treatment phase of being treated for a thrombosis, meaning a patient might have had a PE or DBT a month before and now is undergoing surgery. If they need that and I have to interrupt this treatment phase, there's a possibility that I will place an IVC filter in them if they think that there will be a prolonged period that they will be off anti-cagulation. This needs to be structured with as minimal time as the IVC filter can be placed. So I will place it maybe the day before the procedure. I will stop anti-cagulation in preparation for the procedure and then I will remove that as soon as the patient can tolerate full dose anti-cragulation for the procedure. We actually find this a lot in patients with fibroids or uterine abnormalities that that is they have intermittent compression of their vena cava from this very large fibroid and then they have to undergo surgery to have that removed. So it's both treatment and prophylaxis. Those will be patients that I maybe will do this in. There are also patients that are chemo therapy or cancer patients that need to undergo resection of their cancer that I don't want to delay until the active treatment phase is gone, in which case I might place an IVC filter for that time to bridge them. But I will remove that as soon as anti-cagulation can be restored. I do not usually place IVC filters at this point for patients who have a, I do not place them for transient conditions, meaning that I think it will improve in the short term. Unless someone has a profound thrombocytopenia and thrombosis, that's kind of true. Right, thank you. So from what I've understood about 48 hours and above it, we cannot anti-cragulate. Would be an ideal time to put an IVC and we both want to tell our listeners that the IVC filters that you'd like to put in are temporary, the ones which we can remove as soon as possible and not let them be inside. So we've got ways of telling the patient that as soon as the utility of the IVC is over, filter is over, we should remove the filter as soon as possible. So that they are aware otherwise if it stays in it's an issue later on for anti-cragulation. And I think you know you brought a hospital level treatment guidelines for prophylaxis. I think there should also, if your institution does IVC filters, there should also be a hospital level registry for the IVC filters. This is something that happened out of our, it actually initiated in the Kaiser system in California where they found that if they kept track of their IVC filters and called them at regular basis to remove the IVC filters, they had upwards of a 95, 98% removal rate. But without this, this rate was much lower in the 80s. And so I think if your hospital does IVC filters, you're obligated to have one of these registries. That's excellent information you're doing. And I think we should institute that. Thank you so much for that. Thank you for tuning in to VTE Unplugged, a podcast series curated by Sanofi. Stay tuned as we bring to you the next part of an ongoing discussion between Dr. Shari Brosnahan and Dr. Abhebave.
