Category Archives: Pharmacy

How To Manage TBI In Patients On Warfarin

We all know that the combination of traumatic brain injury (TBI) and warfarin can be dangerous. Here at Regions, we developed a reversal protocol a few years ago. However, we found that just having a list of preferred “antidotes” to give was not enough. The time factor is very important, and we found that we needed to ensure prompt use of these medications when indicated.

So we added features that ensured timely response and reversal. You can download the protocol by clicking the image above or the link at the bottom of this post.

First, we recognized that any patient with a known or suspected TBI who was taking warfarin was at risk. If the initial GCS was <14, then a full trauma team activation is called. This gives the patient priority lab processing and immediate access to the CT scan. In addition, 2 units of thawed plasma are administered while in the resuscitation room. If the head CT is negative, plasma is stopped.

For patients with a GCS of 14 or 15, a “Code RED” is called, ensuring that an ED physician sees the patient immediately. A point of care INR is drawn and the patient is sent for stat head CT. If the head CT is negative with INR>2.5, the patient is admitted for observation and a repeat head CT is obtained 12 hours later. We have seen patients develop delayed hemorrhage when they have high INR.

We apply a restrictive set of criteria to determine if a patient may go home from the ED, which causes us to admit most for observation. And if they do have a positive CT, we use the algoritm listed below for comprehensive management and reversal.

Bottom line: Patients with any head trauma and an elevated INR are a walking time bomb. They need prompt assessment and reversal of their anticoagulation if indicated. Feel free to share your protocols here as well by posting a comment.

Download the full protocol; click here.

Related post:

Another Anticoagulant To Watch Out For

In May, I wrote about a new direct thrombin inhibitor named dabigatran (Pradaxa). This drug appears beneficial for patients who need ongoing anticoagulation without the hassle of blood testing to check drug levels. The danger for trauma patients is that there is no antidote or rapid reversal possible. This means that significant traumatic bleeding, particularly in and around the brain, cannot be stopped! At Regions Hospital, we have seen a few patients on this drug, but luckily they have not had bleeding from trauma.

Late last month, Bristol-Myers Squibb and Pfizer announced that a new drug has shown very favorable results in preventing strokes in patients with atrial fibrillation (apixaban, Eliquis). Indeed, it cut the relatively low risk of stroke in half, compared to warfarin. It also had about a third fewer bleeding complications. It looks like it may also give dabigatran a run for its money.

This drug is a Factor Xa inhibitor, and also has no antidote other than time. There is some evidence that activated charcoal given orally within 3 hours of apixaban dosing may be somewhat helpful in reducing blood concentrations.

Trauma professionals need to be on the lookout for patients who use this drug. Any trauma patient who admits to being on a “blood thinner” needs to be questioned carefully to determine which one it is. If it is one of the newer drugs without an antidote, they need to be monitored continuously for signs of bleeding (read: ICU), especially if they have experienced head trauma.

Bottom line: Be on the lookout for these drugs. If any patients who have fallen are taking this drug (elderly, frequently intoxicated, etc.), contact their primary physician so that the risks vs benefits of continuing it can be considered.

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References

Medication Alert! Dabigatran and Head Trauma

First, there was warfarin, a cheap and effective way of treating deep venous thrombosis (DVT) and pulmonary embolism (PE) in trauma patients. Unfortunately, there is plenty of literature that shows the added risk that this drug poses in injured patients, particularly in head injury. Because of this, many trauma centers have developed “rapid reversal protocols” to quickly restore vitamin K dependent clotting factors in an attempt to improve outcomes. To see our protocol, click here.

Next came clopidogrel (Plavix), which is used to prevent clotting in vascular disease. It irreversibly inhibits platelet aggregation. Counteracting this drug is more complicated due to its long half-life. Platelet infusions are required, but the infused platelets are inhibited by any remaining drug in the plasma. This requires the use of lots of platelets to get some meaningful clot to form again.

Now, we have direct thrombin inhibitors (DTI). Hirudins were the first used, and were never an issue in trauma patients. And their short half-lives obviate the need for reversal. The newest DTIs (argatroban and dabigatran) are a real problem in trauma. Argatroban is not a problem, because it is given by IV only. But dabigatran (Pradaxa) has just been approved for oral use within the last year.

According to the package insert, “there is no antidote to dabigatran etexilate or dabigatran.” And also “dabigatran can be dialyzed (protein binding is low), with the removal of about 60% of drug over 2 to 3 hours; however, data supporting this approach are limited.”

We will be seeing patients taking this drug in the near future. What do we do if they are trauma victims with bleeding in critical places, like the brain? At Regions, we have developed a proposed guideline that combines oral charcoal, dialysis, transfusions and optionally, activated Factor VII. Click here to download the protocol.

If anyone has any experience with these patients, please comment below. And everyone else, keep your fingers crossed!

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Protocols:

Thanks to Colleen Morton MD for developing the dabigatran reversal protocol