Pradaxa (dabigatran) is a new oral anticoagulant that has many advantages over Coumadin (warfarin). Unlike Coumadin, Pradaxa is a direct thrombin inhibitor. Pradaxa is much easier to use. It does not require checking of clotting studies, nor are dietary restrictions necessary. That’s the good news.
Here’s the bad news. Unlike Coumadin, which can be reversed in an emergency with fresh frozen plasma (FFP) within a few hours and vitamin K within about 24 hours, there is no known way to reverse Pradaxa. If a patient who is taking Pradaxa presents with say, severe trauma or a perforated duodenal ulcer, what is an emergency physician or surgeon to do?
My colleague, Michael McGonigal MD, who blogs at Trauma Pro, posted a guideline on the emergency care of bleeding in patients on Pradaxa issued by the Institute for Clinical Systems Improvement (ISCI). A nice algorithm appears on page 2. It suggests holding the drug as step #1. [That is obvious.] Lab tests such as PT, INR, PTT and thrombin time are recommended with the caveat that they do not accurately reflect the bleeding risk or level of Pradaxa in the blood. Activated charcoal may be given if the drug was taken within two hours of arrival. FFP and vitamin K will not help as there is not a deficiency of clotting factors. Renal dialysis may be considered, but realistically, is it practical?
As a last resort, recombinant activated Factor VII (rFVIIa) or prothrombin complex concentrate (PCC) might be tried but get this: “The ICSI work group has included rFVIIa or PCC as options to help with clot formation at the site of bleeding. They do not reverse the drug, the correct dose is unknown, and there is no FDA approval for this use. Thrombosis is a known side effect of rFVIIa and PCC.”
The half-life of Pradaxa is 12-17 hours. Although the guideline does not address semi-emergency surgery, it might be wise in certain instances, such as in a patient with acute appendicitis, to wait at least 12 hours to perform the surgery. Keep in mind that laparoscopic surgery is usually done on patients with normal clotting. Unlike in open surgery, it is sometimes not possible to maintain a completely dry operative field when a laparoscopic procedure is done.
Unfortunately, the ICSI guideline is not very helpful. What it says to me is “Good luck if someone on Pradaxa comes in with head trauma or needs emergency surgery.” It’s not the ICSI’s fault. It seems like there is nothing one can do.
Since all I do is emergency surgery, I’m really looking forward to my first Pradaxa patient.