Warfarin is a common anticoagulant, meaning it is used to prevent blood clots. In this mnemonic video, we'll cover all the important facts about warfarin that any nurse should know for test day. Welcome to the battlefront of the war zone, Private.
I highly recommend paying close attention. Notice the war taking place? Well, this war should anchor your memory to the drug warfarin.
Get it? War for warfarin? Now that you're anchored to the scene, let's get started by talking about how Warfarin is used. The warriors here are getting ready for war by painting their bodies with war paint. Notice how one warrior is mixing paint thinner into the red paint.
Since we don't want all this red paint getting clumpy, right? By the way, thinning this red paint is our symbol for how Warfarin works as a blood thinner to prevent the formation of blood clots. In other words, Warfarin is an anticoagulant drug. Clinically, warfarin is used to prevent clots in patients who have a history of problematic clot formation such as those with DVTs or pulmonary embolisms, heart attacks, strokes, and so on.
Warfarin does, however, have some important side effects that we should talk about. Let's get to those next. One of the warriors went to scope out the battlefield and returned with a bleeding arm.
This is war, after all, and some amount of bleeding is to be expected. The warrior's bleeding should help you remember that warfarin causes bleeding as a major side effect. This should make sense when you think about how warfarin prevents blood from clotting, thereby increasing the risk for uncontrolled bleeding.
As with all drugs that cause bleeding, as the nurse, you'll want to be on the lookout for signs of uncontrolled bleeding, like severe bruising, tarry stools, or a sudden drop in blood pressure. Let's move on to talk about how we can make sure to prevent any bleeding before it happens by monitoring two important lab values. After applying the war paint, one warrior is wiping the paint off his hands with a paper towel. This paper towel is our symbol for PT, since PT stands for paper towels, right? I mean, if TP stands for toilet paper, then PT has to stand for paper towels.
Anyways, PT actually stands for prothrombin time, a lab value that should be tracked to monitor the efficacy of warfarin. The specifics are beyond the scope of the NCLEX, but in a nutshell, the PT is the laboratory measure of the time it takes for the blood to clot. You'll want the PT value here to be two or three times the patient's baseline. In real life, this is really hard to calculate, so we've got an easier way to track this.
Let's talk about that in our next symbol. Take a look at the eyeliner that one of the warriors is holding. In addition to the war paint, the warriors are wearing thick eyeliner. This eyeliner should help you remember INR.
Get it? I-LINE-ER for I-N-R? INR stands for International Normalized Ratio, another lab result actually derived from the PT we just talked about. For reference, INR is calculated by dividing or normalizing the patient's PT by the international average, creating a ratio of how long your blood takes to clot compared to the average person. An INR of 1 is normal, since this means you're right at the average.
An INR of 2 means that your blood takes roughly twice as long to clot compared to the average person. We want the INR to increase in patients taking warfarin, since the idea is to prevent the formation of clots, right? The Warriors are using the eyeliner not only to outline their two eyes, but occasionally to draw a third eye on the forehead. You know, since you gotta have that third eye for extra intimidation. In other words, the Warriors have eyeliner on two to three eyes.
The two to three eyes here should remind you that you should be targeting an INR between two and three in patients taking warfarin. When the INR is between two and three, the warfarin is having a good therapeutic effect and preventing blood clots at an appropriate level. If the INR is under 2, that means the drug dose is too low and the patient is still at risk for developing blood clots. If it is over 3, then the patient's blood is too thinned, leaving the patient at a high risk for severe bleeding. Just remember 2 to 3 eyes to remember INR's sweet spot between 2 and 3. Afterwards, take a look at the tarantula.
In this jungle war zone, tarantulas are pretty common. Here at Pixarise, we use a tarantula to symbolize when something is teratogenic. It's the teratogenic tarantula. Warfarin is teratogenic, and its use can lead to various birth defects. As such, warfarin is contraindicated in pregnancy.
Other, safer anticoagulants may be used in these women. In a war zone, the warriors aren't too concerned with the vegetation they are trampling. In this case, they are destroying kale. Yeah, there's no way anyone would want to eat the kale now that it's been trampled. Which reminds me, people taking warfarin should avoid eating high amounts of leafy greens like kale.
Why? Because leafy greens, and especially kale, are high in vitamin K, which is actually the antidote of warfarin. You can remember this as vitamin kale if it helps you. Eating too many foods high in vitamin K will actually reverse the blood thinning effects of warfarin and put the patients at risk of developing blood clots again. On the other hand, if you want to undo the effects of warfarin, say if a patient has an overdose or is about to undergo a surgery, you can give the patient vitamin K in the form of either an intramuscular injection, or through an IV line.
Just know that vitamin K can be used to reverse warfarin's effects. Alright, that's all for this mnemonic. Let's recap.
Warfarin is a medication that is used to prevent blood clots, which is why it's classified as a blood thinner or anticoagulant. Clinically, warfarin is used to prevent the formation of DVTs, pulmonary embolisms, heart attacks, and strokes in patients who are at a high risk of developing blood clots. Along with its blood thinning action comes an increased risk for uncontrolled bleeding.
To reduce the risk of severe bleeding, patients are monitored using the PT and INR levels. A therapeutic INR level for a patient on warfarin is between 2 and 3. Warfarin is also teratogenic and should not be given to pregnant patients. And finally, patients taking warfarin should avoid eating an excess amount of leafy greens and other foods high in vitamin K. This is because vitamin K is the antidote for warfarin. In cases where we want warfarin's effects to be reversed, vitamin K can be given as an injection or or through an IV.
And now we're actually done with Warfarin. With our newfound knowledge, I'm feeling pretty confident about battling the beast that is the Enclex. See you next time.
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