welcome to unit 3 laboratory values and nursing management of course here we have our disclaimer so causes manifestations and management are not all inclusive those that are listed are generally common or relevant to course material in this presentation we will cover prothrombin time pt international normalized ratio inr and partial thromboplasm time ptt the first one we're going to discuss is prothrombin time so prothrombin time is the amount of time that it takes for the blood to clot in consideration or in relation to the clotting factor prothrombin and prothrombin time is 11 to 12.5 seconds now looking at this graphic of the coagulation cascade and anticoagulants a couple of things so first of all this is a very simplified version of the clotting cascade or coagulation cascade so i want you to appreciate just how complex this process is in your body it's pretty amazing but i don't want you to you don't memorize this you don't have to put all this to your memory i just want you to use the discussion in relation to the coagulation cascade as a means to help you actually understand why pt and say ptt have different times associated with them why certain drugs require more lab value monitoring than others why some of the anticoagulation drugs are more dangerous than others so as we talk through this presentation i'll be referring to this coagulation cascade to help give you some more context so you're not just memorizing this information so since we just talked about pro-thrombin time you can see down here that i have this red square around prothrombin which then is converted into thrombin in the cascade so it takes about 11 to 12.5 seconds for the blood to clot in relation to prothrombin so from here in the clotting cascade from this part of the common pathway when prothrombin is activated to become thrombin it takes about 11 to 12.5 seconds to create a clot now we're going to jump right into international normalized ratio or inr because inr is a ratio of your patient's pt or your pt to a internationally normalized agreed upon value for pt so for example if you had a patient with a pt of 12 because that's within the normal range for a pt so 11 to 12.5 let's say your patient's pt was 12 and the agreed upon uh normalized pt is the same it's 11 to 12.5 so it's it's our normal so if your patient had a uh pt of 12 seconds well the normal is 11 to 12.5 seconds so that's a one-to-one ratio 12 seconds to about 12 seconds one to one or it'll equal an inr of one now a normal ratio it's not always you know quite that perfect so you could have a a ratio of 0.8 to 1.1 i mean that kind of hovers around the one and so that's pretty normal for an inr now over here i want you to look at the preferred or a therapeutic inr in relation to certain conditions don't confuse normal and therapeutic therapeutic means that it's at a level that is providing some kind of therapy or benefit to the patient in relation to a specific condition in this case they have some sort of high risk for clotting so a therapeutic inr is going to be greater than what the normal is and of course the normal is one so hopefully most of us in this class we have a inr of one or close to it so that's normal if we're not on any kind of anticoagulation medication we don't have a clotting factor problem so if we were going to go and have surgery and we were put on coumadin for say dvt prophylaxis now that doesn't happen very often anymore but just for the sake of this discussion if you were put on cuban therapy for dvt prophylaxis we would want your inr to be a little bit elevated we would want your clotting time to be a little bit slower than the normal to reduce your risk of clotting so if i was going in for surgery i'd be at greater risk for clotting so they'd want to thin my blood or slow down my my clotting time just a little bit to help my body uh prevent forming a clot and getting me into some serious trouble with dvts and pes and all that so full anticoagulation therapy where where therapeutic inr begins is a 1.5 to 2. so if you're thinking about just the baseline therapeutic inr it's a 1.5 to 2. but that's really a target inr for dvt prophylaxis if i was a patient who had a dvt or i had atrial fibrillation or i had orthopedic surgery my preferred target therapeutic inr which is prescribed by a provider would be about two to three every patient's a little bit different but for these conditions it's approximately two to three now really quickly i want to touch on atrial fibrillation because you haven't had cardiac yet the the nuts and bolts of that that you have to understand is that is a cardiac condition that is relation to your atria so those top little chambers uh in your heart you've got those two of them and basically it means that the atria fibrillate or they wiggle they don't pump anymore like they should and because they wiggle it causes turbulent blood flow and puts the patient at greater risk for developing a clot then if you get a clot in your heart and your heart pumps you can actually push that clot into your into your lungs or into your brain and so you really need to have a therapeutic inr with this type of condition that's about two to three to help reduce the risk of you developing that clot because oftentimes we can't fix the atrial fibrillation but we can slow down your clotting time to help prevent you forming a clot now with orthopedic surgery and this will become more important when we talk about hip fractures in the care of those patients in unit four but oftentimes in orthopedic surgery and primarily um lower body orthopedic surgery those patients have impaired mobility and so they also require a therapeutic inr to help prevent them forming a clot simply due to venous stasis or just lack of mobility and then also of course you tie in the trauma from the surgery and all of that puts them in a much higher risk for a dvt and that's getting into a discussion of virtuous triad which we'll talk about later on in this this unit and then you've got down here a prosthetic heart valve prophylaxis or a mechanical valve if a patient has a mechanical valve that that puts them at extremely high risk for forming a clot so sometimes they'll have an inr target therapy of anywhere between three to four and that's that's pretty high and we're going to talk a little bit more about what that really means here in a minute but that means that it takes them three to four times the normal person to form a clot so that puts them at really high risk for bleeding so here is a graphic that i've put together to help you understand this whole pti in our relationship just a little bit better so up here at the top you have your normal pt which is someone who does not have anticoagulation therapy on board they don't have any clotting factor deficiencies or coagulopathy so a generally average normal person their pt time should be 11 to 12.5 seconds the inr is calculated in relation to a pt you cannot have an inr without a pt but you can have a pt and not calculate inr because the inr is a ratio of your patient or your pt to the average or normalized pt so if we start over here in the far left this is a normal pt so no anticoagulation disorders no therapy nothing your patient let's just say that they have a pt of 12. we know the standard or normalized pt is 11 to 12.5 so that gives us a one-to-one ratio 12 seconds to about 12 seconds one-to-one ratio my patient has an inr of one if i come over here to a therapeutic pt um let's say my pt for my patient is 24 it's within that range i know the standard pt is 11 to 12.5 that's about twice what a normal pt is the ratio is two to one gives my patient an inr of two moving on to the far right here uh further um or a higher therapeutic pt if my patient's pt is 36 in between 33 to 39 and i know my standard pt is 11 to 12.5 well that's three times the standard pt so the ratio is three to one and that means my patient has an inr of three and this goes on on and on to four five and six now once you get past four uh that's almost something called supra therapeutic so it's more it's it's higher than anything that should be considered safe and therapeutic and usually that means they have either overdosed on their warfarin maybe they've changed their vitamin k intake something has changed and it's too high and it's really really dangerous the highest i've seen is a 10 and that's basically it takes a person 10 times as long to form a clot than a normal person if you have an inr of 10 which of course puts them at super high risk for hemorrhage and it's just it's really really dangerous so you'll usually see targets of an inr anywhere between 1.5 to about 4ish maybe 4.5 in extreme cases so what causes a high ptinr or prothrombin and the related international normalized ratio liver disease if you think about what your liver does one of the many things your liver does is it creates your clotting factors so if you uh don't have a functioning liver and your liver is not creating all the clotting factors including prothrombin then you're going to have a much slower prothrombin time especially if it's not made in adequate amounts and so you're going to have an increased pt inr if you have a hereditary factor disease and of course the most common one people think about is hemophilia if you are lacking some kind of clotting factor then of course your clotting time will be increased if you have a vitamin k deficiency vitamin k is absolutely critical to your body creating clotting factors it's part of that entire process so if you don't have enough vitamin k your liver doesn't have what it needs to make the clotting factors and then of course coumadin therapy if a patient's on coumadin um that's the the trade name and the generic name is warfarin so if you have a patient on coumadin therapy the mechanism of action of coumadin is to block the body's ability to use vitamin k to create clotting factors so then of course a low ptinr would be if maybe we had to replace vitamin k in someone because they had an inr of eight if they had way too high of a coumadin level um like i said because maybe they missed their labs or they changed their diet or whatever and we tried to replace their vitamin k but maybe we overdosed them a little bit too much or they had a weird response to that medication then the low than a low ptinr would be because of excessive vitamin k replacement now one thing i want to say and i want you to put this in your brain do not get vitamin k and potassium or k plus confused potassium is k plus that is a cation right that's electrolytes vitamin k is a vitamin specifically in relation to clotting factors for this unit and vitamin k is also the antidote for coumadin so don't get potassium and vitamin k confused so what do these patients look like if they have an elevated ptinr well what does that mean that means that their pt their prothrombin time is much longer than the average person so what does that make you think of well i hope it makes you think of bleeding bruising you could even see mental status changes if they had a bleed in their brain they may have bleeding at their iv site they might have excess drainage in their jp drain they might have a ton of uh bleeding um into their their dressing like their their bulky dressing maybe after a surgery so just excessive bleeding that you would not expect in relation to the patient's condition uh and status so then what does a low ptinr look like well if a high pt inr is bleeding then a low ptinr is going to be clotting so they might have some kind of thrombus or embolus formation so really quickly let's break down what is a thrombus what is an embolus a thrombus is a blood clot stuck somewhere in your body it may be partially occlusive it may be fully occlusive but an embolus is a thrombus that is on the move okay so an embolus is something that is moving through your body it's traveling so typically where clots begin is in the lower body um the lower extremities so the deep vein thrombosis typically in the calves we're gonna talk more about that in this unit and that's called a dvt for deep vein thrombosis now that might break off become an embolus and move to the lungs and then it would be called a pulmonary embolus it may move to the heart and cause a myocardial infarction or an mi it could even move to the brain and cause an ischemic stroke ischemic means loss of blood flow so if you have a thrombus or a blood clot that blocks off blood flow in the brain it would be ischemic because it's blocking off blood and you may see some mental status changes because of that stroke activity caused by the thrombus so how do we help manage these patients well if you have a high ptinr if it's because of cumin and therapy we might give a vitamin k or maybe if it's because of a vitamin k dietary deficiency we might give you vitamin k we also might give you something called fresh frozen plasma fresh frozen plasma has clotting factors in it so basically that's direct replacement of clotting factors so vitamin k if we give you vitamin k we have to allow your body time for the liver to make those clotting factors so sometimes it takes up to 24 48 hours for your body to fully replace those clotting factors with the vitamin k that we gave you because we have to give your liver some time to actually make those clotting factors but with fresh frozen plasma that is it's kind of it's a blood transfusion it's a blood product transfusion and so it's plasma that has a bunch of clotting factors in it and so that's given in much more emergent maybe even an urgent situation when they have to have clotting factors now because maybe they have to go have a procedure like we can't wait two days for their clotting factors to rebuild we need to have them clotting appropriately now so we're just going to give them clotting factors so that's what ffp is of course these patients are going to be put on bleeding precautions for two reasons first of all if they're already bleeding and they have low volume they're much higher they're much higher risk for a fall the other piece too is that if they have a super high pti or even just a slightly high ptiner they're obviously at higher risk for bleeding and they just can't clot as well so we want to teach them you know if they're brushing their teeth to be very gentle to use a soft bristle brush they also can't shave like many of us can because that can cause little micro abrasions and they could bleed profusely just from small micro abrasion so they would have to use a clipper instead of a razor we might also have to help them with dietary management so if they're on coumadin and they maybe say they really want to get healthy they're trying to make a lifestyle change because the reason they've been put on coumadin is because of some cardiac disease and it's caused a fib or some other problem so they have to know that if they suddenly decide to eat a ton of green leafy salads well that contains a lot of vitamin k and so that's good and fine as long as they talk to their provider and the provider can help them manage their coumadin along with their increased vitamin k intake so a big thing with these patients is to make sure they don't completely stop their intake of vitamin k or greatly increase their intake of vitamin k but instead they keep their intake of vitamin k about the same um so that they don't goof up their inr levels in relation to their cumin intake and so if they decide that they do want to change increase or decrease their amount of vitamin k intake they need to talk to their providers so they can help them adjust their cumin levels to keep their iron where they need it to be so how do we help manage a patient with a low ptiner well first of all it may just be that they need anticoagulation therapy and maybe they need coumadin or maybe something like heparin and we'll talk more about that here in a little bit but some sort of drug that can slow down their their clotting cascade and reduce their risk of forming a clot now that's more preventative so they don't form it in the first place so maybe they have a low pti and r and they're super high risk for clots so they're put on cumin to prevent something from happening now if they have a clot that is formed because of a low ptinr and it's completely occlusive and it's life-threatening they may be put on something called thrombolytics so thrombo means thrombosis lytic means to lyse or to cut to break up just it's also called tpa because it's it's a tissue plasminogen activator so plasmin is a part of the clotting cascade that sometimes is activated as a means to prevent a clot from forming so that's actually a drug that we use to bust up clots i mean it's essentially drano it really is it busts up the clots um instead of like with coumadin or even heparin which we'll talk about again here in a minute which stabilizes clots it's it prevents them from getting bigger getting worse and allows the body to sort of manage the clot by itself or just prevent it from forming in the first place whereas a thrombolytic actually busts it up and they're very very very dangerous drugs and of course with low same thing is high if it's because of a change in their vitamin k intake they might just need some education in relation to dietary management you