does yer school make u memorize clotting cascade?

[chef]

to my surprise i dont have to memorize it! i just need to know the basic concepts of the cascade and what the diff lab tests tell you, ie what abnl tests are telling you. sweet!!

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[Goofyone]

I had to memorize it last year.


Don't remember a damn thing about it though.

 

[MacGyver]

its not that hard...

XII, XI, IX, VIII, X, V, II, XIII (intrinsic)

III, VII, X, V, II, XIII (extrinsic)

throw in calcium at just about every step. Plus theres the high weight proteins at the first part of the intrinsic pathway.

 

[DOtobe]

Originally posted by Goofyone
I had to memorize it last year.


Don't remember a damn thing about it though.

Same here. Not going into Hem/Onc, so don't care.

 

[Purifyer]

Originally posted by MacGyver
its not that hard...

^^^

 

[Blade28]

Don't need to memorize it, per se, but you have to understand the different factors involved in intrinsic vs. extrinsic, vitamin K vs. non-vitamin K, heparin vs. warfarin, etc.

 

[SolidGold]

We did not have to know it either. Just the important stuff. Factor V was really the only factor we needed to know much about, and of course the difference in intrinsic and extrinsic.

I've actually been pleasantly surprised by the amount of stuff that we were not required to "memorize," at least in biochem.

 

[johnhobbes]

We had to memorize it. Not too tough. Learned a good mnemonic:
1972 WEPT: factors 10, 9, 7, and 2 are Vit. K dependent. W:warfarin acts on E: extrinsic pathway. PT: prothrombin time used to check it.

If you know this, then you know heparin acts on intrinsic pathway and PTT is the test used to check it.

 

[jed2023]

Learning the coagulation cascade seems like a pain in the butt at first but it's easier if you learn the names for the factors. Most of them have formal names that make life easier, when you are first learning the pathway. I would also associate the name with its function in the pathway, so that it is not just a number and a name to you but actually means something. To use the simplest example, factor IIa is thrombin, so when you see that, you should think factor IIa, thrombin, cleaves fibrinogen (soluble) allowing polymerization to form fibrin (insoluble). When you see factor 8 or factor 5, you should immediately think cofactor.

As far as names, factor 12=Hagemann factor, factor 3=tissue factor, factor 8= cofactor deficient in Hemophilia A (not sure of the formal name), factor II= prothrombin, factor IIa=thrombin, factor I=fibrinogen, etc.
Most of the factors are either proteases (serine proteases as far as I know) or cofactors, like factors 8 or 5. Knowing their actual names and functions made the cascade a whole lot meaningful for me. And for me, meaning= long term memory. Memorizing a bunch of numbers alone was a bunch of rubbish. I think this is why many students view it as an exercise in futility.

 

[Deuce 007 MD]

Is factor 3=tissue factor also called thromboplastin?

 

[sacrament]

Originally posted by doepug
There is no factor 3.

Factor XIII is tissue factor, which is different from thromboplastin.

Seriously folks, the clotting cascade isn't that hard, and 90% of it is clinically relevant. It's worth learning.

Clinically relevant, certainly. But how many non-hematologist docs actually need to keep the whole cascade locked away in their brains for instant retrieval? A working knowledge of the common clotting disorders/pharmaceuticals does NOT require this.

(We were required to memorize the whole thing, though, in keeping with the original question.)

 

[rxfudd]

Originally posted by johnhobbes
We had to memorize it. Not too tough. Learned a good mnemonic:
1972 WEPT: factors 10, 9, 7, and 2 are Vit. K dependent. W:warfarin acts on E: extrinsic pathway. PT: prothrombin time used to check it.

If you know this, then you know heparin acts on intrinsic pathway and PTT is the test used to check it.

One of the better mnemonics I've seen in a while - good stuff...

 

[doepug]

Originally posted by sacrament
Clinically relevant, certainly. But how many non-hematologist docs actually need to keep the whole cascade locked away in their brains for instant retrieval? A working knowledge of the common clotting disorders/pharmaceuticals does NOT require this.

Unless you're practicing (or going to med school) in the sticks, you need it. When you're in the ER at 3 am managing someone's hemophilia, or when you're on the medicine wards diagnosing a case of von Willebrand's disease (which is surprisingly common), you need it. When you manage a PE and have to start heparin and convert to coumadin, you need to understand it. If you need to give Vitamin K (common) or protamine (common in cardiac surgery), you need to know how the cascade works. When you're caring for someone with liver failure who has a long PT and can't synthesize half of their clotting factors, you need it. When you see your first case of antiphospholipid antibody syndrome, you've gotta know the pathway. In order to comprehend half of the esoteric labs you send off to work up a coagulopathy (e.g. RVVT, fibrinogen mutations, etc), you need to know the cascade. When you have your first patient with Factor V Leiden, you need it. Clearly the cascade is not just for hematologists.

Besides, you'll look like a ***** when an attending gently pimps you by asking an easy question about the clotting cascade. It isn't hard, and you'll looking foolish saying "I know the concepts but can't recite the cascade." You'll also miss a handful of slam-dunk questions on the NBME shelf exams with which you will soon become acquainted.

Don't take shortcuts. Just suck it up and learn some basic physiology.

 

[sacrament]

Originally posted by doepug
Unless you're practicing (or going to med school) in the sticks, you need it. When you're in the ER at 3 am managing someone's hemophilia, or when you're on the medicine wards diagnosing a case of von Willebrand's disease (which is surprisingly common), you need it. When you manage a PE and have to start heparin and convert to coumadin, you need to understand it. If you need to give Vitamin K (common) or protamine (common in cardiac surgery), you need to know how the cascade works. When you're caring for someone with liver failure who has a long PT and can't synthesize half of their clotting factors, you need it.

Besides, you'll look like a ***** when an attending gently pimps you by asking an easy question about the clotting cascade. It isn't hard, and you'll looking foolish saying "I know the concepts but can't recite the cascade."

Don't take shortcuts. Just suck it up and learn some basic physiology.

Gimme a break, do you think the doctors who treat these common problems actually remember jack about the clotting cascade? No way. They follow an algorithm, lightly salted with clinical judgment. von Willebrand's is a very common disorder, and the internist I rotated with last year had a few regular patients with it. Did she remember the entire clotting cascade? I'd bet my bottom dollar that she didn't. She didn't need to. Likewise with the use of heparin. What is the average doc going to know about the mechanism of heparin? That it inhibits thrombin. Will they remember that it also inhibits factors Xa and IXa? Maybe. Will they remember that it inhibits thrombin by binding to anti-thrombin III? Very doubtful. Will it matter? Also very doubtful. (Will they remember that Factor Xa cleaves prothrombin to thrombin? No way, and why should they?) There is no way the average seasoned clinician, far removed from medical school, remembers the exact mechanism of even half of the drugs they commonly prescribe. They'll remember indications, contraindictions, adverse reactions, dosages, etc. etc. etc., (in other words, the implications of the mechanism) and, for some drugs, the exact mechanism itself will also stick in their minds (like who forgets the mechanism for ACEI, or digoxin?) But this nonsense about retaining every shred of basic science info from med school is seriously overzealous. People who buy into that should go hang out with mycin in the chat room (he's there 24/7), and listen to his insane speeches about how he remembers 100% of everything he was ever taught in med school, and how any doctor who doesn't (or has to use a Palm to look anything up) is a total failure. And it sounds like I'm exaggerating his position, but this is verbatim. Conversations like this one are always a great excuse for somebody to bust out their med trivia, ridicule anybody who doesn't remember it, and claim they are going to be much better physicians than you because they remember the name of the enzyme involved in the fourth step of the second pathway of the Mortimer Reaction, which is absolutely critical knowledge if you ever run into a patient with the common cold.

(And I do know the clotting cascade, thank you very much. For how much longer, I cannot say. The crux of my argument is NOT that the cascade is too difficult to remember, since I didn't think it was difficult at all to memorize. I'm no slacker.)

 

[Skip Intro]

my 2 cents:

Not worth memorizing. Not heavily tested on Step I.

Just know this:

PT - warfarin
PTT - heparin
INR - standardized PT

That'll get you by on the wards. The rest you can look up if you have some crazy bleeding or clotting diathesis going on with your patient. Even if you know it, you'll look it up anyway to be sure. Use the brain power for something else.

-Skip

 

[doc05]

you are all naive fools. all these "irrelevant" things you learn in ms1/ms2 are very important. you will more of it than you can imagine while you are an ms3, and plenty more as a resident. you may not be going into hem/onc, but you still need to use it in almost every field (except perhaps psych): don't expect to turf your patients onto another service (eg hem/onc) just because you don't know something.

memorizing it is boring but you will see next year that it is well worth it. impressing a resident or attending with your knowledge goes a long way.

 

[Museless]

Yes, we had to memorize it. Yes, I got quesitons on it on Step 1. And yes, I was pimped on it on the wards.

There will be many, many times you will ask yourself "why do we have to ______ ?" It's true that most of what you memorize, you will forget, and you can look it up later anyway. But you must learn it now so that 1) you will know it exists to look up and 2) when you are looking it up because it matters in a case, it won't be the first time you've heard the details.

 

[sacrament]

So today I performed a very unscientific survey, and asked two IM residents, one IM attending and one ER resident if they remembered the coagulation cascade. One of the IM residents remembered an impressive amount of it, but didn't quite get it right, the other one knew virtually none of it. The IM attending and the ER resident said they bothered remembering only the "memorable" parts (e.g. thrombin cleaves fibrinogen).

Remember: when you get pimped on things, is it always because it's desperately important that you remember it? Or sometimes do you think you might get pimped on whatever trivia your resident/attending happens to remember, for whatever reason, and thinks you probably won't? I've seen a LOT of the latter.

 

[Skip Intro]

Originally posted by Museless
There will be many, many times you will ask yourself "why do we have to ______ ?" It's true that most of what you memorize, you will forget, and you can look it up later anyway. But you must learn it now so that 1) you will know it exists to look up and 2) when you are looking it up because it matters in a case, it won't be the first time you've heard the details.

Hey, I wasn't saying don't look at it and don't learn it. I was saying don't bother memorizing it. There's other things you can use that time for. Clotting cascade, aside from what I said, is low yield.

And, yes, I'm in the middle of my Internal Medicine core rotation now. I've found that, no matter how hard you're pimped, your attending will always make you look stupid. He/she will ask you questions until you can't answer. So, don't sweat it. They don't expect that much out of you. In fact, one attending told a story about a medical student who insisted that they do an HIV test on a patient where they just couldn't quite figure out what was wrong. The attending said they grilled this kid as to why he thought that was an appropriate test in a 70-year-old female with no apparent risk factors. Well, as you can probably guess, the test came back positive. So, I asked him, "What kind of grade did you give this student?" He jokingly said to me, "We failed him." When I asked why he said, "Because he was a little bit too smart."

Now, if you want to talk about being familiar with things, there are some key things you can know about certain coagulopathies, etc. But, memorizing the clotting cascade - in toto - is a waste of time. I (along with my 231 on Step I) continue to stand by that.

-Skip

 

[Smoke This]

Originally posted by doepug
There is no factor 3.

Factor XIII is tissue factor, which is different from thromboplastin.

Seriously folks, the clotting cascade isn't that hard, and 90% of it is clinically relevant. It's worth learning.

Factor III is tissue factor. It was initially called thromboplastin.

 

[Dr. Lector]

So where does prothrombinase fit into the picture?

 

[Blade28]

I don't know...from what I've seen during my rotations, you do need to know the basics of the cascade. Several pulmonologists (DVT, PE), cardiologists (AFib), pathologists (blood transfusion reactions) and even residents have pimped me on basic details during rounds.

 

[SocietyRed]

You would think that pbl schools like SIU wouldnt make us. But they did anyway.