What to Do in Step 2 CK

By askdoc / March 27, 2010
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*note: I wrote this way back in 2007 and posted it in prep4usmle. I am reposting it here because many people have been asking about how to prep for Step 2 CK and I am busy to write one. Although this may need a rewrite, it will do until I actually finish and post a new article.

The purpose of this post is to help people prepare for Step 2 CK. I purposefully did not title this as ‘How to get a 99 in Step 2 CK’ even though I got one using these preparation techniques. The reason is that it takes more than knowing how to prepare to get a 99. How much sacrifice and effort you put into your preparation is most important.

Some of you may already know me, from my post on how to prepare for step 1. I posted it in answer to a question on ‘What to Do’ in Step 1, and it’s purpose is to guide people in how to prepare for step 1 rather than how to get a 99 even though, again, I got one using those prep techniques. I’m posting a link to that thread:

For those who don’t. I am an Old IMG from the Philippines. Graduated way back in 1989 at the top medical college in my country. I took Step 1 last April 24, 2006 and got a 99/256. Took Step 2 CK last November 20, 2006 and got 99/258. Back in late 2004, when I started this journey and like most of you dreaming of 99’s, whenever, I see someone posting that they got 99’s, 2 things always pop up in my mind, wishing that it was me and wondering how it’s done. And always, when I read what they write about how they did it, it talks of what books they read, what lecture they listened to and what QBanks they used. Of course, the problem was, everybody seems to be doing the same things and most of them are not getting 99’s and some are even failing. So the only conclusion I can make is the secret does not lie in the preparation materials rather in how you used the preparation materials. And since different people have different starting points and different capabilities, their preparations and the materials they used must be adjusted accordingly.

Someone once asked in this forum if the reason I know so much about USMLE is I had taken it before. The answer is no, this is the first time I am taking all Steps. The reason I seem to know a lot about it is that it has always in my nature to know as much as I can about any task set before me. I have never failed an exam in my life and even though USMLE is supposed to be really tough especially for old Grads, I’m not about to let this be my first time. So, I set out to discover as much as I can about the exam, analyzing it and planning out what I hoped was a coherent well thought out study plan taking into consideration my special situation (a very old graduate) and my own prep capabilities.

It is not enough to study hard, one has to study smart too. I believe that with proper prep and hard work, anyone can pass this exam, hence this “what to do”. It is also my belief that with proper prep and really hard work, most can get high 80’s and even 90’s. Someday I’ll probably write a post about how to get double 99’s but for now I’ll stick to proper preparation for Step 2 CK.

So How do you prep for Step 2 CK? Well, for one thing, most of what I wrote on how to prep for Step 1 still applies to step 2. KA, KR, TP still applies, although some details differ. What to Master, Know and Be Familiar with still applies although the emphasis is radically different. There is enough differences that if you prepare for both steps in exactly the same way without adjustments, you will tend to do better in one than the other. Explains why double 99’s are uncommon though.

When I started my own review, I was approaching Step 2 CK in exactly the same way I was approaching Step 1. I chose books using the same criteria, looking for books that discussed important concepts in more details rather than just using review books. It wasn’t until 6 weeks into my review that I realized my error. There is a difference.

Firstly, in Step 2 CK you have to master the horses rather than the zebras. You have to know the variations in presentations of common cases their workup in detail and their treatment, including diagnostic criterias that determine whether treatment is even advised or not. Zebras still are important but they are as rare as in real life. Most cases will be typical appearance of common diseases. Atypical appearances of common disease are also common and responsible for a lot of the vagueness. As for zebras, you just have to know enough that you don’t mistake them for horses.

In Step 1, there usually are more zebras than in step 2. The reason is that in Step 1, you are studying important basic medical science concepts and sometimes, these concepts are best illustrated by rare cases. For example, Prader Willi Syndrome is rare and yet illustrates a very important principle in genetics, namely imprinting.  Another example, Lung CA in Step 1 will probably be Small Cell due to para-neoplastic syndrome, rather than AdenoCA and Squamous Cell which you expect to be more common in Step 2.

Next, whereas Step 1 emphasizes facts, Step 2 CK emphasizes decision making. Where Step 1 tests how much you know and understand about medicine, Step 2 concentrates primarily on your ability to use what you know and understand about medicine in decision making. 60% of what you need to know in Step 2 CK, you’ve learned when you did Step 1. But the 40% you don’t is just as important(Which means unless you are a fairly recent grad, you still have to read Texts). Then you have to show that you have the ability to use what you know in clinical decision making.

In Step 2 CK  75% of the Q’s deal with Diagnosis, Work-up and Treatment. The other 25% covers Pathophysio, Preventive Medicine, Biostatistics and Ethics.

The most important skill one should develop is the ability to diagnose the case presented even if the clinical presentation is vague. Even though most of the question will deal with Work-up and Treatment and occasionally pathophysiology, you still must be able to diagnose the case BEFORE you can even begin to think about Work-up and Treatment.

The major complaint of a lot of people (including me) about Step 2 CK is the “vagueness” of the questions. And the reason for the vagueness of the questions is the way the q’s are constructed. Clinical cases are almost never presented classically in Step 2 CK which is so unlike Step 1, where almost all clinical case presentation is classical.

Someone who prepares a Step 2 CK clinical case will usually begin by writing down all the classic signs, symptoms and laboratory results for a certain diagnosis (as is done in Step 1). In the second pass, he will eliminate or alter a lot of signs, symptoms and laboratory result from the presenting case so long as it does not alter the final diagnosis, ie. If you really look at it long and hard, you will realize the diagnosis remains the same. Now to make it even more difficult, on a third pass, he will add signs, symptom and laboratory results that although positive will not really alter your main diagnosis. To make it even harder, he will put on even more irrelevant positives and negatives so you have those kilometric case, that’s so hard to read, understand and clearly time-killers.

Why do this? To test if you can decide which diagnostic clues are relevant and irrelevant. In actual medical practice, patients never present classically, and part of being a good diagnostician is the ability to flesh out relevant and irrelevant facts. Which is one of the reasons why people with longer clinical experience tend to do better in Step 2, since we usually study classic clinical presentations in med school. Whereas, people with longer clinical experience tends to experience a lot of atypical cases.

For example, whereas, the classic presentation of Sarcoidosis is a black, female, in Step 2 CK don’t be surprise if the patient is a white male instead. SLE is possible in males, although classically , patients are females. Not all patients with Lyme Disease will present with rash. Therefore, being able to diagnosis properly despite missing or over-abundant information is crucial to doing well. Atypical presentations abound, but they still will be common cases, therefore be careful not to mistake them for zebras.

Next, for every diagnosis, it is important to know how to work it up and treat them. However, for common cases, one should know in what order work up and treatment should be done, what steps to do depending on diagnostic test results and what to do next depending on the outcome of treatment already done. For some cases, time since presentation, is an important factor in what actions one should take. I’ll illustrate this further next time.

Actually I wanted to finish the whole of part I first before posting this, however, my step 2 CS is on March 23 already and between reviewing, trip preparation and work, there is limited time to write this all down before I leave for LA. Since, I’ve received lots of PM’s on when this will be posted, I’ve decided to post this. I’ll try to finish them by April. There are 3 Parts, Part 1 deals with the difference between Step 1 and Step 2 CK as well as things to note about Step 2 CK. Part II which deals with preparation materials (Kaplan Notes still the best, not because it is really great but others are just not that good) and Part III, which deals with specific prep problems on Step 2 and how to deal with them. I’ve chosen not to rewrite preparation methods common to both Step 1 and Step 2 and advise people to just read my Step 1 post instead.

I would  also like to apologize to everybody whose q’s I’ve failed to answer, or took a long time in answering due to time constraint.

Anyway, if anyone has any questions, I will be back after the Holy Week (fon non-christians, Holy Week is first week of April) and unless you’re in LA at the Hacienda Hotel between 16 and 24, I will be seeing you then.


Sorry for the late posts. Took an extended vacation. However, now I’m back and we’ll continue the discussion.
Let’s take an example of a case, say Acute Cholecystitis. You have to know how to diagnose it first. If diagnostic workup have not yet been done then, UTZ Abdomen is next and depending on findings either further diagnostic workup is needed or therapy. Now for therapy choice is cholecystectomy or cool it down first with fluids and anti-biotics. Here time of presentation is important. First 72 hours after start of symptom, you operate (laparoscopic cholecystectomy first choice), after 72 hours, cool down inflammation (with fluids, antibiotics) before scheduling elective cholecystectomy 5 to 6 weeks later. (Of course this is not complete as depending on diagnostic findings and therapeutic outcomes, other course of action may be needed. but this will suffice for illustration purposes only.)

The actual case presentation may end anywhere in this narrative and you are expected to know what to do next. But first you have to be able to diagnose the case since it will be presented as a case with no diagnosis.
Another example is Acetaminophen poisoning. Here time of presentation is crucial. On first 2 hour, gastric lavage, 2-4 hours activated charcoal, at 4 hour draw blood levels to decide if will use acetylcysteine. This case, time of presentation is most important criteria to decide what to do. (This case actually illustrates another problem with Step 2 CK since other sources will insists that lavage and activated charcoal is only effective first 24 hours. Will discuss this further later)
Now don’t get me wrong, only about 20 to 25% of the q’s will be of this type, the rest will be more straightforward and they will mostly be the more common cases. However, since we don’t know how common a case should be for USMLE to consider it common, the more cases you know how to handle this way, the higher the probability you will score high, since you’ll be able to answer these types of questions and still be able to answer the more straightforward question. Another advantage is that a bigger proportion of Step 3 questions will be this way and it will help you to have a leg up when you prepare for that.

So the best way to study for Step 2CK is to find diagnostic algorithms and therapeutic protocols whenever they exist. Kaplan Notes have good protocols but not complete. Step Up Medicine have some protocols, but others are just lists of diagnostic and therapeutics done for a specific case (no indication of which comes first). Blueprints also have a lot of them. I’ll discuss them in more detail in part 2. You can also learn them in UW and Kaplan QBank although usually it is not presented in complete detail since the q’s are focused on certain aspects of each case. The best way is to know them beforehand and see how they apply when you answer the QBanks.

If given a specific case, say acute pancreatitis, you know step by step workup and treatment, then you have mastered that case correctly.

Now another reason for the complaint of vagueness of the exam has to do with the fact that even when you have diagnosed the case correctly, one or two variables in the presentation can alter management acutely. For example, Primary Hyperparathyroidism is managed surgically except when patient is over 50 and asymptomatic. Another example, a patient you have diagnosed with hepatitis may be fulminant or suffering from hepatic encephalopathy, which changes your therapeutic and diagnostic options, and you have to be able to recognize them clinically, since the case will not tell you outright. If you noticed that all answer choices seem correct, you may have failed to notice tiny details that changes the clinical picture entirely. In contrast in Step 1, once you get the diagnosis, that’s it.

One way to cover this is to know diagnostic criteria for interventions. For example, Thrombolytic therapy can only be done if there is an ST-segment elevation in 2 contiguous leads on a patient with pain onset within six hours. Failure to meet this criteria even if the case points strongly to a diagnosis of MI means you don’t do thrombolytic therapy.

Now, around 15% of Step 2 CK is pathophysiology, hence if you did step one and mastered pathophysio, you have an advantage in Step 2 CK. Kaplan Medicine is not heavy on pathophysio, so Step Up Medicine is a good supplement to cover this. (It’s not complete, but short of going back to Step 1 Patho or Harrison’s and Cecil, this will do.) Although most pathophysio questions will be straightforward (After an appropriate clinical case presentation which you have to diagnose first), there are what I would call “Applied Pathophysiology”.

To illustrate:

Patient has acute shortness of breath and xray show whiteout of both lungs. You know it’s either Left Heart Failure or ARDS. The case presentation will be vague enough that you will not be able to pinpoint if it’s one or the other. The question asks you what to do next. Knowing pathophysio of Left heart failure is increased pressure in left heart causing backflow of fluid to lungs, vs. ARDS where fluid in lungs is secondary increased capillary permeability, answer should be Pulmonary Capillary Wedge Pressure or PCWP.

Another case:

Patient have recurrent episodes of gout. You are asked what to do next. You already know that you don’t treat hyperuricemia on a single attack of gout. The list includes treatment with probenecid and treatment with allopurinol, and treatment with colchicine. Of course the right answer would be to measure 24 hour urine uric acid and if high give allopurinol and if low give probenecid. Colchicine is used for acute attacks. Knowing pathophysiology is important in answering this question.

Now we will pause here and will continue with Part 2 next time.


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