DIP Episode 396 - USMLE Step 2/3 Rapid Review Series 77

Okay, welcome. My name is Divine. This is episode 396 of the Divine Intervention Podcasts. And into this podcast we're going to be continuing the Rapid Review Series for the US Emily Step 2 CK Step 3 exams. And that's going to be Series 77. That's going to be Series 77. So what if they give you a question about 61-year-old male? They tell you that he has this really bad hypertension that has been noticed that his last three of his visits. And they also tell you that the unfisky like exam he has skin hyperpigmentation and they show you some labs and you notice that he has a metabolic alkanosis, he has a hypochylemia. And then they tell you that he's been a long-term smoker. What should you be thinking about? Well, I really hope you're saying, oh, Divine, it sounds an awful lot like this person has small cell, long cancer, small cell, long cancer. Right? So why does this person have this cluster of findings? Well, remember, small cell, long cancer makes a lot of ectopic things. One of the ectopic things it makes is ACTH, a Drone Aquaticotropic Cormon. The thing is, ect is not made in a vacuum. Ect is made from an ancestral molecule known as POMC, POR opio melanocortin. POMC, POR opio melanocortin. So look at the name POR opio. So it gives rise to opio. It's like betaendorphine. Melano, it gives rise to melanocistimolytin hormone. And then Quartin gives rise to ECT.

So whenever you have, in many cases, not in all cases, but in many cases, when you have high ECT, you're going to have an increase in your MSH. So essentially, by seeing that skin hyperpigmentation, that tells you that, huh, this cushioning features that this person has is from an ECT dependent cause. That's one clue that many times POPS UP on our exam questions, and people just ignore it. Well, the presence of skin hyperpigmentation in a cushioning question tells you that, huh, this is a cushioning, I mean, this is an ECT dependent cause of the person's cushings. And the thing is, once you just have that mental framework, it really narrows the playing field for you in terms of what you need to focus on in answering the question correctly, because you know that really on the exams, they're very likely going to be two options. They're going to go after for ACTH dependent causes of cushion syndrome, and he's going to be cushings disease, which is where you have a pituitary adenoma that is making a ton of ACTH, or you have a small cell lung cancer that is making a topic ACTH. So the thing is, small cell lung cancer being able to make a topic ACTH does going to cause you to make a ton of cortisol. And we know that cortisol has some partial activity at our dose-turne receptors. So if you have high levels of cortisol, it actually works just like our dose-turne.

And we know that our dose-turne's life job is to make your absurbe sodium in the kidneys to make your your init potassium in the kidneys and to make your your init protons. So if you have high levels of cortisol, which is a surrogate for high levels of our dose-turne, or which is, let me not say surrogate, will use you, similar effects to a person having high levels of our dose-turne. Then you're going to have hypochylemia, because you're going to be getting rid of all that potassium. And you're going to be getting a metabolic alkalosis, because you're getting rid of all those protons. Now here's one thing I would say that gets many people, I've seen this in my one or one tutoring, I've seen this in my review courses, many people in trouble. Many times when people have our dose-turne-based disorders, they usually don't have hypochylemia. I'm not saying they cannot, but they don't always. In fact, I will say probably about 90% of the time on NV Me exams, when people have our dose-turne problems, they usually do not have hypochylemia. And the reasoning behind that is your body has many systems that control your sodium balance that are beyond our dose-turne. In fact, one of the primary controllers of your sodium balance in the body is EDH. So many times for you to see a person having like really big bad pronounced sodium problems, they must either have an EDH problem of some sort.

Like really one of the true real legitimate causes of hypochylemia, most commonly on NV Me exams, is going to be diabetes insipidus. Because in diabetes insipidus, we have one of two types, there's the nephrogenic kind, where you do not respond to EDH. And then there's the central kind where you don't make EDH. So just be careful of that, because I've literally seen, I've probably seen this many times this year, I've seen this all through my teaching, my career teaching medical students. But you see people, they literally get questions wrong because they assume that, oh, because there's an auto-turne problem, the sodium must be out of work. Many times on NV Me's, I'm not saying all the time, so always be attention to the context of the question. That's something you see me emphasize a lot in my testing and strategies class. But many times on NV Me's, people would have auto-turne problems to not have sodium issues. And really hoping that people take this message to heart, because it's something that can help you get one or two extra questions right on an exam. So again, small cell lung cancer, again, produces a topic as it is, but remember, it can also cause SIEDH. It can produce EDH, et cetera. In that setting, you're going to have hyponitramia. But for the most part, you're not going to have any problems with metabolic alkylosis or hypochylemia. You will for sure have a hyponitramia because you're making all this EDH and EDH anti-diarrytic hormone.

His job is to make your ribs absorb, I mean, water from your urine. So you're going to have hypotonic serum and hyper tonic urine. Your urine is going to be very concentrated. It's going to have a very high specific gravity. It's going to be much greater than 1.012. And then the last thing that is made ectopically in small cell lung cancer, or the panoplastic phenomenon I want you to keep in mind, is Lambert ET and myestemic syndrome. Right? In Lambert ET, you make autoantibodies against the presynaptic VOTEGE GATED calcium channel. When you make these autoantibodies, you block that VOTEGE GATED calcium channel. If you block it, then calcium will not be able to come into the presynaptic neuron. Because remember, normally, if you're looking at neuromuscular transmission, calcium comes in through that presynaptic neuron, you know, through its VOTEGE GATED channel. And then that then causes you to exosite toast, neurotransmitter, especially acetylcholine into the synapse. And then when you have it, you then have that acetylcholine binding to the nicotinic acetylcholine receptors so that you can have skeletal muscle contraction. So if you block those VOTEGE GATED calcium channels, then calcium cannot come in, so you will not have any release of neurotransmitter. In fact, our friends at the MBM is very smart. They can ask, or what is the mechanism behind the neuromuscular weakness in a person that has a small cell long cancer with a new plastic phenomenon?

The answer to that question will be failure of, like they can put an answer that says, fill entry of calcium through VOTEGE GATED channels. But again, the thing is, the MBM is these days. Again, this is something I really amphasized in my testing course. The MBM is these days. One of the big things they focus on is, they focus on seeing if people truly understand the pathophysiology behind fence. Again, that's the thing. That's one of my big problems with people having the wrong approach to learning these days. They learned so many facts, but they don't have any framework. They don't have any context. They don't have any pathophysiology behind it. They just follow these approaches. Again, I'm not going to mention this specific thing, but they just follow these approaches to root memorization. They're like, oh, I'm going to memorize this, memorize this, memorize this. And then you see those people, because they've memorized some Anki deck that is based on some practice exam they'll be taking. They do well on set practice exam. They have force-related scores. And then they take their real exam, which there is no thing that has been made that they can memorize on it. And then they end up falling apart. So again, I'm encouraging you. Repetition, space repetition, Anki, everything is completely fine. In fact, to be honest with you, I do encourage people to use it.

But please, I'm begging you, when you're memorizing all these things, try to add some context, try to add some framework, try to slap in some understanding with that information that you're memorizing. If you're good at memorization and you're good at understanding, you're a pathophimates student, you're a pathophotes teacher. Besides other skills, obviously. So please make sure you understand it, because the MDM is, they realize, for example, this Lambertity Myestemic Syndrome. Now most people, there's probably an Anki deck out there somewhere that tells them, oh, you know, auto-antibodies against pre-synaptic vote educated calcium channels. So what can they easily do as an answer? They will just put failed release of a pseudo-colleam at the neuromuscular synapse. And then people that don't have that extra layer of understanding on top of that factor that they've memorized, they don't fall apart with that question. I'm telling you this, that's why many people these, when they take the exams, they feel like they just get through the whole thing. They're like, wait, what exam did I just take? Is because these exams emphasize understanding. Right? Even the bio-starts questions. Even the bio-statistic questions, they emphasize a lot of understanding, not just blind, root memorization. So hopefully that makes sense. Right? So again, these are the classic things you're going to see with small cell lung cancer, a topic-acity-ish production, S-I-D-H, right?

An Lambertity Myestemic nerve syndrome. Remember in Lambertity Myestemic Syndrome, those people, their muscle weakness gets better, the more they use that muscle. Because as you try to use that muscle more and more and more and more, you begin to bring more calcium that can outcompete those bad nasty antibodies that we find on the surfaces of those vote educated calcium channels. And when you have enough calcium that can outcompete it, right? Then you can have calcium coming in and then you have the release of acetylcholine and then you have good appropriate neuromuscular transmission. In fact, right? The MBM is, it can easily ask, oh, what? In fact, the MBM is, they can ask some of these in Okos questions, right? What do I call a No-Gos question? Where it's literally a step one concept, but they just adapt it to a step two theme. I mean, this is something that in more recent times is becoming more and more prevalent. Where you're like, wow, these people who really, really ask something like this, and you will know your heart as you're taking the exam done, man, the last time I saw this thing was when I was studying for step one, right? Let me bring, let me bring in this pathophase here. Do you know that one way our friends at the MBM is contest this Lambert, it in my aesthetic syndrome is they can say, oh, what is the most likely effect of these autoantibodies on neuromuscular transmission on calcium binding?

And then you end up noticing that while the right answer is that these autoantibodies decrease the affinity of the vote educated calcium channel for calcium. They can even express it in mecheless minting terms. They can literally say, oh, binding of these autoantibodies increases the, it increases the KM, right? Of the, of, you know, of activity of ion transmission of this voltage-gated calcium channel. So again, don't forget this KM business, right? Because again, it's just something that deals with competitive inhibitors. What do we know about competitive inhibitors? Competitive inhibitors, they are basically things that bind to a receptor, right? And when they bind to it, they reduce your affinity. Well, reduced affinity is the same thing as increased KM, right? As increased KM, because now you need a momenty large amounts of calcium to outcompete those nasty antibodies so that you can have appropriate neuromuscular transmission. Again, the name of the game on these NV Me exams is just being able to make these integrations. If you can make these integrations, you'll make your life so primarily better, okay? You'll make your life so primarily better. So just going to keep that in mind. Again, you probably never imagined that, wow, we can generate all these USMLE concepts from L'Hambri DTMI Stenic Syndrome. Well, there you have it. So again, I'll encourage you, make sure you're not just memorizing stuff, make sure you can see things in multiple dimensions.

If you can see things in multiple dimensions, you're going to be able to do really well on your exam. And I guess since we're on the topic of lung cancer, don't forget many lung cancers can have all that pernioplastic things, right? Like, swim or cell lung cancer. Remember, it's the one that has those keratin pearls and intercellular bridges, right? So, swim or cell lung cancer, we know that it has the ability to make parathyroid hormone-related peptide, right? And it literally works like PTH. So your blood calcium is going to be high, right? But your endogenous PTH is going to be low. That means like the PTH. So by missing endogenous PTH, I literally mean the PTH that is coming from your parathyroid glands. That's going to be low because it's going to respond to those low calcium signals, okay? So again, these are just all things to keep in mind. And then don't forget, I've talked about this many times in this podcast, hypertrophic pulmonary osteoarthropathy that happens with lung cancer, where you see a person, and they have this sodium onset development of digital clubbing, of peening many joints and things like that. When you see stuff like that, I really want you to think about hypertrophic pulmonary osteoarthropathy. Many times the next step in those people is you're going to get some kind of lung imaging because the person has a lung cancer.

And then what if they give you a question about a patient and they tell you that, well, this patient, you know, for the past three days, he has been having a lot of pain, painful swallowing, right? And then they show you an image and you see oral throsh on his mouth. And then they say, oh, what is the next best step in, they can say in addition to floconazole therapy. What is the next best step in management or what is the next best step in diagnosis, right? So the thing is, why did I bring this specific question here? The MBM Es, they love doing this thing to people on exams. I don't know what I'm really focusing on exams today. They love doing this thing to people on exams where you're reading the question and you're like, oh, I know exactly what these people are talking about. I think I know what they are going to be putting as one of the answer choices. And then you read the question up to the end and you're like, oh snap, this answer choice I was expecting. They're literally telling me they've already done that. And then you're wondering what do I do next? Well, let me explain how the MBM Es set up those kinds of questions and how they frame these kinds of questions. In fact, this is almost turning out to be like almost like a test against strategies podcast, right? Although I have a formal test against strategy scores, I'll talk about that in a bit.

But basically, what the MBM Es love to do occasionally is they will tell you what you know and then bring out a peripheral concept, bring out a peripheral concept, bring out a peripheral concept. So why do they love to do that? They love to do that because again, they want to see if you have the ability to do what, make integrations. Again, that is something that many people massively, massively, massively struggle with. They just struggle with it. They just have a big, big, big hard time making any kind of integration because they've just learned things in one dimension. They've just memorized stuff. So let me explain. So we see this person has throsh. You see a person they have throsh. They have a sofa joke kind of diocese. Is there a peripheral disorder that we want to screen these people for? I would hope you're telling me, oh, divine. I want to screen this person for HIV. I want to screen this person for HIV. So the thing is, literally, this is a question that looks all about a sofa joke kind of diocese. Well, the actual concept they're going after is HIV. The actual concept they're going after is HIV. Right? So in this case, you want to pick the answer choice that involves some kind or some level of HIV testing. The MBM is, this is like a time-honored method of them writing questions. Let me tell you this.

The MBM is, if you spend good time going through their content and you have a lot of experience with it, you can really decipher how they frame their questions, how they set up their questions. Right? You love to do this thing of, they will be testing something that is around a central concept. This is a throsh question, but it's a HIV question in disguise. Let me tell you this. Do you know that they can do this with many other things? I'll give you other examples. They can make, they can give you a question about the Moseses-Grivedsi. Would the answer choices have nothing to do with you treating the Moseses-Grivedsi or anything like that? And you'll have everything to do with you going to screen the person for HIV. And other way they can do this, they can talk about the person having eye issues. And you notice that, wow, they tell you that, oh, you know, the person gets guns like Lovet therapy and makes a successful recovery. And then they say, what is your next best step in management? And again, it's going to be to screen those people for HIV. So again, if you see all any of these HIV associated infections, it is always prudent to screen those people for HIV. Right? So make sure when you're learning certain diseases, ask yourself, what are some other diseases that are peripherally related to this thing I just learned? Don't forget CMV right now, this with HIV. Don't forget a person. Let's see a person gets diagnosed with crypto-coco meningitis.

And you notice that, wow, the person doesn't have any history of HIV, screen those people for HIV. Or you see a person having like cryptosporidium infection, right? Like cryptosporidium diarrhea. Don't get me wrong. Cryptosporidium can cause infection in other people. But in most other people, it is asymptomatic. But you see a person, they get diagnosed with cryptosporidiosis. And they're like super, super symptomatic. In those situations, you want to go ahead and screen that person for HIV. Right? Or you see a person, they have like really bad TB and they are IV drug users, screen that person for HIV. Or you see a person, they have diagnosed with one STI. Let's say they have diagnosed with chlamydia, organococcal, pelvic inflammatory disease. You need to screen those people for HIV. Again, I'm telling you these. These are things that we'll get you questions right on exams. Many times, when you see certain ST Is, the right answer on MD and the exam is going to be, let's screen them for something that is really bad, like HIV. So that we can catch it and catch it on time. So again, it's very important. It's very high yield to keep these colonizing diseases in mind as you're studying for your exams. Just make sure that these are all things you have at the back of your mind as you study for exams. Or you see an IV drug user and they have like hip-sea and things like that. It may not be a bad idea to screen these people for HIV.

It may literally not be a bad idea to screen these people for HIV. For example, you see a person they have diagnosed with this breakout of these hyper pigmented macules all over the skin. That's the lesser trilatine. You need to screen those people for certain malignancies, especially GI visceral malignancies. You can even screen them for long cancer because of that. Or you see this person, they're really old and they have this separate dermatitis. And things like that. Or you see this person, let me not see really old. That's the wrong context. But you see a person and they have this sudden breakout of really bad seborrheid dermatitis. You may want to screen those people for HIV. Or you see a person, they have this really, really bad apofyrcutinetardar. You want to screen those people for hep-sea. Again, make sure you know the colocalizing disorders. You know the colocalizing disorders. Or you see a person. And wow, all out of the blue all of a sudden, they are like in their 40s or 50s. And then you notice that, man. This person just developed asthma. As a 40 year old, are you kidding? They developed asthma. You notice their IgE is crazy high. And then they have these symptoms all over the place like peripheral neuropathy, cardiac issues, they want to screen those people for truck strokes. Again, make sure you know colocalizing disorders. If I don't think I've ever said this in any podcast. But make sure you know colocalizing disorders, which diseases that you learn.

Now, since we're around 20 minutes, I'm going to go ahead and pause here. Again, as I do at the end of every podcast, I do offer review courses for step two, step three. Obviously, they also apply to complex level tours three. Actually, I have those courses coming up next week. Monday through Saturday with the exception of Wednesday. From five to nine p.m. Pacific Standard Time. I chose that time so that it works for people that are on rotations or people that work or things like that. And then I have an MBA Me Testic in Strategies class. It's going to be taking place this Friday. It's going to be from five to seven thirty p.m. Pacific Standard Time. And then I have a bio statistics bootcamp that is going to be taking place next month on the 21st of July. It's going to be a belief from five to nine p.m. Pacific Standard Time as well. I suspect that that's a course that you're going to find to be supremely, supremely helpful if you struggle bio stats because I know many people bio stats is plug and chalk for them. But the MBA Me is in recent times, having a lot of bio stats questions where it's not plug and chalk is more do you understand this thing that you've just read? Many times you notice you don't have to do math, but you cannot even interpret the question if you don't truly understand bio statistics. So all these courses are going to be held over Zoom if interested in any of them. Shoot me an email through the website and I'll be happy to give you some more information.

And then on a limited basis, I also offer one or one tutoring for step one step two, see key step three. Pretty clear comments call exams, 30 year clerkship, shelf exams. And then I also help with eras applications. I know we're slowly beginning to believe into another era season. So I help with personal statements, rec letters and things like that. I help primarily with editing those things and getting into a finalized form that you can literally drop into your eras application. I also help with mock, mock interviews on a limited basis. So, and you know, I have these podcasts on Apple podcasts, so Google podcasts and on Spotify. So at least the most recent 150 podcasts and then I have a You Tube channel, Divine Intervention, USM, Lee podcast and videos. That's where I post the videos that I make. And then finally, I have a new website called divineinterventionlifelessens.com. In fact, there is a podcast that is tied to it is called the Divine Intervention Life Lessons Podcast. It's an Apple Podcast, many of you know that listen to this podcast normally Christian. So I use Bible based teaching to make like 10 or 12 mini podcasts. We'll just talk about like a common problem that is faced by like most humans, right, along with strategies for resolving those problems. So if you're interested in any of these things, feel free to check them out. And thank you for listening to today's podcast. I'll see you next time. Have a wonderful week and God bless you. Thank you.

Skin hyperpigmentation (due to MSH co-secretion with ACTH).

High cortisol levels act as mineralocorticoids, causing potassium wasting in the kidneys.

Presynaptic voltage-gated calcium channels.

Highly concentrated urine (high specific gravity) and hypotonic serum.

Squamous cell lung cancer or renal cell carcinoma.

Always screen patients with certain ST Is (e.g., Chlamydia), GI issues (e.g., Cryptosporidiosis), or chronic illnesses (e.g., IV drug use).

1) Ectopic ACTH production $\rightarrow$ Cushing's Syndrome; 2) SIADH; 3) Lambert-Eaton Myasthenic Syndrome (LEMS).

Failure of Ca++ influx into the axon terminal, resulting in reduced release of acetylcholine.

Both cause hypokalemia and metabolic alkalosis, but SCLC/ACTH excess is a key paraneoplastic association to remember.

Increased local calcium concentration can temporarily outcompete the autoantibodies binding to the voltage-gated calcium channels.

High urine specific gravity (>1.020) despite hypotonic serum, indicating maximal water reabsorption.

Parathyroid Hormone-Related Peptide (PT HrP).

1) Ectopic ACTH production $\rightarrow$ Cushing's Syndrome; 2) SIADH; 3) Lambert-Eaton Myasthenic Syndrome (LEMS).

Failure of Ca++ influx into the axon terminal, resulting in reduced release of acetylcholine.

Both cause hypokalemia and metabolic alkalosis, but SCLC/ACTH excess is a key paraneoplastic association to remember.

Increased local calcium concentration can temporarily outcompete the autoantibodies binding to the voltage-gated calcium channels.

High urine specific gravity (>1.020) despite hypotonic serum, indicating maximal water reabsorption.

Parathyroid Hormone-Related Peptide (PT HrP).