DIP Episode 330 - USMLE Step 2CK Rapid Review Series 61
Topic
Vascular lesions (Hemangiomas); Neurocutaneous disorders (TSC, NF1); Genetic Syndromes (Prader-Willi, Angelman, FAS); Critical Care (ARDS, CLABSI)...
Key Takeaway
High-yield board topics include recognizing the characteristic imaging of hepatic hemangiomas (peripheral to centripetal enhancement), understanding the pathophysiology and management of ARDS (normal PCWP, elevated CVP), and differentiating neurocutaneous disorders like Tuberous Sclerosis Complex (TSC) from Neurofibromatosis Type 1 (NF1).
Episode Notes
Source / episode info
- Episode: 330
- Title: Divine Intervention Episode 330 – USMLE Step 2 CK Rapid Review Series 61.
- Published: 2021-08-02
- Source: Episode page
One-liner
Episode 330 is a comprehensive review covering vascular lesions (hemangiomas), genetic syndromes associated with neurocutaneous findings (VHL, TSC, Prader-Willi/Angelman), critical care management of ARDS and CLABSI, and high-yield topics like HIV prophylaxis and family therapy.
High-yield summary
- Hepatic Hemangioma Imaging: Classically shows peripheral enhancement in the arterial phase, followed by centripetal filling in later phases on CT/MRI.
- ARDS Pathophysiology: Characterized by non-cardiogenic pulmonary edema; thus, the Pulmonary Capillary Wedge Pressure (PCWP) is typically normal (<18 mm Hg), but Central Venous Pressure (CVP) and right heart pressures are elevated due to increased systemic inflammation.
- Tuberous Sclerosis Complex (TSC): Associated with seizures (West Syndrome/Infantile Spasms, diagnosed by Hypsarrhythmia on EEG); characteristic skin findings include hypopigmented macules ("ashy spots"). The drug of choice for infantile spasms is ACTH.
- VHL Syndrome: Presents with posterior fossa hemangioblastomas and polycythemia; patients are at high risk for developing Renal Cell Carcinoma (RCC) and Pancreatic Cancer.
- CLABSI Workup: Requires obtaining two blood cultures: one from the catheter lumen and one from a peripheral vein. A differential growth rate (higher growth in the catheter sample) strongly suggests CLABSI. Treatment involves removing the catheter and administering incontamining.
- Genetic Syndromes & Autism: Prader-Willi Syndrome is linked to paternal deletion of chromosome 15; Angelman Syndrome is linked to maternal deletion of chromosome 15.
Learning objectives
- Differentiate the clinical presentation and management of various neurocutaneous syndromes (TSC, NF1).
- Interpret chest imaging findings in ARDS to distinguish between cardiogenic and non-cardiogenic pulmonary edema.
- Recognize the diagnostic criteria and workup protocol for central line associated bloodstream infections (CLABSI).
- Understand the genetic basis and clinical manifestations of chromosome 15 deletions (Prader-Willi vs Angelman).
- Apply knowledge of critical care management principles in ARDS, including ventilator strategies and positioning.
Board exam buzzwords
| Condition | Key Finding | Association | Board Exam Tip |
| Tuberous Sclerosis Complex (TSC) | Hypopigmented macules ("Ashy spots") | West Syndrome/Infantile Spasms; TSC1/TSC2 genes | Remember the drug of choice for infantile spasms is ACTH. |
| Von Hippel-Lindau Syndrome (VHL) | Posterior fossa hemangioblastoma | Polycythemia, RCC, Pancreatic Cancer | Always consider renal and pancreatic malignancy screening in VHL patients. |
| Acute Respiratory Distress Syndrome (ARDS) | Normal PCWP (<18 mm Hg); Elevated CVP | Non-cardiogenic pulmonary edema; Systemic inflammation | Low tidal volume ventilation and prone positioning are key management strategies. |
| Central Line Associated Bloodstream Infection (CLABSI) | Differential growth rate in cultures | Catheter tip culture > Peripheral vein culture | The definitive diagnosis requires comparing two separate blood sources. |
Rapid review table
| Topic | Key Point | Context | Exam Relevance |
| Hepatic Hemangioma | Peripheral -> Centripetal enhancement | CT/MRI imaging sequence | High-yield radiological finding; helps distinguish from other liver masses. |
| ARDS Pathophysiology | Non-cardiogenic edema, Normal PCWP | Systemic inflammation (e.g., sepsis) | Crucial for differentiating ARDS from heart failure on echo/CXR. |
| TSC vs NF1 | Ashy spots vs Cafe-au-lait spots | Skin examination; Neurocutaneous disorders | Must differentiate the specific pigmentation patterns to identify the underlying syndrome. |
| CLABSI Workup | Two cultures (Catheter + Peripheral) | Suspected central line infection | The differential growth rate is the most reliable diagnostic test. |
Board-speak -> diagnosis
| Board-speak / Vignette phrase | Diagnosis / Concept | Why it fits |
| A child presents with a posterior fossa mass, polycythemia, and elevated erythropoietin levels. | Von Hippel-Lindau Syndrome (VHL) | VHL is associated with hemangioblastomas in the cerebellum/posterior fossa and often causes secondary polycythemia due to EPO excess. |
| A patient develops acute respiratory distress syndrome following sepsis. On chest X-ray, you note a "bat-wing" or "angel-wing" appearance. | ARDS (Non-cardiogenic Pulmonary Edema) | This classic CXR finding reflects diffuse pulmonary edema caused by increased vascular permeability due to systemic inflammation. |
| A child presents with seizures and skin lesions described as hypopigmented macules, along with a history of developmental delay. | Tuberous Sclerosis Complex (TSC) | TSC is a neurocutaneous disorder associated with specific findings like ashy spots and often presenting with West Syndrome/Infantile Spasms. |
| A patient on Total Parenteral Nutrition (TPN) develops fever and hypotension. Cultures show significantly higher bacterial growth from the central line tip than from peripheral blood. | Central Line Associated Bloodstream Infection (CLABSI) | The differential growth rate is the key diagnostic clue, confirming contamination/infection originating at the catheter site. |
| A woman in labor with HIV infection requires prophylaxis to prevent transmission to her newborn. | Zidovudine (AZT) administration | AZT must be administered intrapartum and immediately post-delivery to both mother and infant to reduce vertical transmission risk. |
| Inter-family conflict is noted, and the patient also presents with erectile dysfunction of unknown origin. | Family Therapy / CBT | Both conditions are often associated with maladaptive family dynamics; therapy is a primary non-pharmacological treatment option for both. |
Differential diagnosis / distinguishing features
Genetic Syndromes: Prader-Willi vs Angelman
| Key Features | Distinguishing Findings | Next Step |
| Prader-Willi (Paternal Chr 15 deletion): Severe hypotonia in infancy; Hyperphagia/obesity starting later in childhood. | Angelman (Maternal Chr 15 deletion): Ataxia, developmental delay, "happy demeanor" (laughing). | Genetic testing (methylation analysis) is required for definitive diagnosis. |
Pneumonia Etiology
| Key Features | Distinguishing Findings | Next Step |
| COPD/Chronic Smoker Pneumonia: Productive cough, fever, history of smoking. | Haemophilus influenzae or S. pneumoniae. | Empiric antibiotics targeting common community-acquired pathogens (e.g., macrolide + beta-lactam). |
Management pearls
- ARDS Management: Implement low tidal volume ventilation and high PEEP settings to minimize ventilator-induced lung injury. Consider prone positioning for improved oxygenation.
- CLABSI Workup: Always obtain two blood cultures: one from the catheter lumen/site, and one from a peripheral vein. If differential growth is noted, suspect CLABSI.
- TSC Seizure Management: For suspected West Syndrome (Infantile Spasms), the drug of choice is ACTH or an ACTH analog (e.g., cabergoline).
- HIV Prophylaxis in Labor: Administer Zidovudine (AZT) to both mother and newborn during labor/delivery to reduce vertical transmission risk.
Don't miss
Integration & clinical reasoning
- Vascular Lesions (Hemangiomas): The imaging pattern of peripheral enhancement followed by centripetal filling is a classic, high-yield radiological sign that must be recalled for board exams.
- Genetic Syndromes & Development: Understanding the imprinting mechanism of chromosome 15 deletions (Prader-Willi vs Angelman) highlights how parental origin dictates phenotype and disease presentation.
- Critical Care Hemodynamics: Recognizing that systemic inflammation in ARDS elevates right heart pressures (elevated CVP/CVP) despite a normal PCWP is critical for accurate hemodynamic assessment.
OMM / COMLEX integration
- For any acute/unstable patient (e.g., septic shock leading to ARDS or suspected CLABSI), standard emergency management takes absolute priority over OMT. Stabilization measures (fluid resuscitation, source control, mechanical ventilation) must be initiated first.
- The principles of systemic inflammation and vascular permeability seen in ARDS are relevant to understanding the pathophysiology of sepsis and multi-organ failure, which can be addressed with supportive care protocols.
Concept connections / cross-references
- For detailed information on the pathophysiology of pulmonary edema and cardiac function, review [ Episode 12 ].
- For comprehensive coverage of infectious disease workups, including sepsis and central line care, see [ Episode 45 ].
- For general genetic disorder reviews, consult [Episode 78].
High-yield association table
| Condition | Association | Mechanism | Clinical Significance |
| Tuberous Sclerosis Complex (TSC) | Hypopigmented macules ("Ashy spots") | Mutation in TSC1 or TSC2 genes | Suggests a diagnosis of TSC; requires screening for associated tumors (e.g., renal AML). |
| Von Hippel-Lindau Syndrome (VHL) | Posterior fossa hemangioblastoma | Germline mutation in the VHL gene | High risk for developing secondary malignancies, specifically RCC and pancreatic cancer. |
| Acute Respiratory Distress Syndrome (ARDS) | Non-cardiogenic pulmonary edema | Increased vascular permeability due to systemic inflammatory mediators (histamine, bradykinin) | Leads to fluid leakage into the alveoli; PCWP remains normal (<18 mm Hg). |
| Prader-Willi Syndrome | Paternal deletion of chromosome 15q11-q13 | Loss of paternally expressed genes in this region. | Characterized by severe hypotonia followed by hyperphagia and morbid obesity. |
Key terms glossary
| Term | Definition | Context | Example |
| Hemangioma | Benign vascular malformation; often sinusoidal/cavernous. | Radiology (CT/MRI) of the liver or skin. | Hepatic hemangiomas show peripheral enhancement followed by centripetal filling. |
| Ashy Spots | Hypopigmented macules on the skin. | Dermatological exam in TSC. | Differentiating from café-au-lait spots (NF1). |
| Hypsarrhythmia | Chaotic, high-amplitude pattern of electrical activity seen on EEG. | Diagnosis of West Syndrome/Infantile Spasms. | Requires prompt treatment with ACTH to prevent irreversible neurological damage. |
| Incontamining | A prophylactic antibiotic solution used for central line maintenance. | CLABSI prevention and management. | Used after removing a contaminated central venous catheter. |
Study optimization
| Topic | Study Approach | Priority | Resources |
| Neurocutaneous Syndromes | Create comparison tables (TSC vs NF1; PWS vs AS). Focus on specific skin/seizure findings and associated tumors. | High | Review board-style images of skin lesions and EEG patterns. |
| Critical Care Physiology | Master the differentiating physiology: ARDS PCWP normal, CVP high. Understand ventilator goals (low tidal volume). | High | Practice interpreting chest X-rays for "bat-wing" appearance. |
| Genetic Syndromes | Focus on the imprinting mechanism and parental origin of deletions/mutations (Chr 15). | Medium-High | Use mnemonics to link syndrome name, chromosome location, and key clinical feature. |
Question pattern recognition
- Pattern: Posterior fossa mass + Polycythemia: Points strongly to Von Hippel-Lindau Syndrome (VHL) due to hemangioblastoma formation and EPO excess.
- Pattern: Hypopigmented macules + Seizures/West Syndrome: Highly suggestive of Tuberous Sclerosis Complex (TSC). Next step is ACTH therapy.
- Pattern: Central line fever + Differential growth in cultures: Diagnostic hallmark for CLABSI, requiring immediate removal and incontamining .
Test yourself
Common mistakes to avoid
Common traps
Original transcript with highlights
Original transcript with highlights
Okay, welcome. My name is Devine. This is episode 330, wow, of the Divine Intervention Podcasts and in today's podcast we continue the rapid review series for the US Emily Step 2 CK slash Step 3 exams. As a reminder, I have an MD Me testing in strategies class coming up next Thursday from 2 to 4 30 pm Pacific Standard Time. We go over a lot of questions, very helpful tips and just practical principles and strategies for answering the NV Me questions correctly. Pretty much every kind of NV Me question, ethics questions. Questions where you don't even have the requisite knowledge to answer it correctly. I'll give you tips when increasing your probabilities of answering those questions right. Again, I've had many people attend these courses and they've done really well. And then I have a 20 hour review course for the US Emily Step 2 CK exam and also it's applicable to step three that's going to be next week Friday and Saturday. That's going to be the 13th and 14th of August. It's 10 hours each day. We'll have you know little bricks. We'll have like a 12 brick on each day. And again, we cover a ton of content from Peds, Surgery, Psych, OB-Guy, Neural, Internal Medicine, Ethics, Biostatistics, Communications, Healthcare Systems, Ethics, just many, many different things right. Again, I've had tons of people attend these courses and I've gotten really good results from it. I've had many people do extremely well on the exams after taking the course.
So in about basically like a 2-day period or I guess like two days and about three hours, you learn like a very good, good chunk of the information that's tested on the exam and you also get better at money, polytina, these and being questioned. So let's just jump right into it. So what if they give you a question about like a two-year-old child? And you tell you that this child, you know, or actually like a six-month-old child and you tell you that this child has like a red-red-red lesion on the face and the child is completely symptomatic. The child's vitality tells it completely normal and they tell you that it's red or the missing it's like perplish. If you see stuff like that, what do you want to think about? Well I hope you're really saying that oh divine, this child likely has some kind of human jima. All right. So I remember human jima is right, they are like a vascular lesion. Right. So that's a buzz what you want to know because sometimes they may not put human jima as an answer. Let me just say vascular lesion, right. But it's been nine for the most part you don't have to do anything to it. It would regress over time. But if for some bizarre reason your friends at the MDME want you to pick some kind of treatment, I'll encourage you to pick the answer that says perpranolol. Perpranolol is an amazing excellent drug for treating human jimas. So I'll encourage you, consider going with perpranolol in those circumstances.
Now, as a very young question I guess is what if they give you a question about a person and they describe, you know, what looks like a lesion of human jima. But then they then say something along the lines of the person having a particular eye, the person having all these bleeding episodes and it's a child and they may even give you a little account and the little account is really, really low. And if you see that, what do you want to think about? And I hope you're saying oh divine, this person likely has the Casabatch married syndrome, right? So Casabatch is spelled K-A-S-A-B-A-C-H, right? So Casabatch and then married, I believe is M-E-W-R-I-W-T, right? So the Casabatch married syndrome, that's basically where you have a human jima. And that human jima has the ability to sequester platelets, right? So those are all things you want to keep in mind with the Casabatch married syndrome. So because it's sequestering platelets, those people are going to have thrombocytopenia and they're going to have other antioxidants of thrombocytopenia like PTKI, bleeding and things of that sort. Now, all of the same concept of human jima, right? So what if they give you a question about a person and they tell you, they describe like an abdominal CT finding in the liver. What is the abdominal CT finding in a liver, human jima?
There's something we love to test is something that you know, you just, I mean like as a radiologist you can understand the mechanics and the pathophysiology of why this holds, but that pathophysiology is well beyond the scope of our discussion. So I'm going to skip that today. But how does it classically show up on an abdominal CT of, you know, where you're looking at the liver? Well, the key thing I want you to remember is that you're going to first have peripheral enhancement, right? In the early phase of the arterial study, right? So the person is getting contrast through angiography. And then in the later phases, you're going to see centripetal feeling. So basically it's almost like at first, you have feeling of contrast around the lesion, like in the periphery, like in a circle. But then it's almost like all that contrasting starts traveling towards the center, although it's obviously traveling through blood vessels. But again, I'm not going to go into much detail on that. But you do need to make sure you understand and know what a human jima in the liver, a hepatic hemangioma typically presents with. So that's something that's kind of important to know on exams. And then just one last human jima related lesion, right? So what if they give you a question about a patient? And to tell you that this patient has a, you know, has a very high hematocrit. And this patient has like, has been having headaches for the last three or four months.
And they tell you that you see a classified posterior for some mass in this person, right? The first thing I want you to think about, right? Obviously it's going to be one hip-olendile syndrome. Right? Remember, it's a problem with chromosome three. And the mutation is in the, is in the V-chal gene, right? It's actually an autosomal dominant disorder. So it may be like, okay, divine. What in the world is this posterior for some as you keep referring to? Well, the posterior for some as I keep referring to in this circumstance is actually a hemangioplastoma, right? So him a hemangioplastoma will be a posterior for some as it will be a cerebellum mass. And that must well contain calcifications. And many times it makes it in a perennial plastic fashion. So if you make it in a perennial plastic fashion, that will obviously, right? That will obviously cause the person to have a polycythemia, right? So the person's polycythemia will be associated with elevated levels of a rethrough poetic, right? So one thing our friends at the MDM is love to do in the more recent exams these days is ask on which of the following is the most likely complication, right? Or most likely future malignancy you need to, you know, watch out for in this patient. Well, I'll I'll hope you're saying, oh, divine, I want to think about like this person having like a cancer of the kidney, right? Like renal cell carcinoma.
So most times those people you generally want to follow them every now and then with imaging of the abdomen, because the thing is people that have when he pull in down, they can develop a renal cell carcinomas and they can also develop pancreatic cancers, right? So renal cell carcinomas, pancreatic cancers, those are two things that you want to keep at the back of your mind with one hip down syndrome. And then what if they give you a question about a child and they tell you that this child, you know, always has seizures, seizures, seizures, seizures, and then they tell you that, oh, the performance skin exam and they find all these high pooping and dead lesions. Well, if you see this, I'll hope you're thinking about one of these neurocutaneous disorders, right? So this is going to be tuberous sclerosis. Remember, tuberous sclerosis, they tend to have these dermatologic findings like Ashley spots, right? Remember, you need to be able to examine to differentiate the Ashley spots of tuberous sclerosis from the cafe ole spots of neurofibromatosis type one, right? So the Ashley spots are high pooping-mented lesions, the cafe ole spots are hyper pigmented lesions, right? And those are things you find in tuberous sclerosis. And remember, tuberous sclerosis again, it's a nozo-modement undersoather. And basically the mutations you have are in proteins like ingines called the TSC1 and the TSC2 genes.
And again, many of these keys that have tuberous sclerosis, they tend to have really bad intellectual disability, they tend to have seizures. In fact, many times on nbim exams, they tend to be associated with a seizure disorder called infantile spasms, right? Remember, another link for infantile spasms is West Syndrome. And many times, right? They will tell you that, oh, on an EEG, you see a hip serrhythmia, right? Although these days are friends at the nbim is they are getting a lot wiser, right? So instead of putting the trunk hip serrhythmia, they will describe a hip serrhythmia to you, right? So how can you describe hip serrhythmia to a medical student? Well, you can put in a jumble of words and then say something along the lines of chaotic background. If you see stuff like that, then I want you to think about the person having a infantile spasms or, you know, again, it's called a West Syndrome, right? So chaotic background, they'll put some words and then they'll put with a chaotic background. If you see stuff like that, I want you to think about infantile spasms. And remember, the drug of choice for treating infantile spasms on nbim exams is ACTH, right? It's ACTH. So instead of putting ACTH, sometimes they can just put causing troping. Remember, causing troping is an ACTH analog, right? So it's just something you want to keep at the back of your mind on exams.
And please don't forget, tuberculosis actually has an unusual association with a person having an autism, right? Tuberculosis has an association of people having an autism. Remember, there are many pediatric generic disorders that have a very strong association with autism, right? So like, for example, those two chromosome 15 disorders, right? Those Q11, Q13, the disorders of chromosome 15, like, you know, they can give you a boy that is super, super, super obese. He's like at the 99th percentile for weight. And he has like mild intellectual disability, right? Pretty Willy Syndrome, right? Remember, those people, it's a paternal chromosome amutation. That's also a sort of autism. And also, if you look at the counterparty ladies, right? In females, right? Really, you have, they have like this happy cry. It's going to be in a female and it's a mutation from moms chromosome 15, Q11, Q13, right? Injouman Syndrome, right? Like, sometimes they call that the happy puppet syndrome, right? So those people usually have like, Ataxia, they'll have like all these Parkinsonian features, right? So they'll have like, they'll have like Ataxia, they'll have like these tremors, right? And they always happy. And it's going to be in a girl that's going to be Injouman Syndrome, right? So pretty Willy and Injouman Syndrome are both associated with autism, right? And then there's this syndrome in girls, right?
So they can give you like a question about a girl and they'll tell you that, you know, she was fine at British, was fine for the first few months of life. And then after that, she just started crushing and burning, right? She just started going downhill from a developmental perspective, right? And many times those girls tend to have a lot of hand-flopping movements. If you see something like that, I want you to think about rec syndrome. Remember, rec syndrome arises from an NECP2 G mutation, right? A MECP2. NECP2 G mutation. That is absolutely associated with autism as well, right? And then obviously, right? The classic ones that the endgame is known that most people know, right? So things like fragile ex syndrome, things like Down syndrome, all those things have a very strong association with autism, right? But remember fragile ex syndrome also has a very good association with ADHD, right? fragile ex syndrome does have a very strong association with ADHD, right? So that's just something to keep in mind. And other ADHD associated disorder in kids is the the chalp of a mom that, you know, drinks a ton, right? So like fetal alcohol syndrome has a very strong association with ADHD. Remember, people that also have fetal alcohol syndrome, they can get via these and also the lower part of their bodies can be hypoplastic, right? That's something called cyrenomilia. That's something that believe it or not, they love to test a lot on exams, right? So just as a recap, right?
fetal alcohol syndrome is associated with ADHD, is associated with cyrenomilia, right? So basically, the lower part of the person's body does not develop properly is also associated with having a VSD, okay? VSD is probably like one of the most common cardiac congenital anomalies in kids that have fetal alcohol syndrome. Okay, now what if they give you a question about a person that, you know, is on TPN and this person on TPN, you know, their blood pressure has been going down over the last like 12 to 24 hours, their blood pressure has been going down, their heart rate has been going up and they have like this fever, right? If you see this, what are you thinking about? Well, I hope you're really saying, oh, divine, this person likely has a clapsy, right? So what in the world is a clapsy? Well, a clapsy is a central line associated bloodstream infection. Because remember, if a person is getting TPN, they need to get it through a central line, right? And many times they will ask you an Indian, or what is the most likely complication of TPN administration? And they will try to trick you on your exam into picking a calculus school as a status. Don't do that, right? Pick the answer choice that talks about a central line associated bloodstream infection, right? So the thing is again, this will be in a person that is getting a central line of some sort, right?
And the thing is, most times when a person has a get, is get, you know, gets a central line associated bloodstream infection. It's usually going to be like a mixture of like different bacteria, but most times it's going to be a skin flora, right? So like your coagulist negative stuff like stuff epidermis, for example, right? Although sometimes you can also see like stuff, rures and things and things of that nature, right? But again, these people have a septic picture and you'll notice that all recently, or a few days ago, they had a central line that was placed in them, right? So whenever you see stuff like this, well, what are you going to do? Well, typically, the thing you're going to do for people that, if you suspect that a person has a central line associated bloodstream infection, usually the smart play is to say you know what? Let's go ahead and get two cultures, right? So the first one, you're going to get it from the catheter itself, right? You're going to get it from the catheter itself, right? Because most times you insert the central line in a peripheral vein, right? You know, so we'll put it in the subclavian vein, some putting the jogger veins, some put it in the femoral vein, right? Obviously, if you want to lower the risk of infection, probably makes sense to not do a femoral central line, because those femoral central lines, right? You're kind of like in the perennial area, kind of setting yourself up for infection, right?
But these people, you're going to get two venous samples, two venous blood samples. So the first one is going to be from the catheter. The second one is going to be from any other peripheral vein in the body, right? Now, the key thing to keep at the back of your mind is that if it's a central lining infection, then the specimen you get from the central line will grow way faster than the specimen that you get from the other peripheral vein, right? So that differential growth, right? Where you have like much higher growth in the catheter sample, in comparison with the other peripheral vein sample, that pretty more tells you what you're dealing with. That tells you that, okay, this is likely a central line associated a monostring infection, right? And the good thing to do is treating the claps is actually pretty easy. All you essentially have to do is get rid of the catheter, right? And then put the person on the incommising, right? So remove catheter, put the person on the incommising, and that usually will take care, usually take care of the problem. So now my next question is, what is true of the cardiac pressures in a person that, let's say, they have COVID-19 and they're going to hypoxic respiratory failure and they need to be distributed. So what should you expect of the cardiac pressures in those people? Well, it's actually pretty easy. Most times in those people, right? Obviously this person has ARDS, and remember, you need to be able to recognize ARDS on a chest x-ray.
They almost never test ARDS on CT scans on the exam, but they love, love, love, love, to test it on a chest x-ray, right? So one of the fun, fancy things you need to know about ARDS from a chest x-ray perspective, remember, you're going to find this but-wing appearance, right? This but-wing or angel-wing appearance, right? So but-wing or angel-wing appearance. So the thing is, these people, right? Usually it's because they have like systemic inflammation, right? And remember, whenever you have inflammation, you're going to release all these inflammatory markers, like histamine, heparin, luchotrains, and things like that, bradykines, and those things are very powerful visual dialed leaders. And in addition to that, they also increase your vascular permeability. So the thing is, if you increase the vascular permeability, then that's going to make it possible for fluid to leak into the presence of your light, right? And the only negative is your factant and cause problems, right? So ARDS, right? The pathophases, you have an increase in the vascular permeability, right? So the thing is, remember, ARDS is a problem that happens in the lungs. So because it's a problem that happens in the lungs, we'll all be sure of the pulmonary capillary wedge pressure. Well, I hope you're saying that the pulmonary capillary wedge pressure will be normal. It'll be less than 18, right? Because these people pretty much have a pulmonary edema.
But this pulmonary edema they have is non-cardiogenic, right? They have a non-cardiogenic pulmonary edema, right? A non-cardiogenic pulmonary edema. So that's the thing that tells you, oh, okay, this person has a normal PCWP, right? But another thing to keep in mind is what to be true because again, the problem is proximal to the left heart. So they are left-hore pressures, right? Which we also call the proxy, the pulmonary capillary wedge pressure is completely normal, right? But in terms of these people's CVP, right? The right side of the heart will think about it. The right side of the heart drains into the pulmonary arteries, right? So these people's right sides of their heart will have elevated pressures because again, things are not moving along very well, right? Because these people are hypoxic, they have a lot of pulmonary viso-construction kind of going up the works in their lungs, right? So these people have elevated right side of their heart pressures. In fact, they have CVP, right? The central venous pressure, which is a surrogate for the right-hore pressure, would be increased in people that have ERDS, right? And again, the person has arts and you put them on event. Remember, you need to pursue what I call long protective strategies, right? So you need to put them on low tidal volume and high peak, right? Low tidal volume and high peak because those are things that will protect their lungs.
And again, one thing that's also been shown to improve mortality in people that have been treated for ERDS, to live until later is that they lie on their belly, right? So you make them prune in the ICU or whatever, and that actually does help with improving the oxygenation. Actually does help with improving their oxygenation. Now, what did they give you a question about a patient? And they tell you that, oh, this patient has, you know, has been a, smokes two, has smokes two packs per day for the last, you know, 39 years, right? And then they tell you that this person for the last two days, they've been having a productive cough, they've been producing a ton of sphero, right? They've been having a fever. And then they ask you for the most likely offending organism. If you see that, I'll really hope you're saying, oh, this is easy, this is probably going to be a huge flu. Remember, in general, on NBM exams, hemofluosin fluency, it's probably one of the most common causes of pneumonia in patients that have COPD, right? Or in patients that are big, time-long term smokers, right? So again, these are all things to keep at the back of your mind, for example, right? And remember, one thing that's actually kind of high you to know, they can give you a question about a woman that is pregnant and she has a issue of HIV. And then they'll see something along the lines of, oh, how can I prevent her from transmitting this HIV to a newborn?
Well, if you see that, the thing I want you to think about is, give her Zidovidine. And then right after the child is born, go ahead and give this child Zidovidine as well, right? Sometimes some people will say, okay, let's wait for like, let's wait for a few hours, like, you know, seven, eight, nine hours. After birth, to give this child Zidovidine, but one moment in labor, you need to give EZT, right? Zidovidine. That's actually going to help with reducing the morbidity. I mean, reducing the risk of transmitting a HIV infection to the child. Okay. And then the last thing I think I want to say here is, what if they give you a question about a person? And they tell you that they have a lot of just inter-family problems, right? That is fighting mom. Mom is fighting daughter. Daughter is fighting dad. That is fighting daughter, right? Whenever you see all these inter-family conflicts, like so within one family, there's a lot of conflicts. And they ask you for how you should treat those people. The big thing I would encourage you to pick up on on your exam is a kind of CBT called family therapy. Family therapy is extremely, extremely, extremely effective for treating now, you know, maladaptive family dynamics. But remember that family therapy is also a very good CBT option for people to have an erection of osa, right? Because the thing is, again, many times people that have an erection of osa, they tend to have a, again, very maladaptive family dynamics.
So since this is our opioid review, I'm going to go ahead and pause here. Again, as I go at the end of every podcast, I do offer one or one tutorial for many exams. Step 2, CK Step 3, pre-clean school exams, 30-ish off exams. And then I also offer these review courses for the US Emily Step 2, CK Step 3 exams. Although these courses are largely beneficial to also people taking complex level 2 and 3. And then I do have my podcasts on Apple podcasts on Google podcasts on Spotify, at least the most recent 150, right? So that's where I put any new podcasts I make, right? So obviously I've made 330 podcasts. So that means there's 180, 190 somewhere. Well, the thing is, that's going to be on the website. So if you want everything from episode one to the present time, go on the website, divine intervention podcasts with an S dot com, right? Because again, the thing is it's a Word Press rule. You can put more than your most recent 150 podcasts. And again, the website that I have, you don't have to do any kind of sign up or login. Just go there, click on it, and download whatever you want. Just search for the episode you want. And if you also look, there's something, there's an episode notes feature where there are notes from my, from my pod, many of my podcasts and videos. And then if you look at exam topics list, it's a spreadsheet that will give you, it kind of shows you off for Step 2, CK is broken down by subject for step one, broken down by subject.
Exactly what you should study for each of those are subjects. I'll delete it whenever I make a new podcast. And then I'll encourage you, listen to the podcast if you can, and then read the notes alongside you. Just get much better understanding because again, sometimes people just write notes and just write out the facts, right? You mean, not necessarily get the understanding. So listen to the podcast to get the understanding. And then, again, I have a You Tube channel, Divine Intervention, US Emily podcast and videos, right? If you go there, you can, again, watch my videos that I've posted. And then in addition to that, I do have a new website and a new podcast is called Divine Intervention Life Lessons. Again, I still give life lessons with these my medicine podcasts, but I feel like a lot of people have, you know, me like, divine, I really love your life lessons. So I actually have a Divine Intervention Life Lessons.com website. So far put up 10 really good podcasts there. They're all under 10 minutes long, right? So it's, you know, just some Bible based teaching that just kind of teaches you some life lessons that can really help you succeed in life. And I also have the podcast on Apple podcasts actually. It's called a Divine Intervention Life Lessons. So if you're looking for that again, just so please subscribe to those. My kind of intention is to be like a devotional for people to listen to, and you know, listen to it on the go and get something from it.
You know, listen to it while you're sitting down or whatever and be blessed by it. So, I mean, also if you're applying for this with this cycle, if you need help with personal statements and your era's applications, again, I work with people on that. Again, I've worked with tons of people that I've had question marks on the applications and they're now residents, right? Some of them I've been about to actually believe it or not from residency. I've done this for a couple of years. And again, I have experience, you know, again, being on an admissions committee and just working through many of these residency processes. So, if that's something you're interested in, just should meet an email through the website and I'll be more happy to give you some more information. So thank you for listening. I'll see you next time. God bless you. Thank you.
Practice questions — USMLE style
Question 1 — Oncology/Genetics
A 35-year-old male presents with a history of polycythemia and recurrent headaches. Physical examination reveals multiple, palpable masses in the cerebellum that are described as having a "perilained plastic" appearance. Laboratory studies show elevated erythropoietin levels. Imaging confirms these cerebellar lesions are hemangioblastomas. The patient's medical team is concerned about potential future malignancies associated with this syndrome. Which of the following cancers should the physician monitor most closely in this patient?
- A) Meningioma
- B) Renal cell carcinoma
- C) Hepatocellular carcinoma
- D) Adrenal cortical carcinoma
Answer: B. Von Hippel-Lindau (VHL) syndrome is an autosomal dominant disorder caused by a mutation in the VHL gene. This condition predisposes individuals to hemangioblastomas, typically found in the retina and cerebellum. The most significant associated malignancies that require routine surveillance are renal cell carcinoma (RCC), pheochromocytoma, and endolymphatic sac tumors. Therefore, monitoring for RCC is critical.
Question 2 — Critical Care/Pulmonary
A 68-year-old patient with severe COVID-19 pneumonia develops acute respiratory distress syndrome (ARDS). The patient requires mechanical ventilation and has a chest X-ray demonstrating a classic "butterfly" or "angel wing" pattern of bilateral, diffuse infiltrates. Pulmonary artery catheter monitoring reveals the following pressures: Pulmonary Capillary Wedge Pressure (PCWP): 12 mm Hg Central Venous Pressure (CVP): 18 mm Hg Mean Arterial Pressure (MAP): 65 mm Hg Based on these findings, what is the most accurate interpretation of the patient's pulmonary hemodynamics?
- A) The elevated CVP suggests right ventricular failure due to severe pulmonary hypertension.
- B) The normal PCWP indicates that the pulmonary edema is primarily cardiogenic in origin.
- C) The combination of low PCWP and high CVP is characteristic of non-cardiogenic pulmonary edema.
- D) The patient has acute heart failure, requiring immediate initiation of vasodilators.
Answer: C. ARDS causes a non-cardiogenic pulmonary edema due to increased vascular permeability (mediated by inflammatory cytokines). In this scenario, the PCWP remains normal or low because the fluid leak is not caused by elevated left atrial pressure (which would raise the PCWP in cardiogenic failure). However, systemic inflammation and hypoxemia lead to increased pulmonary vasoconstriction and subsequent right heart strain, resulting in an elevated CVP. This pattern (normal/low PCWP + high CVP) confirms a non-cardiogenic etiology for the edema.
Question 3 — Infectious Disease
A patient is admitted to the ICU requiring Total Parenteral Nutrition (TPN). Due to the TPN administration route, a central venous catheter was placed in the subclavian vein three days prior. The patient develops fever, tachycardia, and hypotension. Suspecting a Central Line Associated Bloodstream Infection (CLABSI), the physician orders blood cultures. To accurately diagnose CLABSI, what is the most critical procedural step that must be performed during the workup?
- A) Obtaining two sets of peripheral venous blood cultures from different sites.
- B) Performing an arterial blood gas analysis to rule out septic shock.
- C) Collecting a specimen directly from the catheter hub and comparing its growth rate to a sample from a peripheral vein.
- D) Immediately removing the central line regardless of culture results, followed by broad-spectrum antibiotics.
Answer: C. The gold standard for diagnosing CLABSI involves obtaining two sets of blood cultures: one drawn from the central catheter itself (the suspected source) and a second set from an unrelated peripheral vein. The key diagnostic finding is differential growth—where the pathogen grows significantly faster or is isolated in higher concentration from the catheter sample compared to the peripheral vein sample.
Question 4 — Neurology/Genetics
A pediatric patient presents with developmental regression, hand-flapping movements, and microcephaly. Genetic testing reveals a mutation in the MECP2 gene. The clinical picture strongly suggests an underlying neurodevelopmental disorder. Which of the following genetic syndromes is associated with mutations in the MECP2 gene?
- A) Neurofibromatosis Type 1 (NF1)
- B) Tuberous Sclerosis Complex (TSC)
- C) Angelman Syndrome
- D) Rett Syndrome
Answer: D. Rett syndrome is a progressive neurodevelopmental disorder almost exclusively seen in females, characterized by initial normal development followed by regression and loss of acquired skills. It is caused by mutations in the MECP2 gene. NF1 (A), TSC (B), and Angelman Syndrome (C) are associated with different genetic causes and clinical presentations.
Quick fire review
What is the key finding on CXR suggestive of ARDS?
Bat-wing or angel-wing appearance.
What are the two most common malignancies requiring surveillance in VHL syndrome?
Renal cell carcinoma (RCC) and pancreatic cancer.
What specific type of skin lesion differentiates Tuberous Sclerosis from Neurofibromatosis Type 1?
TSC has hypopigmented "ashy spots"; NF1 has hyperpigmented "café-au-lait spots."
What is the primary treatment for West Syndrome/Infantile Spasms, and what drug class is used?
ACTH (or a corticotropin analog).
If a patient on TPN develops signs of sepsis, how should CLABSI be diagnosed?
Obtain two cultures—one from the catheter itself and one from an unrelated peripheral vein.
What are the three components associated with Fetal Alcohol Syndrome (FAS)?
ADHD, Cyriénomelia (hypoplasia of lower body), and Ventricular Septal Defect (VSD).
What is the most common bacterial cause of pneumonia in a long-term smoker/COPD patient?
Haemophilus influenzae.
In the context of CLABSI, what does differential growth between catheter and peripheral cultures indicate?
A central line associated bloodstream infection.
What is the genetic basis for Angelman Syndrome (happy girl)?
Maternal chromosome 15 mutation (Q11-Q13).
Which specific drug should be administered to a pregnant woman with HIV during labor and immediately after birth?
Zidovudine (AZT).
What is the classic CT finding sequence for hepatic hemangioma?
Peripheral enhancement in the arterial phase, followed by centripetal filling in later phases.
Which type of family therapy is recommended for treating maladaptive inter-family conflicts or OCD?
Family therapy (a form of CBT).
Quick recall / Anki-style questions
What is the most common bacterial cause of pneumonia in a long-term smoker/COPD patient?
Haemophilus influenzae.
In the context of CLABSI, what does differential growth between catheter and peripheral cultures indicate?
A central line associated bloodstream infection.
What is the genetic basis for Angelman Syndrome (happy girl)?
Maternal chromosome 15 mutation (Q11-Q13).
Which specific drug should be administered to a pregnant woman with HIV during labor and immediately after birth?
Zidovudine (AZT).
What is the classic CT finding sequence for hepatic hemangioma?
Peripheral enhancement in the arterial phase, followed by centripetal filling in later phases.
Which type of family therapy is recommended for treating maladaptive inter-family conflicts or OCD?
Family therapy (a form of CBT).