Source / episode info
- **Episode:**174
- **Title:**Divine Intervention Episode 174 – USMLE Step 2CK Rapid Review Series 22 (IM).
- **Published:**2019-10-21
- Source:Episode page
One-liner
This episode reviews high-yield board associations covering culture-negative endocarditis (Coxiella burnetii), the metabolic consequences of carcinoid syndrome (pellagra), connective tissue defects (Ehlers-Danlos Syndrome), specific chemotherapeutic toxicities (pulmonary fibrosis, neuropathy), and diagnostic workups for GI/hematologic issues.
High-yield summary
- Endocarditis: When considering culture-negative endocarditis, especially in a patient with fever, think of Coxiella burnetii (Q fever).
- Carcinoid Syndrome: The release of excessive serotonin (5-HT) from a small bowel tumor depletes Tryptophan needed for Niacin synthesis, leading to the "4 Ds of Pelagra": Diarrhea, Dermatitis, Dementia, and Death.
- Ehlers-Danlos Syndrome (EDS): Beyond typical vascular issues, remember that EDS patients are at high risk for small bowel perforation/explosion due to defective collagen membranes.
- Macrocytic Anemia: A macrocytic anemia (high MCV) in a patient with hemolytic or chronic GI blood loss must prompt testing for Folate deficiency, not just B12 deficiency. Alcoholism is also a cause due to impaired folate reabsorption.
- Chemo Toxicity: Pulmonary fibrosis from anti-cancer agents requires remembering the triad: Bleomycin, Cisplatin, and Methotrexate. Methotrexate bone marrow suppression can be reversed with Leucovorin (folinic acid).
Learning objectives
- Identify the specific organisms associated with culture-negative endocarditis (e.g., Coxiella burnetii).
- Explain the metabolic pathway linking carcinoid syndrome, serotonin release, and pellagra development.
- Recognize the high-risk complications of connective tissue disorders like Ehlers-Danlos Syndrome, particularly GI perforation risk.
- Differentiate between causes of macrocytic anemia (B12 vs Folate) and identify specific clinical triggers for folate deficiency (alcoholism, hemolysis).
- Recall the classic triad of chemotherapeutic agents causing pulmonary fibrosis and their respective mechanisms/toxicities.
Board exam buzzwords