Source / episode info
- **Episode:**487
- **Title:**Divine Intervention Episode 487: USMLE Step 2/3 Rapid Review Series 104
- **Published:**2023-10-25
- Source:Episode page
One-liner
This episode reviews high-yield board topics including Marfan syndrome (fibrillin defect), diagnosing aortic dissection, the specific patterns of hemoglobinopathies ({HbA}_2, {HbF}, {HbH}), differential diagnosis for elevated -hCG, and the sequential management of postpartum hemorrhage.
High-yield summary
- Marfan Syndrome (MFS): Caused by a fibrillin defect (autosomal dominant). High risk for aortic dissection, mitral valve prolapse (MVP), and aneurysms in the Circle of Willis. Patients should avoid contact sports.
- Aortic Dissection Workup: Stable patient with chest pain: CT Angiogram with contrast is preferred. Unstable/hemodynamically compromised patient: Transesophageal Echocardiogram (TEE).
- Hemoglobin Electrophoresis Traps: Elevated {HbA}_2 strongly suggests Beta-thalassemia. Alpha-thalassemia cannot be diagnosed by electrophoresis because all major hemoglobin types contain alpha chains, leading to a proportionally decreased pattern.
- Postpartum Hemorrhage (PPH): The most common cause is uterine atony. Management sequence: 1) Uterine massage -> 2) Oxytocin -> 3) Tranexamic Acid ({TXA}) -> 4) Prostaglandins (e.g., Carboprost).
- hCG Differential: Extremely high levels of -hCG in a woman suggest molar pregnancy or choriocarcinoma; if seen in a male with a testicular mass, suspect seminoma.
Learning objectives
- Differentiate the diagnostic workup for aortic dissection based on hemodynamic stability.
- Identify the key genetic defects and clinical manifestations of Marfan syndrome.
- Interpret hemoglobin electrophoresis results to distinguish between Beta-thalassemia and Alpha-thalassemia.
- Outline the sequential, evidence-based management steps for postpartum hemorrhage (PPH).
- Recognize the differential diagnosis for highly elevated \beta-hCG levels in both male and female patients.
Board exam buzzwords