Source / episode info
- **Episode:**468
- **Title:**Divine Intervention Episode 468: USMLE Step 2/3 Rapid Review Series 98
- **Published:**2023-07-05
- Source:Episode page
One-liner
This episode provides a rapid review of high-yield topics including anterior communicating artery aneurysms causing bitemporal hemianopsia, empirical meningitis coverage (including Listeria prophylaxis), the constellation of symptoms in Kawasaki disease, the distinction between acute and chronic mitral regurgitation, and complex drug associations involving aspirin's antiplatelet uses and acid-base disturbances.
High-yield summary
- Bitemporal Hemianopsia: Suggests compression of the optic chiasm, most commonly due to a ruptured aneurysm in the anterior communicating artery (AComm) or Circle of Willis. Risk factors include morphin use or ZQD PKD.
- Empiric Meningitis Treatment: Requires broad coverage: Ceftriaxone (Gram-negatives/Strep), Vancomycin (MRSA/Gram-positives), and Steroids are added if Streptococcus pneumoniae is suspected.
- Listeria Prophylaxis: Ampicillin must be added empirically for meningitis in neonates or immunocompromised patients over age 50 due to high mortality risk.
- Kawasaki Disease (KD): A vasculitis characterized by fever, rash, lymphadenopathy, and mucosal changes; watch for coronary artery aneurysms and acute MI presentation in children. KD is strongly associated with thrombocytosis.
- Acute vs Chronic MR: Acute onset often suggests papillary muscle or chordal tendon rupture following an MI (e.g., due to ventricular wall stress). Chronic onset suggests dilated cardiomyopathy/volume overload.
- Aspirin Toxicity: Overdose causes a mixed acid-base disorder: Respiratory Alkalosis (due to increased respiratory rate) AND Metabolic Acidosis (due to aspirin's salicylic acid component and uncoupling action).
Learning objectives
- Differentiate the causes and management of various types of meningitis based on age and risk factors (e.g., Listeria).
- Recognize the clinical triad and associated complications of Kawasaki disease, particularly cardiac involvement.
- Understand the pathophysiology distinguishing acute vs. chronic mitral regurgitation.
- Master the indications for antiplatelet versus anticoagulant therapy following ischemic stroke or MI.
- Interpret aspirin's complex acid-base disturbance (mixed respiratory alkalosis/metabolic acidosis) and its role in AERD.