Source / episode info
- **Episode:**575
- **Title:**DIP Ep 575: USMLE Step 2/3 Rapid Review Series 118
- **Published:**2025-02-25
- Source:Episode page
One-liner
This rapid review emphasizes integrating basic science knowledge across multiple systems, covering the pathophysiology of scleroderma and GERD complications, hormonal changes in pregnancy (progesterone effects), specific bacterial toxin mechanisms (e.g., Diphtheria, Cholera), thrombotic microangiopathies (HUS), and appropriate pharmacotherapy for GI conditions like PUD.
High-yield summary
- Scleroderma: CREST syndrome is a mnemonic; chronic GERD leads to esophageal strictures/adhesions, increasing the risk of adenocarcinoma.
- Pregnancy Physiology: Progesterone acts as a powerful smooth muscle relaxant, causing LES hypotonia and contributing to urinary stasis (via ureteral dilation), thus elevating UTI risk.
- HUS Pathophysiology: Hemolytic Uremic Syndrome is characterized by MAHA (shistocytes), thrombocytopenia, and acute renal failure; E. coli O157:H7 is the classic cause.
- Toxin Management: Antibiotics are contraindicated in HUS/Shigella infections because they can stimulate toxin release, worsening the condition. Treatment must be supportive care.
- NSAID Use: For patients with PUD, COX-2 selective inhibitors (e.g., Celecoxib) are preferred over non-selective NSAIDs because they spare protective COX-1 prostaglandins in the gastric mucosa.
- Legal Capacity: A Durable Power of Attorney (DPO) only grants decision-making authority when the patient is incapacitated; otherwise, the patient retains full autonomy.
Learning objectives
- Identify the clinical manifestations and complications associated with systemic sclerosis (scleroderma), particularly involving the esophagus.
- Explain the hormonal basis of gastrointestinal changes during pregnancy, including LES relaxation and increased UTI risk.
- Differentiate between various causes of hemorrhagic diarrhea and their underlying pathophysiology (e.g., invasion vs. toxin).
- Recognize the clinical triad and key laboratory findings associated with Hemolytic Uremic Syndrome (HUS) and its primary etiology.
- Select appropriate pharmacotherapy for pain management in patients with concurrent peptic ulcer disease, focusing on COX inhibition mechanisms.