DIP Episode 369 - USMLE Step 2CK/3 Rapid Review Series 70

Source / episode info

**Episode:**369
**Title:**Divine Intervention Episode 369 – USMLE Step 2CK/3 Rapid Review Series 70
**Published:**2022-02-09
Source:Episode page

One-liner

This episode provides a rapid review of critical surgical emergencies, focusing on diagnosing esophageal ruptures using water-soluble contrast, establishing indications for exploratory laparotomy (E-LAP) based on peritonitis signs or free air, and mastering the pathophysiology and pharmacological causes of small bowel obstruction.

High-yield summary

Esophageal Rupture Workup: Suspect rupture with severe chest pain after GERD/vomiting; use water-soluble contrast enema (gastro-graphy) to detect extravasation into the thoracic cavity. Never use barium due to mediastinitis risk.
E-LAP Indications: Must consider E-LAP if signs of peritonitis are present (rebound tenderness, guarding, severe abdominal tenderness), or if there is evidence of perforation/leakage (free air under diaphragm, bile in chest tube).
Anti-cholinergic Effects: Drugs causing ileus/SBOO include opioids, diphenhydramine (antihistamine), tricyclic antidepressants (TCA), and calcium channel blockers (CCBs). These drugs impair GI motility by blocking muscarinic receptors or interfering with smooth muscle contraction.
Initial SBOO Management: Initial management involves NPO status, IV fluids, and placing a nasogastric tube for decompression; hypokalemia correction is crucial due to high association.

Learning objectives

Identify the appropriate diagnostic imaging for suspected esophageal rupture, including contraindications.
Differentiate between various indications requiring an exploratory laparotomy in the abdomen.
Classify and list the common causes of small bowel obstruction (SBOO) by frequency.
Recognize drugs that impair GI motility via anti-cholinergic mechanisms or calcium channel blockade.
Outline the initial management steps for SBOO, including decompression and electrolyte correction.

Board exam buzzwords

Condition	Key Finding	Association	Board Exam Tip
Esophageal Rupture (Boerhaave)	Water-soluble contrast extravasation	Severe chest pain post-vomiting/GERD	Use water-soluble contrast; Barium is contraindicated due to mediastinitis risk.
Small Bowel Obstruction (SBOO)	Air-fluid levels on abdominal X-ray	Adhesions (most common), Hernia, Cancer	Always consider the pharmacological causes (anti-cholinergics).
Peritonitis/Perforation	Rebound tenderness, guarding, free air under diaphragm	Intra-abdominal catastrophe	These signs are surgical emergencies requiring immediate E-LAP.
Anti-cholinergic drugs	Impaired GI motility / Ileus	Opioids, Diphenhydramine, TCAs, CCBs	Remember that anti-muscarinic effects slow peristalsis and cause obstruction.