Poisoning

Caustic Ingestion (Cleaning Products)

• Pathophysiology:

  • Alkalis (bleach, drain/oven cleaner): Liquefactive necrosis $\to$ deep, transmural penetration (most common).
  • Acids (toilet/pool cleaner, battery acid): Coagulative necrosis $\to$ protective eschar limits depth; severe gastric injury.

• Clinical Presentation:

  • Airway: Stridor, hoarseness, drooling (critical signs of upper airway compromise).
  • GI: Dysphagia, odynophagia, severe retrosternal/epigastric pain, hematemesis.
  • High-Yield Rule: Normal oral exam does not rule out severe esophageal/gastric damage.

• Initial Workup & Diagnostic Steps:

  1. ABCs: Assess airway patency immediately.
  2. CXR / Upright AXR: Screen for pneumomediastinum or pneumoperitoneum (perforation) before procedures.
  3. EGD (Gold Standard): Perform within 12–24 hours to assess mucosal damage grade (avoid between 48 hrs–2 wks due to high perforation risk).
  4. CT Chest/Abdomen: If perforation or transmural necrosis is suspected.

• Contraindicated Interventions (High-Yield USMLE Pitfalls):

  • NO emetics (ipecac) $\to$ re-exposes esophagus to caustic agent.
  • NO neutralizing agents (weak acids/bases) $\to$ exothermic reaction causes thermal burns.
  • NO activated charcoal $\to$ ineffective for caustic ions; obscures EGD visualization.
  • NO blind NG tube placement $\to$ mechanical perforation risk. c

• Management:

  • Airway: Early intubation (fiberoptic) or surgical airway if stridor/severe edema is present.
  • Supportive: Keep NPO, IV fluids, IV PPIs, IV analgesia; remove contaminated clothing.
  • Surgical (Laparotomy/Thoracotomy): Immediate indication if signs of perforation, peritonitis, or mediastinitis.

• Complications:

  • Acute: Perforation, mediastinitis, peritonitis, sepsis.
  • Late: Esophageal stricture (most common; requires balloon dilation), Esophageal Squamous Cell Carcinoma (SCC) (screening EGD recommended 15–20 years post-injury).