Caustic burn

Background

• Substances that cause damage on contact with body surfaces
• Degree of injury determined by pH, concentration, volume, duration of contact
• Etiologies for shock include GI bleeding, perforation, volume depletion
  • Intentional ingestion a/w higher grade injuries
• Esophageal injuries
  • Mild injuries - normal function is restored
  • Severe injuries - strictures
• Days 2-14 post-injury are a/w highest tissue friability / risk of perforation
• High-grade caustic burns a/w 1000x increase in esophageal SCC

Alkalis

• Hydroxide ion easily penetrates tissue causing immediate cellular destruction
  • May cause deep penetration into surrounding tissues (e.g. abd/mediastinal necrosis)
• Examples
  • Bleach, drain openers, oven cleaners, toilet cleaner, hair relaxers
  • Household bleach rarely causes significant injury

Acids

• Hydrogen ion leads to cell death and eschar formation, which limits deeper involvement
  • However, due to pylorospasm and pooling high-grade gastric injuries are common
    • Mortality rate is higher compared to strong alkali ingestions
• Ingestion may be complicated by systemic absorption (met acidosis, hemolysis, ARF)
• Examples
  • Auto batteries, drain openers, metal cleaners, swimming pool products, rust remover

Diagnosis

• All pts w/ serious esophageal injuries have some initial sign or symptom
  • E.g. stridor, drooling, vomiting
• Exam eyes and skin (splash and dribble injuries may easily be missed)
• GI tract injury
  • Dysphagia, odynophagia, epigastric pain, vomiting
• Laryngotracheal injury
  • Dysphonia, stridor, respiratory distress
  • Occurs via aspiration of caustic or vomitus or inhalation of acidic fumes

Work-Up

Labs

Only necessary in pts w/ significant injury

• • CBC
  • Chemistry
  • VBG
    • Anion gap acidosis due to lactate production (tissue injury) or from the acid itself
      • May also have non-anion gap acidosis (e.g. HCl)
  • Lactate
  • LFTs
  • Coags
  • Type and screen
  • Calcium level
    • If HF acid exposure
  • ECG
  • Screens for coingestants in suicidal pts
  • May show QT-prolongation if hypocalcemic 2/2 HF acid

Imaging

• Upright CXR
  • Detect peritoneal and mediastinal air
• Left-side down CXR
  • Indicated if unable to tolerate upright CXR
• CT
  • Consider when perforated viscus is suspected or after intentional ingestion

Treatment

1. Prevent personal exposure to the caustic agent
2. Airway
   1. Should be considered as a difficult airway
   2. Blind nasotracheal intubation is contraindicated
   3. First-line is awake oral intubation w/ direct visualization
   4. LMAs, combitubes, bougies are probably unsafe; should be used as last resort
   5. Surgical back-up is recommended
3. Steroids
   1. Some toxicologists recommend single dose of dexamethasone 10mg IV (06mg/kg in peds)
4. Decontaminate in usual manner
5. Activated charcoal
   1. Only consider when coingestants pose a risk for severe systemic toxicity

Source

Tintinalli