Caustic ingestion

Background

Caustics

  • Substances that cause damage on contact with body surfaces
  • Degree of injury determined by pH, concentration, volume, duration of contact
  • Acidic agents cause coagulative necrosis
  • Alkaline agents cause liquefactive necrosis (considered more damaging to most tissues)
  • Corrosive agents have reducing, oxidising, denaturing or defatting potential

Alkalis

  • Accepts protons → free hydroxide ion, which easily penetrates tissue → cellular destruction
    • Liquefactive necrosis and protein disruption may allow for deep penetration into surrounding tissues
  • Examples
    • Sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH3)
    • Found in: bleach, drain openers, oven cleaners, toilet cleaner, hair relaxers

Acids

  • Proton donor → free hydrogen ion → cell death and eschar formation, which limits deeper involvement
    • However, due to pylorospasm and pooling of acid, high-grade gastric injuries are common
      • Mortality rate is higher compared to strong alkali ingestions
  • Can be systemically absorbed and → metabolic acidosis, hemolysis, AKI
  • Examples
    • Hydrochloric acid (HCl), hydrofluoric acid (HF), Sulfuric acid (H2SO4)
    • Found in: auto batteries, drain openers, metal cleaners, swimming pool products, rust remover, nail primer

Clinical Features

  • Signs and symptoms are inadequate to predict presence or severity of injury after caustic ingestion [1]
  • 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

Differential Diagnosis

Caustic Burns

Evaluation

Labs

Only necessary in patients with significant injury or volume of ingestion

  • CBC
  • Chemistry
  • Lactic Acid
  • ECG
  • Calcium level (if Hydrofluoric Acid exposure)
  • Acetaminophen and Salicylate levels (in patients with concern for intentional ingestion)

Imaging

  • 3-View CXR CXR
    • Look for free air under the diaphragm or signs of mediastinal air[2]
  • CT
    • Consider when perforated viscus is suspected but CXR is negative
  • Button battery XR - two rings, will likely need to remove it no matter where it is, whether post-pyloric or pre-pyloric

Management

  • Prevent provider and continued patient exposure to the caustic agent by removing all clothing and decontaminating the patient

Airway Management

  • Monitor closely for stridor, airway edema, hoarseness, or other signs of airway injury
  • Intubate early if signs of airway injury exist, before airway becomes more difficult to manage.
  • Consider awake fiberoptic or video laryngoscopy if concern for difficult airway
  • Blind nasotracheal intubation is contraindicated due to the potential for perforations and false passages

Endoscopy

Should be performed within 12-24 hours of ingestion (too early can underestimate extent of injury, too late increases risk of wound softening and perforation).

Indications
  • Intentional ingestion (higher likelihood of high volume ingestion)
  • Unintentional ingestion with signs of:

Esophageal Stricture Mitigation[3]

Surgical Intervention

  • Indicated for:
    • Perforation
    • Peritoneal signs

Caustic Specific Treatment

  • Can include chelation, dialysis, or specific antidotes
    • Especially in caustics that cause systemic toxicity

Controversial or Contraindicated

  • Antibiotics
    • No evidence to support or reject the use of prophylactic antibiotics
    • Only indicated if also giving steriods (see stricture mitigation above)
  • Activated charcoal
    • May infiltrate damaged mucosa & interfere with EGD
    • Only consider when coingestants pose a risk for severe systemic toxicity
    • Zinc chloride and mercuric chloride systemic absorptions may outweigh interference with endoscopy
  • Gastric lavage
    • Contraindicated due to potential to cause reflux of caustic agent into esophagus, creating more damage
  • Dilution with water or milk causes vomiting, elevating risk for perforation
    • Possible benefit only for solid alkali ingestions
  • Neutralization generates excess heat

Disposition

  • All patients with symptoms from a caustic ingestion should be admitted
  • All patients with intentional ingestion should be evaluated by psych prior to discharge

Prognosis

  • Depending on severity may have full return of mobility and function or can progress to perforation followed by stricture formation
  • Days 2-14 post-injury are associated with highest tissue friability / risk of perforation
  • High-grade caustic burns associated with 1000x increase in esophageal SCC

See Also

References

  1. Gaudreault, P. et al. Predictability of esophageal injury from signs and symptoms: a study of caustic ingestion in 378 children. Pediatrics. 1983;71(5):767-770.
  2. Muhletaler C. et al. Acid corrosive esophagitis: radiographic findings. AJR Am J Roentgenol. 1980. Jun;134(6):1137-40. PMID: 6770621
  3. High Doses of Methylprednisolone in the Management of Caustic Esophageal Burns. Pediatrics 2014;133:e1518–e1524