Clinical Pearls & Morning Reports
Ingestions of caustic substances are a relatively uncommon but serious concern in the United States. For many other nations, however, they remain a consequential public health problem associated with substantial morbidity and mortality. Read the NEJM Review Article here.
Q: What is the most immediate risk to life in cases of caustic ingestion?
A: After caustic ingestion, a person’s most immediate risk to life is loss of the airway, which can occur from direct contact during swallowing or emesis or from edema that extends locally from an injured esophagus. Because of the rapid progression of many injuries, particular attention should be paid to the inability to control oral secretions or a change in voice, indicating impending airway compromise.
Q: After a caustic ingestion, when should endoscopy be performed, if indicated?
A: Endoscopy should be performed in the first 24 to 48 hours after ingestion, since wound softening increases the risk of perforation.
A: The standard toxicologic principles of gastrointestinal decontamination do not apply to patients with caustic ingestions, since clinical attempts to empty the stomach can potentially increase injury. In addition, activated charcoal does not adsorb caustics, and adherent particles of activated charcoal will obscure endoscopic visualization. Although blind nasogastric-tube insertion has occasionally been recommended for acid ingestions and is still performed by one third of international experts, there is no evidence to support the efficacy or safety of this procedure. Similarly, although dilution and neutralization are theoretically beneficial, thermal injury is possible from the heat of neutralization. Even if this risk might be overstated, the clinical benefit of neutralization has never been shown. Further concerns over distention-induced injury of damaged tissues caused by gas generated during neutralization and the risk of emesis prevent recommendations for neutralization at this time. A single exception would be the use of water immediately after ingestion (usually at home) to irrigate adherent materials in the oropharynx or esophagus if the patient can swallow, speak clearly, and breathe without difficulty. Early irrigation is likely to be most useful for ingestion of powdered caustics, which can prolong injury by adhering to tissues.
A: While use of glucocorticoid therapy for caustic ingestions fell out of favor, recently, an interest in glucocorticoids was rekindled. It should be noted, however, that one consensus conference recommended that glucocorticoids not be used. Two other pharmacotherapies for ingestion of caustics are supported by sufficient clinical data: sucralfate and mitomycin C. In a single case report, the administration of sucralfate was associated with atypically rapid healing. A subsequent animal model showed that sucralfate had favorable healing properties as compared with placebo. Mitomycin C provides an alternative approach, minimizing the clinical effects of strictures by making them more amenable to mechanical dilation. Mitomycin C induces fibroblast apoptosis, reducing scarring. In a randomized and blinded trial, 40 patients with caustic-induced strictures were given either endoscopically administered mitomycin C or placebo, with subsequent mechanical dilation. Patients treated with mitomycin C had a significant reduction in symptoms and required fewer dilations than the placebo group. One unanswered question is whether mitomycin C increases the long-term risk of malignant transformation because of its ability to damage DNA.