Caustics are substances that can cause histological and functional damage on contact and include both alkalis (pH >7) and acids (pH <7). The most common alkali exposure is household bleach (sodium hypochlorite with hydroxide), which is usually benign except in intentional ingestions. The most common acid exposures are drain cleaners (sulfuric acid), automobile batteries, and masonry cleaners (hydrochloric acid).
Common features of caustic ingestions include dysphagia, odynophagia, epigastric pain, and vomiting with gastrointestinal (GI) tract injuries. Dysphonia, stridor, and respiratory distress can be seen with laryngotracheal injury. Esophageal injuries are graded by direct endoscopic visualization: (1) edema and hyperemia; (2) ulcerations, blisters, and exudates (2a—noncircumferential; 2b—circumferential); (3) deep ulceration and necrosis. Intentional ingestions are associated with higher-grade injury that can lead to the development of strictures. Most ingestions with serious injury are symptomatic with stridor, drooling, or vomiting, although distal GI injury without oral or facial burns is possible. Disc battery ingestions are often asymptomatic, though batteries >15 mm in diameter can become lodged in the esophagus and cause pressure necrosis.
Caustic exposures to the cornea are particularly serious if they involve alkalis. Dermal exposures to caustics usually produce only local pain and irritation. However, alkali and sodium hydrofluoric acid burns can penetrate deeply. Alkali exposures lead to liquefactive necrosis, which is more severe than the coagulation necrosis caused by most acids. Hydrofluoric acid can cause systemic hypocalcemia, hypomagnesemia, and hyperkalemia with subsequent ventricular dysrhythmias.
DIAGNOSIS AND DIFFERENTIAL
The diagnosis is clinical. Routine laboratory tests are recommended for severely affected patients and include electrolytes, assessment of acid–base status, and monitoring for potential gastrointestinal bleeding. Monitor serum calcium and magnesium levels and perform an ECG in patients with hydrofluoric acid exposures, especially ingestions. Consider chest and/or abdominal radiographs in symptomatic caustic ingestions to assess for free air or to investigate for foreign body in cases of suspected disc battery ingestion. Noncontrast CT of the chest and abdomen may be useful if perforated viscus is suspected, especially after ingestion of strong acids. Early endoscopic evaluation (ideally <12 hours after ingestion) is indicated for intentional caustic ingestions, and unintentional cases presenting with stridor, oral burns, vomiting, drooling, or inability to tolerate oral intake.
EMERGENCY DEPARTMENT CARE AND DISPOSITION
Focus treatment on decontamination, early anticipatory airway management, stabilization of hemodynamic status, and delineation of extent of injury.
Remove contaminated clothing and irrigate exposed skin with copious amounts of water. Alkali burns may require local debridement and removal of devitalized tissue followed by additional irrigation.
Perform aggressive ocular decontamination with normal saline for a minimum of 15 minutes with frequent monitoring of ocular pH until a pH of 7.5 to 8.0 is achieved.
Gastric decontamination in the form of activated charcoal, ipecac, or gastric lavage is contraindicated.