Which of the following is most reliable for confirming the occurrence of a significant esophageal caustic injury?

D. Endoscopy.

DISCUSSION: In the absence of physical or radiographic evidence of upper airway obstruction or esophagogastric perforation, the presence of a significant caustic injury can be defined reliably only by direct visualization at the time of endoscopy. Although the history may shed light on the possibility of a burn and its severity, all too often the event goes unwitnessed or the type and amount of ingested substance are not known with certainty. The identification of oropharyngeal burns clearly indicates the need for endoscopy, but as many as 70% of patients with such lesions escape associated esophageal injury. Conversely, 10% to 30% of patients with no external evidence of burns have subsequently been confirmed by esophagoscopy to have sustained damage. In the absence of an identifiable perforation, a barium esophagogram can rarely be considered unequivocally diagnostic of acute injury, though such an injury may be suggested when the esophagus appears atonic and dilated, rigid and persistently narrowed, or excessively irritable. Because of the importance of early confirmation of the presence or absence of a significant esophageal burn as a guide to formulating appropriate treatment, esophagoscopy should be performed expeditiously as soon as sufficient time has elapsed to allow gastric emptying and stabilization of the patient, preferably within the first 12 to 48 hours after ingestion.