[Upper gastrointestinal tract injury caused by ingestion of caustic substances]

To determine the distribution, extension and severity of injuries produced by the ingestion of caustic substances in the upper gastrointestinal tract, and to assess the relationship of these factors with the type of caustic substance ingested, whether intake was accidental or deliberate and the appearance of strictures or death.

Between 1993 and 1999, 138 patients (74 males and 84 females) who underwent upper gastrointestinal endoscopy in our unit within the first 24 hours after ingestion of caustic substances were included in the study. Mean age was 47 years (14-97 years). The severity of caustic injury was evaluated using the classification of Showkat et al.

The type of caustic substance ingested was as follows: lye in 84 patients (53%), nitric acid in 21 (13%), different caustic mixtures in 43 (27%) and unknown in 10 patients (6%). Lesions were grade I in 51 patients(32%), grade II in 33 (21%) and grade III in 20 (13%). No lesions were seen in 54 patients (34%). Of the 158 patients, gastric injury was found in 91 (57.5%), esophageal burn in 72 (45.5%) and duodenal injury in 28 (18%). Ingestion was accidental in 80 patients (51%) and voluntary in 62 (39%); the reasons for ingestion were unclear in 16 patients (10%). Voluntary ingestion and acid use were associated with greater severity of lesions (p < 0.0005). Eight patients (5.0%) died, 10 patients (6.3%) required emergency surgery, and 7 (4.4%) developed esophageal-gastric strictures that required surgery or endoscopic treatment.

The most common type of caustic substance ingested was lye. In 66% of the patients, lesions were absent or superficial. The more severe injuries, producing strictures and higher mortality, were related to voluntary and nitric acid ingestion. The part of the digestive tract most frequently affected after lye and acid ingestion was the stomach.