Evaluation of Residual Toxic Substances in the Stomach Using Upper Gastrointestinal Endoscopy for Management of Patients With Oral Drug Overdose on Admission: A Prospective, Observational Study

The guidelines on the indications for gastric lavage were published in 1997, and a less-aggressive initial approach has been used for poisoned patients. Clinical studies have shown that the outcomes of retrieval of residual toxic substances in the stomach are variable and that no beneficial effect is obtained. However, the presence of residual toxic substances in the stomach before gastric lavage has not been estimated. The objective of this study was to evaluate the residual stomach contents on admission of patients with oral drug overdoses using upper gastrointestinal endoscopy. A 2-year prospective study of 167 patients with oral drug overdoses was performed. Endoscopy was performed on admission to observe the gastric body, fornix, and pyloric antrum. Patients were classified into 3 groups according to the digestive phase (tablet/food phase, soluble/fluid phase, and reticular/empty phase). The groups were compared with respect to time elapsed since ingestion, and numbers and variety of orally overdosed drugs. The numbers of patients in each phase were as follows: tablet/food phase, 73; soluble/fluid phase, 50; and reticular/empty phase, 44. The tablet/food and soluble/fluid phase groups contained the greatest numbers of patients who presented within 1 to 2 hours since ingestion. In the tablet/food group, only 12 of 73 patients (16%) presented within 1 hour since ingestion, and 3 patients presented >12 hours since ingestion. In the soluble/fluid phase group, only 9 of 50 patients (18%) presented within 1 hour since ingestion, and 2 patients presented >12 hours since ingestion. The reticular/empty phase group contained the greatest number of patients presenting within 2 to 4 hours since ingestion, and 3 patients presented within 1 hour since ingestion. The residual stomach contents before lavage were variable in all of the groups. The residual gastric content before the performance of gastric lavage is variable in overdosed patients on admission. This may influence the efficiency of gastric lavage with respect to retrieval of residual toxic substances in the stomach. This study may contribute to the development of a strategy for treating patients who have orally overdosed on drugs in the future.