A diagnostic tool for self-poisoned patients: Analysis of gastric content and lavage fluids.

Approximately 500 patients per year are admitted to the emergency department (ED) of the Erasmus University Medical Center presenting with intoxications with medication. For adequate treatment, it is sometimes important to know which drugs in which quantities were ingested. This can require laboratory analysis of blood or urine samples; however, these samples do not provide information about the possible effects that can still be expected. We performed toxicological screening on the gastric content of three patients admitted to our ED in January and February 2018. These patients underwent gastric lavage or received a gastric tube as part of routine care. The gastric fluid was analysed via UPLC-MS/MS using the Waters method for toxicological screening. In all three patients, we successfully determined drugs in the gastric content. In two patients, we identified more different drugs in the gastric content than in blood plasma. In the other patient, admitted approximately six hours after a severe autointoxication with the betablocker metoprolol, we found significant amounts of metoprolol in the gastric content acquired by gastric lavage. We therefore believe that analysis of gastric content after an intoxication can have multiple applications; for example, it may provide information about symptoms of intoxication that can be expected, it may aid patient care and may provide insight in the toxicokinetics of different drugs. In conclusion, we demonstrate that toxicological screening and quantification of drug levels in gastric content is possible and has potential as an adjunct in patient care, but limitations need to be addressed before implementation in clinical practice.