Study objective: To determine whether the urine Trinder spot test, performed by emergency physicians, is a sensitive bedside screen for salicylates.
Design: Prospective, blinded human protocol with subjects serving as their own controls.
Setting: Urban Level I medical center.
Participants: Ten male and two female volunteers with negative urine toxicologic screen results before the start of the study.
Interventions: Each participant ingested 975 mg of nonenteric coated aspirin. Serum and urine samples were collected before ingestion and 2 and 4 hours after ingestion. Three emergency physicians and a toxicology technician independently performed Trinder spot tests. Results were recorded as positive or negative for salicylate on the basis of color change (a purple reading was considered positive).
Results: All postingestion urine specimens were detected by all testers with 100% sensitivity. Two false positives occurred in the preingestion samples. Serum quantitative assays confirmed the presence of salicylates in all postingestion specimens.
Conclusion: This pilot study suggests that emergency physicians can use the Trinder spot test as a sensitive bedside salicylate screen, potentially saving time and quantitative assay expense.