Routine Laboratory Screening for Acetaminophen and Salicylate Ingestion in Preadmission Psychiatric Patients Is Unnecessary

Study objective: Screening preadmission psychiatric patients for acetaminophen or salicylate overdose is unnecessary in the absence of specific clinical concern for medication ingestion. Methods: This was a multicenter retrospective cohort study of 3 Veteran's Administration emergency departments that medically evaluate patients prior to psychiatric admission. During the 10-year study period, these departments followed screening protocols that required the measurement of acetaminophen and salicylate levels on every patient prior to psychiatric admission. We examined all the acetaminophen and salicylate assays performed to see if any that were sent for screening led to a diagnosis of overdose and/or the administration of antidotal therapy. Results: A total of 33,439 combined acetaminophen and salicylate assays were sent on 10,482 unique patients over approximately 17,000 patient encounters. An estimated 29,000 assays were sent for screening purposes only-87% (95% confidence interval [CI] 85% to 89%) of salicylate assays and 85% (95% CI 83% to 87%) of acetaminophen assays. We identified 43 patients with elevated acetaminophen levels and 11 with elevated salicylate levels. Among these patients, only 6 in total had their levels drawn for screening purposes only, with no history of suspected ingestion; in all but 1 patient, the levels were only slightly above the reference range. None of the patients with elevated levels identified by screening had clinical toxicity or received antidotal therapy. Conclusion: Over a 10-year period, 3 Veteran's Administration emergency departments performed psychiatric preadmission screening protocols with acetaminophen and salicylate assays approximately 17,000 times without diagnosing a single case of toxicity. Our results suggest that this practice is unnecessary and wasteful.

Automated summary

The study found that screening preadmission psychiatric patients for acetaminophen or salicylate overdose is unnecessary, as approximately 85-87% of the assays were sent for screening purposes only and no cases of toxicity were diagnosed.