Focused use of drug screening in overdose patients increases impact on management.

Drug poisoning is a common cause for attendance in the emergency department. Several toxicology centres suggest performing urinary drug screens, even though they rarely influence patient management. STUDY OBJECTIVES: Measuring the impact on patient management, in a University Emergency Department with approximately 40 000 admissions annually, of a rapid urinary drug screening test using specifically focused indications. Drug screening was restricted to patients having a first psychotic episode or cases demonstrating respiratory failure, coma, seizures, a sympathomimetic toxidrome, severe opiate overdose necessitating naloxone, hypotension, ventricular arrhythmia, acquired long QT or QRS >100 ms, and high-degree heart block. METHODS: Retrospective analysis of Triage® TOX drug screen tests performed between September 2009 and November 2011, and between January 2013 and March 2014. RESULTS: A total of 262 patients were included, mean age 35 ± 14.6 (standard deviation) years, 63% men; 29% poisoning with alcohol, and 2.3% deaths. Indications for testing were as follows: 34% were first psychotic episodes; 20% had acute respiratory failure; 16% coma; 8% seizures; 8% sympathomimetic toxidromes; 7% severe opioid toxidromes; 4% hypotension; 3% ventricular arrhythmias or acquired long QT intervals on electrocardiogram. A total of 78% of the tests were positive (median two substances, maximum five). The test resulted in drug-specific therapy in 6.1%, drug-specific diagnostic tests in 13.3 %, prolonged monitoring in 10.7% of methadone-positive tests, and psychiatric admission in 4.2%. Overall, 34.3% tests influenced patient management. CONCLUSIONS: In contrast to previous studies showing modest effects of toxicological testing, restricted use of rapid urinary drug testing increases the impact on management of suspected overdose patients in the ED