Oral Fluid Testing for Illicit Substance Use in Preanaesthetic Care

OBJECTIVE: Due to specific risks associated with illicit drug use, the preanaesthetic detection of illicit substances is essential. This prospective observational study evaluated oral fluid testing and self reporting of illicit drug use compared with confirmatory blood testing. METHODS: Consecutively enrolled preanaesthetic and emergency room patients (n = 939) completed a paper-based lifestyle questionnaire. An oral fluid sample was obtained and analysed for illicit substance use by a point-of-care testing device (Drager Drugtest (R) 5000). Patients who tested positive by self reporting or oral fluid testing underwent confirmatory blood testing (n = 117). RESULTS: Self reporting revealed more overall illicit substance use and more users of cannabinoids, amphetamines, opioids, cocaine and benzodiazepines than oral fluid testing. Self reporting was more sensitive than blood testing for the detection of overall illicit substance use, and for use of cannabinoids and benzodiazepines. CONCLUSIONS: Self reporting revealed higher rates of illicit substance use than oral fluid testing in preanaesthetic patients, and may lead to more interventions and more appropriately tailored treatment and anaesthesia compared with oral fluid testing.