Monitoring ethanol exposure in a clinical setting by analysis of blood, breath, saliva, and urine

Background: Several new technologies have been developed for estimating blood alcohol concentration (BAC), among others, by the analysis of alcohol in saliva specimens. The Q.E.D.(TM) is a new quantitative test designed for measuring ethanol in saliva and promising results have been obtained in various experimental settings. Methods: In the present study, venous BAC was determined in 28 patients on arrival and when they were discharged from a detoxification unit. The results were compared with breath, saliva, and urine alcohol concentrations. Headspace gas chromatography was used for analysis of ethanol in blood and urine, and breath alcohol was determined with an Alcolmeter S-D2 instrument. Results: The concentration of alcohol in urine was always higher than the BAC (mean difference, 0.62 mg/ml) and individual values were highly correlated (n = 42; r = 0.92). The handheld breath-alcohol instrument (Alcolmeter S-D2) showed good agreement with venous BAC (n = 52; r = 0.97; mean difference, 0.04 mg/ml). The saliva-alcohol test failed to perform well in our tests (n = 36; r = 0.75; mean difference, 0.55 mg/ml) mainly because of problems encountered in obtaining a sufficient sample for analysis in highly intoxicated patients. Conclusions: Because of the relatively low cost of the Q.E.D.(TM) saliva test, in comparison with a breath alcohol analyzer, the saliva test could be a cost-effective alternative in public health settings where mildly to moderately intoxicated persons are encountered.