Ethanol determination using automated analyzers: limitations and pitfalls

Abstract Ethanol is one of the most frequently encountered toxic substances in both clinical and forensic settings. From a societal standpoint, substantial costs are incurred due to the excessive use of ethanol, both in terms of loss of life and economic burden. The effects of ethanol on humans (pharmacodynamics) has been extensively studied over the past several decades. Our understanding of how the human body metabolizes and eliminates ethanol (pharmacokinetics) has also been extensively studied and allowed rather sophisticated methods to analyze ethanol levels in various bodily fluids. Ethanol testing is often requested in life-threatening emergency settings, as well as for monitoring patients in alcohol and other drug treatment programs and when evaluating patients' suitability for organ transplant. The large number of non-clinical (forensic) applications of ethanol testing are well outside the scope of this chapter. Many clinical laboratories currently utilize automated chemistry analyzers to perform rapid testing of ethanol on bodily fluids, especially serum or plasma and urine. Proper performance and interpretation of the results require an understanding of the analytical interferences as well as pre- and post-analytical considerations. Beyond ethanol testing, testing of other markers designed to assess ethanol use are also commonly utilized in the clinical laboratory. Ethanol testing has been in use for decades and does not appear to be leaving the clinical laboratory anytime in the near future.