A Response to “Serum-Ethanol Determination: Comparison of Lactate and Lactate Dehydrogenase Interference in Three Enzymatic Assays”

We agree with the authors of a recent article (1) in their belief that the best method for ethanol analysis is gas chromatography. However, we have some comments on the impact of this article on legal proceedings in cases that involve driving under the influence of alcohol. The authors' conclusion was based on postmortem samples and in vitro studies. The only clinical cases described in the article were those related to two patients with chronic liver failure and endstage liver disease; lactate dehydrogenase (LDH) and lactate concentrations were 2379 and 8015 IU/L and 15.4 and 12.3mM, respectively (normal, less than 170 IU/L and 0.7-1.8mM). The authors' conclusion is misleading to law enforcement agencies, attorneys, and even some pathologists because the average individual found driving under the influence or even an intoxicated person with traumatic injury does not match the pathology or the LDH and lactate concentrations described in this article. We would like to caution the forensic toxicology community that such a conclusion does not apply to situations in which an injured driver has received lactated Ringer's solution intravenously prior to having his blood taken for a blood alcohol test. Their in vitro study with nonphysiologic concentrations of lactate and LDH did not apply to a living person. Their approach was not scientifically sound. Table I in the article did not show any case where LDH and lactate concentrations matched the 682 IU/L and 14mM listed in the article. We caution forensic toxicologists that the concentrations in this article did not apply to living subjects who are able to drive a motor vehicle and might apply only to extremely rare clinical situations and postmortem cases. As an aside, we disagree with the authors' comments on gas chromatography. We have never considered gas chromatography to be costly or time consuming.