Kronstrand Christoffer, Nilsson Gunnel, Chermà Maria D, Ahlner Johan, Kugelberg Fredrik C, Kronstrand Robert
Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden.
Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden; Division of Drug Research, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
Forensic Sci Int. 2019 Jan;294:189-195. doi: 10.1016/j.forsciint.2018.11.014. Epub 2018 Nov 26.
Driving under the influence of alcohol is a major problem for traffic-safety and a popular defence argument is alleged consumption after driving, commonly referred to as the hip-flask defence. Forensic toxicologists are often called as expert witnesses in drinking and driving cases where the suspect has claimed the hip-flask defence, to assess the credibility of the explanation. Several approaches to help the expert have been introduced but the scientific data used to support or challenge this is solely based on data from controlled single doses of ethanol administered during a short time and in abstinent subjects. In reality, we believe that even in drinking after driving cases, the subject many times has alcohol on board at time of the hip-flask drink. This questions the applicability of the data used as basis to investigate the hip-flask defence. To fill this knowledge gap, we aimed to investigate how blood and urine ethanol kinetics vary after an initial drinking session of beer and then a subsequent hip-flask drink of three different doses of whiskey. Fifteen subjects participated in the study and each provided 10 urine samples and 17 blood samples over 7h. The initial drink was 0.51g ethanol/kg and the second was either 0.25, 0.51, or 0.85g/kg. Our data suggested that the difference between the ethanol concentrations in two consecutive urine samples is a more sensitive parameter than the ratio between urine and blood alcohol to detect a recent intake when ethanol from previous intakes are already present in the body. Twelve subjects presented results that fully supported a recent intake using the criteria developed from a single intake of ethanol. Three subjects showed unexpected results that did not fully support a recent intake. We conclude that data from one blood sample and two urine samples provide good evidence for investigating the hip-flask defence even if alcohol was on board at the time of the hip-flask drink.
酒后驾车是交通安全的一个主要问题，一种常见的辩护理由是声称在驾车后饮酒，通常被称为“小酒瓶抗辩”。在嫌疑人提出“小酒瓶抗辩”的酒驾案件中，法医毒理学家常被传唤为专家证人，以评估该解释的可信度。已经引入了几种帮助专家的方法，但用于支持或质疑这一说法的科学数据仅基于在短时间内给戒酒的受试者单次服用乙醇的对照数据。实际上，我们认为即使在驾车后饮酒的案件中，受试者在饮用小酒瓶中的酒时体内很多时候已经有酒精了。这就质疑了用作调查“小酒瓶抗辩”依据的数据的适用性。为了填补这一知识空白，我们旨在研究在最初饮用啤酒后，再饮用三种不同剂量威士忌的小酒瓶酒，血液和尿液中的乙醇动力学是如何变化的。15名受试者参与了该研究，每人在7小时内提供了10份尿液样本和17份血液样本。最初饮用的乙醇量为0.51克/千克，第二次饮用的量分别为0.25、0.51或0.85克/千克。我们的数据表明，当体内已经存在先前摄入的乙醇时，连续两份尿液样本中乙醇浓度的差异比尿液与血液酒精含量的比值是检测近期饮酒的更敏感参数。12名受试者的结果完全支持根据单次摄入乙醇制定的标准来判定近期饮酒。3名受试者的结果出人意料，不完全支持近期饮酒的判定。我们得出结论，即使在饮用小酒瓶中的酒时体内已有酒精，一份血液样本和两份尿液样本的数据也能为调查‘小酒瓶抗辩’提供有力证据。
