Evaluating alleged drinking after driving--the hip-flask defence. Part 2. Congener analysis

The second part of this review describes the principles and practice of forensic congener analysis as an alternative way to evaluate claims of drinking alcohol after driving. Congener analysis was developed, perfected and practised in Germany as a way to evaluate hip-flask defences. This kind of defence challenge arises frequently when the drunk driving suspect is not apprehended at the wheel and especially after hit-and-run incidents. Besides ethanol and water, alcoholic beverages contain trace amounts of many other low-molecular substances, known collectively as the congeners, which impart the characteristic smell and taste to the drink. Importantly, the congener profile can be used to identify a particular kind of alcoholic beverage. Forensic congener analysis entails making a qualitative and quantitative analysis of ethanol, methanol, n-propanol and the isomers of butanol in blood and urine from the apprehended driver and comparing the results with the known congener profile of the alcoholic beverage allegedly consumed after driving. Interpreting the results of congener analysis requires knowledge about the absorption, distribution and elimination pattern of the congener alcohols, including their oxidation and conjugation reactions, and any metabolic interactions with ethanol. Complications arise if drinks with widely different congener profiles are consumed or if the same beverage was ingested both before and after driving. Despite these limitations, congener analysis can furnish compelling evidence to challenge or support claims of drinking alcohol after driving.     

"Cognac alibi" as a drunk-driving defense and medico-legal challenge

Some drivers with positive forensic ethanol analyses, offer an explanation that they consumed alcohol a short time before a traffic accident or after driving. In medico legal practice this is commonly known as hip-flask defense, but to us as "cognac alibi" defense. In these cases, the lawyers require the medico legal experts to offer as much information as possible so that the court may come to the most reliable conclusions about the driver's blood alcohol concentration at the moment of the traffic accident (BAC(Acc)). At the Institute of Forensic Medicine our own analytical approach was established to study this medico legal problem. It consists of three inter-related phases in which it combines the obtained BAC values, with testimonies of the drunk driving suspect andalso witnesses. A specific algorithm was designed for calculating absorption and elimination of consumed alcohol. All the above-mentioned elements and blood-ethanol values calculated according to Widmark's method were inserted into appropriate cells of MS Excel software in order to calculate BAC in the function of time. The result is a relevant analysis of the drunk driving suspect's BAC in 5-minute intervals, as well as a graphic representation in chart form.     

Top ten defence challenges among drinking drivers in Sweden.

This paper gives a review and opinion about defence challenges arising during the prosecution of drinking drivers in Sweden. The statutory limit of blood-alcohol concentration (BAC) is two-tiered; 0.2 mg/g (21 mg/100 ml) and 1.5 mg/g (159 mg/100 ml). In rank order of occurrence, the top ten defence challenges are shown in Table I. The hip-flask defence occurs in more than 90% of all challenges. Because the burden of proof in Swedish law rests on the prosecution, the charge of driving under the influence of alcohol is often dropped when alleged drinking after the offence is an issue.     

Treffsicherheit der Berechnung der Tatzeitblutalkoholkonzentration in Nachtrunkkonstellationen

Background

The calculation of a detectable minimum or maximum blood alcohol concentration (BAC) in the legal sense follows rules based on the basic principle of in dubio pro reo. In traffic law the question of the minimum detectable BAC is often asked in a situation concerning an irrefutable hip flask defence. In this situation the legal principle of in dubio pro reo currently requires the extreme upper and lower values to be included in the calculation, even if this is very problematic from a pharmacokinetic aspect.

Aim

The study aimed to estimate the accuracy of BAC calculations in hip flask defence constellations.

Material and methods

Drinking experiments were carried out with 55 volunteer subjects to simulate a hip flask defence constellation. In group 1 (n?=?32) a large amount of alcohol was drunk before the theoretical offence followed by a small amount of alcohol after the event and in group 2 (n?=?23) a small amount of alcohol was drunk before the theoretical offence followed by a large amount of alcohol after the event. In group 1 there was a time lapse of approximately 60 min between drinking before and after the theoretical event and of 30 min between the two alcohol intake times in group 2. Within this lapse of time, a particular time for the alleged offence was defined shortly before the start of the second alcohol intake. A back calculation to the theoretical time of the offence was performed starting from two fictive points in time of blood sampling of 120 min after the last alcohol intake before the offence occurred. The results of the back calculation were compared with the values measured at the theoretical time of the event.

Results

In most cases the estimated results of the back calculation were approximately 0.05 g alcohol/kg body weight lower than the measured values; however, in three male subjects the back calculation was higher than the analysis values.

Conclusion

The well-established equations for back calculation of the BAC at the time of the event lead to false estimations where resorption is greatly prolonged or where diffusion is drastically affected. However, overestimation can be justified due to a strong resorptive phase and in cases of extreme underestimation this at least does not lead to a disadvantage for the affected individual. The comparatively few miscalculations do not fundamentally cast doubt on the basic principles for estimating the amount of alcohol consumed after an offence. It could be shown that this concerns cases where the amount of alcohol present in the subject’s body, formulated according to current legislation, would have led to a clearly higher blood alcohol concentration irrespective of the alcohol consumed after the offence.     

Alcohol study on blood concentration estimation: Reliability and applicability of Widmark formula on Chinese male population

Widmark formula suggests estimating blood alcohol concentration level (BAC) on a given amount of alcohol administrated with knowledge of subject’s body weight and sex. The idea has been referenced extensively in forensic science with application in drink driving prosecution. A sample of Chinese subjects was collected in the drinking experiment, and in this study we mainly focus on the verification of the validity of Widmark formula on Chinese male population. A promising result is obtained where the extrapolated BAC measurement is directly proportional to the amount of alcohol administrated, and inversely to the subject’s body weight. The results noted in the general linear model is further supported by the nonlinear regression analysis and a concordant argument reaches by deploying the concept to the BAC level attained at peak.     

Professional pilots' evaluation of the extent, causes, and reduction of alcohol use in aviation.

Pilots holding the ATP rating were surveyed to obtain judgments concerning the seriousness of the alcohol problem in various areas of aviation, the reasons for alcohol use, and the probable effectiveness of strategies intended to reduce alcohol use in aviation. Alcohol use was judged to be a more serious problem in general aviation than in corporate, charter, regional, and major airline activities. Respondents identified the individual's inability to control alcohol use as a primary reason for drinking and flying, and they endorsed remedies that are directed toward those individuals who are seen as the source of the problem. Other factors considered important causes of drinking and flying included pilots' beliefs that they can compensate for alcohol's effects and their lack of knowledge about the rate of decrease in blood alcohol concentration (BAC) that occurs as a function of time and amount consumed.     

Problems in blood alcohol testing of severely injured drivers brought to emergency departments in Japan

Breath alcohol tests are widely used to control DUI (driving under the influence) in Japan. However, this test is not applied to injured drivers transported to emergency hospitals. In such cases, BAC (blood alcohol concentration) testing should be done to prove DUI. In this paper, we tried to clarify two important issues on the BAC testing in Japan using a questionnaire survey and experiments about contamination of antiseptic ethanol. First, we have described the doctor's dilemma with DUI cases; our present questionnaire survey showed that the police often request the doctor to volunteer blood samples of the suspected drunk drivers brought to emergency hospitals since they have not been granted the right to order blood sampling in Japan. Then, doctors face a serious dilemma whether comply with the police request or not, resulting in widely different responses. Secondly, we have estimated the effects of antiseptic ethanol routinely used as a dermal antiseptic on the BAC tests. Our present experiments showed that uptake of ethanol can occur under certain conditions. Given the actual conditions outlined in the questionnaire, there seem to be a definite risk of ethanol contamination in BAC testing. Obviously, the time has come to discuss problems in BAC testing of injured drivers brought to emergency hospitals in Japan.     

On determining the relationship between blood alcohol concentration and smooth pursuit eye movements

Residual impairment after alcohol consumption implies that the relationship between blood alcohol concentration (BAC) and deficits in performance of some task is not the same when becoming intoxicated as it is when returning to sobriety. A pilot study was performed to determine the feasibility of and the appropriate methodology for studies on residual impairment of smooth pursuit performance. Four subjects consumed alcohol for 2 h. Measurements of BAC and smooth pursuit eye movements were made every 30 min during drinking and for 4 h after drinking. Pursuits were elicited by having subjects track a sinusoidal target (0.40 Hz and 0.60 Hz) for 10 s. Impairment of smooth pursuit was quantified with frequency analysis scores. Frequency analysis scores declined as BAC increased. As BAC decreased, frequency analysis scores tended to increase toward pre-drink levels. The relationship between BAC and frequency analysis score was not significantly different on the ascending and descending limbs of the blood alcohol curve. However, the idea that residual impairment does not occur could not be conclusively demonstrated for several reasons. First, as BAC returned to pre-drink levels, frequency analysis scores were inconsistent for each subject perhaps because of boredom and fatigue. Second, the relationship between BAC and frequency analysis score varied between subjects. Finally, because the recording periods were short, the effect of alcohol on sustained attention could not be assessed. In this paper, potential artifacts in studies of residual impairment of pursuits are discussed and potential solutions to the methodological problems encountered in the pilot study are provided.     

Determination of phosphatidyl ethanol (PEth) 16:0/18:1 in dried blood samples of drivers involved in traffic accidents: A pilot study

In routine forensic toxicology practices, blood alcohol concentration (BAC) levels are measured in traffic accidents that ended up in emergency departments. Nevertheless, since the elimination of ethanol from the blood is fast and the detection time is short, BAC cannot indicate the occurrence of chronic excessive alcohol consumption. Phosphatidylethanol (PEth) is a unique ethanol direct biomarker that occurs only in the presence of phospholipase D enzyme in erythrocyte membranes during alcohol intake, and it indicates alcohol intake.In this study, both whole blood and dried blood samples were collected from 50 patients who were admitted to Cukurova University Hospital Emergency Department due to a traffic accident. While studying BAC in whole blood samples, PEth 16:0/18:1 analysis was performed on dried blood samples by LC-MS/MS.According to the BAC (50 mg/dL) value, the legal limit in Turkey, the optimal threshold PEth 16:0/18:1 value was set as 160 ng/mL and over. This study determined that 15 people with above PEth 16:0/18:1 concentrations above 160 ng/mL were classified as excessive alcohol consumption.The data obtained in this study showed a positive correlation between BAC and PEth concentration when driving under the influence of ethanol.     

The effect of blood in the oral cavity on breath alcohol analysis

The theory that blood (containing alcohol) present in the oral cavity may falsely increase breath analysis recently led to a successful appeal against a drink driving conviction. Subjects who had previously consumed vodka (37.2% alc/vol), at 30 ml/10 kg and reached a BAC (blood alcohol concentration) of between 0.05 and 0.10% were then given four oral solutions consisting of a control (distilled water), and 0.05, 0.10 and 0.15% aqueous alcohol (ethanol) solutions, administered in coded form. A four-way cross-over, blind, randomized assay was conducted with the solutions, with breath analyses conducted in the presence or absence of solution in the mouth. The first trial group (n = 18) received 2 ml of solution, and we found that the simulated 0.15, 0.10 and 0.05% alcohol solutions in the mouth produced BAC reading increases of 0.0088 +/- 0.0014, 0.0062 +/- 0.0008 and 0.0055 +/- 0.0010% respectively (p < 0.001). The second trial group (n = 20) received 1 ml of solution and produced BAC reading increases of 0.0047 +/- 0.0011 (p < 0.001), 0.0023 +/- 0.0008 (p < 0.01) and 0.0020 +/- 0.0006% (p < 0.05) respectively. In conclusion, these studies indicate that small volumes of blood (containing alcohol) in the mouth would not have a practical effect on breath analysis readings.     

Alkoholbedingte Fahruntüchtigkeit

The judgement and evidence on offences related to alcohol impaired driving by expert witnesses essentially relates to the following areas: the analysis of blood and breath alcohol, back calculation of blood alcohol concentrations (BAC) to the time of the offence, absconding after an accident, and calculation and judgement of post-offence drinking, including congener analysis, calculation of BAC from consumption statements, judgment of relative driving inability and responsibility in case opinion on functional and metabolic alcohol tolerance, alcohol abuse and medical psychological investigation. Relevant basics of alcohol physiology (“ethanology”) and of widely accepted forensic standards are presented.     

Ultra-rapid rate of ethanol elimination from blood in drunken drivers with extremely high blood-alcohol concentrations

The rate of alcohol elimination from blood was determined in drunken drivers by taking two blood samples about 1 h apart. These cases were selected because the individuals concerned had reached an extremely high blood-alcohol concentration (BAC) when they were apprehended. This suggests a period of continuous heavy drinking leading to the development of metabolic tolerance. Use of double blood samples to calculate the elimination rate of alcohol from blood is valid provided that drunken drivers are in the post-absorptive phase of the BAC curve, the time between sampling is not too short, and that zero-order elimination kinetics operates. Evidence in support of this came from other drunken drivers in which three consecutive blood samples were obtained at hourly intervals. The mean BAC (N = 21) was 4.05 g/l (range, 2.71–5.18 g/l), and the average rate of alcohol elimination from blood was 0.33 g l⁻¹ h⁻¹ with a range of 0.20–0.62 g l⁻¹ h⁻¹. The possibility of ultra-rapid rates of ethanol elimination from blood in drunken drivers having extremely high BAC deserves to be considered in forensic casework, e.g., when retrograde extrapolations and other blood-alcohol calculations are made. The mechanism accounting for more rapid metabolism is probably related to induction of the microsomal enzyme (CYP2E1) pathway for ethanol oxidation, as one consequence of continuous heavy drinking. However, the dose of alcohol and the duration of drinking necessary to boost the activity of CYP2E1 enzymes in humans have not been established.     

Assistance of ethyl glucuronide and ethyl sulfate in the interpretation of postmortem ethanol findings

Postmortem ethanol formation is a well-known problem in forensic toxicology. The aim of this study was to interpret findings of ethanol in blood, in a large collection of forensic autopsy cases, by use of the nonoxidative ethanol metabolites, ethyl glucuronide (EtG), and ethyl sulfate (EtS). In this study, according to previously published literature, antemortem ethanol ingestion was excluded in EtS-negative cases. Among 493 ethanol-positive forensic autopsy cases, collected during the study period, EtS was not detected in 60 (12 %) of the cases. Among cases with a blood alcohol concentration (BAC) of ≤0.54 g/kg, antemortem ethanol ingestion was excluded in 38 % of the cases, while among cases with a BAC of ≥0.55 g/kg, antemortem ethanol ingestion was excluded in 2.2 % of the cases. For all cases where ethanol was measured at a concentration >1.0 g/kg, EtS was detected. The highest blood ethanol concentration in which EtS was not detected was 1.0 g/kg. The median concentrations of EtG and EtS in blood were 9.5 μmol/L (range: not detected (n.d.) 618.1) and 9.2 μmol/L (range: n.d. 182.5), respectively. There was a statistically significant positive correlation between concentration levels of ethanol and of EtG (Spearman’s rho?=?0.671, p?p?相似文献   

Acetonaemia as an initial criterion of evaluation of a probable cause of sudden death

The archived head-space chromatograms of ethanol determinations in autopsy blood in the years 1996-2003 were analysed. One hundred and two cases with elevated acetone level >250mmol/l were selected in which the biochemical profiles of volatile alcohols (methanol, isopropanol and n-propanol) were determined after "post-hoc" calibration of the constant internal standard. Based on the files obtained from the Prosecutor's Office, the circumstances of death and those preceding death (alcoholism, prolonged or single consumption of alcohol, intoxications with other substances, hypothermia, undernourishment, diabetes) were analysed and the most probable cause of endogenous or exogenous ketonaemia were determined. All cases of unexplained deaths in alcoholics with the ethanol concentration <0.4g/l occurred after withdrawal of long-term consumption of alcohol while all alcoholics with the ethanol concentration >0.4g/l died during the so-called drinking bout. In the group of hypothermia-related deaths with ethanol concentrations <0.4g/l, the acetone concentration was statistically significantly higher than that in hypothermia group with ethanol concentration >0.4g/l in which "congeneric" concentrations of methanol and isopropanol were additionally observed. Furthermore, an algorithm of further diagnostic management was suggested to distinguish the most likely origin of acetonaemia, i.e. accumulation of exogenous "denaturants" of alcohol consumed and cases of endogenous ketogenesis.     

Measurement of direct ethanol metabolites in a case of a former driving under the influence (DUI) of alcohol offender,now claiming abstinence

A 37-year-old female subject had been convicted of driving under the influence of alcohol, and 19 months later, claimed abstinence after supervised disulfiram treatment. Our aim was to elucidate the value of direct ethanol metabolites as measures of abstinence. Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE) in hair, phosphatidylethanol in whole blood and EtG and ethyl sulphate in urine were measured. The results were compared with self-report of alcohol consumption and traditional blood biomarkers for chronically elevated alcohol consumption as carbohydrate deficient transferrin (CDT), gamma glutamyl transpeptidase, mean corpuscular erythrocyte volume, aspartate aminotransferase and alanine aminotransferase. EtG was found in distal parts of hair only, whereas the proximal parts were negative. Furthermore, FAEE concentrations were found in the typical distribution over the hair length and showed values typical for either moderate social drinking or abstinence. CDT was above cut-off in 9 out of 16 analyses with a decreasing tendency and the lowest values in the last 2 months before the end of sampling. The data suggest that in addition to traditional markers, a combination of direct ethanol metabolites can be useful in the expert assessment of judging driving ability. A careful individual interpretation of the results for the different markers, however, is an absolute necessity.     

Pilots' knowledge of blood alcohol levels and the 0.04% blood alcohol concentration rule

A national sample of licensed pilots was surveyed regarding their knowledge of the Federal Aviation Administration's (FAA) 0.04% blood alcohol concentration (BAC) limit, the relationship between the number of drinks and BAC, and the manner in which BAC decays with time. A majority of the 1039 respondents were unaware of the 1985 0.04% BAC rule change. In addition, many lacked an understanding of the relationship between the amount of alcohol consumed and the resulting BAC, and of the rate at which BAC decays. The number of drinks necessary to raise BAC to specific levels was frequently overestimated, and the amount of time necessary for BAC to decay was frequently underestimated. These errors were more pronounced for moderate and heavy drinkers than for abstainers and infrequent drinkers. These results suggest that pilots could have difficulty if they attempt to use the 0.04% BAC value as a guide to safety in their flying activities.     

Correlation between postmortem ethanol levels in the blood and the testicle

Summary This study emphasizes the value of the presence of ethanol in the testicle. It proves particularly useful in cases where blood and urine are no more present in the body.In 633 cases where blood or urine were still available, a highly positive correlation between the blood alcohol and the amount of alcohol present in the testicle could be demonstrated, thus confirming the research carried out in the Department of Legal Medicine as far back as 1943.An attempt is further made to assess the possible influence of such factors as putrefaction, submersion or post-traumatic anemia on this correlation.Presented at the 9th Meeting of the International Association of Forensic Sciences, Bergen/Norway, June 1981     

Diagnostic meaning of urinary ethyl glucoside concentrations in relationship to alcoholic beverage consumption

Incidents and accidents often involve the drinking of alcoholic beverages. We investigated compounds that indicate the consumption of alcoholic beverages even after ethanol (EtOH) becomes undetectable in blood and urine. Ethyl glucoside (EG) has been isolated as a possible drinking marker, and a GC–MS/MS method for EG isomers has been developed. EG isomers in several alcoholic beverages were analyzed. In sake, only αEG was observed in high concentrations. In wine and beer, both α and βEG were detected. Whisky, however, did not contain EG. EtOH and EG concentrations were analyzed in urine up to 48 h after ingestion. Maximum EtOH concentrations were reached in 1–2 h and was mostly eliminated in 6 h. Maximum EG concentrations were reached in 3–6 h, gradually decreased, and remained low after 24 h. After drinking sake, the αEG concentrations were much higher than that of other alcoholic beverages. After drinking wine or beer, βEG was detected, but lower than αEG. Also, αEG was detected in urine after drinking whisky that contained no EG. This suggested that αEG may be synthesized in vivo. Disaccharide-degrading enzymes such as α-glucosidase are present in the human small intestine. It was considered that αEG was synthesized when alcohol was consumed with certain foods, such as carbohydrates. In actual forensic autopsy cases, EtOH and EG isomer analysis provided useful information regarding drinking history. In conclusion, it is considered that urinary EG isomers can be used as drinking markers that complement EtOH analysis.     

Survey of pilots' attitudes and opinions about drinking and flying

A mailed questionnaire was used to obtain biographic, attitude, and reported behavioral data from pilots with regard to consumption of alcoholic beverages and flying. A 40.8% return of 835 mailings was obtained. Only 12 pilots reported having flown after drinking. Approximately 50% of the respondents indicated it would be safe to fly within 4 h after drinking some amount of alcoholic beverage. Based upon alcohol absorption and oxidation rates, it was estimated that 27-32% of the respondents considered flying after drinking, within a time period which would result in a 15mg% BAC or higher, to be safe behavior. Discriminant analysis showed liquor consumption and opinions regarding number of mixed drinks which could safely be consumed within 1 h before flying would correctly classify 67.5% of the respondents in terms of attitude toward drinking and flying.