Ethanol distribution ratios between urine and capillary blood in controlled experiments and in apprehended drinking drivers.

Healthy men drank 0.51, 0.68, and 0.85 g of ethanol per kilogram of body weight as neat whisky in the morning after an overnight fast. During 6 to 8 h after the whisky was consumed, nearly simultaneous specimens of fingertip blood and pooled bladder urine were obtained for analysis of ethanol using an enzymatic method. The mean ratios of ethanol concentration [urine alcohol concentration (UAC)/blood alcohol concentration (BAC)] were mostly less than unity during the absorption phase. The UAC exceeded the BAC in the postpeak phase. The mean UAC/BAC ratios varied between 1.4 and 1.7 when the BAC exceeded 0.50 mg/mL. When the BAC decreased below 0.40 mg/mL, the UAC/BAC ratios increased appreciably. The mean UAC/BAC ratios of ethanol were not dependent on the person's age between the ages of 20 and 60 years old, but there were large variations within the age groups. In apprehended drinking drivers (N = 654) with a mean BAC of 1.55 mg/mL, the UAC/BAC ratio of ethanol varied widely, with a mean value of 1.49. In 12 subjects (3.2%), the ratio was less than or equal to unity. In a second specimen of urine obtained approximately 60 min after an initial void (N = 135), the mean UAC/BAC ratio was 1.35 (standard deviation = 0.17). The magnitude of the UAC/BAC ratio of ethanol can help to establish whether the BAC curve was rising or falling at or near the time of voiding. The status of alcohol absorption needs to be documented if drinking drivers claim ingestion of alcohol after the offence or when back-estimation of the BAC from the time of sampling to the time of driving is required by statute.     

Ethyl glucuronide concentrations in two successive urinary voids from drinking drivers: relationship to creatinine content and blood and urine ethanol concentrations

The concentrations of alcohol in blood (BAC) and two successive urine voids (UAC) from 100 drunk drivers were compared with the concentration of ethyl glucuronide (EtG), a minor metabolite of ethanol in urine, and the urinary creatinine content as an indicator of dilution. The subjects consisted of 87 men with mean age 42.2+/-14.2 years (+/-standard deviation, S.D.) and 13 women with mean age 42.5+/-14.4 years. Ethanol was measured in blood and urine by headspace gas chromatography (GC) and EtG was determined in urine by liquid chromatography-mass spectrometry (LC-MS). The mean UAC was 2.53+/-1.15g/l for first void compared with 2.35+/-1.17g/l for second void, decreasing by 0.18+/-0.24g/l on average (P<0.001 in paired t-test). The ratios of UAC/BAC were 1.35+/-0.25 for first void and 1.20+/-0.16 for second void and the difference of 0.15+/-0.27 was statistically significant (P<0.001). The UAC/BAC ratio was not correlated with creatinine content of the urine specimens, whereas the concentration of urinary EtG was positively correlated with creatinine (r=0.64 for first void and r=0.62 for second void). The UAC was not correlated with urinary EtG directly (r=-0.03 for first void and r=0.08 for second void) but after adjusting for the relative dilution of the specimens (EtG/creatinine ratio) statistically significant positive correlations were obtained (r=0.58 for first void and r=0.57 for second void). The dilution of the urine, as reflected in creatinine content, is important to consider when EtG measurements are interpreted. The excretion of EtG in urine, like glucuronide conjugates of other drugs, is influenced by diuresis. EtG represents a sensitive and specific marker of acute alcohol ingestion with applications in clinical and forensic medicine.     

Urine/blood ratios of ethanol in deaths attributed to acute alcohol poisoning and chronic alcoholism

The concentrations of ethanol were determined in femoral venous blood (BAC) and urine (UAC) and the UAC/BAC ratios were evaluated for a large case series of forensic autopsies in which the primary cause of death was either acute alcohol poisoning (N=628) or chronic alcoholism (N=647). In alcohol poisoning deaths both UAC and BAC were higher by about 2g/l compared with chronic alcoholism deaths. In acute alcohol poisoning deaths the minimum BAC was 0.74 g/l and the distribution of UAC/BAC ratios agreed well with the shape of a Gaussian curve with mean+/-standard deviation (S.D.) and median (2.5th and 97.5th centiles) of 1.18+/-0.182 and 1.18 (0.87 and 1.53), respectively. In alcoholism deaths, when the BAC was above 0.74 g/l (N=457) the mean+/-S.D. and median (2.5th and 97.5th centiles) UAC/BAC ratios were 1.30+/-0.29 and 1.26 (0.87 and 2.1), respectively. When the BAC was below 0.74 g/l (N=190), the mean and median UAC/BAC ratios were considerably higher, being 2.24 and 1.58, respectively. BAC and UAC were highly correlated in acute alcohol poisoning deaths (r=0.84, residual S.D.=0.47 g/l) and in chronic alcoholism deaths (r=0.95, residual S.D.=0.41 g/l). For both causes of death (N=1275), the correlation between BAC and UAC was r=0.95 and the residual S.D. was 0.46 g/l. The lower UAC/BAC ratio observed in acute alcohol poisoning deaths (mean and median 1.18:1) suggests that these individuals died before absorption and distribution of ethanol in all body fluids were complete. The higher UAC/BAC ratio in chronic alcoholism (median 1.30:1) is closer to the value expected for complete absorption and distribution of ethanol in all body fluids.     

Peak blood-ethanol concentration and the time of its occurrence after rapid drinking on an empty stomach

Healthy men, 20 to 60 years old, drank a moderate dose of ethanol in the morning after an overnight fast. They consumed either neat whisky in amounts corresponding to 0.34, 0.51, 0.68, 0.85, or 1.02 g of ethanol per kilogram of body weight or 0.80 g/kg ethanol solvent diluted with orange juice. The peak blood-ethanol concentration (BEC) increased with the dose administered, but the time required to reach the peak was not markedly influenced over the range of doses studied. At a dose of 0.68 g/kg, the peak BEC ranged from 52 to 136 mg/dL (N = 83), and slow absorption (a late-occurring peak) produced a lower peak BEC. The peak BEC was reached between 0 and 45 min for 77% of the subjects (N = 152) and between 0 and 75 min for 97% of them. The time of peaking in venous blood occurred, on average, 10 min later than in capillary (fingertip) blood although the peak BEC was not appreciably different; the mean venous BEC was 97.0 mg/dL (range, 76 to 112 mg/dL), and the mean capillary BEC was 99.6 mg/dL (range, 75 to 123 mg/dL). When subjects drank 0.80 g/kg ethanol diluted with orange juice over 30 min, the average BEC increment between the end of drinking and the peak was 33 mg/dL (range, 0 to 58 mg/dL). The rate of absorption of ethanol was 1.78 mg/dL/min (range, 0.52 to 4.8 mg/dL/min), and the peak BEC occurred within 60 min after the end of drinking in 92% of the trials. The largest BEC increment (mean, 21 mg/dL; range, 0 to 44 mg/dL) was seen during the first 15 min after the drinking period.     

Relationship between blood and urine alcohol concentrations in apprehended drivers who claimed consumption of alcohol after driving with and without supporting evidence

For various reasons, many people suspected of driving under the influence of alcohol (DUIA) are not apprehended sitting behind the wheel, but some time after the driving. This gives them the opportunity to claim they drank alcohol after the time of driving or after they were involved in a road-traffic crash. Alleged post-offence drinking is not easy for the prosecution to disprove, which often means that the DUIA charge is dropped or the person is acquitted if the case goes to trial. The routine practice of sampling and measuring the concentration of alcohol in blood (BAC) and urine (UAC) and calculating urine/blood ratios (UAC/BAC) and the changes in UAC between two successive voids furnishes useful information to support or challenge alleged drinking after driving. We present here a retrospective case series of DUIA offenders (N = 40) in half of which there was supporting evidence of an after-drink (eye witness or police reports) and in the other half no such evidence existed apart from the suspect's admission. When there was supporting evidence of an after-drink, the UAC/BAC ratio for the first void was close to or less than unity (mean 1.04, median 1.08, range 0.54–1.21) and the UAC increased by 0.21 g/L (range 0.02–0.57) between the two voids. Without any supporting evidence of post-offence drinking the mean UAC/BAC ratio was 1.46 (range 1.35–1.93) for the first void, verifying that absorption and distribution of alcohol in all body fluids and tissues was complete. In these cases, the UAC between successive voids decreased by 0.25 g/L on average (range 0.10–0.49), indicating the post-absorptive phase of the BAC curve. Long experience from investigating claims of post-offence drinking leads us to conclude that in the vast majority of cases this lacks any substance and is simply a last resort by DUIA offenders to evade justice. Unless supporting evidence exists (eye witness, police reports, etc.) of post-offence drinking the courts are encouraged to ignore this defence argument.     

The influence of sex hormones on the elimination kinetics of ethanol

The goal of the investigation was to research the influence of sex hormones on the elimination kinetics of ethanol. Forty-seven healthy men (average age 25+/-6.1 years) and 61 healthy women (average age 24+/-2.4 years) received 0.79-0.95g of ethanol/kg body weight in the form of an alcohol beverage of their choice. The target concentration for both sexes was a blood alcohol concentration (BAC) of 1.10g/kg. Blood samples for the determination of the ethanol concentration followed in the elimination phase in 10-20min intervals. The sex hormone levels (estradiol, progesterone and testosterone) were determined concomitantly from the serum. In men, the mean testosterone concentration was 5.3+/-1.6ng/ml, the mean estradiol concentration was 34.6+/-13.6pg/ml and the mean progesterone concentration was 0.9+/-0.3ng/ml. In women, the mean estradiol concentration was 47.6+/-52.6pg/ml and the mean testosterone concentration was 0.8+/-0.4ng/ml. Progesterone displayed a so-called dummy effect in women. In the high progesterone group (n=11), the mean concentration was 11.1+/-3.5ng/ml and in the low progesterone group (n=50) the mean was 0.6+/-0.3ng/ml. The mean hourly elimination rate (beta60) was 0.1677+/-0.0311g/kg/h in men. In women, the mean hourly elimination rate was 0.2044+/-0.0414g/kg/h in the high progesterone group and 0.1850+/-0.0276g/kg/h in the low progesterone group (p<0.05). The beta60 for women in the low progesterone group was significantly higher than that of the men, whose progesterone levels fell within a similar range (p>0.01). These results allow one to conclude that the gender differences in the pharmacokinetics of ethanol can partly, but not completely, be explained by progesterone levels.     

A pharmacokinetic study of ethyl glucuronide in blood and urine: applications to forensic toxicology

This pharmacokinetic study investigated the kinetics of ethanol and its metabolite ethyl glucuronide (EtG) in blood and urine during the whole time course of absorption and elimination. There are few previous studies on the kinetics of EtG in blood, and we wanted to evaluate whether such knowledge could yield valuable information regarding the time of ethanol ingestion in forensic cases, such as, for instance, drunk driving. Ten male volunteers consumed ethanol at a fixed dose of 0.5 g/kg body weight in a fasted state. Blood samples were collected for 14 h and urine samples were collected for 45-50 h after the start of drinking. EtG reached its maximum concentration (C(max)) in blood after a median of 4 h (range 3.5-5), a median of 3 h (range 2-4.5) after C(max) for ethanol. The ethanol-to-EtG ratios in blood (ethanol in g/L, EtG in mg/L) were >1 only for the first median 3.5 h (range 2.5-3.5) after drinking. EtG elimination occurred with a median half-life of 2.2 h (range 1.7-3.1 h), and the renal clearance was 8.32 L/h (median, range 5.25-20.86). The concentrations of EtG were always much higher in urine than in blood. The total amount of EtG excreted in the urine was median 30 mg (range 21.5-39.7), representing 0.017% (median, range 0.013-0.022) of the ethanol given, on a molar basis. The information from the present study may be a valuable supplement to determine the time of ethanol ingestion. For this purpose, two subsequent increasing EtG values and a high ethanol-to-EtG ratio in blood would support information of recent drinking.     

Concentration-time profiles of ethanol in capillary blood after ingestion of beer.

Blood ethanol profiles were determined in experiments with healthy volunteers after they had drunk beer. When 330 ml of light beer (1.8% w/v ethanol) was consumed in 5 min by four men and four women, the average peak blood-alcohol concentration (BAC) reached was 8 mg/100 ml (range 2-11). After nine men had drunk 660 ml of beer (3.0% w/v or 3.6% w/v ethanol) in 25 minutes on an empty stomach, the average peak BAC was 32 mg/100 ml (range 26-44) and 37 mg/100 ml (range 23-54) respectively. When the same two beers were consumed by another nine men together with a meal, the peak BAC was 24 mg/100 ml (range 20-29) and 28 mg/100 ml (range 20-39) respectively. The peak BAC occurred earlier when beer was ingested together with food; mean 32 min (range 30-50) compared with 41 min (range 30-70) with an empty stomach. The rate of disappearance of alcohol from blood (beta-slope) was 12 mg/100 ml/h in the fed state and 15 mg/100 ml/h when subjects were fasted. The apparent volume of distribution of ethanol (Vd) was 0.65 l/kg (SD 0.07) for the empty stomach condition but exceeded unity when beer was ingested together with food. It seems that part of the dose of alcohol when consumed with food never reaches the systemic circulation.     

Comparison of ethanol concentrations in venous blood and end-expired breath during a controlled drinking study

Concentration-time profiles of ethanol were determined for venous whole blood and end-expired breath during a controlled drinking experiment in which healthy men (n=9) and women (n=9) drank 0.40-0.65 g ethanol per kg body weight in 20-30 min. Specimens of blood and breath were obtained for analysis of ethanol starting at 50-60 min post-dosing and then every 30-60 min for 3-6 h. This protocol furnished 130 blood-breath pairs for statistical evaluation. Blood-ethanol concentration (BAC, mg/g) was determined by headspace gas chromatography and breath-ethanol concentration (BrAC, mg/2l) was determined with a quantitative infrared analyzer (Intoxilyzer 5000S), which is the instrument currently used in Sweden for legal purposes. In 18 instances the Intoxilyzer 5000S gave readings of 0.00 mg/2l whereas the actual BAC was 0.08 mg/g on average (range 0.04-0.15 mg/g). The remaining 112 blood- and breath-alcohol measurements were highly correlated (r=0.97) and the regression relationship was BAC=0.10+0.91BrAC and the residual standard deviation (S.D.) was 0.042 mg/g (8.4%). The slope (0.91+/-0.0217) differed significantly from unity being 9% low and the intercept (0.10+/-0.0101) deviated from zero (t=10.2, P<0.001), indicating the presence of both proportional and constant bias, respectively. The mean bias (BAC - BrAC) was 0.068 mg/g and the 95% limits of agreement were -0.021 and 0.156 mg/g. The average BAC/BrAC ratio was 2448+/-540 (+/-S.D.) with a median of 2351 and 2.5th and 97.5th percentiles of 1836 and 4082. We found no significant gender-related differences in BAC/BrAC ratios, being 2553+/-576 for men and 2417+/-494 for women (t=1.34, P>0.05). The mean rate of ethanol disappearance from blood was 0.157+/-0.021 mg/(g per hour), which was very close to the elimination rate from breath of 0.161+/-0.021 mg/(2l per hour) (P>0.05). Breath-test results obtained with Intoxilyzer 5000S (mg/2l) were generally less than the coexisting concentrations of ethanol in venous blood (mg/g), which gives an advantage to the suspect who provides breath compared with blood in cases close to a threshold alcohol limit.     

The relationship between alcohol elimination rate and increasing blood alcohol concentration--calculated from two consecutive blood specimens

In the period 1991-2005, a blood-alcohol concentration (BAC) analysis was carried out at the Institute of forensic medicine in Novi Sad including 2023 two consecutive blood specimens using the Headspace Gas Chromatography method. Cases with no alcohol concentration values, as well as cases where blood samples were taken within 1 h after the criminal act, were not taken into consideration. Following this rule, 1198 cases were considered in this study and all samples were grouped in 29 ranges of BAC1 of delta(BAC) = 0.1 g/kg, starting from 0.1-0.19 g/kg to 2.9-2.99 g/kg of absolute alcohol. Gathered results and elimination curve differ from the zero-order model of elimination proposed by Widmark and point to an elimination process similar to a well-known Michaelis-Menten elimination kinetics model and its variants. Results reported in this study show dependence of alcohol elimination rate (beta-slope) and BAC value. The analysis of beta60-slope versus BAC shows that a correlation between beta60 (y) and BAC (x) has a logarithmic trend line. The value of alcohol elimination rate shows a slight increment with increase of BAC alcohol, with the mean value of beta60 = 0.221 +/- 0.075 g/kg. Differences in values of beta60 among consecutive intervals of delta(BAC) = 0.1 g/kg are not significant (p>0.05). When obtained samples were grouped into ranges of 0.5 g/kg each in these intervals beta60 had the following values by range: 0.1-0.49 g/kg = 0.139 g/kg +/- 0.035; 0.5-0.99 g/kg = 0.184 g/kg +/- 0.043; 1-1.49 g/kg = 0.213 g/kg +/- 0.052; 1.5-1.99 g/kg = 0.239 g/kg +/- 0.058; 2-2.49 g/kg = 0.265 g/kg +/- 0.073; 2.5-2.99 g/kg = 0.306 g/kg +/- 0.096. Differences in values of beta slope among consecutive intervals of delta(BAC) = 0.5 g/kg are significant (p<0.01). The elimination curve in the BAC interval 0.5-2.5 g/kg has a linear trend, while beta-slope (y)/BAC (x) correlation is given as beta60 = 0.15 g/kg + (0.05 g/kg x BAC). Retrograde calculation of the blood alcohol concentration in tempore criminis (BAC(tc)) based on the determined alcohol concentration in the blood specimen (BAC(t)) shows a statistically significant difference between BAC(tc) calculated using a standard zero-order model versus corrected methodology. The higher the BAC(t) and the longer the calculation time, the greater and statistically more significant (p<0.01) is the difference between the calculated values of BAC(tc).     

Reliability of breath-alcohol analysis in individuals with gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) is widespread in the population among all age groups and in both sexes. The reliability of breath alcohol analysis in subjects suffering from GERD is unknown. We investigated the relationship between breath-alcohol concentration (BrAC) and blood-alcohol concentration (BAC) in 5 male and 5 female subjects all suffering from severe gastroesophageal reflux disease and scheduled for antireflux surgery. Each subject served in two experiments in random order about 1-2 weeks apart. Both times they drank the same dose of ethanol (approximately 0.3 g/kg) as either beer, white wine, or vodka mixed with orange juice before venous blood and end-expired breath samples were obtained at 5-10 min intervals for 4 h. An attempt was made to provoke gastroesophageal reflux in one of the drinking experiments by applying an abdominal compression belt. Blood-ethanol concentration was determined by headspace gas chromatography and breath-ethanol was measured with an electrochemical instrument (Alcolmeter SD-400) or a quantitative infrared analyzer (Data-Master). During the absorption of alcohol, which occurred during the first 90 min after the start of drinking, BrAC (mg/210 L) tended to be the same or higher than venous BAC (mg/dL). In the post-peak phase, the BAC always exceeded BrAC. Four of the 10 subjects definitely experienced gastric reflux during the study although this did not result in widely deviant BrAC readings compared with BAC when sampling occurred at 5-min intervals. We conclude that the risk of alcohol erupting from the stomach into the mouth owing to gastric reflux and falsely increasing the result of an evidential breath-alcohol test is highly improbable.     

Alcohol metabolism of local Chinese in Hong Kong: a statistical determination on the effects of various physiological factors

A study was designed to examine the elimination rate of alcohol from the body of the local Chinese after consumption of different types of alcoholic drinks. The breath alcohol of 184 healthy volunteers was determined and converted into blood alcohol levels after they finished drinking. Information on the type and volume of alcoholic drinks consumed, age group, sex, drinking habit, and drinking on empty stomach or with/after meal was recorded for each participant. The results show that the elimination rate of an individual can be explained in terms of physiological variables including sex and drinking habit. The determined elimination rates allow forensic toxicologists to back calculate the blood alcohol concentration (BAC) of the drivers at the time of accident in drunk driving cases. The elimination rates of blood alcohol at 95% prediction intervals for male and female are in the range of 9.5-23.8 mg/100 ml/h and 11.1-37.1 mg/100 ml/h, respectively.     

Kinetics of ethanol in biological sections

Ethanol concentration in alveolocapillary blood (ACB), venous blood (VB), capillary blood (CB), saliva and urine was measured in healthy men and women aged 19-45 years 20, 40, 60, 90, 120, 180, 240 and 300 min after a single intake of 20% ethanol solution in soda water in a dose 0.8 g/kg body mass. Two types of kinetic curves were established. Calculations with Vidmark equation for different biomedia were made. Ethanol levels in all BM studied coincided in the resorption phase. In the elimination phase, ethanol concentration forms a sequence: ACB < saliva < VB < urine. Correlations and correlation coefficients of ethanol concentrations in different BM were estimated. The ethanol concentration correlation urine/ACB 1.71 +/- 0.15 and VB/ACB 1.45 +/- 0.07 is proposed for use in tests for alcohol intoxication.     

Consumption of a large dose of alcohol in a short time span.

Blood alcohol concentrations (BAC) and time to peak BAC were determined in 16 subjects after ingestion of a large quantity of alcoholic beverages within a short drinking time span not exceeding 30 min. The first group (7 subjects) consumed alcohol after a 3- to 4-h fast. In the second group (9 subjects) the consumption of alcohol took place after eating a large meal. Venous blood samples taken 30 min after drinking finished were compared to the near-simultaneous Breathalyzer results. In addition, the minimum duration of a BAC plateau for these drinking circumstances was assessed.     

酒的种类对乙醇代谢动力学的影响

目的乙醇代谢动力学受诸多因素影响,关于酒的种类对其影响少见报道。方法本研究让志愿者在相同的饮酒时间内,饮用含相同乙醇量的啤酒、白酒,将所得数据用药代动力学计算程序DAS Ver1.0进行处理。结果乙醇的体内过程符合一级吸收、非线性消除、一室模型,权重为1。啤酒与白酒相比,吸收速度快,峰浓度高,达峰时间早,消除速度快。结论酒的种类对乙醇代谢动力学有影响,如果根据乙醇的代谢动力学规律来推测饮酒个体某一时刻的BAC,或根据BAC推测实际饮酒量,应该充分考虑到酒的种类对乙醇代谢动力学的影响。     

Inter- and intra-subject variability in ethanol pharmacokinetic parameters: effects of testing interval and dose

Calculation of a blood alcohol concentration (BAC) at the time of an offence by forward or back-extrapolation, using population average values for ethanol pharmacokinetic parameters or a single estimate of individual specific parameters, ignores the possibility of inter- and intra-subject variability. In order to estimate inter- and intra-subject variability in the elimination rate and absorption rate, BAC was measured over time in 12 male volunteers on 4 occasions. Subjects received 0.44 g kg(-1) body weight of ethanol on the first study day, and 0.70 g kg(-1) body weight on subsequent study days 1, 11 and 12 weeks later, to enable comparisons in variability over short and long time periods and when the same or different doses were administered. Evidence of both inter- and intra-subject variability was found, with inter-subject variability substantially smaller than intra-subject variability when the dose varied. Forensically important differences in pharmacokinetic parameters were observed within individuals between occasions. These findings could have an important impact on medico-legal issues related to ethanol pharmacokinetics.     

Widmark factors for local Chinese in Hong Kong. A statistical determination on the effects of various physiological factors

The Widmark formula has been widely adopted in forensic applications to drink driving cases for the last 70 years. It is known that the amount of alcohol consumed and the body weight of the drinkers are important information for the estimation of blood alcohol concentration (BAC). However, the direct application of the Widmark factors derived from Caucasian to the calculation of BAC for the Chinese population often encounters serious challenges. Owing to this inherent weakness, a thorough analysis to determine the theoretical Widmark factors for the Chinese population, r(0) at the start of drinking and the practical factors, r(peak), at peak BAC was conducted. In the present study, other factors such as gender, stomach condition and other physiological conditions are taken into account. The determined theoretical Widmark factors, r(0,) for local Chinese male and female are 0.68 and 0.59 (with BAC in the units of weight/volume), respectively, demonstrating the applicability of the Widmark formula to the Chinese population. The practical factors at peak BAC, r(peak), were also determined to serve the forensic purpose of refuting the "hip-flask" defence in drink driving cases. Findings show that gender and stomach condition are the key factors that could statistically explain the variability of both r(0) and r(peak).     

论道路交通事故与驾驶员血中酒精含量关系

目的探讨道路交通事故与饮酒驾车血中酒精含量关系及其法医学意义,为预防、控制道路交通事故提供重要依据。方法对2005份道路交通事故肇事驾驶员血酒精鉴定资料进行系统分析性研究。结果饮酒驾车以男性为主,女性饮酒驾车出现醉酒驾车的比例与男性无差别。市区驾驶员醉酒驾车高于郊区。驾驶员BAC<20mg/100mL肇事导致死亡的比例高于饮酒驾车肇事组(BAC20￣79mg/100ML),而BAC≥80mg/100mL则低于饮酒驾车肇事组。结论应降低饮酒驾车和醉酒驾车BAC标准,以利于减少交通事故肇事死亡率。     

Interpreting results of ethanol analysis in postmortem specimens: a review of the literature

We searched the scientific literature for articles dealing with postmortem aspects of ethanol and problems associated with making a correct interpretation of the results. A person's blood-alcohol concentration (BAC) and state of inebriation at the time of death is not always easy to establish owing to various postmortem artifacts. The possibility of alcohol being produced in the body after death, e.g. via microbial contamination and fermentation is a recurring issue in routine casework. If ethanol remains unabsorbed in the stomach at the time of death, this raises the possibility of continued local diffusion into surrounding tissues and central blood after death. Skull trauma often renders a person unconscious for several hours before death, during which time the BAC continues to decrease owing to metabolism in the liver. Under these circumstances blood from an intracerebral or subdural clot is a useful specimen for determination of ethanol. Bodies recovered from water are particular problematic to deal with owing to possible dilution of body fluids, decomposition, and enhanced risk of microbial synthesis of ethanol. The relationship between blood and urine-ethanol concentrations has been extensively investigated in autopsy specimens and the urine/blood concentration ratio might give a clue about the stage of alcohol absorption and distribution at the time of death. Owing to extensive abdominal trauma in aviation disasters (e.g. rupture of the viscera), interpretation of BAC in autopsy specimens from the pilot and crew is highly contentious and great care is needed to reach valid conclusions. Vitreous humor is strongly recommended as a body fluid for determination of ethanol in postmortem toxicology to help establish whether the deceased had consumed ethanol before death. Less common autopsy specimens submitted for analysis include bile, bone marrow, brain, testicle, muscle tissue, liver, synovial and cerebrospinal fluids. Some investigators recommend measuring the water content of autopsy blood and if necessary correcting the concentration of ethanol to a mean value of 80% w/w, which corresponds to fresh whole blood. Alcoholics often die at home with zero or low BAC and nothing more remarkable at autopsy than a fatty liver. Increasing evidence suggests that such deaths might be caused by a pronounced ketoacidosis. Recent research has focused on developing various biochemical tests or markers of postmortem synthesis of ethanol. These include the urinary metabolites of serotonin and non-oxidative metabolites of ethanol, such as ethyl glucuronide, phosphatidylethanol and fatty acid ethyl esters. This literature review will hopefully be a good starting point for those who are contemplating a fresh investigation into some aspect of postmortem alcohol analysis and toxicology.     

The association of alcohol-induced blackouts and grayouts to blood alcohol concentrations

The primary aim of this study was to investigate the association between measured blood alcohol concentration (BAC) and the presence and degree of amnesia (no amnesia, grayout, or blackout) in actively drinking subjects. A secondary aim was to determine potential factors other than BAC that contribute to the alcohol-induced memory loss. An interview questionnaire was administered to subjects regarding a recent alcohol associated arrest with a documented BAC greater than 0.08 g/dL for either public intoxication, driving under the influence, or under age drinking was administered. Demographic variables collected included drinking history, family history of alcoholism, presence of previous alcohol-related memory loss during a drinking episode, and drinking behavior during the episode. Memory of the drinking episode was evaluated to determine if either an alcohol-induced grayout (partial anterograde amnesia) or blackout (complete anterograde amnesia) occurred. Differences in (1) mean total number of drinks ingested before arrest, (2) gulping of drinks, and (3) BAC at arrest were found for those having blackouts compared with no amnesia; while differences in drinking more than planned were found between the no amnesia and grayout groups. A strong linear relationship between BAC and predicted probability of memory loss, particularly for blackouts was obvious. This finding clinically concludes that subjects with BAC of 310 g/dL or greater have a 0.50 or greater probability of having an alcoholic blackout.