Venous Blood Alcohol Concentration Research Articles

Comparison of venous blood alcohol concentrations and breath alcohol concentrations measured with Draeger Alcotest 9510 DE Evidential

Most comparisons of blood alcohol concentrations (BAC) and breath alcohol concentrations (BrAC) are either derived from drinking trials with rigid drinking protocols or from investigative authorities’ data with considerable time differences between the determination of BAC and BrAC. In general, only comparisons of relatively low BAC–BrAC pairs are available. Therefore, the relationship between BAC and BrAC was examined even for high BAC above 2g/kg.The results of a large-scale drinking test under realistic conditions with 78 test persons and short time intervals between BAC and BrAC measurements are presented.It was shown that the conversion factor Q varies greatly (between 1571:1 and 2394:1) and increases with increasing BAC. A constant conversion factor that is suitable for variable forensic purposes could not be presented.

Acute alcohol intoxication and bispectral index monitoring.

Bispectral index (BIS) monitoring is commonly used to decrease the risk of awareness during anaesthesia. We aimed to determine the relationship between blood alcohol concentration and brain function (as measured by BIS) in healthy adults. In this prospective observational study, 21 anaesthetic registrars self-regulated alcohol consumption over a 3-h period. Expired alcohol concentration (breathalyser) and BIS measurements were performed hourly for 4h. A venous blood alcohol sample was taken at the conclusion of the study period. The main outcome measures were the correlation between blood alcohol and brain function as measured by BIS and the change in BIS from baseline (∆BIS) at 4h. The median number of standard drinks consumed was 9.1 (IQR 7.7-12.3), range 5.4-17. At 4h, there was a moderate inverse correlation between BIS and blood alcohol (r=-0.49, P=0.029) and between ∆BIS and blood alcohol (r=-0.46, P=0.043). In healthy young adults, we found a moderate correlation between venous blood alcohol concentration and BIS. This suggests that acute alcohol consumption can decrease BIS. This information may be relevant when providing anaesthesia to intoxicated patients who require urgent or time-critical surgery, although certain limitations of this study should be kept in mind.

Assessment of the breath alcohol concentration in emergency care patients with different level of consciousness.

BackgroundMany patients seeking emergency care are under the influence of alcohol, which in many cases implies a differential diagnostic problem. For this reason early objective alcohol screening is of importance not to falsely assign the medical condition to intake of alcohol and thus secure a correct medical assessment.ObjectiveAt two emergency departments, demonstrate the feasibility of accurate breath alcohol testing in emergency patients with different levels of cooperation.MethodAssessment of the correlation and ratio between the venous blood alcohol concentration (BAC) and the breath alcohol concentration (BrAC) measured in adult emergency care patients. The BrAC was measured with a breathalyzer prototype based on infrared spectroscopy, which uses the partial pressure of carbon dioxide (pCO2) in the exhaled air as a quality indicator.ResultEighty-eight patients enrolled (mean 45 years, 53 men, 35 women) performed 201 breath tests in total. For 51% of the patients intoxication from alcohol or tablets was considered to be the main reason for seeking medical care. Twenty-seven percent of the patients were found to have a BAC of <0.04 mg/g. With use of a common conversion factor of 2100:1 between BAC and BrAC an increased agreement with BAC was found when the level of pCO2 was used to estimate the end-expiratory BrAC (underestimation of 6%, r = 0.94), as compared to the BrAC measured in the expired breath (underestimation of 26%, r = 0.94). Performance of a forced or a non-forced expiration was not found to have a significant effect (p = 0.09) on the bias between the BAC and the BrAC estimated with use of the level of CO2. A variation corresponding to a BAC of 0.3 mg/g was found between two sequential breath tests, which is not considered to be of clinical significance.ConclusionWith use of the expired pCO2 as a quality marker the BrAC can be reliably assessed in emergency care patients regardless of their cooperation, and type and length of the expiration.

Comparison of breath-alcohol screening test results with venous blood alcohol concentration in suspected drunken drivers

Hand-held electronic breath-alcohol analyzers are widely used by police authorities in their efforts to detect drunken drivers and to improve road-traffic safety. Over a three month period, the results of roadside breath-alcohol tests of drivers apprehended in Finland were compared with venous blood alcohol concentration (BAC). The mean (median) time between sampling blood and breath was 0.71h (0.58h) with a range from 0 to 6h. Some hand-held instruments gave results as the concentration of alcohol in breath and were converted into BAC assuming a blood–breath alcohol ratio (BBR) of 2260. The mean venous BAC (1.82g/kg) in traffic offenders was higher than the result predicted by the hand-held breath analyzers (1.72g/kg). In 1875 roadside tests, the relationship between venous BAC (x) and BrAC (y) was defined by the regression equation y=0.18+0.85x. The coefficients show both a constant bias (y-intercept 0.18g/kg) and a proportional bias (slope=0.85). The residual standard deviation (SD), an indicator of random variation, was ±0.40g/kg. After BAC results were corrected for the time elapsed between sampling blood and breath, the y-intercept decreased to 0.10g/kg and 0.004g/kg, respectively, when low (0.1g/kg/h) and high (0.25g/kg/h) rates of alcohol elimination were used. The proportional bias of 0.85 shows that the breath-alcohol test result reads lower than the actual BAC by 15% on average. This suggests that the BBR of 2260 used for calibration should be increased by about 15% to give closer agreement between BAC and BrAC. Because of the large random variation (SD±0.40g/kg), there is considerable uncertainty if and when results from the roadside screening test are used to estimate venous BAC. The roadside breath-alcohol screening instruments worked well for the purpose of selecting drivers above the statutory limit of 0.50g/kg.

Examination of Some Performance Characteristics of Breath Alcohol Measurements Obtained with the Intoxilyzer(R) 8000C Following Social Drinking Conditions

The Intoxilyzer 8000C was used to measure breath alcohol concentration (BrAC) in 10 healthy subjects under social drinking conditions. Measurements commenced within 5 min of the end of drinking (EOD). For 14 blood-breath pairs, measured BrACs were compared to corresponding venous blood alcohol concentrations (vBAC) of samples drawn at least 30 min after EOD and within 5 min of the corresponding breath test. BAC was analyzed using an enzymatic method. Concentration differences between breath and blood (BrAC - vBAC) ranged from -32 to +3 mg/dL (untruncated BrAC) and from -32 to -4 mg/dL (truncated BrAC). The Invalid Sample message was actuated in five out of 23 BrAC profiles. In the remaining 18 samples, residual mouth alcohol was evaluated by comparing the maximum difference between successive (5 min apart) measurements (MID5) over 20-30 min after EOD with the precision of replicate BrAC values taken 30-40 min after EOD (5 mg/dL or less; precision unaffected by breath sample volume over the range of 2-3 L). MID5 values occurred within the first three measurements in 16/18 cases, indicative of a significant mouth alcohol effect. Thus, mandatory delays should be used with the Intoxilyzer 8000C prior to testing to minimize the probability of overestimation of BrAC due to mouth alcohol.

Laboratory Evaluation of a New Evidential Breath-Alcohol Analyser Designed for Mobile Testing – the Evidenzer

The Evidenzer is a new kind of forensic breath-alcohol analyser, designed for use both at a police station (stationary) and also in a police vehicle (mobile) at the roadside. In this paper we report the accuracy and precision of the Evidenzer, determined under controlled laboratory conditions. The results were compared with a well-established breath-alcohol instrument (Intoxilyzer 5000S) and also with the concentration of alcohol in venous blood. Twenty healthy volunteers (10 men and 10 women) consumed ethanol (0.4 g/kg) in 15 minutes starting two to three hours after their last meal. Venous blood and breath were obtained for determination of ethanol at 15-30 minute intervals for up to four hours post-dosing. There was a good overall agreement between the two breath-alcohol instruments and the mean bias was only 0.003 mg/L (95% limits of agreement of -0.016 to 0.023 mg/L). The standard deviation (SD) of measuring ethanol in breath was about the same for both instruments, being 0.006 mg/L, and this corresponds to a relative precision or coefficient of variation (CV) of 4.7%. When the Evidenzer was used to analyse ethanol vapour (0.50 mg/L) generated from a wet-bath simulator, i.e. in-vitro conditions, the coefficient of variation was 0.7% indicating high analytical precision. The concentration of ethanol in venous blood and breath were highly correlated (r = 0.95) although systematic differences existed depending on time after drinking when comparisons were made. Both breath-alcohol instruments gave results higher than venous blood alcohol in tests made at 15 minutes after the end of drinking whereas at all later times the venous blood-alcohol concentration was higher

Monitoring Ethanol Exposure in a Clinical Setting by Analysis of Blood, Breath, Saliva, and Urine

Several new technologies have been developed for estimating blood alcohol concentration (BAC), among others, by the analysis of alcohol in saliva specimens. The Q.E.D. is a new quantitative test designed for measuring ethanol in saliva and promising results have been obtained in various experimental settings. In the present study, venous BAC was determined in 28 patients on arrival and when they were discharged from a detoxification unit. The results were compared with breath, saliva, and urine alcohol concentrations. Headspace gas chromatography was used for analysis of ethanol in blood and urine, and breath alcohol was determined with an Alcolmeter S-D2 instrument. The concentration of alcohol in urine was always higher than the BAC (mean difference, 0.62 mg/ml) and individual values were highly correlated (n=42; r=0.92). The handheld breath-alcohol instrument (Alcolmeter S-D2) showed good agreement with venous BAC (n=52; r=0.97; mean difference, 0.04 mg/ml). The saliva-alcohol test failed to perform well in our tests (n=36; r=0.75; mean difference, 0.55 mg/ml) mainly because of problems encountered in obtaining a sufficient sample for analysis in highly intoxicated patients. Because of the relatively low cost of the Q.E.D. ' saliva test, in comparison with a breath alcohol analyzer, the saliva test could be a cost-effective alternative in public health settings where mildly to moderately intoxicated persons are encountered.

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.

Variability of the Blood/Breath Alcohol Ratio in Drinking Drivers

The ratio of blood-alcohol concentration (BAC) to breath-alcohol concentration (BrAC) was determined for 799 individuals apprehended for driving under the influence of alcohol (DUI) in Sweden. The BrAC was determined with an infrared analyzer (Intoxilyzer 5000S) and venous BAC was measured by headspace gas chromatography. The blood samples were always taken after the breath tests were made and the average time delay was 30 +/- 12 min (+/- SD), spanning from 6 to 60 min. The blood/breath ratios of alcohol decreased as the time between sampling blood and breath increased (F = 15.4, p < 0.001), being 2337 +/- 183 (6 to 15 min), 2302 +/- 202 (16 to 30 min), 2226 +/- 229 (31 to 45 min), and 2170 +/- 225 (46 to 60 min). When the BAC was corrected for the metabolism of alcohol at a rate of 0.019 g%/h, the mean blood/breath ratios were 2395 +/- 193 (6 to 15 min), 2416 +/- 211 (16 to 30 min), 2406 +/- 223 (31 to 45 min), and 2407 +/- 210 (45 to 60 min); no significant differences (F = 0.197, p > 0.05). The overall mean time-adjusted blood/breath ratio (+/- SD) was 2407 +/- 213 and the 95% limits of agreement (LOA) were 1981 and 2833. During 1992, 1993, and 1994, the mean blood/breath ratios of alcohol were remarkably constant, being 2409 +/- 288, 2407 +/- 206, and 2421 +/- 235, respectively, and the values were not significantly influenced by the person's age, gender, or blood-alcohol content. In 34 individuals (4.3%), the blood/breath ratio was less than 2100 after compensating for metabolism of alcohol between the times of sampling blood and breath. This compares with 156 individuals (19.6%) having a blood/breath ratio less than 2100:1 without making any correction for the metabolism of alcohol.

Arteriovenous differences of blood alcohol concentrations after celiac plexus block.

After a celiac plexus block with ethyl alcohol, patients sometimes complain of symptoms of alcohol intoxication. We studied the consecutive changes of arterial and venous blood alcohol concentrations in 11 patients and investigated whether an arteriovenous difference exists. We performed a celiac plexus block with 10 ml absolute ethyl alcohol. The sampling sites were radial artery and internal jugular vein. Blood samples were collected at 0, 5, 10, 15, 30, 60, 120, 240 and 480 minutes after the block. The maximum level was reached 15 minutes after injection in both arterial and venous blood, 29.9 +/- 19.4 and 27.7 +/- 21.8 mg/dl (means +/- SD), respectively. Arteriovenous differences were observed 5 and 10 minutes after ethyl alcohol injection (p less than 0.01). There was a significant negative correlation between the ratio of arteriovenous differences to venous sampling and the time elapsed after the block (r = 0.41, p less than 0.01).

Differences between capillary and venous blood-alcohol concentrations as a function of time after drinking, with emphasis on sampling variations in left vs right arm.

Twelve healthy men drank 0.8 g of ethanol per kilogram of body weight during 30 min after an overnight (10 h) fast. At nine exactly timed intervals (30-390 min after the start of drinking), blood was sampled through indwelling catheters in cubital veins on the left and right arms. Immediately thereafter, capillary blood was sampled from fingertips on the left and right hands. The blood ethanol concentration (BAC) was determined by headspace gas chromatography. The SD for alcohol determinations in venous blood, including the left vs right arm sampling variation, was 30 mg/L (range 8.3-83 mg/L), whereas for capillary blood the SD was 35 mg/L (range 11-60 mg/L). This difference much exceeded the purely analytical errors: SD = 2.67 mg/L for venous blood and 14.2 mg/L for fingertip blood. During the first 60 min after the subjects started to drink, capillary BAC exceeded venous BAC, the mean difference at 30 min being 136 mg/L (range 36-216 mg/L). In the postabsorptive state later than 60 min after drinking, venous BAC exceeded capillary BAC [mean difference 58 mg/L (range 0.0-170 mg/L]), the values for venous and capillary BAC crossing 37 min (range 6-77 min) after the end of drinking. Apparently, the source of blood analyzed, venous or capillary, must be considered in clinical pharmacokinetic studies of ethanol.

Accuracy and precision of breath alcohol measurements for subjects in the absorptive state.

Published data are analyzed in order to estimate the accuracy of breath-alcohol measurements for subjects during absorption of orally ingested ethanol. Simultaneous measurements of breath alcohol concentration (BrAC) and venous blood alcohol concentration (VBAC) show that actual VBAC can be overestimated by more than 100% for a significant amount of time after drinking stops. The maximum error found for four individual subjects is +230%, +190%, +60%, and +30%. The magnitude of these errors indicates that results from quantitative evidential breath alcohol analyzers are far less accurate for the absorptive state than they are during the postabsorptive state, but the specifications for accuracy and precision given by manufacturers of these instruments do not reflect this. The results also indicate that there is a significant likelihood that subjects will be in the absorptive state when tested under field conditions. I conclude that estimates of BAC based on BrAC measurements are not reliable in the absorptive state and that the uncertainty associated with such estimates should be accounted for, particularly when the results are used in connection with law enforcement.

Alcohol absorption, gastric emptying and a breathalyser.

1 The value of a portable breathlyser (Alcometer AE-M2) in the assessment of gastric emptying after alcohol ingestion was investigated by comparing breath and venous blood alcohol concentrations with simultaneous scintigraphic measurements of gastric emptying rate. 2 Alcohol absorption, as determined by the area under the venous blood alcohol concentration-time curve during the first 30 min, correlated with gastric emptying during the same period, implying dependence of the rate of alcohol absorption on gastric emptying rate. 3 There was no correlation between breath and venous alcohol concentrations during the first 15 min after alcohol ingestion, but a significant correlation was observed thereafter. 4 Breath alcohol measurements may be sufficient to detect gross alterations in gastric emptying but measurements of venous blood alcohol are likely to be more reliable.

ENHANCEMENT OF ETHANOL TOXICITY BY ETHACRYNIC ACID.

SummaryTreatment with ethacrynic acid increases the lethality of ethanol in mice. Dogs treated with ethacrynic acid and ethanol have higher venous blood alcohol concentrations than those given alcohol alone, Ethacrynic acid has been demonstrated to be a weak in vitro inhibitor of alcohol dehydrogenase. Mechanism of action and possible clinical significance have also been discussed.

ALCOHOL LEVELS IN BODY FLUIDS AFTER INGESTION OF DISTILLED SPIRITS

Known volumes of 70-proof distilled spirits were fed to 68 volunteers, making a total of 141 separate doses. The amount of alcohol appearing in the venous blood, saliva, and urine at various time intervals after ingestion was determined by a modified Widmark method, and in the breath by the Breathalyzer. The relationship between time after ingestion, venous blood alcohol concentration (VBA), and Breathalyzer reading (BR) was as follows:(1) between 0.5 and 2.5 hours after ingestion, VBA = (BR + 0.048) ± 0.124 mg/ml;(2) between 30 to 40 minutes after ingestion, VBA = (BR − 0.071) ± 0.065 mg/ml;(3) between 2 to 2.5 hours after ingestion, VBA = (BR + 0.102) ± 0.117 mg/ml. The weighted average ratios of saliva and urine alcohols to venous blood alcohol were 1.12:1 and 1.24:1, respectively. The standard error of estimating the venous blood alcohol indirectly from the saliva alcohol was ±0.075 mg/ml, and from urine alcohol ±0.081 mg/ml when the samples were obtained from 0.5 to 2.5 and from 0.75 to 2.5 hours after drinking, respectively. Over the range of concentrations studied alcohol disappeared from the venous blood at the rate of 0.13 ±0.05 mg/ml/hr and the quantity eliminated from the whole body, per 100 lb of body weight per hour, approximated 0.4 fl. oz of 70-proof distilled spirits.

ALCOHOL LEVELS IN BODY FLUIDS AFTER INGESTION OF DISTILLED SPIRITS

Known volumes of 70-proof distilled spirits were fed to 68 volunteers, making a total of 141 separate doses. The amount of alcohol appearing in the venous blood, saliva, and urine at various time intervals after ingestion was determined by a modified Widmark method, and in the breath by the Breathalyzer. The relationship between time after ingestion, venous blood alcohol concentration (VBA), and Breathalyzer reading (BR) was as follows:(1) between 0.5 and 2.5 hours after ingestion, VBA = (BR + 0.048) ± 0.124 mg/ml;(2) between 30 to 40 minutes after ingestion, VBA = (BR − 0.071) ± 0.065 mg/ml;(3) between 2 to 2.5 hours after ingestion, VBA = (BR + 0.102) ± 0.117 mg/ml. The weighted average ratios of saliva and urine alcohols to venous blood alcohol were 1.12:1 and 1.24:1, respectively. The standard error of estimating the venous blood alcohol indirectly from the saliva alcohol was ±0.075 mg/ml, and from urine alcohol ±0.081 mg/ml when the samples were obtained from 0.5 to 2.5 and from 0.75 to 2.5 hours after drinking, respectively. Over the range of concentrations studied alcohol disappeared from the venous blood at the rate of 0.13 ±0.05 mg/ml/hr and the quantity eliminated from the whole body, per 100 lb of body weight per hour, approximated 0.4 fl. oz of 70-proof distilled spirits.