DUI Professional is the most advanced blood alcohol extrapolation simulator in the world. Presets exist for almost all senarios but may be modified in the simulator by toxicologists and expert witnesses.
Ethanol is absorbed primarily in the small intestine. Although there is some absorption from the stomach, it is significantly slower than that from the intestine. Accordingly, the presence of food in the stomach will delay the absorption of ethanol. Thus, the resulting peak alcohol levels will generally be lower for most drinking patterns. DUI Pro uses the following absorption rates as default settings:
These rates may be modified.
Higher ethanol concentrations in the gastrointestinal tract cause a greater concentration gradient and therefore hasten the rate of absorption. The absorption process continues until the alcohol concentration in the blood and that in the gastrointestinal tract are at equilibrium.
Once ethanol reaches the systemic circulation it is immediately distributed to other body compartments at a rate proportional to the blood now to that area and is eventually distributed equally to total body water. Because the brain receives a rapid blood now, high concentrations in the brain are achieved rapidly. Deitrich, Richard, Palmer, John D. Human Pharmacology, Molecular to Clinical. , pg. 426 (Mosby, 1994).
Peak blood-alcohol levels can vary between different types of alcoholic beverages. The following results were published in B. O'Neill, A.F. Williams & KM. Dubowski, Variability in Blood Alcohol Concentration: Implications for Estimating Individual Results, 44:2 J. Stud. on Alcohol 228 (1983):
Drink | Average Peak BAC% | Time to Peak |
---|---|---|
Beer | 0.093% (w/v) | 40 minutes |
Champagne | 0.094% (w/v) | 52 minutes |
Mixed Whiskey | 0.091 % (w/v) | 37 minutes |
Straight Whiskey | 0.102% (w/v) | 35 minutes |
BAC | % Viewed as Drunk |
---|---|
0 to .05 | 10% |
.051 to .010 | 34% |
.101 to .150 | 64% |
.151 to .200 | 86% |
.201 to .250 | 96% |
.251 to .300 | 99% |
.301 to .350 | 99% |
.351 to .400 | 89% |
Above .400 | 100% |
Ethyl Alcohol, in 2 Toxicology 110 (Academic Press 1961)
Men = 0.73
Women = 0.63
Maximum "r" = 0.73 + (2 x 0.067) = 0.864
Minimum "r" = 0.73 - (2 x 0.067) = 0.596
Maximum "r" = 0.66 + (2 x 0.082) = 0.824
Minimum "r" = 0.66 - (2 x 0.082) = 0.496
K. Dubowski published the following values in Human Pharmacokinetics of Ethanol. I. Peak Blood Alcohol Concentrations and Elimination in Male and Female Subjects, 5:4 Alcohol Technical Rep. 55-63 (1976):
Dubowski's values are used as the default settings in DUI Professional.
Alcohol is primarily eliminated by the liver by enzymatic oxidation. Less than 10% is excreted from breath, perspiration and urine. In most calculations, the standard elimination rate for most individuals is 0.015% per hour. However, this rate may vary between individuals. Studies by Widmark, Dubowski and Watson have all confirmed a mean 0.015% elimination rate.
In a study by Winek and Murphy (C.L. Winek & K.L. Murphy, The Rate and Kinetics Order of Ethanol Elimination, 25 Forensic Sci. Int'; 159-166 (1984), they found the following elimination rates:As default values, DUI Professional uses an average 0.015% per hour distribution rate spanning two standard deviations based on Dubowski's data. Thus, 95% of the population should fall within the following range:
Minimum Elimination Rate = 0.0080
Maximum Elimination Rate = 0.0220
DUI Professional combines the minimum "r" distribution constant with the maximum elimination rate to achieve the minimum blood alcohol level. Conversely, the maximum "r" distribution constant is factored with the minimum elimination rate to achieve the maximum blood alcohol level.
One of the most common methods of calculating an expected blood-alcohol level is to utilize the 'Widmark' equation. The Widmark equation relates the amount of ethanol absorbed into the bloodstream to body weight and blood alcohol content. It is expressed as:
where
The distribution constant ("r") is a measure of the concentration of alcohol in the body as a whole, compared to the alcohol concentration in the blood. The original values proposed by IMdmark were 0.68 for men and 0.55 for women. E.M.P. Widmark, Principles & Applications of Medicalegal Alcohol Determinations (Scitran, Santa Barbara, CA, trans.)(Biomedical Pubs. : Davis, CA 1981). More recent work suggests slightly higher values of 0.73 and 0.66 for men and women respectively.