Principles And Pitfalls in Alcohol Toxicity, Part 3

Human AnatomyTime

A delay of the emptying of the stomach into the small intestine will delay absorption of the majority of the alcohol. Such a delay is important in calculating the peak blood alcohol content (BAC) or extrapolating from a given level. Conditions which may delay the stomach emptying into the intestine such as scarring or spasm of the pylorus (point of connection between the stomach to the small intestine), will delay the absorption of the alcohol from the small intestine as well, and therefore will affect the blood alcohol content curve. In addition to the delaying of the stomach into the small intestine, factors of the amount of alcoholic consumed, the presence of food, the time that the alcohol was ingested, and some other individual parameters such as medication use are important factors in assessing blood alcohol levels and peak alcohol levels.

Metabolism of Alcohol

Addressing alcohol abuse effects requires an understanding of alcohol metabolism.
The liver is the major organ to metabolize and eliminate alcohol. From a pharmacological point of view, the process of metabolism of alcohol is a linear function of time, and it can be affected by increasing the concentration of alcohol in the blood. As a rule of thumb, the mean rate of alcohol elimination is about 100 mg/kg/hr or about 15 mg/100 ml/hr for a 70 kilo person which corresponds to 8-10 cc per hour. What that means is that it takes about 1-1/2 hours to metabolize the alcohol in 1 ounce of 100 proof whisky or in 12 ounces of beer.(1) It is well accepted that the time from the last drink to maximal concentration in blood usually ranges from 30 to 90 minutes. This however may vary between individuals, depending on various physiological conditions. This information is important in assessing whether an individual’s arrest or involvement in a collision was while the individual had reached the peak level of blood alcohol content, and was on the rising limb of the curve, or whether the individual was on the down slope of the curve after having reached the peak blood alcohol concentration. (2)

References:
1. Winek, Charles; Esposito, Francis “Blood Alcohol Concentrations: Factors Affecting Predictions” pgs. 34-61.
2. Morgan Jones, Ben; Vega, Arthur; “Original Investigations. Cognitive Performance Measured on the Ascending and Descending Limb of the Blood Alcohol Curve*” . Psychopharmacologia (Berl) 23, 99-114; 1972.

About Nachman Brautbar, M.D., F.A.C.P.

Experienced in internal medicine, toxicology, occupational medicine, alcohol, drugs, and nephrology, with a specialization in toxicology; evaluation, analysis & interpretation of urine drug/alcohol tests; drug/alcohol concentrations in the blood; findings in blood and urine samples; assessment of driving under the influence. His list of academic appointments includes Associate Professor of Pharmacology and Medicine, and Clinical Professor of Medicine at the University of Southern California, School of Medicine. Dr. Brautbar is a peer reviewer for the Department of Human Health Services, earlier Agency for Toxic Substances and Disease Registry (ATSDR). Dr. Brautbar has been on the faculty of the National Judicial College and has lectured to judges on the issue of scientific evidence. He has been a visiting professor at national and international scientific institutions and centers such as Yale, Harvard, Mayo Clinic, and NIH. Dr. Brautbar is a fellow of the Collegium Ramazzini. Dr. Brautbar has testified in the California State Senate and the United States Senate on toxic groundwater contamination.

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