Archive for March, 2006

Coagulation of Blood Sample = Higher Blood Alcohol

Sunday, March 5th, 2006

When a blood sample is taken from a DUI suspect for later analysis, it is usually done in one of two ways. The suspect may have the blood drawn at the police station by a technician, using a prepared kit containing a vial, or it may be taken by a nurse or technician at a medical facility. In either event, it is critical that the vial in which the blood is contained is sterile and contains two things: a preservative and an anticoagulant. The preservative, in conjunction with refrigeration, is to prevent the blood from fermenting — and thereby producing alcohol in the vial before it is tested. The anticoagulant is to prevent the blood from coagulating, or clotting.

Why are we concerned about coagulation of the blood?

Blood is made up of a mixture of solid particles supended in a liquid. The solid particles consist of red blood cells, white blood cells and clotting platelets; the liquid portion is called serum or plasma. (The percentage by volume of the solid particles to the liquid is called the hematocrit of the blood: a hematocrit of .47, for example, would indicate that the individual’s blood consists of 47 percent solid particles — cells and platelets — and 53 percent plasma.)

When blood clots, the liquid portion (plasma) separates from the solid portion (blood cells and clotting platelets). This will be seen in the sample vial as a red clump at the bottom (cells) with a yellowish liquid on top (plasma). When this sample is tested at the laboratory, usually days later, it is the plasma that is tested for alcohol content; the clotted cells at the bottom are not included.

So what? Well, alcohol is attracted to water — that is, it is soluble in water. And since plasma is a liquid and contains water, and alcohol is attracted to water, the plasma in the blood sample will contain a higher percentage of alcohol than in the whole blood sample. The higher the percentage of plasma in the sample being tested, the higher will be the blood alcohol concentration (BAC). Put another way, if two subjects have the same BAC in their bodies but the blood sample from one has clotted and so has a higher percentage of plasma, that person’s “sample” will show a higher BAC.

Unfortunately, it is not uncommon for blood samples collected by police agencies or hospital personnel to contain no anticoagulant, or to contain insufficient amounts of the chemical. (And, of course, we have the emerging practice of just letting the police officer himself perform the blood draw and sample preservation out on the highway.)

An additional problem is that the kits used by technicians usually contain a vial already containing a preservative (commonly sodium fluoride) and an anticoagulant (commonly potassium oxalate) in powder form at the bottom. However, when the blood is added to the vial, the technician does not vigourously shake it — and the chemicals are not mixed with the blood. Result: coagulation — and a falsely high blood alcohol result.


Can Alcohol be Produced Within the Body?

Wednesday, March 1st, 2006

Can alcohol be manufactured by the human body itself? Apparently so.

In an interesting scientific article, two physicians at Union Memorial Hospital in Baltimore reported that they detected the odor of beer in three of their patients. This was in an isolated hospital setting; there was no access to alcoholic beverages. The doctors had urine samples taken and analyzed by gas chromatography. Result? All three showed the presence of alcohol in their systems. Two of these were then tested for actual blood-alcohol concentration (BAC). One showed a BAC of .043%. The other was .121% — or 1 1/2 times the legal limit for DUI!  The physicians commented:

The presence of alcohol in human specimens containing glucose and yeast should come as no surprise…Several have made this observation. Under normal circumstances trace amounts of alcohol may be found in the blood; the alcohol is then channeled into an energy pathway by hepatic alcohol dehydrogenase…

The Japanese report the “auto brewery syndrome” in which they have seen middle aged patients with bowel abnormalities, most often after surgery, who have yeast overgrowth, usually candida, in the G.I. tract and who ferment ingested carbohydrates, producing enough alcohol to result in drunkeness.  Mullholland and Townsend, “Bladder Beer – A New Clinical Observation”, 95 Transactions of the American Clinical Climatological Association 34 (1983).

In other words, the body is making alcohol by itself — in some cases, enough to become legally intoxicated.

This has been confirmed by other studies. Swedish researchers, for example, have found that:

Increasing evidence has emerged to show that endogenous ethanol does exist, and the concentrations seen have large inter-individual variations.  Our results show a markedly skewed distribution of values…The reason for the wide inter-individuaal variation in healthy abstaining individuals is hard to explain.  Jones et al., “Determination of Endogenous Ethanol in Blood and Breath By Gas Chromatography”, 18 Pharmacology, Biochemistry and Behavior 267 (1983).

How many folks with “immaculately conceived” alcohol in their systems have been arrested and convicted for DUI? These people were innocent, right?

Wrong. In the rush to convict drunk drivers (and with federal pushing), all 50 states have now passed so-called per se laws: driving with a BAC of .08% or more. Neither impairment, intent, negligence or even knowledge is required: The crime consists of simply having the alcohol in your body.  Even if you’ve had nothing to drink.