March 3, 2015

Detection and General Deterrence DWI Detection and Standardized Field Sobriety Testing

Detection and General Deterrence  DWI Detection and Standardized Field Sobriety Testing
Common Drink Sizes 
  • Can of beer – 12 ounces of fluid @ 4 percent alcohol equals 0.48 ounces of pure ethanol 
  • Glass of wine – 4 ounces of fluid @ 12 percent alcohol equals 0.48 ounces of pure ethanol 
  • Shot of whiskey (80 proof) – 1 and • ounces @ 40 percent alcohol equals 0.50 ounces of pure ethanol 

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Standardized Field Sobriety Test Course 
  • Over the millennia during which people have used and abused ethanol, some common sized servings of the different beverages have evolved.  Beer, for example, is normally dispensed in 12 ounce servings.  Since beer has an ethanol concentration of about four percent, the typical bottle or can of beer contains a little less than one half ounce of pure ethanol. 
  • A standard glass of wine has about four ounces of liquid. Wine is about 12 % alcohol, so the glass of wine also has a bit less than one half ounce of ethanol in it. 
  • Whiskey and other distilled spirits are dispensed by the "shot glass", usually containing about one and one quarter ounce of fluid. At a typical concentration of 40 % ethanol (80 proof), the standard shot of whiskey has approximately one half ounce of ethanol. 

Therefore, as far as their alcoholic contents are concerned, a can of beer, a glass of wine and a shot of whiskey are all the same. 
(National Institute on Alcohol Abuse and Alcoholism of the National Institute of Health.) 
Session 2 – Detection and General Deterrence 
Alcohol is a CNS Depressant 

Alcohol is the most abused drug in the United States 

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Standardized Field Sobriety Test Course 
Ethanol is a Central Nervous System Depressant. It doesn't affect a person until it gets into their central nervous system, i.e., the brain, brain stem and spinal cord. Ethanol gets to the brain by getting into the blood.  In order to get into the blood, it has to get into the body. 
There are actually a number of different ways in which ethanol can get into the body.  It can be inhaled.  Ethanol fumes, when taken into the lungs, will pass into the bloodstream and a positive blood alcohol concentration (BAC) will develop. 
However, prolonged breathing of fairly concentrated fumes would be required to produce a significantly high BAC.  Ethanol could also be injected, directly into a vein; it would then flow with the blood back to the heart, where it would be pumped first to the lungs and then to the brain. And, it could be inserted, as an enema, and pass quickly from the large intestine into the blood. But none of these methods are of any practical significance, because alcohol is almost always introduced into the body orally, i.e., by drinking. 
Session 2 – Detection and General Deterrence 
Absorption of Al 

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Standardized Field Sobriety Test Course 
Once the ethanol gets into the stomach, it has to move into the blood. The process by which this happens is known as absorption. One very important fact that pertains to alcohol absorption is that it doesn't have to be digested in order to move from the stomach to the blood. 
Another very important fact is that alcohol can pass directly through the walls of the stomach. These two facts, taken together, mean that, under the right circumstances, absorption of alcohol can be accomplished fairly quickly. The ideal circumstance for rapid absorption is to drink on an empty stomach. 
When the alcohol enters the empty stomach, about 20 % of it will make its way directly through the stomach walls. The remaining 80 % will pass through the stomach and enter the small intestine, from which it is readily absorbed into the blood.  Because the body doesn't need to digest the alcohol before admitting it into the bloodstream, the small intestine will be open to the alcohol as soon as it hits the stomach. 
But what if there is food in the stomach?  Suppose the person has had something to eat shortly before drinking, or eats food while drinking; will that affect the absorption of alcohol? 
Yes it will.  Food has to be at least partially digested in the stomach before it can pass to the small intestine. When the brain senses that food is in the stomach, it commands a muscle at the base of the stomach to constrict, and cut off the passage to the small intestine. The muscle is called the pylorus, or pyloric valve. As long as it remains constricted, little or nothing will move out of the stomach and into the small intestine.  If alcohol is in the stomach along with the food, the alcohol will also remain trapped behind the pylorus. Some of the alcohol trapped in the stomach will begin to break down chemically before it ever gets into the blood. In time, as the digestive process continues, the pylorus will begin to relax, and some of the alcohol and food will pass through. But the overall effect will be to slow the absorption significantly.  Because the alcohol only slowly gets into the blood, and because the body will continue to process and eliminate the alcohol that does manage to get in there, the drinker's BAC will not climb as high as it would have if he or she had drunk on an empty stomach. 
Session 2 – Detection and General Deterrence 
Distribution of Alcohol 
Getting the ethanol into the body’s tissues and organs 
Ethanol goes wherever it finds water 

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Standardized Field Sobriety Test Course 
Once the alcohol moves from the stomach into the blood, it will be distributed throughout the body by the blood. Alcohol has an affinity for water. The blood will carry the alcohol to the various tissues and organs of the body, and will deposit the alcohol in them in proportion to their water contents. 
Brain tissue has a fairly high water content, so the brain receives a substantial share of the distributed alcohol.  Muscle tissue also has a reasonably high water content, but fat tissue contains very little water. Thus, very little alcohol will be deposited in the drinker's body fat. This is one factor that differentiates alcohol from certain other drugs, notably PCP and THC, which are very soluble in fat. 
Session 2 – Detection and General Deterrence 
Distribution of Alcohol (Cont.) 
Which parts of the body have lots of water? 
The brain, the liver, muscle tissue 
Which parts of the body do not have lots of water? 
Bones, fatty tissue 
  • The average male is 68 percent water 
  • The average female is 55 percent water. 

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Standardized Field Sobriety Test Course 
The affinity of alcohol for water, and its lack of affinity for fat, helps explain an important difference in the way alcohol affects women and men.  Pound for pound, the typical female's body contains a good deal less water than does the typical man's. 
This is because women have additional adipose (fatty) tissue, designed in part to protect a child in the womb. A Swedish pioneer in alcohol research, E.M.P. Widmark, determined that the typical male body is about 68 % water, the typical female only about 55 %. Thus, when a woman drinks, she has less fluid --pound for pound --in which to distribute the alcohol. 
If a woman and a man who weighed exactly the same drank exactly the same amount of alcohol under the same circumstances, her BAC would climb higher than his. When we couple this to the fact that the average woman is smaller than the average man, it becomes apparent that a given amount of alcohol will cause a higher BAC in a woman than it usually will in a man. 
Session 2 – Detection and General Deterrence 
Elimination of Alcohol 
Getting the ethanol out of the body: 
• Direct excretion 
  • Breath 
  • Sweat 
  • Tears 
  • Urine 

• Metabolism 
• Primarily in the liver 

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