In DUI cases numerous medical conditions can influence how blood alcohol testing is done accurately. One big problem when testing a person for a specfic alcohol concentration is to take into consideration Hematocrit levels. Hematocrit represents the fraction of whole blood composed of red cells and is correlated with the acqueous content of the blood, the higher the hematocrit, the lower the concentration of water in the blood and vice versa. In the simplest terms it is a ratio or a formula. In other words, it is a value expressed as a ratio of the solid components of blood (cellular material) to the liquid components of blood (water). In a normal healthy being it can vary the amount of alcohol contained in the blood.
People with abnormally low hematocrit are sometimes called "Anemic". Normal hematocrit levels are 45 % for men and 40 % for women. Perhaps the best way to imagine the concept of hematocrit in your mind is to compare the sample with a glass full of rocks vs. a glass filled with no rocks. Here is the problem when it is related to DUI chemical testing for ethanol in the blood: The higher the hematocrit equals more solids in the blood, therefore less water and consequently a higher alcohol concentration. A person with lower than normal hematocrit has less solids in their blood, more water and therefore a lower blood alcohol concentration.
What does all this mean as far as DUI defense? Well, studies have concluded that a person whose hematocrit levels are out of whack or not within normal paramaters can have a breath test result with a higher than actual blood alcohol level as much as 14%, more commonly in the range of 10-14 percent variation.