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 parameters 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.
Here is the bottom line when it comes to hematocrit and DUI cases:
A higher hematocrit means less plasma and less water in the blood, which is where alcohol actually dissolves. Because of that, people with higher hematocrit values will have artificially higher breath alcohol readings, even when their true blood alcohol level is the same.
One expert put together an Excel calculator that allows you to plug in a hematocrit value and see how much that factor could impact a breath test result. The second tab shows the range of values associated with different hematocrit levels.
Example: 0.080 g/210L reading from the instrument
HCT: 0.52
True BrAC: 0.078
