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Alcohol Serum to Whole Blood

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July 01, 2008, 10:09
A. Carroll
Alcohol Serum to Whole Blood
Greetings,

I recieved toxicology report indicating that the blood result was as follows:

Alcohol Serum @ 3.6f mg/dl

Would I still use the same formula (dividing by 1.16) to find the whole blood number? If so, which way does the decimal go? If I move the decimal to the left two spaces it comes out as 0.031. When moved to the right two spaces, it comes out as 310.0, so I then move the the decimal left, thus giving me a .310.

This lady could not stand up and EMS insisted on transporting her. I tend to believe the .310 number would be the right one. Any input? Please?

Thanks,
Adam
July 01, 2008, 10:33
AlexLayman
Is it possible this person was not intoxicated on alcohol?
July 01, 2008, 10:42
AlexLayman
The water content of serum and whole blood is 98% and 86%, respectively. Because ethanol preferentially partitions into the aqueous rather than the cellular phase of blood, higher levels are obtained with serum or plasma. Serum and plasma levels average 1.09 to 1.18 times higher than whole blood levels. The concentration of ethanol in arterial and capillary blood is about 25% higher than venous blood after initial consumption of alcohol.

Source: ClinLab

PS: The same page also says a 120 pound person will have 50-100 mg/dl after 1 to 3 drinks so 3.6 seems basically sober... at least for alcohol. Perhaps the units should have been grams instead of milligrams which, according to the chart on the linked page, would be 10 drinks... that seems more like "could not stand up" drunk.
July 01, 2008, 15:12
JohnFLopez
Adam,

Shoot me an email at JohnF.Lopez@co.travis.tx.us and I will send you an excel sheet I did that calculates the number for you. Based on the 3.6 mg/DL that you indicated the BAC would be about .003. Either the units on the report are off or the person was on something else.
July 01, 2008, 23:22
A. Carroll
I took a closer look at the toxicology and noticed that she also tested positive for Cocaine which by the hospitals chart would have to be more than 300 ng/ml and she also tested positive for Benzodiazepine, which by this hospitals chart would have to be more than 200 ng/ml. That might help explain her not being able to stand.