Question

Mr. Andy Capp was recently arrested by San Antonio police for allegedly driving under the influence of alcohol (DUI). Calculate his estimated BAC range based on the following factors. Andy (male) at the time of the incident weighed 160 lbs (pounds) and told his defense attorney that he had only consumed six (6) beers and four (4) shots of hard liquor that night. He recalls that he had started drinking at 6:00 pm at the Hilltop Pub and was pulled over by police for the alleged DUI offense that night at 11:30 pm just two blocks from his residence after running over a neighbor’s mailbox.

He has had several prior alcohol related charges over the last two years. Based on this scenario what was his estimated BAC range (expressed in g/dL) at the time of the offense? What is this BAC range expressed in mg/dL? Show your work for partial credit.

Ms. Anna Capp now states that she was driving instead of her husband and hit the mailbox. Calculate her BAC range (in g/dL) based on her weighing 110 lbs and her claims that she consumed 4 beers and 2 shots of hard liquor starting at 6:00 pm at the Hilltop Pub. Show your work for partial credit.

Answer 1

BAC is the Blood Alcohol content which is the concentration of Alcohol (gm) present in the Blood.

BAC is calculated by the Widmarks formula to know the alchol intoxication.

The Widmarks formula for estimated peak blood alcohol concentration i.e. EBAC is :

Lets understand its values:

· 0.806 is a constant for body water in the blood (mean 80.6%),

· SD is the number of standard drinks, that being 10 grams of ethanol each,

· 1.2 is a factor to convert the amount in grams to Swedish standards set by The Swedish National Institute of Public Health

· BW is a body water constant (0.58 for males and 0.49 for females),

· Wt is body weight (kilogram),

· MR is the metabolism constant (0.015 for males and 0.017 for females) and

· DP is the drinking period in hours.

· 10 converts the result to permillage of alcohol

Now lets calculate the BAC for Mr. Andy Capp who is arrested by San Antonio police ( for us the drink Standards belongs to USA)

1) Weight of Mr. Andy = 160lbs = 72.5 kg

2) Standard Drink calculation had by Mr. Andy

6 Beers + 4 Shots

375 ml can of mid-strength beer (3.5% alcohol) = 1 standard drink => 6 beers x 1 = 6 Standard Drinks

30 ml shot of spirits (40% alcohol) = 0.95 standard drinks => 4 Shots x 0.95 = 3.8 Standard Drinks

Total Standard Drink = 9.8 Standard Drink

3) DP or Drinking Period = 6 pm to 11. 30 pm = 5.5 hours

4) BW = 0.58 for male

5) Metabolism rate= 0.015

Now let's put all these values in our formula

EBAC = ( 0.806 x 9.8 x1.2 / 0.58 x 72.5 - 0.015 x 5.5) x 10

= (9.47/42.05 - 0.0825) x10

= (0.225 - 0.0825) x10

= 0.1425 x 10

= 1.42 g/dL

So the estimated BAC of Mr. Andy Capp was 1.42 g/dL

This can also be 1420 mg/dL

If it was his wife

Then,

weight = 110 lbs = 50 kg

Standard Drink = 4 Beers x 1 + 2 Shots x 0.98 = 5.96 i.e. approx 6

BW= 0.49

MR= 0.017

DP = 5.5 hrs

EBAC = ( 0.806 x 6 x1.2 / 0.49 x 50 - 0.017 x 5.5) x 10

=(5.80/24.5 - 0.0935) x 10

=(0.236 - 0.0935) x 10

= 0.143 x 10

= 1.43 g/dL

This can also be 1430 mg/dL

So Mr. Andy Capp's wife was also almost equally drunk. At this point, they may have almost a complete loss of motor control, and there's a good chance of vomiting or passing out. They are likely having serious memory impairments, and should seek professional medical care. And should not operate a vehicle at all.