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Dan McFeeley
12-11-2004, 03:04 PM
Hello all --

I'm posting this from the emergency room, where I make my working abode. Although it's a fairly busy night, my only duty at the moment is to monitor a patient, which I'm doing from the nursing station, leaving me free to do this post. This all started with a conversation with the unit secretary over calculating blood alcohol levels. We see a fair amount of this -- many motor vehicle accidents have alcohol and/or drugs involved, severely intoxicated people are brought to the ER, etc., etc.

A good number of these patients will minimize the amount of alcohol they've consumed . . . "Oh, I only had a few beers." The blood alcohol level tells the true tale. I've worked out a mental shorthand method of guesstimating the probable amount that was actually consumed from the lab results, and then confronting the patient with it. We use mg/dl in the ER, which is the same thing as blood alcohol concentration used by the law, just move the decimal point over. 100 mg/dl in the ER is the same thing as .100 BAC, the legal limit in many states. One beer will raise the blood alcohol level of the average 150 lb male 20 points, or 20 mg/dl. Five beers in one hour will put this male at 100 mg/dl, or .100 BAC. I work from this, making adjustments for body weight and gender.

That was the jist of the conversation tonight, however, I've been in the habit of translating blood alcohol levels into amount of beer consumed. Tonight, we were discussing a particularly high alcohol level which I translated into well over a 12 pack of beer. The unit secretary, a level headed person, pointed out to me that I needed to expand my horizons since, due to the high blood alcohol level, the medium consumed was more likely hard liquor. Dang. She caught me out on that one and I should know better. I've seen it too many times myself.

I shared this failing on my part with tonight's ER physician, DR. STEVEN DECKER of Riverside Medical Center, who not only agreed with the unit secretary, he added that I need to figure out how to work this out for mead (I've shared my meads with our ER staff so they're familiar with my hobby). So, at DR STEVEN DECKER's special request, I am sharing this with the board (and yes he knows I'm doing this ;D ).

Seriously, it's not a bad idea to be aware when too much is too much. As I was saying above, we see quite a bit of this in the ER, and some incredibly high alcohol levels in patients who have a long abuse history. Generally speaking, a blood alcohol level of 350 mg/dl is sufficient to result in death, and I've seen reports of death from much lower levels. Alcoholic patients in the ER are often seen with levels around 400 mg/dl or 500 mg/dl, but still "walking and talking," as we put it. I've worked with patients in the 600's, and our staff have told me about patients in the 700's. Our ER staff, myself included, get so used to high levels like this, 200's, 300's, and more, we tend to forget that consistent levels (i.e., repeat visits to the ER with the same levels) like this are indications of some serious abuse.

The formulas for calculating finishing alcohol level are fairly simple and give results that are a good approximation. Here's one -- alcohol content by volume is equal to the starting gravity minus the final gravity, and dividing that result by 7.36. Here's an example:

A mead starts with an SG of 1.080 and ends at .992.

1082 - 992 = 88

88/7.36 = 11.9565

or, 12% alcohol by volume.

This can get tricky, unfortunately, if you do what I do, which is to add a little bit of this and that, top off, blend. It makes the figures really confusing . . .

Guesstimate your mead is about wine strength or maybe slightly stronger, especially if you're using an alcohol tolerant yeast, and you're on fairly safe grounds for working out a ball park figure. A four ounce glass of wine is about the same alcoholic strength as one beer. The average person, regardless of body size or gender, will process alcohol at a rate of approximately 20 to 25 mg/dl per hour. In other words, about one standard drink per hour. You can work out the math from here, using my short hand method as listed above.

There's a time and a place for recreational drinking, but straying from those areas can become a problem. The worst case scenarios are what we see here in the ER. Have fun, enjoy your hobby, but keep it safe out there. :)

Oh yeah, standard disclaimer -- none of the above qualfies as medical advice in any way, shape or form.

Talon
12-12-2004, 07:44 PM
WOW! That's a good way to help us stay on the straight and narrow! We can calculate exactly how much we can drink to stay under the legal limit. (Of course nothing can be better than responsible drinking in the first place.)

Assuming I do process 25mg/dl an hour (erring on the high side), the alcohol I consume raises my blood alcohol at 25 points per drink and the legal limit is .080 in Florida... Calculating for a 150lbs male (although I weigh more than this)...
I can drink 2 to 3 4oz glasses of mead in one hour assuming that they are measuring at or under 12% abv.

So, assuming that beer is 6%abv, alcohol will raise your blood alcohol level by 20 points, so 1% alcohol will raise your blood alcohol by 3 and 1/3 points. So, in theory a person could drink a full serving of 100% alcohol and have a blood alcohol of 333mg/dl. To make calculations more convenient, let's say alcohol as a 1%Abv:3mg/dl ratio. Let's take Bacardi 151 as an example... It's 75% alcohol. So, 75abv*3mg/dl = 225mg/dl per one serving.

Is there a calculation for how fast a body absorbs alcohol when consumed? My numbers don't seem to be quite right...

Talon.

Dan McFeeley
12-12-2004, 10:54 PM
So, assuming that beer is 6%abv, alcohol will raise your blood alcohol level by 20 points, so 1% alcohol will raise your blood alcohol by 3 and 1/3 points. So, in theory a person could drink a full serving of 100% alcohol and have a blood alcohol of 333mg/dl. To make calculations more convenient, let's say alcohol as a 1%Abv:3mg/dl ratio. Let's take Bacardi 151 as an example... It's 75% alcohol. So, 75abv*3mg/dl = 225mg/dl per one serving.

Is there a calculation for how fast a body absorbs alcohol when consumed? My numbers don't seem to be quite right...


Beer is more like 3% to 4% alcohol content . . .

The figures I tossed out were rough ball park figures, not enough for exact calculations but enough to more or less keep you straight. Basically, 3 to 4 standard drinks, can of beer, 4 ounce glass of wine or mead, shot of hard liquor, consumed within an hour, should be enough, in fact, it's probably pushing the limit for a lot of people.

Also -- women don't process alcohol quite the same way as men. For a number of reasons, women will have higher blood alcohol levels then men when all other things are considered equal.

Here's a link to a blood alcohol calculator you can check out for better figures:

http://www.rupissed.com/

Another one:

http://info.insure.com/auto/baccalc.html

And another:

http://www.dot.wisconsin.gov/safety/motorist/drunkdriving/calculator.htm


I've played with different BAL calculators on the 'net and gotten different figures. Best to play it conservative, go with the lowest number, and simply be careful in situations where you're drinking and might be called to drive afterwards, or in a social setting where impaired judgment from too much alcohol is not a good thing. ;)

jab
12-13-2004, 02:42 AM
So, I think it is pretty safe to say most people I saw at the MeadFest were tanked!

-jb

Vicky Rowe
12-13-2004, 05:34 AM
LOL....oddly, I didn't get *really* squiffed until the afters party in David Meyer's suite on Saturday night. I got pretty happy, and sat around shooting the breeze with Mike Faul and Scott and Ross Pirtle.

I met all sorts of people that night, and had some *great* conversations......