Simplified formula for clinical application.

1. Common Formula Derivation
Jagadi Ntugwa, MD
EXCELLENT COLLEGE
CMT DEPARTMENT-2021

2. Alcohol units
• One unit equals 10ml or 8g of pure alcohol, which is around the
amount of alcohol the average adult can process in an hour.
• This means that within an hour there should be, in theory, little or no
alcohol left in the blood of an adult, although this will vary from
person to person.

3. Cont.
• The number of units in a drink is based on the size of the drink, as
well as its alcohol strength.
• For example, a pint of strong lager contains 3 units of alcohol, whereas
the same volume of low-strength lager has just over 2 units.
• Knowing your units will help you stay in control of your drinking.

4. Cont.
• To keep health risks from alcohol to a low level if you drink most
weeks
• Men and women are advised not to drink more than 14 units a week on
a regular basis
• Spread your drinking over 3 or more days if you regularly drink as
much as 14 units a week
• If you want to cut down, try to have several drink-free days each week

5. Cont.
• Strength (ABV) x volume (ml) ÷
1,000 = units
• For example, to work out the
number of units in a pint (568ml)
of strong lager (ABV 5.2%):
• 5.2 (%) x 568 (ml) ÷ 1,000 =
2.95 units

6. Formula derivation
Let
Percentage=P (n/100), Total volume of the drink=V, Total units=U
Amount of alcohol(in volume)=P×V
1 unit ≡ 10mls of pure alcohol
U ? ≡ PV
i.e U=PV/10
=nV/100×10
=nV/1000

7. Pack-Year Index
• Is a unit for measuring the amount a person has smoked over a long
period of time.
• It is calculated by multiplying the number of packs
of cigarettes smoked per day by the number of years the person has
smoked.
• For example, 1 pack-year is equal to smoking 20 cigarettes (1 pack)
per day for 1 year, or 40 cigarettes per day for half a year, and so
on.
• One pack-year is the equivalent of 365.24 packs of cigarettes or 7,305
cigarettes, in a year as smoker.

8. Formula derivation
PYI =Packs × Years
1 pack ≡20cigarates
??? ≡N
Then =N/20
Thus formula appears as;
PYI =N × Years/20

9. IV fluid Formula-Drop rate
Let Total volume to be administered be V(in mls)
Total time for fluid running be T(in minutes)
Drop factor be D(/ml)
Then V should run in time T
Remember D=/ml
So Total drops in V=DV

10. Cont.
Thus Total drops should run in time T
i.e Total drops →T
? ←1 Minute
=Total drops/T
=DV/T
=
Drop factor×Total Volume to be administered
Total time required to run fluid

11. THE END
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