1. Chapter 6
Metric System

2. Metric System Used most often in medication system
Is based on the decimal system
Is gradually replacing apothecary and household system

3. The three units of metric system Table 6-1
Length: Meter (m)
Volume: Liter (L)
Weight: Gram (g)

4. Common Refixes: Table 6-2
Kilo 1,000 one thousand times
Hecto 100 one hundred times
Deka 10 ten times
Deci 0.1 one tenth
Centi: 0.01 one hundredth part of
Milli: one thousandth part of
Micro one millionth part of

5. Box 6-1 common metric abbreviations
From smallest to largest
weight
Microgram=mcg
milligrammg
Gram=g
Killogram=kg
Volume
Milliliter=mL
deciliter=dL
Liter=L

6. Box 6-2 Metric System Rules
use Arabic numbers to express quantities: 1, 1,000, 0.5
Express parts of a unit or fractions of a unit as decimals: 0.4 g, not 2/5 g
Quantity always in front of a unit of measure: 1,000 mg, 0.75 mL
A full space between the number and abbreviation: 2 mL
Place a leading zero to the left of the decimal point: 0.4 mL; eliminate trailing zeros: 2 mg not 2.0 mg

7. Metrics: Rules (Cont.) DO NOT USE mu symbol “μ” with grams
mcg NOT “μg”
DO NOT USE “cc” for mL
2 mL NOT 2 cc
Avoid periods (mg NOT mg.)
Place commas in values at 1,000 or above
Do not add “s” on a unit to make it plural.

8. Box 6-3 Metric Equivalents
Weight
1 kg=1,000 g
1 g=1,000 mg
1 mg=1, 000 mcg
Volume
1 liter (L)=1,000 mL
1 mL=0.001 L
Length
1 =100 cm=1,000 mm
1 mm=0.1 cm=0.001 m

9. Not metric, used in home care
1 quart=1,000 mL
1 pint=500 mL

10. Chap 7
Apothecary

11. Apothecary and household systems
Is primarily used for dosages at home
Expresses quantities in fractions and Arabic numbers
Has measures such as table spoon (tbs) and teaspoon (tsp).

12. Drop and grain
Drop (gtt), it is not a standardized unit of measure
1 gr=60 mg. The grain is a unit of weight in the apothecary system.
Gr 90=___g, 630mg =gr___

13. Box 7-1 household/metric equivalents
Teaspoon (t, tsp), 1 tsp=5 mL
Tablespoon (T, tbs), 1 tbs=15 mL
Ounce (oz), 1 oz=30 mL
Measuring cup (C), 1 cup=8 oz=240 mL
Pint (pt), 1 pt=2 cups=16 oz=500 mL(*close to)
Quart (qt0, 1 qt=2 pt=4 cups= 32 oz=1000mL*
Pound (lb), 1 lb=16 oz, 1 kg=2.2 lb

14. Safety Alert!
Do NOT use the following abbreviations and symbols: gr (grains, apothecary unit of weight) confused with metric gram m (minim) mistaken for mL Ʒ (dram, apothecary drop) mistaken for 3 (ounce, apothecary symbol) obsolete ss, ss (apothecary symbol for ½ ) mistaken for 55

15. Converting within and between systems
Chap 8
Converting within and between systems

16. Using conversion factor method

17. Converting: Points Memorization is essential
1 glass=6 oz, 1 bowl=6 oz (old)
Think of equivalents as ratios
1 g = 1,000 mg is a conversion factor
1 g : 1,000 mg is a ratio

18. Converting Within or Between Systems
conversion factor method
Consider the size of the units
Larger to smaller—multiply
Smaller to larger—divide
Can use
Ratio proportion method
Dimensional analysis method

19. Converting: Conversion Factor
Larger to smaller
Multiply by the conversion factor
(household) (metric)
4 oz = ____ mL
(large) (small)
Equivalent: 1 oz = 30 mL
Conversion factor = 30
Multiply 4 by 30
Answer: 120 mL

20. Converting: Conversion Factor (Cont.)
Smaller to larger
Divide by the conversion factor
(metric) (household)
120 mL (small) = ____ oz (large)
Equivalent: 1 oz = 30 mL
Conversion factor = 30
Divide 120 by 30
Answer: 4 oz

21. Converting: Conversion Factor (Cont.)
Pounds to kilograms
Divide by the conversion factor
(household) (metric)
110 lb (small) =____kg (large)
Equivalent: 1 kg = 2.2 lb
Conversion factor = 2.2
Divide 110 by 2.2
Answer: 50 kg

22. Converting: Ratio and Proportion
Pounds to kilograms
1 kg : lb = x kg : lb
2.2x =
x = 50kg

23. Case Study 2
Mr. Hain is complaining of 7 out of 10 abdominal pain. There is an order for 1,000 mcg of Dilaudid IV every 3 hours prn for severe pain. It has been 4 hours since he last received Dilaudid, and you decide to give it. Dilaudid is only available in 2 mg/mL. How many milliliters will you give?

24. Case Study 2 (Cont.)
Answer: 0.5 mL

25. Calculating Intake and Output
Abbreviated as I&O
Used to monitor fluids consumed, injected, and excreted
Includes intake of “pseudo” solids that become liquid at body temperature—gelatin, popsicles
Includes liquids that exit the body—diarrhea, urine, vomitus, chest tube drainage
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

26. Calculating I&O (Cont.)
Preferred method is milliliters (mL)
May require conversion—household to metric
Recorded during the hour within which the fluid is consumed, injected, or excreted
Totaled every 24 hours
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

27. Calculating I&O (Cont.)
I&O record usually has key for conversions (e.g., 6 oz coffee cup = 180 mL)
After conversions, items are added for totals
1/3 glass apple juice (1 glass = 6 oz) = 60 mL
1/2 cup coffee (1 cup = 8 oz) = 120 mL
1/2 pint milk (1 pint = 500 mL) = 250 mL
430 mL
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

28. Figure 8-1 Sample I&O flow sheet
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

29. Calculating I&O (Cont.)
Record intravenous (IV) fluid intake
Method of recording varies with institutions
Urine is sometimes recorded hourly
Adult hourly output should be 30 mL or more
To find average, add up total urine and divide by number of hours being recorded
Check institution policies to comply with charting requirements on I&O record
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

30. Case Study 2 1.5 L of IV D5 NS 4 oz ice chips 100 mL IV Flagyl
You have obtained an order for 40 mEq potassium chloride IV once to be started by the oncoming nurse. Mr. Hain’s nausea and abdominal pain are well controlled with prn medication, and he is in stable condition. Before you give a report to the oncoming nurse you must calculate Mr. Hain’s input and enter the data in milliliters.
1.5 L of IV D5 NS
4 oz ice chips
100 mL IV Flagyl
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

31. Answer: 1,720 mL Case Study 2 (Cont.)
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.

32. What is the Average Hourly Output?
740 mL in 8 hours
280 mL in 4 hours
610 in 24 hours
Which is insufficient urine output?
1)-92.5 mL/hr
2)-70 mL/hr
3)-25.4 mL/hr = insufficient
Mosby items and derived items © 2014, 2010, 2006, 2002, 1998, by Mosby, Inc., an imprint of Elsevier Inc.