Transcript Chapter 3 - papademas.net

Chapter 3
Metric, Apothecary, and
Household Systems of
Measurement
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Metric System
• Weight equivalents
– 1 g = 1000 mg
– 1 mg = 1000 mcg
• A gram is greater than a milligram, which is
greater than a microgram.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Grams to Milligrams and Milligrams to
Grams Quick Method
• Write order
• Write equivalents measure needed
• Show which way decimal point should move by drawing
arrow
• Make open part of arrow always face larger measure
• Remember equivalent 1 g = 1000 mg
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
The physician has order 0.4 g of medication. How many
milligrams is contained in this medication?
A. 4
B. 40
C. 400
D. 4000
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
C. 400
You want to convert grams to milligrams: 0.4 g >
400 mg. The arrow tells you to move the decimal
point three places to the right.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Milligrams to Micrograms and Micrograms
to Milligrams Quick Method
• Write order
• Write equivalents measure needed
• Show which way decimal point should move by drawing
arrow
• Make open part of arrow always face larger measure
• Remember equivalent 1 mg = 1000 mcg
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
Is the following statement true or false?
4 mg is equal to 4000 mcg
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
True
You want to convert milligrams to micrograms: 4
milligrams > 4000 mcg. The open part of the arrow faces
the larger measure.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Apothecary System
• Gradually replaced by metric system
• Equivalents between metric and apothecary system not
exact
• Roman numerals designate amounts
• Grain only solid dosage
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Grain
• Generally 60 mg = 1 gr
• EXCEPTIONS 65 mg = 1 gr
– Acetaminophen (Tylenol)
– Aspirin
• Metric gram (g; gm; Gm) confused with grain (gr)
• WRITE OUT word “grain”
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Household Abbreviations
• Used for medications administered at home
• Examples
– Pint
– Quart
– Teaspoon
– Tablespoon
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Conversions Among Liquid Measures
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
The order is to administer 10 mL of a medication. How
many teaspoons of this medication will you administer to
the patient?
A. ½
B. 1
C. 1½
D. 2
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
D. 2
1 teaspoon is equivalent to 5 mL. ½ teaspoon is
equivalent to 2.5 mL. 1½ teaspoon is equivalent to 7.5
mL. 2 teaspoons is equivalent to 10 mL.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Temperature
• Convert Fahrenheit to Centigrade
– C = (F – 32) × 5/9
• Convert Centigrade to Fahrenheit
– F = (C × 9/5) + 32
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Question
The client’s temperature using an oral electronic
thermometer is 40 centigrade. What is the client’s
Fahrenheit temperature?
A. 100
B. 101
C. 103
D. 104
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Answer
D. 104
When the Celsius reading is 40:
F = (40 × 9/5) + 32 = (72) + 32 = 104
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins