Chapter 9 Measurement Systems

Objectives  Define all key terms.  Compare three systems of measurement used for drug dosages.  State the basic units of measurement in the metric system.  Correctly convert between the systems of measurement.

Measurement Systems  Avoirdupois  Apothecary  Household  Metric

Critical Thinking  Would you rather be weighed in kilograms or pounds? Why?

Household Measures  3 t = 1 T  2 T = 1 fluid oz  8 oz = 1 cup  2 cups = 1 pint  4 quarts = 1 gallon  1 juice glass = 4 oz  1 teacup = 6 oz  1 glass = 8 oz

Critical Thinking  Does it bother you that 1 oz = something between 360 and 480 gtts, minims, or grains? What does this say about the accuracy of this system?

Metric System  KiloThousands  Deci Tenths  Centi Hundredths  MilliThousandths  MicroMillionths

Critical Thinking  Do you have trouble seeing the decimal point? Do you think pharmacists ever do? How can you be sure that a patient is given 0.5 gram instead of 5 grams?

Converting from One Unit to Another  Kilo × 1000 to get to unit  Centi divided by 100 to get to unit  Milli divided by 1,000 to get to unit  Micro divided by 1,000,000 to get to unit

Conversions  1 gram = 1,000 mg  1 gram = 15 grains  1 grain = 60 mg  1 mg = 1/1,000 gram  1 grain = 1/15 gram  1 mg = 1/60 grain

King Gram Story  King Gram had 1,000 servants named mg.  King Gram owned 15 grain fields.  In each grain field, 60 mg worked.  Each mg is 1/1,000 of the workforce.  If one mg is sick, 1/60 of the workforce in the grain field is sick.  If King Gram gives away 1 grain field, that is 1/15 of his wealth.

Question  Students, can you recite the King Gram story?  Or would you prefer to memorize the conversions?

Converting from One Unit to Another  Grams to kilogramsDivide by 100  Grams to milligrams Multiply by 100  Kilograms to gramsMultiply by 1,000  Milligrams to gramsDivide by 1,000  Liters to millilitersMultiply by 1,000  Milliliters to litersDivide by 1,000

Converting through 1 oz  1 oz = 2 T  1 oz = 6 t  1 oz = 8 drams  1 oz = 360–480 gtts, grains, minims  1 oz = 30 mL

Summary  What new piece of information in this chapter were you most interested to learn?  What questions do you still have about the information in this chapter?  Return to Objectives to determine extent of learning.Objectives

Credits Publisher: Margaret Biblis Acquisitions Editor: Andy McPhee Developmental Editor: Yvonne N. Gillam Production Manager: Samuel A. Rondinelli Manager, Electronic Development: Kirk Pedrick Technical Project Manager, EP: Frank Musick Design Associate, EP: Sandra Glennie The publisher is not responsible for errors or omission or for consequences from application of information in this presentation, and makes no warranty, expressed or implied, in regards to its content. Any practice described in this presentation should be applied by the reader in accordance with professional standards of care used with regard to the unique circumstances that may apply in each situation.