Measurement and Dosage Calculation - Triton College



Measurement and Dosage Calculation

-Fraction- way of expressing an amount that is part of a whole

-Numerator- the top number of a fraction

-Denominator- the bottom number of the fraction

-Simplifying fractions- to reduce a fraction to its lowest terms

-Multiplying fractions- multiply numerator by numerator and denominator by denominator

-Dividing fractions- invert (flip over) the divisor, then multiply the two fractions

-Decimal fractions- fractions expressed as decimals

-Refer to pages 36-40 for math review

-Dosage range- different amounts that can produce therapeutic effects

-Convert- change from one unit or system to another in the course of your daily routine

-System of measurements

-Apothecary system- a very old an infrequently used

-Grain (gr) - basic unit of weight

-Minim (m) - basic unit of volume

-Dosage quantities are written in lowercase roman numerals

-Fractions are expressed in Arabic numerals rather than decimals

-Metric system

-Meter- unit of length

-Liter- volume

-Gram- weight

-Prefixes- indicate smaller or larger units in the system

-Kilo- 1000

-Hect- 100

-Deca- 10

-Deci- 1/10

-Centi- 1/100th

-Milli- 1/1000th

-Micro- 1/1000000th

-1cc = 1ml

-Household system

-Weight- Ounce, pound, and ton

-Volume- Drop, drops, teaspoon, tablespoon, teacup, cup, pint, quart, and gallon

-Equivalents

-16 ounces = 1 pound

-3 teaspoon = 1 tablespoon = ½ ounce

-16 tablespoons = 1 cup = 8 fluid ounces

-2 cups = 1 pint

-2 pints = 1 quart

-4 quarts = 1 gallon

-Temperature scales

-Fahrenheit- 32 degrees is the freezing point of water and 212 degrees is the boiling point of water

-Celsius- 0 degrees is the freezing point of water and 100 degrees is the boiling point of water

-Conversion between Fahrenheit and Celsius

- Fo = 1.8 Co + 32

- Co = (Fo – 32) / 1.8

-Converting among measurement systems- can be accomplished, refer to page 47, table 3.8 and 3.9

-Drug calculation

- Calculating the number of tablets, capsules, and milliliters

- Want / have

-Want- desired dose

-Have- available dose per tablet

- Dosage calculations with conversions

- (Dosage in ordered unit) x (conversion fraction) = (dose in desired unit)

-Refer to page 50-51

-Children’s doses

- Adjusting doses by age

- (Patient’s age, in months) x (usual adult dose) / (adult age, always 150 in months) = (child’s dose)

-Refer to page 52

- Adjusting doses by weight

- (Patient’s weight) x (usual adult does) / (adult weight, always 150 lbs) = child’s dose

-Refer to page 52

- Parenteral therapy

- (Order amount to be delivered/ total time of delivery) x (tubing drop factor / 1 cc) x (1 hour / 60 minutes) = drops a minute

-Refer to pages 52-53

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download