1. Conversion and Calculations of Healthcare Measurements

2. Solution Concentrations Volume of Solutions/Blood
Metric Units
Measurements are used often in Healthcare.
The Clinical laboratory uses measurement in almost all aspects of its operation.
Ex.
Solution Concentrations
Cell Counts
Density of Specimens
Volume of Solutions/Blood
Dilutions
Time
Temperatures

3. Which method is best to convert between units?
Converting between units can be done in different ways. Initially, students learn to convert units using the ladder method. This method is not appropriate for healthcare. As conversions progress in difficulty, particularly between measurement systems it is best to use the dimensional analysis /proportional relationship method.

4. Scientists and Healthcare Professionals Work in Metric Units
Measurements made in the Healthcare Laboratory have a direct impact on the quality of patient care. It can be a matter of determining a diagnosis, follow the course of a disease and prescribing the correct treatment. The measurement must be reliable, accurate, standardized and precise. Measurements in healthcare can mean the difference between life and death.
Reinforce the importance of precision and accuracy of measurement in Health Care.

5. 4/20/01
0.5 versus 5

6. Systems of Measurement
United States
English System of Measurement, sometimes called the U.S. customary system. Used in every day life in the U.S. for measurement.
English Units for Distance:
Inch, feet, yard, mile, etc.
Example: How many inches are
there in 12 feet?
12 inches (”) =1foot (’)
12” * 12’ = 144”

7. English System of Measurement
Other common Units in the English System Pound Cups Pint Miles These units are not accurate enough for scientific measurement; hence the most accurat system the metric system is used.

8. Metric System
Used internationally by scientists and Healthcare In most countries the metric system is used in everyday The metric system is based on the power of 10, decimal system with a fundamental unit Due to the decimal system very, very small quantities can be measured accurately and easily.

9. Groups of Ten
The Metric system is based on Powers of Ten. Ten of one unit equals 1 of the next, and ten of those equals 1 of the next… and so on and so on.
Have students come up with a mnemonic to help them remember the powers of 10
Example: King Henry Died Basically Drinking Chocolate (Kilo, Hecta, Deca, Basic Unit, Deci, Centi, Milli, Micro, Nano).

10. Base Units of the Metric System
Different units are used to measure different things.
Length – Meters
Mass – Grams
Volume – Liters
Density – Mass/Volume
Also part of the Metric System:
Temperature - Celsius
Differentiate between the English and Metric Measurement in Healthcare. Emphasize the base units for length (m), mass (g), volume (L), density (g/ml). Temperature ©, and the tools to conduct each measurement.
It may be a good idea to demonstrate the different measurements for the class.

11. Measurements of Length
Base Unit
Meter
Type of Measure
Length
Tool
Ruler

12. Measurements of Mass
Base Unit
Gram
Type of Measure
Mass
Tool
Scale

13. Measurements of Volume
Base Unit
Liter
Type of Measure
Volume
Tool
Graduated Cylinder

14. Measurement of Temperature
Base Unit
Degree Celsius
Type of Measure
Temperature
Tool
Thermometer

15. Temperature is not reported in metric or SI units
Three Scales
Fahrenheit
boiling point 212° F
freezing point 32 ° F
Used in the U.S. for cooking, body temperature and weather
Celsius
boiling point 100° C
freezing point 0° C
Used for making most scientific temperature measurements. Most countries other than the US use the Celsius scale for everyday temp.
Kelvin
The Kelvin scale is a scientific scale for the temperature above absolute zero (0 K, °C). The difference in scales is

16. Conversion of Temperature

17. Conversion of Temperature
If someone says that the temperature will be 303 K today, how can you express that temperature in °C and °F? Try to Solve
To convert from Kelvin to Celsius: TC = TK - 273
To convert from Celsius to Fahrenheit: TF = 9/5(TC) + 32

18. Conversion of Temperature
If someone says that the temperature will be 303 K today, how can you express that temperature in °C and °F?
To convert from Kelvin to Celsius: TC = TK  TC = TC = 30°C
To convert from Celsius to Fahrenheit: TF = 9/5(TC) TF = 9/5(30) TF = 86°F
Temperature Conversion Answer
30°C, 86°F

19. International System of Units
Standardize scientific measurements worldwide
In the U.S. SI units are mandated in all federal agencies
SI units are derived from the metric system are based on seven fundamental units.

20. Again the Fundamental Units of the Metric System are…
Different units are used to measure different things. Length – Meters Mass – Grams Volume – Liters Density – Mass/Volume Also part of the Metric System: Temperature - Celsius

21. Common Basic Units in Healthcare
Liter Meter Gram In the laboratory it is more common to measure smaller units than the basic units.

22. Metric System uses Power of 10
Prefixes are added to the base unit (ex. liter,meter or gram) to indicate larger or smaller units.

23. cm=centimeter cc=cubic cm milli- m thousandth 1/1000 = 0.001 10-3
mega- M
million
1,000,000
106
kilo- k
thousand
1,000
103
kilograms
deci- d
tenth
1/10 = 0.1
10-1
dm3=liter
centi- c
hundredth
1/100 = 0.01
10-2
cm=centimeter cc=cubic cm
milli- m
thousandth
1/1000 = 0.001
10-3
mg=milligram mL=milliliter
micro-
millionth
1/1,000,000 =
10-6
µg=microgram
nano- n
billionth
1/1,000,000,000 =
10-9
nm=nanometers
Examples
Metric facts: 1 cubic centimeter = 1 milliliter (1 cc=1mL) Liter = 1 cubic decimeter = 1,000 cubic centimeters = 1,000 milliliters Lower case “m” stands for meter or “milli”. Capital “L” for liter.

24. Unit Prefixes
Simply add a prefix to the unit to show the quantity, size or value in powers of ten
Units Larger than the base:
deca = 10 x
hecto = 100 x
kilo = 1,000 x
Units Smaller than the base:
deci = .1 x
centi = .01 x
milli = .001 x

25. What to do to solve metric conversions problems?
Identify what you are asked. Write down what is given or known. Look for relationships between knowns and unknowns (use charts, equations). Rearrange the equation to solve for the unknown. Do the computations, cancel the units, check for reasonable answers.

26. Steps of Dimensional Analysis
Start with what value is known, proceed to the unknown.
Starting point = the number and unit provided by the question
Final destination = the units desired after converting
Draw the dimensional lines (count the “jumps”).
Insert the unit relationships.
Cancel the units.
Do the math, include units in answer.

27. Dimensional jumps between prefixes
How many jumps between deci and giga 10-1 x 10 9 = 10 jumps (9-(-1) =10)
For the next few slides instructs students to identify the known and unknown and set up a proportional relationship, using both the chart and dimensional jump methods. Demonstrate both methods to the students.

28. Write the KNOWN, identify the UNKNOWN.
EX. How many km is 582 mm ?
582mm = ______km

29. Draw the # of dimensional “jumps”
EX. How many km is 582 mm ?
582 mm2 x_____ x_____x_____x_____x_____x_____

30. Using the dimensional jump method
582 mm x_____ x_____x_____x_____x_____x___

31. *Units leftover SHOULD be units of
Cancel Units
582mm x mm cm dm m
dkm hm km
*Units leftover SHOULD be units of
UNKNOWN

32. Insert Relationships (Prefixes from the known to the unknown)
How many km is 582 mm ?
582 mm x_.1cm_ x_____x_____x_____x_____x_____
.1dm
.1m
.1dkm
.1hm
.1km
1 dm
1 mm
1cm 1m
1dkm
1hm

33. Do the Math
582mm x mm cm dm m
dkm hm km

34. Do the Math
582mm x = km

35. Chart Method Convert 5234 millimeters to meters
Starting amount
equal
End Amount
5234 millimeters
0.001
= meters
milli
5234 millimeters meters
1000

36. Convert 21 mg per liter (21 g/L) to grams per 100 cc
Starting amount
equal
equal
equal
End Amount
21 mg Liter
0.001 milli
1L 1000cc
= g cc

37. Conversion of Metric Units to Metric Units
The ratio and proportion procedures is probably the most useful way to convert one unit of measure to another
Ex.
How many milligrams equal 0.025g?
The unknown ratio is 0.025g to “x” mg.
Make a ratio:
0.025g/x mg = 1g/1,000mg
x= X 1,000
x = 25 mg
Hence 25mg = g