Additional Conversions Used In Health Ca

• 1. Calculate with Confidence 5 thedition Gray Morris Mosby items and derived items 2010 by Mosby, Inc., an affiliate of Elsevier Inc.

2. Additional Conversions Usefulin the Health Care Setting Unit Two: Chapter 9 Mosby items and derived items 2010 by Mosby, Inc., an affiliate of Elsevier Inc. 3. Additional Useful Conversions:Objectives

• After reviewing this chapter, you should be

• able to:

• • Convert between Celsius and Fahrenheit temperatures

• • Convert between units of length: inches, centimeter, and millimeters

• • Convert between units of weight: pounds and kilograms, pounds and ounces to kilograms

4. Converting BetweenCelsius and Fahrenheit

• Temperature reading followed byF= Fahrenheit (e.g., 98 F)

• Followed byC= Celsius (formerly centigrade) (e.g., 36 C)

• Freezing point of H 2 O is 32 F and 0 C

• Boiling point of H 2 O is 212 F and 100 C

5. Figure 9-1 Celsius and Fahrenheit temperature scales. (From Clayton BD, Stock YN:Basic pharmacology for nurses,ed. 14, St. Louis, 2007, Mosby.)Note:Glass thermometers pictured here are for demonstration purposes only. Electronic digital temperature devices are more commonly used in health care settings. Figure 9-2 Ranges of normal temperature values and physiological consequences of abnormal body temperature. (From Potter PA, Perry AG:Fundamentals of nursing,ed. 7, St. Louis, 2009, Mosby.) 6. Temperature Conversion Formulas

• To convert from Celsius to Fahrenheit, multiply by 1.8 orand add 32

• Example: Convert 37.5 C to F

• F = 1.8(C) + 32or F = 9/5(C) + 32

• F = (1.8)37.5 + 32

• F = 67.5 + 32

• F = 99.5

7. Temperature Conversion Formulas (contd)

• To convert from Fahrenheit to Celsius, subtract 32 and divide by 1.8 or

• Example: Convert 68 Fto C

• Formula:C = (F - 32)9/5

• C = (68 - 32)9/5

• C = 369/5, which inverts to be C = 365/9

• C = 180/9

• C = 20

8. Conversions: Metrics and Length

• Metric measures are used for

• • Pupil size

• • Babys head circumference

• • Wounds and incisions(lengthwidthdepth in cm or mm)

• Conversion factor: 1 cm = 10 mm

• If incision is 25 cm, how many mm is it?

• 25 mm = 2510 = 2.5 cm or 25 = 2.5 cm

9. Conversions: Metrics and Length (contd)

• Convert 30 cm to inches (in)

• Conversion factor: 1 in = 2.5 cm

• Think smaller to larger (divide)

• 302.5 = 12 in

10. Conversions Relating to Weight

• Body weight is important in calculating doses for certain medications

• Delivered in mg or mcg per kilogram

• Nurse needs to calculate safety of doses documented as mg/kg

• May need to convert pounds and ounces in pediatric calculations

11. Conversions Relating to Weight (contd)

• Pounds to Kilograms

• Conversion factor: 2.2 lb = 1 kg

• Smaller to larger (divide lb value by 2.2)

• Round answers to nearest tenth

• • Example:Convert 65 lb to kilograms

• • kg = 652.2 = 29.54rounds to29.5 kg

12. Conversions Relating to Weight(cont)

• Poundsandounces to kilograms

• • Convert oz to nearest tenth of lb and add to pounds

• • Equivalent: 16 oz = 1 lb

• • Convert total lb to kg, then round to nearest tenth

13. Conversions Relating to Weight (contd)

• Pounds and ounces to kilograms (contd)

• • A child weighs 10 lb 2 oz

• • Think smaller to larger

• • • 2 oz 16 = 0.12rounds to0.1 lb

• • • 10 lb + 0.1 lb = 10.1 lb

• • Think smaller to larger

• • • 10.12.2 = 4.59rounds to4.6 kg

14. Conversions Relating to Weight (contd)

• Kilograms to Pounds

• Multiply by 2.2 (think larger to smaller)

• Equivalent: 1 kg = 2.2 lb

• A child weighs 24.7 kg; convert to pounds

• lb = 24.72.2 = 54.34rounds to54.3 lb

• • (weight in kg)(equivalent)

15. Military Time

• International time

• Uses a 24-hour clock

• Helps prevent errors by eliminating repetition of numbers

• No colon (:) or a.m./p.m. designations

• Midnight = 0000 and 2400

• 1:00 a.m. = 0100

• Now referred to as Computer Time

16. Figure 9-3 Clocks showing traditional and military time. 17. Time: Traditional to Computer

• To convert a.m. time, omit the colon and a.m., then add a zero to the beginning to make a four-digit number

• • Example: 8:45 a.m. = 0845

• To convert p.m. time, omit the colon and p.m., then add 1200 to the time

• • Example: 7:50 pm = 1950

18. Time: Computer to Traditional

• To convert times between 0000 and 1200,delete any zero at the beginning, insert colon, and add a.m.

• • Example: 0845 = 8:45 a.m.

• To convert times between 1200 and 2400, subtract 1200, insert colon, and add p.m.

• • Example: 1950 = 7:50 p.m.