1. Medical Dosage Calculation Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton CHAPTER Tenth Edition A Dimensional Analysis Approach Household and Metric Systems 4

2. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Directory Classroom Response System Questions Lecture Note Presentation

3. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Classroom Response System Questions

4. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #1 How many milligrams would you administer po to the patient if the order for the sedative drug, triazolam (Halcion), was 0.075 grams?

5. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #1 Choices 1.1.75 mg 2.7.5 g 3.0.75 mL 4.75 mg

6. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #1 Response 1.1.75 mg 2.7.5 g 3.0.75 mL 4.75 mg

7. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #2 ¼ pint = ? ounces

8. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #2 Choices 1.4.5 oz 2.2 oz 3.4 oz 4.0.02 oz

9. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #2 Response 1.4.5 oz 2.2 oz 3.4 oz 4.0.02 oz

10. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #3 The prescriber ordered 5% D/W 0.7 L IV every eight hours. How many milliliters are contained in this amount of solution?

11. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #3 Choices 1.70 mL 2.0.7 mL 3.700 mL 4.0.5 mL

12. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #3 Response 1.70 mL 2.0.7 mL 3.700 mL 4.0.5 mL

13. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #4 The patient must receive 0.75 milligrams of dexamethasone po stat (“immediately.”) What is the equivalent dose in micrograms?

14. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #4 Choices 1.75.0 g 2.750 mcg 3.75 mL 4.7.5 mcg

15. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #4 Response 1.75.0 g 2.750 mcg 3.75 mL 4.7.5 mcg

16. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #5 Change 0.25 liters to milliliters.

17. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #5 Choices 1.250 mL 2.25 mL 3.2.5 mL 4.4 mL

18. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Question #5 Response 1.250 mL 2.25 mL 3.2.5 mL 4.4 mL

19. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Lecture Note Presentation

20. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton glass ounce cup teaspoon The Household System

21. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Because the volume of ordinary household spoons, cups, or glasses may vary, some of the equivalences in the following Table are only approximate. Alert

22. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.1 Household Equivalents of Liquid Volume

23. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.2 Household Equivalents of Weight

24. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.3 Household Equivalents for Length

25. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton 2 oz = ? T Example 4.1 The prescriber directs the patient to take 2 ounces of a laxative agent, citrate of magnesia, whenever necessary. How many tablespoons would the patient take?

26. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton You want to cancel the ounces and obtain the equivalent amount in tablespoons. Because 2 T = 1 oz, the fraction is Example 4.1 (continued)

27. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The calculation would look like this: The patient should take 4 tablespoons of citrate of magnesia whenever necessary. Therefore, 2 ounces is approximately the same as 4 tablespoons. Example 4.1 (continued)

28. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton A patient drank 24 oz of the laxative agent COLYTE. How many glasses did the patient drink? 24 oz = ? glasses 3 1 = 3 glasses Example 4.2

29. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Weight in the Household System oz. pound ounce lb.

30. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton An infant weighs 8 pounds 11 ounces. What is the weight of the infant in ounces? First, you need to change the 8 pounds to ounces. Example 4.3

31. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The equation would be You want to cancel the pounds and obtain the equivalent amount in ounces. 8 lb =? oz Example 4.3 (continued)

32. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Because 16 oz = 1 lb, the fraction is Example 4.3 (continued)

33. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Then, you would add the extra ounces. 139 oz So, the 8-pound, 11-ounce infant weighs 11 oz =128 oz + 139 ounces. Example 4.3 (continued)

34. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Example 4.3 (length) A child is 3 ft 2 in tall. Find the child’s height in inches.

35. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The Metric System milliliter liter mL cubic centimeter

36. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The Metric System The metric system is the most widely used system of measurement in medical dosage calculation.

37. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.4 Format of the Metric System

38. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.5 Metric Prefixes Used in Health Care

39. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.6 Metric Equivalents of Liquid Volume

40. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.7 Metric Equivalents of Weight

41. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Table 4.8 Metric Equivalents of Length

42. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Convert 1,750 milliliters to an equivalent volume in liters? For this example, to convert 1,750 milliliters to liters is a jump of 3 places to the left, literdecicentimilli LmL Example 4.4

43. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton In 1,750 mL, move the decimal point 3 places to the left as follows: So, 1,750 mL = 1.75 L 1,750 mL = 1,750.mL = 1 7 5 0 L Example 4.4 (continued)

44. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Convert 4.5 kilograms to an equivalent amount in grams. To convert kg to g, jump 3 decimal places to the right. kilogramgrammilligrammicrogram kggmgmcg Example 4.5

45. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Move the decimal point 3 places to the right. 4.5 kg = 4.500 kg = 4 5 0 0 g So, 4.5 kilograms is equivalent to 4,500 grams. Example 4.5 (continued)

46. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton If the prescriber ordered 0.5 L of 5 % dextrose in water, how many milliliters were ordered? Example 4.5 (continued)

47. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The patient is to receive 1750 mL of 0.9 % NaCL IV q12h. What is this volume in liters and what does this order mean? Example 4.5 (continued)

48. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The order reads 125 mcg of Lanoxin (digoxin) PO daily. How many milligrams of this cardiac medication would you administer to the patient? How would it be administered? Example 4.5 (continued)

49. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton The order reads Glucotrol (glipizide) 15 mg PO daily ac breakfast? How many grams of this hypoglycemic agent would you administer? How and when? Example 4.5 (continued)

50. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Convert 4.5 kilograms to an equivalent amount in grams. Example 4.5 (continued)

51. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton A would has a length of 0.7 centimeters. What is the length of this wound in millimeters? Example 4.5 (continued)

52. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Chapter Summary The metric system is the dominant system used in health care. It is important to memorize the equivalences between the various units of measurement of the household and metric systems.

53. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton It is important to memorize the abbreviations for the various units of measurement. To convert units of measure in the metric system, use the shortcut method of moving the decimal point. Always jump 3 places except for cm-mm conversions, which use a 1 place jump. Chapter Summary

54. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton kilogramgrammilligrammicrogram kgg, Lmg, mLmcg Chapter Summary Memorize and Remember, each jump is 3 places in this chart:

55. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Chapter Summary (You must know these rules) Abbreviations for units of measurement are not followed by periods. Example: 40 mg and 5 t (not 40 mg. and 5 t.). Abbreviations for units of measurement are not made plural by adding the letter s. Example: 70 mcg and 3 oz (not 70 mcgs and 3 ozs).

56. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Insert a leading zero for decimal numbers less than 1. Example: 0.05 g and 0.34 mL (not.05 g and.34 mL). Omit trailing zeros for decimal numbers. Example: 7.3 mL and 0.07 g (not 7.30 mL and 0.070 g). Numbers greater than 999 need commas. Example: 2,500 mL and 20,000 mcg (not 2500 mL and 20000 mcg). Chapter Summary

57. Copyright ©2012, ©2008 by Pearson Education, Inc. All rights reserved. Medical Dosage Calculations: A Dimensional Analysis Approach, Tenth Edition June L. Olsen Anthony P. Giangrasso Dolores Shrimpton Leave space between the number and the unit of measurement. Example: 60 mL and 100 g (not 60mL and 100g). Avoid the use of fractions with metric units of measurement. Example: 0.5 mL and 1.5 g (not 1/2 mL and 1 1/2 g). Chapter Summary