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 Calculating Pediatric Dosages 12

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 A 10 year old child has a fever of 101 degrees F, and 400 mg po of the antipyretic acetaminophen (Tylenol) has been ordered. If the elixir is labeled 160 milligrams per 5 milliliters, how many teaspoons will you give to the child?

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 1.0.25 t 2.5 tsp 3.2 ½ tsp 4.0.4 t

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 1.0.25 t 2.5 tsp 3.2 ½ tsp 4.0.4 t

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 The prescriber ordered: amoxicillin 20 mg/kg q8h. Calculate the dose of this antibiotic for a child who weighs 42 kilograms.

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 1.240 mg 2.270 mg 3.820 mg 4.840 mg

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 1.240 mg 2.270 mg 3.820 mg 4.840 mg

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 A child is to receive an IV bolus of 1% lidocaine, 0.1 milligram per kilogram. How many milliliters will you prepare for a child who weighs 40 kilograms?

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 1.0.4 mL 2.0.004 mL 3.000.3 mL 4.000.04 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 Resopnse 1.0.4 mL 2.0.004 mL 3.000.3 mL 4.000.04 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 Prescriber’s order: Lanoxin (digoxin) 0.1 mg IM daily. The label reads 0.1 mg/mL injection. What is the 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 1.0.1 mcg 2.0.01 mcg 3.0.001 mcg 4.0.0001 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 1.0.1 mcg 2.0.01 mcg 3.0.001 mcg 4.0.0001 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 A child who weighs 18 kg is to receive Motrin (ibuprofen) 8 mg/kg po q4h prn for pain. The label reads 100 mg/5 mL. How many milliliters will you administer?

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 1.0.7 mL 2.0.9 mL 3.7.3 mL 4.7.2 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 1.0.7 mL 2.0.9 mL 3.7.3 mL 4.7.2 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 Learning Objectives 1.Determine if a pediatric dose is within the safe dose range. 2.Calculate pediatric oral and parenteral dosages based on body weight. 3.Calculate pediatric oral and parenteral dosages based on body surface area. 4.Perform calculations necessary for administering medications using a volume control chamber. 5.Calculate daily fluid maintenance.

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 Figure 12.1 A bottle of oral medication and a measuring spoon.

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 Figure 12.2 Liquid medication administration devices:Two droppers, an oral syringe, and a measuring spoon.

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 Example 12.1 Order: erythromycin 30 mg/kg po q6h. Read the label below. The child weighs 38 kilograms. How many milliliters of the drug will you administer to this child?

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 Start with the size of the patient. Example 12.1 28.5 mL 4 1

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 Example 12.2 A drug is ordered: 0.045 mg IM stat. The child weighs 40 kilograms, and the recommended dose is (0.001-0.002) milligram per kilogram. Is this ordered dose safe for this child?

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 Using the minimum recommended dose of 0.001 mg/kg, find the minimum recommended dose in mg for this child. Using the maximum recommended dose of 0.002 mg/kg, find the maximum recommended dose in mg for this child. Example 12.2

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 Example 12.2 So, the safe dose range for this child is (0.04–0.08) mg. Because the prescribed dose of 0.045 mg is in this range, it is a safe dose for this child.

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 Figure 12.5 Volume control chamber.

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 Pediatric Daily Fluid Maintenance Formula For the first 10 kg of body weight: 100 mL /kg For the next 10 kg of body weight: 50 mL / kg For each kg above 20 kg of body weight: 20 mL / kg

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 The order is maintenance for a child who weighs 35 kg. At what rate should the pump be set in mL/h? Divide the child’s weight (35 kg) into three portions as follows: 35 kg = 10 kg + 10 kg + 15 kg Example 12.3

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 1st Portion 10 kg x 100 mL kg =1,000 mL 2nd Portion 10 kgx 50 mL kg =500 mL 3rd Portion 15 kgx 20 mL kg =300 mL Total 35 kg1,800 mL Example 12.3

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 The daily “maintenance” was determined to be 1,800 mL per day. So, the pump would be set at 75 mL/h. Example 12.3

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 Chapter Summary Taking shortcuts in pediatric medication administration can be fatal to the child. Check to see if the order is in the safe dose range. Consult a reliable source when in doubt about a pediatric medical order.

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 Chapter Summary Question the order or check your calculations if the ordered dose differs from the recommended dose. Pediatric dosages are sometimes rounded down (truncated) to avoid the danger of an overdose. IV bags of no more than 500 mL should be hung for pediatric patients.

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 Chapter Summary No more that 2 mL should be given IM to a pediatric patient. Because accuracy is crucial in pediatric infusions, electronic control devices or volume control chambers should always be used. For a volume control chamber, a flush is always used to clear the tubing after a medication is infused.

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 Chapter Summary Know the facility policy regarding the inclusion of medication volume as part of the total infusion volume. Minimal and maximal dilution volumes for some IV drugs are recommended in order to prevent fluid overload, minimize irritation to veins, and reduce toxic effects.

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 Chapter Summary When preparing IV drug solutions, the smallest added volume (minimal dilution) results in the strongest concentration; the largest added volume (maximal dilution), results in the weakest concentration. Daily fluid maintenance depends on the weight of the child and includes both oral and parenteral fluids.