Calculations in Pediatric Medication Administration

1
Calculations in Pediatric Medication
Administration

• Barbara Weatherford MS, RN

2
Common Conversions

• 2.2 pounds 1 kilogram (Kg)
• 16 oz 1 pound
• 1000g 1 Kg
• 1 teaspoon (tsp) 5cc
• 3 tsp 1 tablespoon (T)
• 1 ml 1 cc
• 1000 ml 1 liter (L)
• 1 oz 30 cc or 30 ml

3
Practice problems

• 0.5 L _____ ml
• 1000g _____ Kg
• 250 ml _____L
• 2 kg _____ lb
• 2 g _____ mg

4
Answers

• 0.5 L 500 ml
• 1000g 1 Kg
• 250 ml .25 L
• 2 kg 4.4 lb
• 2 g 2000 mg

5
Calculating tsp cc

• 5cc 1 tsp
• Order The order reads Tylenol for fever gt 102
  R, 80 mg po q4 prn for a 3 year old.
• Tylenol liquid comes 160 mg/5cc.
• How many ccs of Tylenol will you give?

6
Tylenol calculation

• Tylenol ordered is 80 mg, comes prepared as
  160/5cc.
• equation
• 160/5 80/x
• 160x 400
• x 2.5cc

7
Discharge meds

• This same 3 year old is now being discharged and
  you need to teach the mother how to administer
  Tylenol at home.
• 5cc 1 tsp
• 2.5 cc ½ (.5) tsp
• How do you instruct her to measure the dose at
  home?

8
Calculating weight based doses

• The order reads Rocephin (ceftriazone sodium),
  100 mg/kg of body weight, in divided doses every
  12 hours IV (not to exceed 4 g), for Alice, who
  weighs 66 pounds. How many milligrams will Alice
  receive?

9
Answer

• 1500 mg
• convert pounds to kilograms -66 lb30 kg
• compute the number of milligrams based on 100
  mg/kg ( 100 X 30 3000 mg)
• divide 3000 by 2 (every 12 hours) 1500

10
Weight based 2

• The order reads Garamycin (gentamycin sulfate)
  IV , 6mg/kg/day, for a child weighing 52 pounds.
  How many milligrams will be given daily?

11
Answer

• 141.8 or 142 mg.
• It is a good idea to double check your
  calculations with another licensed nurse.
• In clinical, your instructor will check all of
  your calculations.
• NEVER be hesitant to ask someone to check your
  math.

12
Is this a safe dose?

• Why do we need to check the dose on a new order?
• Dosages for children based on body size and
  weight (BSA).
• Most reference manuals give adult dosages of meds
  unless you have a pediatric drug reference book

13
Is this a safe dose?

• Role of RN in medication safety is to check
  initial dosages EVEN if there is a unit dose
  system and the pharmacist has checked the dose
  and the pediatrician has been in practice for 25
  years and is excellent.
• Making mistakes is not about being a good or bad
  person, it is about following the steps to good
  medication safety

14
Is this a safe dose?

• You will be asked by your instructor for every
  new medication you administer, Is this a safe
  dose? Please have your calculations ready.

15
Is this a safe dose?

• Order Tylenol ( Acetaminophen) liquid, 5cc(160
  mg) po q 4h, prn for temp over 102.
• The child weighs 30 lbs (13.6 kg)
• Drug reference states dosage for children is
  10-15 mg/kg/dose q 4h as needed. Max. 5 doses/ 24
  hours
• Is this a safe dose?

16
YES!

• 10-15mg/kg/dose
• weight 13.6 kg x 15 204 mg.
• ordered dose 180 mg
• safe dose

17
Calculating IVs

• Almost all pediatric IVs on pumps
• Depending on setting, there may be different
  pumps for children under 2 and different policies
  on use of buretrols.

18
IV calculation

• Order D5W 50 ml with 20 mEq KCL to infuse at 8
  mEq KCL/hr per IV pump.
• How many ml/hr will you administer?
• 20 ml/hr

19
IV calculation

• ratio-proportional method
• 20 mEq 50 ml 8mEq x
• 20x 400
• x 400/20 20 ml/hr
• Fraction
• 20 mEq 8mEq 20x 400
• 50ml x x400/20
  20ml/hr

20
IV IV calculation

• Order Decadron(Dexamethasone) 1.5 mg q 6h IV.
  Decadron is packaged 4mg/cc in a 1 ml vial.
• What is the dose in ml?
• The drug reference states for IV infusion, dilute
  in NaCl or D5W and infuse over 15-30 minutes.
• You plan to dilute in 10 cc and infuse over 15
  minutes. What will be the IV rate?

21
Decadron problem

• dosage to be administered .375 mg in 10 cc of
  diluent
• IV pump rate 40 cc per hour or 10 cc/15 min
• Set pump for 40 cc/hr, amt to be infused at 10
  cc. More on pumps in lab and clinical
  orientation at your site.

22
Calculating doses using BSA

• BSA body surface area
• common with chemotherapy and pediatrics
• be familiar with concept, will not be tested on
  it but you may see in practice.
• Use of nomogram