Review: D x Q = X Desired dose X Quantity = Unknown H Dose on hand Dose unit Physician orders Morphine Sulfate 2 mg IV q 4 hours prn pain. Stock: 4 mg/ml vial. How many ml will you give? Physician orders Gentamicin Sulfate 30 mg IM q 8 hours. Stock: 40 mg/ml vial. How many ml will you give? Physician orders Furosemide 12 mg PO q 8 hrs. Stock 10 mg/ml. How many ml will you give?
Pediatric Calculations: Step 1. Determine weight in kg Step 2. Determine safe dose range Step 3. Determine if ordered dose is safe Step 4. Calculate dose needed based on supply Practice: The HCP orders Acetaminophen 145 mg q 4-6 hours prn for fever/pain. The patient weighs 14.5 kg. The safe dose range for this drug is 10-15 mg/kg/dose, with a maximum of 5 doses/24 hrs. Stock 160 mg/5 ml 1. Determine weight in kg 2. Determine safe dose range 3. Determine if the dose is safe 4. Calculate how much to administer
Practice: The HCP orders Omnicef 125 mg PO BID for 10 days for a child weighing 33 pounds. The safe dosage range is 7 mg/kg q 12 hours. Available as 125mg/5ml. 1. What is the weight in kg? 2. What is the safe dosage range? 3. Is the ordered dose safe? 4. How much will the nurse instruct the parent to give? Pediatric Example: Order: Vancomycin 400 mg IV q 8 hours is ordered for a 12- yr-old with CF weighing 66 lbs. The safe dose range is 40 mg/kg/day in divided doses q 6-8 hours, maximum of 3-4 grams/day. Availability is Vancomycin 400mg/100 ml of NS. The medication needs to be administered over 90 minutes. Will you carry out this order? What is the flow rate for the infusion? Total ml ordered X 60 min/hr = ml/hr Total min ordered
IV formulas- determining drop factor: Calculate drop factor Used when need to manually regulate IV rate in gtts/min Volume x drop factor = gtts/min Minutes *drop factors may be 10, 15, 20, or 60 gtts/ml Drop Factor Examples: Order: Ampicillin 500 mg IV in 100 ml of NS, infuse over 45 minutes. The infusion set is calibrated for a drop factor of 20 gtt/ml. The order reads: Administer 1000cc of D5NS over 10 hrs. The drop factor on your tubing is 15 gtts/cc. How many gtts/min? Volume X drop factor = gtts/min Minutes
Calculating Flow Rate-Examples Order: Ampicillin 500 mg IV q 6 hours. Label: Ampicillin 500 mg/50 ml of NS. Administer over 30 minutes. How will you program the pump? Order: Rocephin 1 gram IV before surgery. Concentration is Rocephin 1 gram/100 ml of D5W. Administer over 20 minutes. What is the flow rate? Order: Vancomycin 500 mg IV q 12 hours. Pharmacy label: Vancomycin 500 mg/0.9% NS 100 ml. Administer over 2 ½ hours. What is the flow rate?
Summary of Rounding Pounds to kg Round to 2 decimal places Ex: 25 lbs. will be 11.36 kg Oral meds or IV meds Round one decimal place Ex: 2.56 ml will become 2.6 ml IV flow rates Round to nearest whole number Ex: 25.4 ml/hr will be 25 ml/hr Drops per minute Round to nearest whole number 62.6 gtts per minute will be 63 gtts/min
Pediatric Math Practice #1: 1. Order: Ferrous Sulfate 200 mg PO TID. Stock is 125mg/ml. How many ml will you give? (round to first decimal place) 2. Order: Amoxil 60 mg PO q 8 hours. Stock: 125mg/5ml. How many ml will you give? (round to first decimal place) 3. Order: Meperidine 20 mg IM stat. Stock: 50 mg/ml. How many ml will you give? (round to first decimal place) 4. Order: Colace syrup 10 mg PO BID. Stock: 20mg/5ml. How much will you administer? (round to first decimal place) 5. Order: Augmentin 175 mg PO q 8 hours. Child weighs 13.2 kg. Safe dose is 25-45 mg/kg/day in divided doses q 8 hours. (round to first decimal place) A. What is the safe individual dose? 6. Cefdinir is ordered for a child weighing 14.1 kg. The safe dosage is 7 mg/kg q 12 hours. A. What is the safe individual dose for this child? (round to first decimal place) 7. The physician orders gentamycin 80 mg IV q 8 hours for a child weighing 10 kg. The safe dose range is 6-7.5 mg/kg/day. 8. Order: Ampicillin 150 mg IM q 6 hours. The child weighs 21.82 kg. The safe dosage range is 25 to 50 mg/kg/day in divided doses q 6 hours. Stock: Ampicillin 125 mg/ml. 9. Order: Cloxacillin 250 mg PO q 6 hours. Child weighs 20 kg. The safe dose range is 50 mg/kg/day in divided doses q 6 hours. Stock: Cloxacillin 125mg/5ml.
10. Acetaminophen is ordered for a child weighing 25 lbs. The safe dose range is 10-15 mg/kg/dose. A. What is the safe individual dose range for this child? (round to first decimal place) 11. Order: Amoxicillin 275 mg PO q 8 hours for 10 days. Child weighs 10 kg. The safe dose range is 80-90 mg/kg/day in 3 divided doses. Stock: amoxicillin 125mg/5ml. 12. Tobramycin 100 mg IV q 8 hours is ordered for a child weighing 80 lbs. The safe dose range is 6-7.5 mg/kg/day in divided doses q 8 hours. 13. The HCP orders cephalexin 250 mg q 6 hours for a child weighing 29 kg. The safe dosage range is 75-100 mg/kg/day in 4 divided doses. 14. D5W is infusing at 100 ml/hour. You hung a 1 liter bag at 1500. What time will your infusion end? (Use military time) 15. Vancomycin 100 mg IV q 8 hours is ordered. You are to infuse the medication over 2 hours. Your availability is 100 mg/50ml. What is your flow rate? (round to nearest whole number) 16. Order: Administer 250 ml bolus of NS over 2 hours. What is your flow rate? (round to nearest whole number) 17. Order: Fortaz 2 grams q 8 hours. Your availability is 2grams/50 ml of D5 ½ NS. Infuse over 30 mins. What is your flow rate? (round to nearest whole number) 18. Order: 350 ml of D5 ½ NS to infuse over 8 hours. What is the hourly rate? (round to nearest whole number) 19. Order: 2L of D5 ¼ NS with 20 meq of KCl to infuse at 125 ml/hr. How many hours will the infusion last? 20. Order: 575 ml of TPN to infuse over 20 hours. What is the hourly rate? (round to nearest whole number)