Example 3: A 30 kg patient is ordered a PCA bolus dose of Hydromorphone 0.12 mcg. You find out that as per Pain Service Dosing Guidelines, a usual bolus dose is 3-5 mcg/kg.

a)Was the ordered PCA bolus dose therapeutic? Explain your rationale.

b)Provide the equivalent of the 0.12 mcg dose of Hydromorphone in mcg/kg for this patient.

Example 6: The prescribed dose of Acetaminophen is 10 mg/kg/dose q 4 hrs. The child weighs 30 kg.

a)How much will he receive in one day?

b)How much will he receive q4h?

Example 7: The order is as follows: Morphine Infusion 5 mg in 50 ml Normal Saline, to deliver 20 mcg/kg/hr, run infusion at 6 ml/hr. The patient’s weigh is 30kg. Morphine is available in 10 mg/ml injection ampoules.

a. The recommended dose for Morphine infusion is 0.01 -0.04 mg/kg/hr. Is the dose you are giving appropriate?

b. What is the volume of Morphine you must draw up to make up the above infusion?

Example 9: You need to infuse 50 ml of an IV medication over 10 minutes. Provide the rate in ml/hr that will need to be set on the infusion pump.

ANSWER

Calculating Medication Doses: Ensuring Safe Administration

Medication dosing is a critical aspect of healthcare, ensuring patients receive the appropriate amount of medication for their condition. In this essay, we will explore several examples of medication dosing calculations and discuss the rationale behind each calculation.

Example 3: Hydromorphone PCA Bolus Dose

Therapeutic Dose Evaluation:
The ordered PCA bolus dose of Hydromorphone is 0.12 mcg. According to Pain Service Dosing Guidelines, the usual bolus dose range is 3-5 mcg/kg. To determine if the ordered dose is therapeutic, we need to calculate the patient’s weight-based dose using the lower and upper limits of the guideline range.

Patient’s Weight: 30 kg
Usual Bolus Dose Range: 3-5 mcg/kg

Lower Limit: 3 mcg/kg * 30 kg = 90 mcg
Upper Limit: 5 mcg/kg * 30 kg = 150 mcg

The ordered dose of 0.12 mcg is significantly below the therapeutic range of 90-150 mcg. Therefore, the ordered PCA bolus dose is not therapeutic and needs adjustment.

Equivalent Dose in mcg/kg:
To determine the equivalent dose of 0.12 mcg Hydromorphone in mcg/kg, we can use the patient’s weight.

Equivalent Dose = 0.12 mcg / 30 kg = 0.004 mcg/kg

Example 6: Acetaminophen Dosing

Total Dose in One Day:
Prescribed Dose: 10 mg/kg/dose
Patient’s Weight: 30 kg

Total Dose = 10 mg/kg * 30 kg = 300 mg

Dose q4h:
The patient receives the dose every 4 hours. To calculate the total dose in 24 hours, we can use the following calculation:

Total Dose in 24 Hours = 300 mg * (24 hours / 4 hours) = 1800 mg

Example 7: Morphine Infusion

Appropriateness of Dose:
Patient’s Weight: 30 kg
Ordered Infusion Rate: 20 mcg/kg/hr

Calculated Infusion Dose = 20 mcg/kg/hr * 30 kg = 600 mcg/hr
The calculated dose falls within the recommended dose range of 0.01 – 0.04 mg/kg/hr, confirming the appropriateness of the dose.

Volume of Morphine to Draw:
Morphine Concentration: 10 mg/ml
Ordered Infusion Rate: 6 ml/hr

Dose in mg = 600 mcg = 0.6 mg (since 1 mg = 1000 mcg)
Volume to Draw = Dose / Concentration = 0.6 mg / 10 mg/ml = 0.06 ml

Example 9: IV Medication Infusion Rate

To calculate the infusion rate in ml/hr for infusing 50 ml of medication over 10 minutes (0.1667 hours), we can use the following calculation:

Infusion Rate = Volume / Time = 50 ml / 0.1667 hours ≈ 300 ml/hr

Conclusion

Accurate medication dosing calculations are crucial to ensuring patient safety and effective treatment. By performing these calculations and evaluating the therapeutic range, healthcare professionals can confidently administer medications and optimize patient outcomes. It is essential to use weight-based dosing guidelines and consider medication concentrations to ensure accurate administration and prevent medication errors.