Final answer:
To deliver 0.24 mg/kg/hr of morphine to a 15 lb dog at a delivery rate of 20 mL/hr, 40.8 mg of morphine should be added to a 500 mL bag of fluids.
Step-by-step explanation:
To determine the amount of morphine to be added to the 500 mL bag of fluids, we first need to calculate the dosage based on the weight of the dog. The dog weighs 15 lb, which is approximately 6.8 kg. The dosage is given as 0.24 mg/kg/hr, so we multiply the weight of the dog by the dosage to get the hourly dosage.
Hourly dosage = 6.8 kg * 0.24 mg/kg/hr = 1.632 mg/hr
Since the delivery rate is 20 mL/hr, we can use this to calculate the concentration of morphine needed in the bag of fluids.
Concentration = Hourly dosage / Delivery rate = 1.632 mg/hr / 20 mL/hr = 0.0816 mg/mL
The concentration of morphine in the bag of fluids is given as 15 mg/mL. We can use this information to calculate the volume of morphine needed.
Volume = Concentration * Bag volume = 0.0816 mg/mL * 500 mL = 40.8 mg
Therefore, 40.8 mg of morphine should be added to the 500 mL bag of fluids to deliver the desired dosage to the 15 lb dog.