Question:

A cat has just arrived to the veterinary clinic with low blood pressure. The cat weighs 5 kg, and as the on call Vet you want to use a bag of saline to prepare a dopamine drip for the cat. Based on the cat's weight you want it to receive 5 ml/hour of drip that has a concentration of 0.3mg/ml.

You also want the cat to receive the drip for at least 48 hours so you need to prepare 250 ml of the dopamine drip. How much dopamine do you need to add from a stock concentration of dopamine (200mg/5ml) to a final volume of 250 ml of saline?