Final answer:
To administer the prescribed 4 mg dose of dexamethasone from a concentration of 10 mg/mL, calculate the volume using the formula Dose ordered (mg) / Concentration (mg/mL). This results in a volume of 0.4 mL to be administered intravenously.
Step-by-step explanation:
To administer the correct dose of dexamethasone, we need to perform a simple calculation based on the concentration of the medication provided. The doctor has prescribed 4 mg of dexamethasone, and the available medication is in a concentration of 10 mg/mL. To find out how many mL of the vial is needed for a 4 mg dose, we use the following calculation:
Dose ordered (mg) / Concentration (mg/mL) = Volume to administer (mL)
Using the figures provided:
4 mg / 10 mg/mL = 0.4 mL
Therefore, you would administer 0.4 mL of the dexamethasone to the patient.