Correct Answer: 2.4

Here's how to calculate the volume (mL) of the reconstituted cefazolin solution the nurse should administer for each dose:

1. We know the following:

Prescribed dose: 800 mg cefazolin (given)

Vial information:

Contains 1 gram cefazolin (given) = 1000 mg (since 1 gram = 1000 milligrams)

Reconstituted with 2.5 mL sterile water for injection (given)

Yields a total volume of 3.0 mL (given)

2. We need to find the concentration of cefazolin (mg/mL) in the reconstituted solution.

3. Then, we can find the volume (mL) to administer for the prescribed dose (800 mg) considering the concentration.

Steps:

a. Calculate the concentration after reconstitution:

Total volume after reconstitution = 3.0 mL (given)

Total amount of cefazolin after reconstitution = 1 gram (from the vial) = 1000 mg

Concentration (mg/mL) = Total amount of medication (mg) / Total volume after reconstitution (mL)

Concentration (mg/mL) = 1000 mg / 3.0 mL

Concentration (mg/mL) = 333.33 mg/mL (round to one decimal place)

b. Calculate the volume to administer:

Volume to administer (mL) = Dose (mg) / Concentration (mg/mL)

Volume to administer (mL) = 800 mg / 333.33 mg/mL

Volume to administer (mL) = 2.4 mL (round to nearest tenth)

Therefore, the nurse should administer approximately 2.4 mL of the reconstituted cefazolin solution intramuscularly every 6 hours.