In: Nursing
The physician has ordered ampicillin 1.4 grams (g) intravenous (IV) every 4 hours for your patient. SHOW YOUR WORK !
1. The ampicillin for injection is available in a vial that has 2 g in 5 mL. How many mL will you need to withdraw from the vial for the 1.4-g dose?
2. You add the ampicillin you withdrew from the vial to a 50 mL IV bag of normal saline. The physician’s order specifies to infuse this IV bag with ampicillin over 30 minutes. At what rate (in mL/hr) will you set the IV pump?
1. A vial of ampicillin contains 5 ml = 2 gms of the drug.
Dose ordered in grams = 1.4 gms
Dose ordered in ml = ??. Lets consider the required dose in ml as X.
5ml = 2gms
X ml = 1.4 gms. So by applying cross multiplication principles 2X = 5 x 1.4
So X = 5 x 1.4 / 2 = 7 / 2 = 3.5 ml.
So 3.5 ml of the drug in a vial containing ampicillin has 1.4 gms of the drug. You need to withdraw 3.5 ml.
2. Nurse adds 3.5 ml of ampicillin to 50 ml IV Normal Saline which needs to be infused over 30 minutes.
Infusion pump needs to be set at ________ml/hr.
Formula for calculating ml/hr flow rate = Total volume to be infused / time in hrs.
Here total volume to be infused = 50 ml NS + 3.5 ml ampicillin = 53.5ml
Time = 30 minutes = 0.5 hrs
ml/hr = 53.5 ml / 0.5 hrs
= 107 ml/hr.
So the infusion pump is to be set at 107 ml/hr, so that 53.5 ml of the fluid will be infused over 30 minutes.