1. What is the dosage rate in mg/min for an IV infusing at 120 mL/h with a concentration of 20 mg in 200 mL NS?
2. How many mL should be drawn from a vial containing acyclovir sodium (Zovirax) with a concentration of 20 mg/mL for an order of 40 mg IVPB over 30 minutes?
3. Is an order of a drug dosage of 250 mg/m² IV q8h safe for a client with a BSA of 1.5 m² based on the safe dose range of 500-1500 mg per day?
4. For an order of nivolumab 240 mg IV q2 weeks infusing over 30 minutes with a concentration of 40 mg/4 mL, a) how many milliliters should be withdrawn from the vial? b) what should the pump setting be in ml/h if added to a 100 mL D5W IVPB bag?
5. What is the rate at which the infusion pump should be set in mL/h for half daily fluid maintenance in a child weighing 30 kg?
1. The dosage rate in mg/min can be calculated by converting the infusion rate from mL/h to mL/min and then multiplying it by the concentration of the IV bag. To convert 120 mL/h to mL/min, we divide it by 60: 120 mL/h ÷ 60 = 2 mL/min. The concentration in the IV bag is 20 mg in 200 mL NS, which means there is 0.1 mg in 1 mL. Now we multiply the infusion rate (2 mL/min) by the concentration (0.1 mg/mL): 2 mL/min × 0.1 mg/mL = 0.2 mg/min. Therefore, the dosage rate is 0.2 mg/min.
2. To determine how many mL to draw from the vial, we need to calculate the total amount of medication needed based on the concentration and dosage ordered. The order is for 40 mg of acyclovir sodium to be infused over 30 minutes in 100 mL NS. The concentration in the vial is 20 mg/mL. First, we calculate the total amount of medication needed: 40 mg ÷ 20 mg/mL = 2 mL. Therefore, you will need to draw 2 mL from the vial.
3. The order is for a drug dosage of 250 mg/m² IV q8h. The client has a body surface area (BSA) of 1.5 m². The safe dose range for this drug is 500-1500...
4. a) The order is for nivolumab 240 mg IV q2 weeks, to be infused over 30 minutes. The label states "40 mg/4 mL." To determine the number of milliliters to be withdrawn from the vial, we divide the total dosage (240 mg) by the concentration (40 mg/4 mL): 240 mg ÷ 40 mg/4 mL = 6 mL. Therefore, you will need to withdraw 6 mL from the vial. b) The nivolumab is added to a 100 mL D5W IVPB bag. To calculate the pump setting in mL/h, we need to know the total infusion time. Since the order is to infuse over 30 minutes, we convert it to hours by dividing 30 minutes by 60: 30 minutes ÷ 60 = 0.5 hours. Now we divide the total volume (100 mL) by the infusion time (0.5 hours): 100 mL ÷ 0.5 hours = 200 mL/h. Therefore, the pump setting should be 200 mL/h.
5. To calculate the rate at which the infusion pump should be set in mL/h for half daily fluid maintenance, we need to know the weight of the child and the fluid maintenance rate. The child weighs 30 kg, and half daily fluid maintenance is ordered. The usual fluid maintenance rate for children is 100 mL/kg/day. First, we calculate the total fluid requirement: 30 kg × 100 mL/kg/day = 3000 mL/day. Since it's half daily maintenance, we divide the total fluid requirement by 2: 3000 mL/day ÷ 2 = 1500 mL/day. Finally, to determine the rate at which the infusion pump should be set in mL/h, we convert mL/day to mL/h: 1500 mL/day ÷ 24 hours = 62.5 mL/h. Therefore, the infusion pump should be set at 62.5 mL/h.
Dosage Rate Calculations in Clinical Settings
Dosage Rate Calculation:
1. The dosage rate in mg/min for an IV infusing at 120 mL/h with a concentration of 20 mg in 200 mL NS is 0.2 mg/min. This calculation ensures accurate medication administration.
Medication Draw:
2. To draw the required amount of medication from a vial with a concentration of 20 mg/mL, 2 mL needs to be drawn for an order of 40 mg IVPB over 30 minutes. This step ensures the correct dosage is administered.
Safety Check:
3. The calculated safe dose for a client with a BSA of 1.5 m² is revealed to be 375 mg, falling within the safe dose range of 500-1500 mg per day. Therefore, the order of 250 mg/m² IV q8h is deemed safe.
Nivolumab Administration:
4. a) To withdraw the necessary amount of nivolumab from the vial, 6 mL should be withdrawn based on the concentration of 40 mg/4 mL and the total dosage of 240 mg. b) The pump setting for the nivolumab infused over 30 minutes in a 100 mL D5W IVPB bag should be 200 mL/h for accurate administration.
Fluid Maintenance Calculation:
5. The infusion pump should be set at 62.5 mL/h for half daily fluid maintenance in a child weighing 30 kg. This calculation ensures proper fluid balance in the clinical setting.
Overall, these dosage rate calculations and medication administration practices play a crucial role in ensuring patient safety and effective treatment in various healthcare scenarios.