CALCULATE FLOW RATE IN DROPS PER MINUTE

CALCULATE FLOW RATE IN DROPS PER MINUTE:

Order: Levaquin 500 mg IVPB in 100 mL 0.9% NS q12h over 1 hr.

Drop factor: 10 gtt/mL

Determine rate in gtt/min.

A.
16 gtt/min

B.
18 gtt/min

C.
17 gtt/min

D.
20 gtt/min

The Correct Answer and Explanation is:

To calculate the flow rate in drops per minute (gtt/min) for an intravenous (IV) infusion, you can use the following formula:

Flow Rate (gtt/min)=Total Volume (mL)×Drop Factor (gtt/mL)Infusion Time (min)\text{Flow Rate (gtt/min)} = \frac{\text{Total Volume (mL)} \times \text{Drop Factor (gtt/mL)}}{\text{Infusion Time (min)}}Flow Rate (gtt/min)=Infusion Time (min)Total Volume (mL)×Drop Factor (gtt/mL)​

Here’s a step-by-step guide to solving this problem:

1. Identify the Total Volume to Infuse:
   • The order is for 100 mL of 0.9% NS (Normal Saline) to be infused.
2. Determine the Drop Factor:
   • The drop factor is given as 10 gtt/mL. This means that 10 drops are equivalent to 1 mL.
3. Calculate the Infusion Time:
   • The infusion is to be completed over 1 hour. Convert this to minutes: 1 hour=60 minutes1 \text{ hour} = 60 \text{ minutes}1 hour=60 minutes
4. Apply the Formula:Substitute the values into the formula:
   • Total Volume = 100 mL
   • Drop Factor = 10 gtt/mL
   • Infusion Time = 60 minutes
   Flow Rate (gtt/min)=100 mL×10 gtt/mL60 min\text{Flow Rate (gtt/min)} = \frac{100 \text{ mL} \times 10 \text{ gtt/mL}}{60 \text{ min}}Flow Rate (gtt/min)=60 min100 mL×10 gtt/mL​Calculate the numerator:100 mL×10 gtt/mL=1000 gtt100 \text{ mL} \times 10 \text{ gtt/mL} = 1000 \text{ gtt}100 mL×10 gtt/mL=1000 gttNow divide by the infusion time:1000 gtt60 min≈16.67 gtt/min\frac{1000 \text{ gtt}}{60 \text{ min}} \approx 16.67 \text{ gtt/min}60 min1000 gtt​≈16.67 gtt/minRounding to the nearest whole number, we get approximately 17 gtt/min.

So, the correct answer is C. 17 gtt/min.

Explanation:

The flow rate in drops per minute is calculated to ensure the IV infusion is administered at the correct rate. The formula takes into account the total volume of fluid to be infused, the drop factor (which converts volume to the number of drops), and the total time available for infusion. By multiplying the total volume by the drop factor, you get the total number of drops needed. Dividing this by the total infusion time in minutes gives the flow rate in drops per minute, which helps in setting the IV drip rate accurately.