IV Infusion Rate Calculator (mL/hr)
This means the infusion pump should be set to deliver 0 mL every hour.
How to Calculate Rate of Infusion in mL/hr
Calculating the correct intravenous (IV) flow rate is a fundamental skill for nurses and healthcare providers. It ensures that patients receive the prescribed volume of medication or fluids over the correct duration. The most common unit for programming electronic infusion pumps is milliliters per hour (mL/hr).
The Infusion Rate Formula
The math behind calculating the flow rate is straightforward. You are essentially dividing the total amount of fluid by the total time allowed for administration.
Rate (mL/hr) = Total Volume (mL) ÷ Total Time (Hours)
If the time is given in minutes, the formula converts slightly:
Rate (mL/hr) = (Total Volume (mL) ÷ Total Time (Minutes)) × 60
Step-by-Step Calculation Example
Imagine a physician orders 1,000 mL of Normal Saline to be infused over 8 hours.
- Identify Volume: 1,000 mL
- Identify Time: 8 Hours
- Divide: 1,000 ÷ 8 = 125
The infusion pump should be set to 125 mL/hr.
Handling Complex Durations
Sometimes an order may specify a duration involving both hours and minutes (e.g., 1 hour and 30 minutes). In this case:
- Convert the minutes to a decimal of an hour: 30 mins ÷ 60 = 0.5 hours.
- Add to the full hours: 1 + 0.5 = 1.5 hours.
- Divide total volume by 1.5.
For example, to infuse 500 mL over 1 hour and 30 minutes: 500 ÷ 1.5 = 333.33 mL/hr (usually rounded to the nearest whole number, 333 mL/hr).
Why Accuracy Matters
Setting the correct rate of infusion is critical for patient safety. An infusion rate that is too fast can lead to fluid overload, electrolyte imbalances, or medication toxicity. Conversely, a rate that is too slow may result in dehydration or sub-therapeutic medication levels. Always double-check your calculations and verify pump settings against the prescriber's order.