MIVF Rate Calculator (Maintenance IV Fluid)
Understanding the MIVF Rate Calculator
The MIVF (Maintenance Intravenous Fluid) Rate Calculator is an essential clinical tool designed to help healthcare professionals and students estimate the fluid requirements for patients who cannot maintain adequate oral intake. Proper fluid management is critical to maintaining homeostasis, preventing dehydration, and avoiding electrolyte imbalances.
How is Maintenance Fluid Calculated?
This calculator utilizes the standard Holliday-Segar method, often referred to as the "4-2-1 Rule," to determine the hourly fluid requirement in milliliters per hour (mL/hr). This method calculates the rate based on the patient's weight in kilograms:
- First 10 kg: 4 mL/kg/hr
- Next 10 kg (11-20 kg): 2 mL/kg/hr
- Remaining weight (>20 kg): 1 mL/kg/hr
For example, for a patient weighing 70kg:
1. First 10kg = 40 mL/hr
2. Next 10kg = 20 mL/hr
3. Remaining 50kg = 50 mL/hr
Total Rate = 110 mL/hr
Understanding Drop Factor (gtt/mL)
While infusion pumps can be set directly to milliliters per hour (mL/hr), manual gravity infusions require the nurse to count drops per minute (gtt/min). The "Drop Factor" is a property of the specific IV tubing being used:
- Macrodrip sets (10, 15, 20 gtt/mL): Used for adults or rapid fluid administration.
- Microdrip sets (60 gtt/mL): Used for pediatrics or precise medication delivery.
This calculator automatically converts the calculated mL/hr rate into drops per minute based on the tubing factor you select, ensuring you can set up both electronic pumps and gravity drips accurately.