Background

The Basic version of the CRRT UF Calculator is designed to provide essential calculations for ultrafiltration (UF) rates during a 12-hour shift. Users begin by entering the starting net fluid balance, which represents the fluid balance (positive for gain, negative for removal) at the beginning of the shift. They then input the prescribed 24-hour net fluid balance goal, such as -1000 mL, representing a net removal of 1 liter over a 24-hour period.

The user selects the shift type, either day or night. Day shift is responsible for achieving 50% of the 24-hour goal, adjusted for the starting balance, while night shift is responsible for the remaining goal. Predicted intake is entered as calculated cumulative volumes for primary IV fluids and enteral fluids based on rate while secondary IV fluids are totals for the entire shift. The calculator dynamically calculates the total predicted intake by summing these values. Results include the remaining 24-hour goal, which is the difference between the prescribed goal and the starting balance, and the shift-specific goal, adjusted for the selected shift type. The gross CRRT output needed is then calculated as the predicted intake minus the shift-specific goal, and the UF rate is determined by dividing the gross output by 12 hours.

The calculator updates calculations automatically as users modify the input fields. The reset button clears all input fields and resets the results to default values, making it easy to start a new calculation. This version is ideal for quick and straightforward UF rate calculations, focusing on basic intake and shift-specific goals.

How To

1. Enter the starting net fluid balance at the beginning of the shift. This value represents how much fluid the patient has gained or lost up to this point. Positive values indicate fluid gain, while negative values indicate fluid removal.

2. Input the prescribed 24-hour net fluid balance goal. This is the target fluid balance for the entire day, such as -1000 mL for removing 1 liter.

3. Select the shift type as either day or night. Day shift aims for 50% of the 24-hour goal, adjusted for the starting balance, while night shift is responsible for achieving the remaining goal.

4. Enter the predicted intake volumes for primary IV fluids, secondary IV fluids, and enteral fluids for the shift. These should represent the total fluid volumes expected to be administered.

5. Review the results, which will dynamically update as you input values. The calculator will show the predicted intake, remaining 24-hour goal, shift-specific goal, required CRRT output, and suggested UF rate. Note: If the UF rate is calculated to be negative, it will display as “0 mL/hr.” Negative UF rates are not possible because the CRRT machine cannot infuse fluid back into the patient to adjust for over-removal. Instead, a UF rate of “0” indicates no additional fluid should be removed by the machine during the shift. This typically reflects cases where the patient is already meeting their fluid balance goal through natural outputs (e.g., urine, drains) or minimal fluid intake.

6. Adjust the input values as needed to account for changes in the patient’s care plan, such as additional fluids or a modified goal.

7. Use the reset button to clear all inputs and results if you want to start a new calculation. This will reset everything to default values.

This process provides a simple way to calculate the required UF rate based on basic fluid intake and shift-specific goals.

ADVISORY: The term “predictive” in this calculator refers to the user making a calculation based on their clinical acumen and the assumption that fluid volumes and rates—such as intake and output—will not significantly change or vary over time. While the calculator provides a framework for estimating ultrafiltration rates and meeting fluid balance goals, it relies on the user to input accurate data and account for potential variability in fluid administration or losses.

This assumption is important to recognize, as clinical conditions can evolve, and unforeseen factors may alter the predicted volumes. Users should re-evaluate and adjust inputs as necessary to ensure the calculation remains reflective of the patient’s real-time needs and circumstances. The predictive nature of the tool is intended to aid decision-making but does not replace clinical judgment or the need for ongoing assessment.