Calculator Inputs
The page stays single column, while the calculator uses a responsive 3, 2, and 1 column field layout.
Example Data Table
| Case | Weight (kg) | Hematocrit (%) | Exchange (PV) | Plasma Volume (L) | Target Exchange (L) | Predicted Removal (%) |
|---|---|---|---|---|---|---|
| Example A | 60 | 35 | 1.00 | 2.73 | 2.73 | 63.21 |
| Example B | 75 | 42 | 1.25 | 3.05 | 3.81 | 71.35 |
| Example C | 90 | 38 | 1.50 | 3.91 | 5.86 | 77.69 |
Formula Used
PV (L) = 0.07 × weight (kg) × (1 − hematocrit fraction)
Exchange Volume (L) = PV × exchange multiplier
Removal Fraction = 1 − e^(−exchange multiplier)This gives about 63% removal at 1.0 PV and about 78% at 1.5 PV.
Processed Blood Volume (L) = Exchange Volume ÷ ((1 − hematocrit) × separator efficiency)
ACD-A (mL) = processed blood volume (mL) ÷ blood-to-ACD ratio
Session Minutes = exchange volume (mL) ÷ plasma removal rate (mL/min)
These equations support session planning. They do not replace bedside assessment, laboratory monitoring, or institutional protocols.
How to Use This Calculator
- Enter the patient’s body weight and hematocrit.
- Choose the exchange multiplier in plasma-volume units.
- Enter the number of planned sessions.
- Set the replacement fluid percentages for albumin and FFP.
- Enter machine planning values like plasma rate and separator efficiency.
- Enter the blood-to-ACD ratio used by your protocol.
- Press Calculate Exchange Plan.
- Review the result panel above the form.
- Use the Plotly chart to visualize removal efficiency.
- Download the summary as CSV or PDF if needed.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates plasma volume, target exchange dose, replacement fluid split, processed blood volume, anticoagulant need, and approximate session time for a planned exchange.
2) Why is hematocrit required?
Hematocrit helps estimate the plasma fraction of blood. Higher hematocrit means less plasma volume for the same body weight.
3) What is the exchange multiplier?
It is the number of plasma volumes planned for exchange. A value of 1.0 means one estimated plasma volume, while 1.5 means one and a half.
4) Why does removal not increase linearly?
Removal follows an exponential pattern. Early exchanged volume removes the largest share, while additional volume produces smaller incremental gains.
5) What does the processed blood volume mean?
It estimates how much whole blood must pass through the system to achieve the selected plasma exchange target, after accounting for hematocrit and separator efficiency.
6) Why include albumin and FFP percentages?
They split the total replacement volume into the fluid types you plan to use. Any remaining percentage is displayed as other replacement fluid.
7) Is the session time exact?
No. It is an engineering estimate based on the entered plasma removal rate. Real procedures may differ because of access flow, pauses, alarms, and protocol steps.
8) Can I use this as a final treatment order?
No. Use it for planning support only. Final clinical decisions require specialist review, machine-specific guidance, and institutional safety checks.