Calculate fluid removal requirements for hemodialysis sessions.
Total Fluid Goal: mL
Required UF Rate: mL/hr
How to Calculate UF Rate in Dialysis
Ultrafiltration (UF) is the process of removing excess fluid from the blood during hemodialysis. Calculating the correct UF rate is critical to ensure patient safety and prevent complications like hypotension, muscle cramps, or cardiovascular stress.
The UF Rate Formula
The calculation involves determining the total fluid volume that needs to be removed and dividing it by the treatment time:
A patient has a pre-dialysis weight of 75 kg and a target dry weight of 73 kg. They plan to drink 200 mL of water during a 4-hour treatment, and the machine rinseback is 200 mL.
Weight difference: 75 – 73 = 2.0 kg (2000 mL)
Additional fluids: 200 mL (intake) + 200 mL (rinseback) = 400 mL
Total Goal: 2000 + 400 = 2400 mL
UF Rate: 2400 mL / 4 hours = 600 mL/hr
Safety Considerations
Clinical guidelines (KDOQI) often suggest that UF rates should generally not exceed 10 to 13 mL/kg/hr. Removing fluid faster than the body can refill the vascular space from the interstitial tissue can lead to sudden drops in blood pressure and organ ischemia.
function calculateUF() {
var preWeight = parseFloat(document.getElementById('preWeight').value);
var dryWeight = parseFloat(document.getElementById('dryWeight').value);
var intake = parseFloat(document.getElementById('fluidIntake').value) || 0;
var rinse = parseFloat(document.getElementById('rinseBack').value) || 0;
var duration = parseFloat(document.getElementById('txDuration').value);
var resultArea = document.getElementById('resultArea');
var totalGoalSpan = document.getElementById('totalGoal');
var ufRateSpan = document.getElementById('ufRateResult');
var safetyWarning = document.getElementById('safetyWarning');
if (isNaN(preWeight) || isNaN(dryWeight) || isNaN(duration) || duration maxSafeRate) {
safetyWarning.innerHTML = "Caution: The calculated rate (" + ufRate.toFixed(0) + " mL/hr) exceeds the suggested safety threshold for this patient's dry weight (" + maxSafeRate.toFixed(0) + " mL/hr). Consult a physician regarding treatment duration or dry weight goals.";
safetyWarning.style.display = 'block';
} else {
safetyWarning.style.display = 'none';
}
// Smooth scroll to result
resultArea.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}