.btc-wrapper {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.btc-header {
text-align: center;
margin-bottom: 25px;
color: #d32f2f;
}
.btc-input-group {
margin-bottom: 20px;
}
.btc-label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #444;
}
.btc-input {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.btc-select {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
background-color: #fff;
box-sizing: border-box;
}
.btc-row {
display: flex;
gap: 20px;
flex-wrap: wrap;
}
.btc-col {
flex: 1;
min-width: 200px;
}
.btc-btn {
background-color: #d32f2f;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background-color 0.2s;
}
.btc-btn:hover {
background-color: #b71c1c;
}
.btc-result-box {
background-color: #fff;
border-left: 5px solid #d32f2f;
padding: 20px;
margin-top: 25px;
border-radius: 4px;
display: none;
}
.btc-result-item {
margin-bottom: 15px;
border-bottom: 1px solid #eee;
padding-bottom: 10px;
}
.btc-result-item:last-child {
border-bottom: none;
margin-bottom: 0;
}
.btc-result-label {
font-size: 14px;
color: #666;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.btc-result-value {
font-size: 28px;
font-weight: 700;
color: #2c3e50;
}
.btc-error {
color: #d32f2f;
font-weight: bold;
margin-top: 10px;
display: none;
text-align: center;
}
.btc-article h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
}
.btc-article h3 {
color: #d32f2f;
margin-top: 25px;
}
.btc-article ul {
padding-left: 20px;
}
.btc-article li {
margin-bottom: 10px;
}
.btc-info-box {
background-color: #e3f2fd;
border: 1px solid #bbdefb;
padding: 15px;
border-radius: 4px;
margin: 20px 0;
}
function calculateTransfusionRate() {
// Get inputs
var volume = document.getElementById('bloodVolume').value;
var timeValue = document.getElementById('transfusionTime').value;
var timeUnit = document.getElementById('timeUnit').value;
var dropFactor = document.getElementById('dropFactor').value;
var errorBox = document.getElementById('btcError');
var resultBox = document.getElementById('btcResult');
// Reset display
errorBox.style.display = 'none';
resultBox.style.display = 'none';
// Validation
if (volume === "" || timeValue === "" || parseFloat(volume) <= 0 || parseFloat(timeValue) <= 0) {
errorBox.innerHTML = "Please enter valid positive numbers for Volume and Duration.";
errorBox.style.display = 'block';
return;
}
// Convert strings to numbers
var volNum = parseFloat(volume);
var timeNum = parseFloat(timeValue);
var dropNum = parseFloat(dropFactor);
// Logic Variables
var timeInMinutes;
var timeInHours;
// Normalize time
if (timeUnit === 'hours') {
timeInMinutes = timeNum * 60;
timeInHours = timeNum;
} else {
timeInMinutes = timeNum;
timeInHours = timeNum / 60;
}
// Calculations
// 1. Flow Rate in mL/hr (Volume / Time in Hours)
var mlPerHour = volNum / timeInHours;
// 2. Drip Rate in gtt/min ((Volume * Drop Factor) / Time in Minutes)
var gttPerMin = (volNum * dropNum) / timeInMinutes;
// Rounding
// IV pumps usually allow 1 decimal place, but typically whole numbers for blood
var mlPerHourDisplay = mlPerHour.toFixed(1);
if (mlPerHourDisplay.endsWith('.0')) {
mlPerHourDisplay = Math.round(mlPerHour);
}
// Drops must be whole numbers (you cannot count half a drop)
var gttPerMinDisplay = Math.round(gttPerMin);
// Display Results
document.getElementById('resGttMin').innerHTML = gttPerMinDisplay + ' gtt/min';
document.getElementById('resMlHr').innerHTML = mlPerHourDisplay + ' mL/hr';
resultBox.style.display = 'block';
}
Blood Transfusion Rate Calculator
Volume of PRBCs, Platelets, or Whole Blood
10 gtt/mL (Macrodrip – Standard Blood Set)
15 gtt/mL (Macrodrip)
20 gtt/mL (Macrodrip)
60 gtt/mL (Microdrip – Pediatric)
Hours
Minutes
Please enter valid positive numbers for volume and time.
Manual IV Drip Rate
0 gtt/min
Drops per minute to count in the chamber
Pump Flow Rate
0 mL/hr
Setting for electronic infusion pump
How to Calculate Blood Transfusion Rate
Calculating the correct blood transfusion rate is a critical nursing skill required to ensure patient safety and prevent complications such as Transfusion-Associated Circulatory Overload (TACO). Whether administering Packed Red Blood Cells (PRBCs), platelets, or Fresh Frozen Plasma (FFP), the infusion rate must be carefully calculated based on the total volume, the time prescribed, and the administration set being used.
Standard Blood Administration Tip: Most blood administration sets are "Y-type" tubing with a standard drop factor of 10 gtt/mL to facilitate the passage of viscous blood cells without damage (hemolysis). Always verify the drop factor on the packaging before calculating.
The Transfusion Rate Formula
There are two primary ways to calculate the rate depending on whether you are using an electronic pump or gravity flow.
1. Calculating Drops Per Minute (Gravity Flow)
When administering blood via gravity, you must calculate the drip rate (gtt/min). The formula is:
(Total Volume (mL) × Drop Factor (gtt/mL)) ÷ Time (minutes) = gtt/min
Example: A patient is prescribed one unit of PRBCs (250 mL) to be infused over 4 hours using a 10 gtt/mL tubing set.
- Volume: 250 mL
- Drop Factor: 10 gtt/mL
- Time: 4 hours = 240 minutes
- Calculation: (250 × 10) ÷ 240 = 2500 ÷ 240 = 10.4 gtt/min
- Rounding: Round to the nearest whole number: 10 drops per minute.
2. Calculating mL Per Hour (Electronic Pump)
If using an infusion pump, the calculation is simpler as pumps are programmed in milliliters per hour.
Total Volume (mL) ÷ Time (hours) = mL/hr
Using the previous example:
- Calculation: 250 mL ÷ 4 hours = 62.5 mL/hr
Safety Considerations for Blood Transfusion
- Start Slow: Standard protocol usually dictates starting the transfusion slowly (e.g., 2 mL/min or 120 mL/hr) for the first 15 minutes to monitor for immediate adverse reactions.
- Time Limits: A single unit of blood must typically be completed within 4 hours to reduce the risk of bacterial growth. If the rate is too slow to finish in 4 hours, the blood bank may need to split the unit.
- Tubing Size: Always use a large-bore IV (typically 18G or 20G) to prevent hemolysis, though smaller gauges may be used for pediatric patients with caution.
Common Drop Factors
The "Drop Factor" refers to how many drops it takes to make 1 mL of fluid. This is printed on the tubing package.
- 10 gtt/mL: Most common for blood (allows cells to pass freely).
- 15 gtt/mL: Common standard macrodrip.
- 20 gtt/mL: Common standard macrodrip.
- 60 gtt/mL (Microdrip): Used for pediatrics or very precise medication titration (rarely for adult blood transfusion due to viscosity).