Lemmens-Bernstein-Brodsky Equation for Estimated Blood Volume

Developed in 2006 by Dr. Lemmens, Dr. Bernstein, and Dr. Brodsky, this equation predicts estimated blood volume (ᵢBV) across a full spectrum of body weights and body mass indices (BMI) for patients unstressed by acute trauma or critical illness. The formula is:

$$ BV_{male} = \frac{weight \times 70}{\sqrt{\frac{BMI}{22}}} $$ $$ BV_{female} = BV_{male} \times 0.92857 $$
Where:

• \(BV\) = Blood Volume (in mL)
• \(weight\) = Weight (in kilograms)
• \(BMI\) = Body Mass Index, calculated as \(weight (kg) / height (m)^2\)

Results are shown in mL, L, and cups, adjusted for sex, with female blood volume being 92.857% of male blood volume, matching the provided example (e.g., height = 185 cm, weight = 100 kg, female = 5,640 mL, male = 6,074 mL).

How to Use the Blood Volume Calculator

This calculator uses the Lemmens-Bernstein-Brodsky Equation to estimate blood volume based on a person's weight, height, and sex. Enter the required values, select the appropriate units for weight (kg, oz, lb) and height (m, cm, ft, in), and click "Calculate" to see the results in mL, L, and cups for the selected sex.

Understanding Estimated Blood Volume

Estimated blood volume (ᵢBV) varies with body weight, height, and BMI, providing a prediction for healthy individuals without acute trauma or critical illness. Key factors include:

• Sex: The equation calculates male blood volume using the base formula, and female blood volume as 92.857% of the male value, reflecting physiological differences.
• Weight: Measured in kilograms (converted from oz or lb).
• Height: Measured in meters (converted from cm, ft, or in) to calculate BMI.
• BMI: Body Mass Index, used to normalize the blood volume calculation.

Results are displayed in milliliters (mL), liters (L), and cups for the selected sex only, with units converted accordingly (1 cup = 236.588 mL).

Frequently Asked Questions (FAQ)

Here are some common questions about the Blood Volume Calculator using the Lemmens-Bernstein-Brodsky Equation:

• What is the Lemmens-Bernstein-Brodsky Equation?
  This equation, developed in 2006, estimates blood volume based on weight, height, and BMI for patients without acute trauma or critical illness, covering a wide range of body weights and BMIs, with sex-specific adjustments.


• Why are there different results for males and females?
  The equation calculates male blood volume using the base formula, and female blood volume is set to 92.857% of the male value, accounting for physiological differences, as shown in the example (height = 185 cm, weight = 100 kg, female = 5,640 mL, male = 6,074 mL).


• Can this calculator be used for children or pregnant women?
  No, this equation is designed for healthy adults unstressed by trauma or illness. Children, pregnant women, or individuals with medical conditions may require different methods or clinical assessment.


• What units should I use for weight and height?
  You can enter weight in kilograms (kg), ounces (oz), or pounds (lb), and height in meters (m), centimeters (cm), feet (ft), or inches (in). The calculator converts these to kilograms and meters for the calculation.


• Is the result accurate for everyone?
  This equation provides an estimate for healthy adults. Individual variations, medical conditions, or dehydration can affect actual blood volume, so consult a healthcare professional for precise measurements.