Dead Space Fraction (Vd/Vt) — Ventilation Efficiency

Calculate the dead space fraction (Vd/Vt) using the Bohr-Enghoff equation: Vd/Vt = (PaCO2 − PETCO2) / PaCO2 to assess ventilation efficiency and pulmonary embolism risk.

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Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.
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How It Works

Calculate the dead space fraction (Vd/Vt) using the Bohr-Enghoff equation: Vd/Vt = (PaCO2 − PETCO2) / PaCO2 to assess ventilation efficiency and pulmonary embolism risk

Each component has a specific meaning:

  • Bohr-Enghoff equation: Vd/Vt = / PaCO2 — The bohr-enghoff equation: vd/vt = / paco2 recorded for the scenario being assessed.

Note: Interpret the dead space fraction result against the thresholds and context described above.

How to Use

Enter the Bohr-Enghoff equation: Vd/Vt = / PaCO2 for the scenario you are assessing. Calculate the dead space fraction (Vd/Vt) using the Bohr-Enghoff equation: Vd/Vt = (PaCO2 − PETCO2) / PaCO2 to assess ventilation efficiency and pulmonary embolism risk. Use the dead space fraction result to inform your calculation.

Frequently Asked Questions