Deadspace to Tidal Volume Ratio: Vd/Vt = (PaCO2 - PeCO2) / PaCO2
20 to 40% in spontaneously breathing patients 40 to 60% in mechanical ventilated patients
Vd/Vt: Deadspace to Tidal Volume Ratio in % PaCO2: The partial pressure of carbon dioxide in the arterial blood in mmHg. PeCO2: The partial pressure of carbon dioxide in the exhaled air in mmHg.
