TABLE 1

A simple two-compartment alveolar model containing a shunt compartment and a normal alveolar unit

	Compartment 1 (shunt)	Compartment 2 (ventilated)	Combined output
V′_A	0.0 L·min⁻¹	4.5 L·min⁻¹	4.5 L·min⁻¹
Q′	1.5 L·min⁻¹	3.0 L·min⁻¹	4.5 L·min⁻¹
V′_A/Q′	0.0 L·L⁻¹	1.5 L·L⁻¹	1.0 L·L⁻¹
P_aCO₂	46 mmHg	37 mmHg	40 mmHg
P_ACO₂	46 mmHg	37 mmHg	37 mmHg
Alveolar V_D/V_T			7.5%

V′_A: alveolar ventilation; Q′: perfusion; P_aCO₂: arterial CO₂ tension; P_ACO₂: alveolar CO₂ tension; V_D/V_T: alveolar dead space.