Theoretical Lung Volume Calculation

Values for MVV and FVC were determined using formulae that depend on body surface area (BSA), and age(A):

BSA = 0.007184 * W^0.425 * H^0.725

MVV(male) = (78.2 * BSA) - (1.873 * A) + 72.70
MVV (female) = (67.18 * BSA) - (0.965 * A) + 26.3
FVC(male) = (0.051 * H) - (0.025 * A) - 3.55
FVC(female) = (0.033 * H) - (0.023 * A) - 1.40

where weight(W) is in kg, height(H) is in cm, and BSA is in meters squared.

The values of VC, FRC, RC and FEV1/FVC were obtained from tables found in "Respiratory Function in Disease" by David V. Bates, 1989, p.108-9. A value of 0.5 litres was assumed for VT, and other volumes were determined arithmetically i.e.

ERV = FRC - RV
IRV= VC - ERV - 0.5
IC = IRV + 0.5