Table 1

Resting PFT in an upright sitting and supine position

Upright sitting positionSupine position
MeasuredLLNULNReference (mean value)% of referenceMeasured% of reference
VC L4.134.336.175.2579%2.7051%
TLC L5.796.078.377.2280%4.1758%
FRC L2.392.434.413.4270%1.6548%
IC L3.403.4798%2.5273%
RV L1.651.242.581.9187%1.4777%
ERV L0.731.7342%0.1810%
RV/TLC %29193728102%35126%
FEV1 L3.073.325.004.1674%
FEV1/VC %#7469928194%
PEF L·s−18.117.5911.579.5885%
FEF25% L·s−16.935.4411.068.2584%
FEF50% L·s−13.523.147.485.3166%
FEF75% L·s−10.911.113.672.3938%

LLN: lower limit of normality; ULN: upper limit of normality; VC: vital capacity; TLC: total lung capacity; FRC: functional residual capacity; IC: inspiratory capacity; RV: residual volume; ERV: expiratory reserve volume; FEV1: forced expiratory volume in 1s; FVC: forced vital capacity; PEF: peak expiratory flow; FEFx%: forced expiratory flow measured after x% of the FVC has been exhaled. #: spirometric evidence of an obstructive ventilatory defect as defined by a reduced FEV1/VC ratio less than the fifth percentile of the predicted value [1].