Table 5 Lung function measurements.
From: Comprehensive systems biology analysis of a 7-month cigarette smoke inhalation study in C57BL/6 mice
Maneuver | Measurement | Unit | Interpretation cues | ||
|---|---|---|---|---|---|
SnapShot perturbations (lung: single compartment) | Single frequency (150 breath/min) forced oscillation waveform (sinusoidal) | resistance (R) | cmH2O.s/ml | indicative of whole thorax | dynamic lung resistance |
compliance (C) | ml/cmH2O | ease with which lungs can be extended | |||
elastance (E) | cmH2O/ml | elastic rigidity of the lungs | |||
Primewaves (lung: multiple compartments) | Broadband (multi-frequency) forced oscillation waveforms, typically denoted by duration (e.g., ‘Prime-8’) that also reflects frequency content | tissue elasticity (H) | cmH2O/ml/s | indicative of lung tissue | reflects energy conservation in the lungs |
tissue damping (resistance) (G) | cmH2O/ml/s | reflects energy dissipation in the lungs | |||
tissue hysteresivity | Î=G/H | ||||
Newtonian resistance (Rn) | cmH2O.s/ | indicative of large airways | resistance of the central airways | ||
ml | |||||
Pressure-volume loops | Slow (stepwise or continuous) inflation to total lung capacity (TLC) and deflation back to functional residual capacity | elasticity index in Salazar-Knowles equation (K) | /cmH2O | ||
Maximum volume in Salazar-Knowles equation (A) | ml | indicative of total lung capacity | |||
quasi-static compliance (Cst) | ml/cmH2O | elastic recoil at given volume | |||
quasi-static elastance (Est) | cmH2O/ml | elastic recoil at given volume | |||
hysteresis (area in PV loops) | cmH2O/ml | measure of atelectasis | |||
Positive end-expiratory pressure | Positive end-expiratory pressure of 2–3 cm H2O is adequate to maintain a normal end-expiratory lung volume in small animals | end-expiratory lung volume (Vtr end) | ml | ||
Negative pressure forced expiration | Lungs are inflated to TLC and then rapidly switched to a negative pressure reservoir, resulting in an expiratory flow | forced expiratory volume in 0.1 s (FEV0.1) | ml | ||
forced expiratory volume in 0.2 s (FEV0.2) | ml | ||||
forced vital capacity (FVC) | ml | ||||
FEV0.1/FVC | % | ||||
FEV0.2/FVC | % | ||||
