Alveolar Tidal recruitment/derecruitment and Overdistension During Four Levels of End-Expiratory Pressure with Protective Tidal Volume During Anesthesia in a Murine Lung-Healthy Model.

Purpose: We compared respiratory mechanics between the positive end-expiratory pressure of minimal respiratory system elastance (PEEP) and three levels of PEEP during low-tidal-volume (6 mL/kg) ventilation in rats.

Methods: Twenty-four rats were anesthetized, paralyzed, and mechanically ventilated. Airway pressure (P), flow (F), and volume (V) were fitted by a linear single compartment model (LSCM) P(t) = E × V(t) + R × F(t) + PEEP or a volume- and flow-dependent SCM (VFDSCM) P(t) = (E + E × V(t)) × V(t) + (K + K × |F(t)|) × F(t) + PEEP, where E and R are respiratory system elastance and resistance, respectively; E and E× V are volume-independent and volume-dependent E, respectively; and K and K × F are flow-independent and flow-dependent R, respectively.