Fig. 1.
Protocol (A) and timeline representation of the experimental protocol (B). Arterial blood gases and echocardiography were evaluated at BASELINE and FINAL. BGA blood gas analysis; ECHO echocardiography; FDA functional data acquisition; FiO2 fraction of inspired oxygen; ZEEP zero end-expiratory pressure; PEEP positive end-expiratory pressure; VT tidal volume. Twenty-four hours after intratracheal administration of Escherichia coli lipopolysaccharide, rats received standard (10 mL/kg/h, NORMO) or high (30 mL/kg/h, HIGH) volume of Ringer’s lactate. For 30 min, all rats, regardless of fluid status, were mechanically ventilated with VT = 6 mL/kg and PEEP = 9 cmH2O, and then randomized to the following groups: abrupt PEEP decrease from 9 to 3 cmH2O (FAST) or gradual PEEP decrease (0.2 cmH2O/min) from 9 to 3 cmH2O (SLOW) for 30 min