Fig. 1

High tidal volume results in decreased barrier protection and increased inflammatory response. When ventilating the mice at different tidal volumes, heart rate remained stable for the two lower tidal volumes. However, in the initial first hour of ventilation with tidal volume of 30 mL/kg heart rate increased but then remained stable (A). Pressure needed to maintain the applied tidal volumes remained relatively stable throughout the ventilation period (B). Increased protein concentration in BALF was detected in the 30 mL/kg tidal volume range (C). Pro-inflammatory cytokine, IL-6, expression increased significantly in the mice that were ventilated at 30 mL/kg (D). Standard deviation of the means is shown. Significant difference from the SB controls are shown (P ≤ 0.01 = **; P ≤ 0.0001 = ****)