Fig. 2.

Plasma levels of cytokines.

After 3 h of mechanical ventilation, plasma levels of inflammatory cytokines were higher than in basal (BAS) nonventilated animals (# P < 0.1 and ## P < 0.05 compared with BAS). LPS-instilled rats had higher MCP-1 levels than saline-instilled rats (†† P < 0.05). LPS-instilled rats receiving 7 cmH₂O PEEP (LPS-7) presented lower levels of inflammatory mediators than those receiving 2 cmH₂O PEEP (LPS-2). The application of 7 cmH₂O PEEP (PEEP-7) reduced IL-10 levels in both saline-instilled and LPS-instilled animals. The application of PEEP-7 also reduced IL-6 levels in saline-instilled rats. Bars represent means ± SEM. ∗ P < 0.1 and ∗∗ P < 0.05 comparing PEEP-7 vs. 2 cmH₂O PEEP.