Fig. 3

The impacts of positive end-expiratory pressure in animals with hypovolemia and intracranial hypertension (Series III, n = 6 per group). Data were presented as mean and standard deviation. RM-ANOVA was used. The corresponding changes of mean arterial pressure were presented in grey lines (showing means only), solid line: control group, dash line: chest wall strapping group. A ICP significantly decreased when PEEP was increased (p < 0.001 for both groups), and the magnitude was significantly greater in the chest wall strapping group than in the control group (p = 0.018). B P_tiO₂ decreased when PEEP was increased (p < 0.001 for both groups), and the magnitude was greater in the chest wall strapping group than in the control group (p = 0.020). C CO significantly decreased with PEEP increment (p < 0.001 for both groups), there was a significantly greater decrease in CO in the chest wall strapping group than in the control group (p = 0.020). D CPP significantly decreased with PEEP increment (p < 0.001 for both groups), no difference was observed between groups (p = 0.205). ICP intracranial pressure, PEEP positive end-expiratory pressure, P_tiO₂ brain tissue O₂ tension, CO cardiac output, CPP cerebral perfusion pressure