PEEP titration: the effect of prone position and abdominal pressure in an ARDS model.

Prone position and PEEP independently improved lung compliance (P < .0001). There was no interaction. As expected, intra-abdominal hypertension increased the PEEP needed for the best lung compliance (P < .0001 supine, P = .007 prone). However, best PEEP was not significantly different between prone (12.8 ± 2.4 cmH2O) and supine (11.0 ± 4.2 cmH2O) positions when targeting lung compliance CONCLUSIONS: Despite complementary mechanisms, prone position and appropriate PEEP exert their positive effects on lung mechanics independently of each other.