Do lung recruitment manueves decrease gastric mucosal perfusion?

Objective: To evaluate effects of lung recruitment maneuvers on gastric mucosal perfusion, systemic circulation, and lung mechanics in patients with acute lung injury. Design: Prospective observational clinical study. Setting: General intensive care unit of university hospital. Patients and participants: Fourteen patients with acute lung injury (ten in the main study group and four in a validation group). Interventions: Three 2-min-long recruitment maneuvers (RM) with transient increases in mean airway pressure to 35 cmH(2)O (RM1 and RM2) and 44 cmH(2)O (RM3). Measurements and results: Measurements of systemic hemodynamics, gastric mucosal perfusion (laser Doppler flowmetry), and lung mechanics were performed immediately before, at the end of, and 3 min after each RM. Cardiac index decreased during all RMs while mean arterial pressure decreased only during RM3. Gastric mucosal perfusion was not significantly changed during any of the RMs. When comparing values obtained before the first RM with values after the third RM there was a significant decrease in cardiac index (P=0.043) and a non-significant (P=0.051) decrease in gastric mucosal perfusion. There were no significant changes in systemic oxygenation or lung mechanics after three RMs, even though four patients showed marked transient increases in systemic oxygenation during RMs. Conclusions: In this study of ten patients there were no significant changes in gastric mucosal perfusion during lung recruitment maneuvers. There was, however, a trend towards gradual decreases in gastric mucosal perfusion.