PEEP-induced Lung Recruitment Maneuver Combined with Prone Position for ARDS

<bold>Rationale:</bold> Prone position (PP) and PEEP-induced lung recruitment maneuver(LRM) are both efficacy in improving oxygenation and prognosis in patients with ARDS. The synergistic effect of PP combined with PEEP-induced LRM in patients with ARDS remains unclear. <bold>Objectives:</bold> To explore the effects of PP combined with PEEP-induced LRM on prognosis in patients with moderate to severe ARDS and the predicting role of lung recruitablity. <bold>Method:</bold> Patients with moderate to severe ARDS were consecutively enrolled. The patients were prospectively assigned to either the intervention(PP with PEEP-induced LRM)or control group (PP group) (Fig. 1). The clinical outcome, respiratory mechanics and EIT monitoring results in the two groups were compared. Lung recruitablity (recruitment to inflation ratio,R/I)was measured during PEEP-induced LRM procedure and was used for predicting the response to LRM. <bold>Results:</bold> Fifty-eight patients are included in the final analysis, among which 28 patients(48.2%) received PEEP-induced LRM combined with PP.PEEP-induced LRM can enhance the effect of PP by significant improving in oxygenation (PaO₂/FiO₂ 75.8vs4.75,P<0.001) and compliance of respiratory system (2 vs -1,P=0.02) among ARDS patients (Fig. 2). Based on EIT measurement, PP combined with PEEP-induced LRM increase ventilation distribution mainly in the dorsal region (5.0 vs. 2.0, P=0.015).R/I ratio was measured in 28 subjects. The higher R/I ratio was related with greater oxygenation improvement after LRM (140.50 vs 47.60,P=0.016). <bold>Conclusion:</bold> In patients with moderate to severe ARDS,PEEP-induced LRM combined with PP can improve survival. R/I may be useful to predict the response to LRM.