Mechanical Ventilation During VV ECMO: A Review of Ventilatory Parameters and Novel Stress Indices

Introduction: Venovenous extracorporeal membrane oxygenation (VV-ECMO) is increasingly utilized for managing severe acute respiratory distress syndrome (ARDS), enabling ultraprotective ventilation strategies. However, optimal ventilatory parameters during VV-ECMO remain unclear. Recently proposed physiological indices, including mechanical power (MP), hazard ratio of driving pressure (HRDrive), and hazard ratio elastic (HRElastic), have emerged as critical metrics to quantify ventilator-induced lung injury (VILI) and potential lung recovery. This review aims to synthesize current evidence on ventilatory practices pre- and post-ECMO initiation and evaluate these novel markers across established protective thresholds.


Methods: A review of literature was conducted using PubMed, Scopus, and Cochrane databases from 2009–2025, focusing on studies comparing ventilatory parameters before and after initiating VV-ECMO in adult ARDS patients. Extracted data included tidal volume (Vt), respiratory rate (RR), positive end-expiratory pressure (PEEP), plateau pressure (Pplat), driving pressure (ΔP), fraction of inspired oxygen (FiO₂), and PaO₂/FiO₂ ratio. Additionally, MP, HRDrive, and HRElastic were calculated when feasible, using physiologically derived formulas and thresholds.


Results: Twelve studies met inclusion criteria. Initiation of VV-ECMO resulted in substantial reductions in Vt (6.13 ± 1.3 to 3.68 ± 0.6 mL/kg predicted body weight), Pplat (29.8 ± 3.5 to 25.2 ± 3.2 cmH₂O), ΔP (18.6 ± 3.2 to 11.1 ± 2.5 cmH₂O), RR, and MP, signaling a shift towards ultraprotective ventilation. Calculated hazard ratios consistently transitioned from harmful stress zones pre-ECMO to reparative or protective zones post-ECMO, with HRDrive improving from +0.24 to –0.76 and HRElastic from +0.32 to –1.12, reflecting improved conditions for lung healing.


Conclusions: VV-ECMO significantly facilitates protective ventilatory strategies by reducing mechanical stress indices, supporting lung recovery potential. The application of MP, HRDrive, and HRElastic offers a robust physiological framework for assessing ventilator-lung interactions during ECMO. These findings underscore the value of physiologically-guided ventilation, warranting further research to optimize individual ventilator settings and enhance patient outcomes in severe ARDS.