Prone Positioning May Improve Outcomes for Patients on ECMO for Severe ARDS

Prone positioning (PP) has shown benefits in patients with refractory hypoxemia from acute respiratory distress syndrome (ARDS).¹ The EOLIA trial demonstrated extracorporeal membrane oxygenation (ECMO) can be used for patients with progressive hypoxemia or hypercarbia despite PP and other therapies for ARDS.² The current paper is a retrospective, multicenter cohort study to assess the feasibility and efficacy of PP in patients on venovenous ECMO (VV-ECMO). The authors compared patients from four centers where PP is performed routinely on VV-ECMO patients with patients from two other centers where VV-ECMO patients remain supine. All patients underwent lung protective ventilation with driving pressures < 10 cm H₂O to 12 cm H₂O, respiratory rate < 20 breaths/minute, and moderate positive end-expiratory pressures (PEEP).

Of the 240 patients on VV-ECMO studied, 107 underwent PP and 133 remained supine. Patients were mostly male (65%) with an average age of 48-49 years. Pneumonia was the predominant cause of ARDS (91% to 92.5%). The partial pressure of oxygen to fraction of inspired oxygen (P/F) ratio of patients before ECMO in the PP and supine groups was 73 and 76, respectively, and each group had undergone an average of two days of mechanical ventilation before being placed on ECMO. The PP group first underwent proning on average four days from the start of ECMO. Notable differences between the two groups included a higher rate of acute kidney injury requiring dialysis in the PP group (15.9% vs. 6.8%), while the supine group had higher rates of hypertension (34.6%), immunodeficiency (22.6%), and asthma-chronic obstructive pulmonary disease (12.78%) than the PP group (20.6%, 14%, and 6.4%, respectively).