Mechanical Ventilation Management during Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome An International Multicenter Prospective Cohort

Abstract

Rationale: Current practices regarding mechanical ventilation in patients treated with extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome are unknown. Objectives: To report current practices regarding mechanical ventilation in patients treated with ECMO for severe acute respiratory distress syndrome (ARDS) and their association with 6-month outcomes. Methods: This was an international, multicenter, prospective cohort study of patients undergoing ECMO for ARDS during a 1-year period in 23 international ICUs. Measurements and Main Results: We collected demographics, daily pre- and per-ECMO mechanical ventilation settings and use of adjunctive therapies, ICU, and 6-month outcome data for 350 patients (mean +/- SD pre-ECMO Pa-O2/FIO2 71 +/- 34 mm Hg). Pre-ECMO use of prone positioning and neuromuscular blockers were 26% and 62%, respectively. V-T (6.4 +/- 2.0 vs. 3.7 +/- 2.0 ml/kg), plateau pressure (32 +/- 7 vs. 24 +/- 7 cm H2O), driving pressure (20 +/- 7 vs. 14 +/- 4 cm H2O), respiratory rate (26 +/- 8 vs. 14 = 6 breaths/min), and mechanical power (26.1 +/- 12.7 vs. 6.6 +/- 4.8 J/min) were markedly reduced after ECMO initiation. Six-month survival was 61%. No association was found between ventilator settings during the first 2 days of ECMO and survival in multivariable analysis. A time-varying Cox model retained older age, higher fluid balance, higher lactate, and more need for renal-replacement therapy along the ECMO course as being independently associated with 6-month mortality. A higher VT and lower driving pressure (likely markers of static compliance improvement) across the ECMO course were also associated with better outcomes. Conclusions: Ultraprotective lung ventilation on ECMO was largely adopted across medium- to high-case volume ECMO centers. In contrast with previous observations, mechanical ventilation settings during ECMO did not impact patients' prognosis in this context.