Venovenous extracorporeal membrane oxygenation versus conventional mechanical ventilation to treat refractory hypoxemia in patients with acute respiratory distress syndrome: a retrospective cohort study

OBJECTIVE: To compare the treatment outcome of venovenous extracorporeal membrane oxygenation (VV-ECMO) versus mechanical ventilation in hypoxemic patients with acute respiratory distress syndrome (ARDS) at a referral center that started offering VV-EMCO support in 2010. METHODS: This retrospective cohort study enrolled adults with severe ARDS (PaO(2)/FiO(2) ratio of <100 with FiO(2) of ≥90 or Murray score of ≥3) who were admitted to the intensive care unit of Siriraj Hospital (Bangkok, Thailand) from January 2010 to December 2018. All patients were treated using a low tidal volume (TV) and optimal positive end-expiratory pressure. The primary outcome was hospital mortality. RESULTS: Sixty-four patients (ECMO, n = 30; mechanical ventilation, n = 34) were recruited. There was no significant difference in the baseline PaO(2)/FiO(2) ratio (67.2 ± 25.7 vs. 76.6 ± 16.0), FiO(2) (97 ± 9 vs. 94 ± 8), or Murray score (3.4 ± 0.5 vs. 3.3 ± 0.5) between the ECMO and mechanical ventilation groups. The hospital mortality rate was also not significantly different between the two groups (ECMO, 20/30 [66.7%] vs. mechanical ventilation, 24/34 [70.6%]). Patients who underwent ECMO were ventilated with a significantly lower TV than patients who underwent mechanical ventilation (3.8 ± 1.8 vs. 6.6 ± 1.4 mL, respectively). CONCLUSION: Although VV-ECMO promoted lower-TV ventilation, it did not improve the in-hospital mortality rate. Trial registration: www.clinicaltrials.gov (NCT 04031794).