EARLY GAS EXCHANGE PARAMETERS NOT ASSOCIATED WITH SURVIVAL IN COVID-19-ASSOCIATED ARDS PATIENTS REQUIRING PROLONGED VENOVENOUS EXTRACORPOREAL MEMBRANE OXYGENATION

ABSTRACT

SESSION TITLE ECMO and ARDS in COVID-19 Infections SESSION TYPE Rapid Fire Original Inv PRESENTED ON 10/17/2022 1215 pm - 115 pm PURPOSE: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an important salvage therapy for patients with severe COVID-19 associated acute respiratory distress syndrome (ARDS). Whether gas exchange after initiation of ECMO predicts survival remains unknown. The present study aims to investigate if gas exchange parameters are associated with survival during ECMO support of COVID-19 associated ARDS. METHODS: We retrospectively evaluated all ARDS patients initiated on VV-ECMO according to ELSO guidelines between 2018 and 2021 at a tertiary academic medical center. ECMO sweep and ventilator fraction of inspire oxygen (FiO2) were catalogued every eight hours for all patients and compared between COVID-19 survivors and non-survivors at Days 0, 7, 14, 21, and 28 of ECMO using the Mann-Whitney U test. Cohort characteristics were compared between patients with and without COVID-19 using the chi-squared test for categorical comparisons and the Mann-Whitney U test for comparison of non-parametric continuous variables. Statistical significance was considered as p<0.05 for all tests. RESULTS: Forty-two ARDS patients were initiated on VV-ECMO during the study period, including 30 patients with COVID-19. Mortality was similar between patients with and without COVID-19 (43.3% vs 41.7%, p=0.92). ECMO duration (31 [33.5] vs 9.5 [7.0] days, p=0.002), median sweep (7.0 [4.5] vs 4.3 [4.0], p< 0.001), and median ventilator FiO2 (0.55 [0.50] vs 0.45 [25], p < 0.001) were significantly increased in patients with COVID-19 compared to those without. Among COVID-19 patients, median sweep did not differ between survivors and non-survivors at Day 0 (3.5 [1.0] vs 4.0 [1.0], p=0.20), Day 7 (6.0 [3.0] vs 7.5 [2.3], p=0.38), Day 14 (6.0 [2.5] vs 8.0 [3.3], p=0.14), Day 21 (8.0 [3.5] vs 9.0 [3.0], p= 0.97), or Day 28 (7.5 [3.5] vs 8.0 [3.0], p=0.74). Median ventilator FiO2 was significantly lower in COVID-19 survivors compared to non-survivors at Day 28 (0.50 [0.16] vs 0.81 [0.40], p=0.03), but not at Day 0 (0.75 [0.52] vs 0.60 [0.25], p= 0.98), Day 7 (0.90 [0.50] vs 1 [0.45], p = 0.54), Day 14 (0.90 [0.50] vs 1 [0.08], p=0.08), or Day 21 (0.80 [0.10] vs 0.90 [0.40], p=0.62). CONCLUSIONS: Survival was similar between ARDS patients with and without COVID-19 despite significantly increased ECMO duration and gas exchange support in patients with COVID-19. Early gas exchange parameters after initiation of ECMO were not associated with survival in patients with COVID-19. At Day 28 of ECMO, COVID-19 survivors had significantly lower ventilator FiO2 requirements compared to non-survivors. CLINICAL IMPLICATIONS Gas exchange parameters did not discriminate survivors from non-survivors until day 28 of ECMO in patients with COVID-19 associated ARDS. Given the need for increased gas exchange support and duration of ECMO therapy in this population, gas exchange parameters prior day 28 of ECMO may not be suitable markers for prognostication. DISCLOSURES No relevant relationships by Andrew Davis No relevant relationships by Malcolm DeCamp No relevant relationships by Hilary Faust No relevant relationships by James Maloney No relevant relationships by Daniel McCarthy No relevant relationships by Michael Peliska