ABSTRACT
INTRODUCTION: Patients supported on extracorporeal membrane oxygenation (ECMO) due to COVID-19 are at an increased risk of both thromboembolic complications and thrombocytopenia. Bivalirudin, a direct thrombin inhibitor, is increasingly being utilized for anticoagulation in the ECMO patient though there is largely a lack of literature within the COVID-19 population. The objective of our study was to evaluate the safety and efficacy of alternative anticoagulation with bivalirudin in patients on ECMO with COVID-19 respiratory failure. METHOD(S): This was a non-interventional retrospective chart review conducted at a single center large community hospital between January 2020 - November 2021. We included both venovenous (VV) and venoarterial (VA) adult ECMO patients anticoagulated with bivalirudin that tested positive for COVID-19. Patients were excluded if their duration of ECMO cannulation was less than 48 hours. Descriptive statistical analyses were performed utilizing median with interquartile range and frequency with percent as appropriate. RESULT(S): Overall, 180 ECMO patients were included in the study. The duration of ECMO cannulation was 29 (9-54) days and our cohort experienced a 42% mortality rate. The rate of thrombotic events including in-circuit thrombosis, arterial and venous thrombotic events was 22%. The median initial platelet count on ECMO was 206 (157-274) and the median nadir was 85 (48-121). ELSO defined major bleeding occurred at a rate of 53% within this cohort. CONCLUSION(S): To our knowledge, this study describes the largest number of patients anticoagulated with bivalirudin for ECMO secondary to COVID-19. Our results suggest similar rates of thrombotic events compared to ELSO registry data. While the half-life of bivalirudin is short, clinicians should still be cautious of bleeding due to lack of a specific reversal agent. Retrospective studies with a comparator cohort, as well as randomized trials are warranted to further evaluate the selection of intravenous anticoagulants in the ECMO population with and without COVID-19.
ABSTRACT
INTRODUCTION: Venovenous (VV) extracorporeal membrane oxygenation (ECMO) has been used successfully to treat COVID-19 patients in severe respiratory failure. The objective of our multi-center study is to evaluate mortality, time of ECMO initiation, and demographics in COVID-19 patients treated with VV-ECMO. METHOD(S): Electronic medical records from March 2020 to October 2021 were studied in 49 sites across the United States. Patients treated with ECMO who tested positive for COVID-19 were included in this retrospective data analysis (N=363, age interquartile range: 37-55 years). Odds of inhospital mortality were compared using logistic regression models. At thresholds 1-7 days, patients classified as 'early ECMO' were matched to 'delayed ECMO' patients using coarsened exact matching, resulting in 7 independent analyses for early/delayed ECMO cannulation relative to the number of days of pre-ECMO mechanical ventilation (MV). RESULT(S): There were no significant differences in mortality in patients who received early or delayed ECMO. There were also no significant differences in mortality between races, body mass index (BMI), smoking status, hypertension, chronic kidney disease, coronary artery disease, steroid use, or diabetes pre-cannulation. Lastly, pre-cannulation factors associated with mortality in COVID-19 patients treated with ECMO include the use of vasopressors, which was associated with an 87% increase in mortality (p=0.017, confidence interval [CI] 1.12, 3.15);proning, which was associated with a 85% increase in mortality (p=0.015, CI 1.13, 3.06);and the use of baricitinib, which was associated with a four-fold increase in mortality (p=0.041, CI 1.11, 17.6). CONCLUSION(S): We found no evidence that particular demographic characteristics (including race, BMI, or smoking status) contribute to mortality, nor did we find evidence that the length of time on MV prior to ECMO influences mortality. The analysis of large datasets in the ECMO population may better inform clinical decision making.
ABSTRACT
INTRODUCTION: Venovenous extracorporeal membrane oxygenation (VV-ECMO) is typically used to support severe ARDS after the failure of invasive mechanical ventilation (IMV). IMV may cause harm in patients with preexisting barotrauma, shock, or immune compromise. METHOD(S): Single center case-control study of VV-ECMO before IMV (awake ECMO;n=24) compared to conventional ECMO (n=76) after IMV in COVID-19 patients. Groups were compared at baseline before cannulation (awake ECMO) or intubation (conventional ECMO). Propensity matching was performed based on body mass index and injury severity (Simplified Acute Physiology Score II [SAPS II], PaO2:FiO2 ratio). The primary outcome was survival to discharge. Secondary measures of duration of IMV and adverse events were examined. Multivariable adjustments were performed. RESULT(S): Awake ECMO compared to conventional ECMO patients at baseline were more tachypneic (mean +/- standard deviation: 36.3 +/- 9.6 vs 27.4 +/- 7.3;p< 0.0001) with lower SpO2 (median [interquartile range]: 87% [81-92.5] vs 93% [87-96];p=0.01) but similar SAPS II. Fifteen (68%) of awake ECMO patients eventually required IMV. Survival to discharge in awake ECMO trended towards improvement compared to conventional ECMO (70.8% vs. 52.6%;p=0.12). After propensity matching, awake ECMO was associated with increased survival (adjusted odds ratio 6.84 [95% confidence interval 1.08 - 43.38]). Awake ECMO was associated with less duration of IMV before and after propensity matching. Adverse events were similar between groups. CONCLUSION(S): Awake ECMO before IMV is associated with acceptable survival, similar adverse events, and shorter duration of IMV compared to conventional ECMO. This strategy may be preferable in carefully selected patients.