Bleeding and Thrombotic Complications in COVID-19-Associated ARDS Requiring ECMO.

BACKGROUND: We analyzed bleeding and thrombotic complications in COVID-19-associated ARDS requiring extracorporeal membrane oxygenation (ECMO). METHODS: This was a single-center observational study of adult subjects undergoing ECMO for COVID-19 (n = 67) or all other cause of ARDS (n = 60), excluding trauma patients. RESULTS: In the COVID-19 group, duration of invasive mechanical ventilation prior to ECMO was lower (2 [0-4] d vs 3 [1-6] d) and ECMO retrieval less frequent (71% vs 87%). No significant differences were found in Simplified Acute Physiology Score II, Acute Physiology and Chronic Health Evaluation II (APACHE II), or in the in-hospital survival predicted by the Respiratory ECMO Survival Prediction score. During the first 7 d of ECMO support, the COVID-19 group presented higher platelets and fibrinogen, lower activated partial thromboplastin time, but no differences in D-dimer. Thrombotic complications were similar between groups. Higher rates of severe bleeding, namely airway bleeding (37.3% vs 15.0%) and hemothorax (13.4% vs 3.3%), were found in COVID-19, with lower hemoglobin and higher red blood cell transfusions. COVID-19 ARDS was associated with longer ECMO duration (47 [17-80] d vs 19 [12-30] d) and absence of a statistically significant difference concerning in-hospital mortality. CONCLUSIONS: COVID-19-associated ARDS requiring ECMO presented high rates of severe bleeding complications and a protracted course. Further studies are needed to clarify the risks and benefits of ECMO in severe COVID-19-associated ARDS.

Comparative outcomes of extracorporeal membrane oxygenation for COVID-19 delivered in experienced European centres during successive SARS-CoV-2 variant outbreaks (ECMO-SURGES): an international, multicentre, retrospective cohort study.

BACKGROUND: To inform future research and practice, we aimed to investigate the outcomes of patients who received extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) due to different variants of SARS-CoV-2. METHODS: This retrospective study included consecutive adult patients with laboratory-confirmed SARS-CoV-2 infection who received ECMO for ARDS in 21 experienced ECMO centres in eight European countries (Austria, Belgium, England, France, Germany, Italy, Portugal, and Spain) between Jan 1, 2020, and Sept 30, 2021. We collected data on patient characteristics, clinical status, and management before and after the initiation of ECMO. Participants were grouped according to SARS-CoV-2 variant (wild type, alpha, delta, or other) and period of the pandemic (first [Jan 1-June 30] and second [July 1-Dec 31] semesters of 2020, and first [Jan 1-June 30] and second [July 1-Sept 30] semesters of 2021). Descriptive statistics and Kaplan-Meier survival curves were used to analyse evolving characteristics, management, and patient outcomes over the first 2 years of the pandemic, and independent risk factors of mortality were determined using multivariable Cox regression models. The primary outcome was mortality 90 days after the initiation of ECMO, with follow-up to Dec 30, 2021. FINDINGS: ECMO was initiated in 1345 patients. Patient characteristics and management were similar for the groups of patients infected with different variants, except that those with the delta variant had a younger median age and less hypertension and diabetes. 90-day mortality was 42% (569 of 1345 patients died) overall, and 43% (297/686) in patients infected with wild-type SARS-CoV-2, 39% (152/391) in those with the alpha variant, 40% (78/195) in those with the delta variant, and 58% (42/73) in patients infected with other variants (mainly beta and gamma). Mortality was 10% higher (50%) in the second semester of 2020, when the wild-type variant was still prevailing, than in other semesters (40%). Independent predictors of mortality were age, immunocompromised status, a longer time from intensive care unit admission to intubation, need for renal replacement therapy, and higher Sequential Organ Failure Assessment haemodynamic component score, partial pressure of arterial carbon dioxide, and lactate concentration before ECMO. After adjusting for these variables, mortality was significantly higher with the delta variant than with the other variants, the wild-type strain being the reference. INTERPRETATION: Although crude mortality did not differ between variants, adjusted risk of death was highest for patients treated with ECMO infected with the delta variant of SARS-CoV-2. The higher virulence and poorer outcomes associated with the delta strain might relate to higher viral load and increased inflammatory response syndrome in infected patients, reinforcing the need for a higher rate of vaccination in the population and updated selection criteria for ECMO, should a new and highly virulent strain of SARS-CoV-2 emerge in the future. Mortality was noticeably lower than in other large, multicentre series of patients who received ECMO for COVID-19, highlighting the need to concentrate resources at experienced centres. FUNDING: None.

Evaluation of urinary cysteinyl leukotrienes as biomarkers of severity and putative therapeutic targets in COVID-19 patients.

BACKGROUND: Cysteinyl leukotrienes (CysLT) are potent inflammation-promoting mediators, but remain scarcely explored in COVID-19. We evaluated urinary CysLT (U-CysLT) relationship with disease severity and their usefulness for prognostication in hospitalized COVID-19 patients. The impact on U-CysLT of veno-venous extracorporeal membrane oxygenation (VV-ECMO) and of comorbidities such as hypertension and obesity was also assessed. METHODS: Blood and spot urine were collected in "severe" (n = 26), "critically ill" (n = 17) and "critically ill on VV-ECMO" (n = 17) patients with COVID-19 at days 1-2 (admission), 3-4, 5-8 and weekly thereafter, and in controls (n = 23) at a single time point. U-CysLT were measured by ELISA. Routine markers, prognostic scores and outcomes were also evaluated. RESULTS: U-CysLT did not differ between groups at admission, but significantly increased along hospitalization only in critical groups, being markedly higher in VV-ECMO patients, especially in hypertensives. U-CysLT values during the first week were positively associated with ICU and total hospital length of stay in critical groups and showed acceptable area under curve (AUC) for prediction of 30-day mortality (AUC: 0.734, p = 0.001) among all patients. CONCLUSIONS: U-CysLT increase during hospitalization in critical COVID-19 patients, especially in hypertensives on VV-ECMO. U-CysLT association with severe outcomes suggests their usefulness for prognostication and as therapeutic targets.