COVID-19 and Extracorporeal Membrane Oxygenation.

INTRODUCTION: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently and rapidly emerged and developed into a global pandemic. In SARS-CoV-2 patients with refractory respiratory failure, there may be a role for veno-venous extracorporeal membrane oxygenation (V-V ECMO) as a life-saving rescue intervention. METHODS: This review summarizes the evidence gathered until June 12, 2020; electronic databases were screened for pertinent reports on coronavirus and V-V ECMO. Search was conducted by two independent investigators; keywords used were SARS-CoV-2, COVID-19, ECMO, and extracorporeal life support (ECLS). RESULTS: Many patients with COVID-19 experience moderate symptoms and a relatively quick recovery, but others must be admitted into the intensive care unit due to severe respiratory failure and often must be mechanically ventilated. Further deterioration may require institution of extracorporeal oxygenation. Infection mechanisms may trigger "cytokine storm," an inflammatory disorder notable for multi-organ system failure; together with other metabolic and hematological changes, these amplify the changes pertinent to ECMO therapy, often exaggerating blood coagulation disorders. Thirty-two studies were found describing experiences with ECMO in the treatment of COVID-19. Of 4,912 COVID-19 patients, 2,119 (43%) developed ARDS and 2,086 (42%) were transferred to the ICU; 1,015 patients (21%) were treated with ECMO. While in an overall cohort, observed mortality was 640 (13%), the mortality within ECMO subgroups reached up to 34.6% (range 0-100%). CONCLUSION: The efficacy of ECMO treatment for COVID-19 is largely dependent on the expertise of the center in ECLS due to the interplay between the changes in hematological and inflammatory modulators associated with both COVID-19 and ECMO. In order to support gas exchange during early infection with SARS-CoV-2, ECMO has a strong rationale for the treatment of the most critically ill patients. Due to the limited resources during a global pandemic, ECMO should be reserved for only the most severe cases of COVID-19.

Does ASTRAL score at hospital admission predict symptomatic haemorrhagic transformation in acute ischaemic stroke after revascularisation? A pilot single-centre study.

INTRODUCTION: Accurately predicting outcomes after acute ischaemic stroke (AIS) is a major clinical goal. The aim of this pilot study was to evaluate the prognostic validity and accuracy of the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) score in predicting symptomatic haemorrhagic transformation (sHT) in patients with AIS who have undergone revascularisation. MATERIAL AND METHODS: Consecutive patients hospitalised for AIS who underwent treatment with intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT) were identified, and their ASTRAL scores at hospital admission were estimated. The study endpoint was sHT within 24 hours of stroke onset. The predictive performance of the ASTRAL score was investigated through logistic regression analysis and discrimination and calibration tests. RESULTS: Sixty-eight AIS patients, with a median age of 69 (58-79) years, were included. sHT occurred in 20 (29.4%) of the 68 patients. The ASTRAL score was significantly higher in patients who developed sHT compared to non-sHT patients [36 (34-38) versus 24 (17-32); p<0.001]. The ASTRAL score was an independent predictor of sHT, and showed good discriminative power (area under the curve 0.88; 95% confidence interval, 0.789-0.965). CONCLUSIONS AND CLINICAL IMPLICATIONS: ASTRAL score is an independent predictor of sHT and shows high predictive accuracy in patients with AIS. Future studies are warranted to confirm these results.

Immunological and Hematological Response in COVID-19.

INTRODUCTION: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently and rapidly emerged and developed into a global pandemic. Through the renin-angiotensin system, the virus may impact the lung circulation, but the expression on endothelium may conduct to its activation and further systemic damage. While precise mechanisms underlying these phenomena remain to be further clarified, the understanding of the disease, its clinical course, as well as its immunological and hematological implications is of paramount importance in this phase of the pandemic. METHODS: This review summarizes the evidence gathered until 12 June; electronic databases were screened for pertinent reports on coronavirus and inflammatory and hematological changes. Search was conducted by two independent investigators; keywords used were "SARS-CoV-2," "COVID-19," "inflammation," "immunological," and "therapy." RESULTS: The viral infection is able to trigger an excessive immune response in predisposed individuals, which can result in a "cytokine storm" that presents an hyperinflammation state able to determine tissue damage and vascular damage. An explosive production of proinflammatory cytokines such as TNF-α IL-1ß and others occurs, greatly exaggerating the generation of molecule-damaging reactive oxygen species. These changes are often followed by alterations in hematological parameters. Elucidating those changes in SARS-CoV-2-infected patients could help to understand the pathophysiology of disease and may provide early clues to diagnosis. Several studies have shown that hematological parameters are markers of disease severity and suggest that they mediate disease progression. According to the available literature, the primary hematological symptoms-associated COVID-19, and which distinguish patients with severe disease from patients with nonsevere disease, are lymphocytopenia, thrombocytopenia, and a significant increase in D-dimer levels. CONCLUSIONS: SARS-CoV-2 infection triggers a complex response altering inflammatory, hematological, and coagulation parameters. Measuring these alterations at certain time points may help identify patients at high risk of disease progression and monitor the disease severity.

Coronavirus Disease 2019 (COVID-19): A Short Review on Hematological Manifestations.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a rapidly spreading and devastating global pandemic. Many researchers are attempting to clarify the mechanisms of infection and to develop a drug or vaccine against the virus, but there are still no proven effective treatments. The present article reviews the common presenting hematological manifestations of coronavirus disease 2019 (COVID-19). Elucidating the changes in hematological parameters in SARS-CoV-2 infected patients could help to understand the pathophysiology of the disease and may provide early clues to diagnosis. Several studies have shown that hematological parameters are markers of disease severity and suggest that they mediate disease progression.

Hemostasis in Coronavirus Disease 2019-Lesson from Viscoelastic Methods: A Systematic Review.

Hemostatic unbalance is often observed in patients with coronavirus disease 2019 (COVID-19), and patients with severe disease are at high risk of developing thromboembolic complications. Viscoelastic methods (VEMs), including thrombelastography (TEG) and thromboelastometry (TEM), provide data on the nature of hemostatic disturbance. In this systematic review, we assessed the performance of TEG and TEM in the assessment of blood coagulation and fibrinolysis in patients with COVID-19. PubMed, Scopus, Web of Science Core Collection, medRxiv, and bioRxiv were systematically searched for clinical studies evaluating TEG and/or TEM variables in COVID-19 individuals. Ten studies, with a total of 389 COVID-19 patients, were included, and VEMs were performed in 292 of these patients. Most patients (90%) presented severe COVID-19 and required mechanical ventilation. TEG and TEM variables showed that these patients displayed hypercoagulability and fibrinolysis shutdown, despite the use of appropriate thromboprophylaxis. However, the mechanism underlying these phenomena and their clinical significance in COVID-19 patients who developed thrombosis are still not clear. Further studies are warranted if VEMs might help to identify those at highest risk of thrombotic events and who therefore may derive the greatest benefit from antithrombotic therapy.