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2.
Shock ; 57(1): 1-6, 2022 01 01.
Article in English | MEDLINE | ID: covidwho-1281907

ABSTRACT

BACKGROUND: The pathomechanisms of hypoxemia and treatment strategies for type H and type L acute respiratory distress syndrome (ARDS) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 (COVID-19) have not been elucidated. MAIN TEXT: SARS-CoV-2 mainly targets the lungs and blood, leading to ARDS, and systemic thrombosis or bleeding. Angiotensin II-induced coagulopathy, SARS-CoV-2-induced hyperfibrin(ogen)olysis, and pulmonary and/or disseminated intravascular coagulation due to immunothrombosis contribute to COVID-19-associated coagulopathy. Type H ARDS is associated with hypoxemia due to diffuse alveolar damage-induced high right-to-left shunts. Immunothrombosis occurs at the site of infection due to innate immune inflammatory and coagulofibrinolytic responses to SARS-CoV-2, resulting in microvascular occlusion with hypoperfusion of the lungs. Lung immunothrombosis in type L ARDS results from neutrophil extracellular traps containing platelets and fibrin in the lung microvasculature, leading to hypoxemia due to impaired blood flow and a high ventilation/perfusion (VA/Q) ratio. COVID-19-associated ARDS is more vascular centric than the other types of ARDS. D-dimer levels have been monitored for the progression of microvascular thrombosis in COVID-19 patients. Early anticoagulation therapy in critical patients with high D-dimer levels may improve prognosis, including the prevention and/or alleviation of ARDS. CONCLUSIONS: Right-to-left shunts and high VA/Q ratios caused by lung microvascular thrombosis contribute to hypoxemia in type H and L ARDS, respectively. D-dimer monitoring-based anticoagulation therapy may prevent the progression to and/or worsening of ARDS in COVID-19 patients.


Subject(s)
COVID-19/physiopathology , Hemostasis/physiology , Hypoxia/physiopathology , Respiratory Distress Syndrome/physiopathology , Thrombosis/physiopathology , Anticoagulants/therapeutic use , Biomarkers/blood , Blood Platelets/metabolism , COVID-19/drug therapy , Extracellular Traps/metabolism , Fibrin/metabolism , Fibrin Fibrinogen Degradation Products/analysis , Fibrinolysis , Humans , Lung/blood supply , Microvessels/physiopathology , Phenotype , Respiratory Distress Syndrome/drug therapy , SARS-CoV-2 , Thrombosis/drug therapy
4.
Vasc Health Risk Manag ; 17: 273-298, 2021.
Article in English | MEDLINE | ID: covidwho-1262578

ABSTRACT

COVID-19 sepsis is characterized by acute respiratory distress syndrome (ARDS) as a consequence of pulmonary tropism of the virus and endothelial heterogeneity of the host. ARDS is a phenotype among patients with multiorgan dysfunction syndrome (MODS) due to disseminated vascular microthrombotic disease (VMTD). In response to the viral septicemia, the host activates the complement system which produces terminal complement complex C5b-9 to neutralize pathogen. C5b-9 causes pore formation on the membrane of host endothelial cells (ECs) if CD59 is underexpressed. Also, viral S protein attraction to endothelial ACE2 receptor damages ECs. Both affect ECs and provoke endotheliopathy. Disseminated endotheliopathy activates two molecular pathways: inflammatory and microthrombotic. The former releases inflammatory cytokines from ECs, which lead to inflammation. The latter initiates endothelial exocytosis of unusually large von Willebrand factor (ULVWF) multimers and FVIII from Weibel-Palade bodies. If ADAMTS13 is insufficient, ULVWF multimers activate intravascular hemostasis of ULVWF path. In activated ULVWF path, ULVWF multimers anchored to damaged endothelial cells recruit circulating platelets and trigger microthrombogenesis. This process produces "microthrombi strings" composed of platelet-ULVWF complexes, leading to endotheliopathy-associated VMTD (EA-VMTD). In COVID-19, microthrombosis initially affects the lungs per tropism causing ARDS, but EA-VMTD may orchestrate more complex clinical phenotypes, including thrombotic thrombocytopenic purpura (TTP)-like syndrome, hepatic coagulopathy, MODS and combined micro-macrothrombotic syndrome. In this pandemic, ARDS and pulmonary thromboembolism (PTE) have often coexisted. The analysis based on two hemostatic theories supports ARDS caused by activated ULVWF path is EA-VMTD and PTE caused by activated ULVWF and TF paths is macrothrombosis. The thrombotic disorder of COVID-19 sepsis is consistent with the notion that ARDS is virus-induced disseminated EA-VMTD and PTE is in-hospital vascular injury-related macrothrombosis which is not directly  related to viral pathogenesis. The pathogenesis-based therapeutic approach is discussed for the treatment of EA-VMTD with antimicrothrombotic regimen and the potential need of anticoagulation therapy for coinciding macrothrombosis in comprehensive COVID-19 care.


Subject(s)
COVID-19/epidemiology , Endothelial Cells/metabolism , Fibrinolytic Agents/therapeutic use , Hemostasis/physiology , SARS-CoV-2 , Sepsis/complications , Thrombosis/etiology , COVID-19/complications , Humans , Pandemics , Phenotype , Sepsis/metabolism , Thrombosis/drug therapy , Thrombosis/metabolism
5.
Mol Metab ; 53: 101262, 2021 11.
Article in English | MEDLINE | ID: covidwho-1253402

ABSTRACT

OBJECTIVE: Obesity, in particular visceral obesity, and insulin resistance emerged as major risk factors for severe coronavirus disease 2019 (COVID-19), which is strongly associated with hemostatic alterations. Because obesity and insulin resistance predispose to thrombotic diseases, we investigated the relationship between hemostatic alterations and body fat distribution in participants at risk for type 2 diabetes. SUBJECTS: Body fat distribution (visceral and subcutaneous abdominal adipose tissue) and liver fat content of 150 participants - with impaired glucose tolerance and/or impaired fasting glucose - were determined using magnetic resonance imaging and spectroscopy. Participants underwent precise metabolic characterization and major hemostasis parameters were analyzed. RESULTS: Procoagulant factors (FII, FVII, FVIII, and FIX) and anticoagulant proteins (antithrombin, protein C, and protein S) were significantly associated with body fat distribution. In patients with fatty liver, fibrinogen (298 mg/dl vs. 264 mg/dl, p = 0.0182), FVII (99% vs. 90%, p = 0.0049), FVIII (114% vs. 90%, p = 0.0098), protein C (124% vs. 111%, p = 0.0006), and protein S (109% vs. 89%, p < 0.0001) were higher than in controls. In contrast, antithrombin (97% vs. 102%, p = 0.0025) was higher in control patients. In multivariate analyses controlling for insulin sensitivity, body fat compartments, and genotype variants (PNPLA3I148MM/MI/TM6SF2E167kK/kE), only protein C and protein S remained significantly increased in fatty liver. CONCLUSIONS: Body fat distribution is significantly associated with alterations of procoagulant and anticoagulant parameters. Liver fat plays a key role in the regulation of protein C and protein S, suggesting a potential counteracting mechanism to the prothrombotic state in subjects with prediabetes and fatty liver.


Subject(s)
Body Fat Distribution , COVID-19/complications , Diabetes Mellitus, Type 2/epidemiology , Fatty Liver/epidemiology , Hemostasis/physiology , Aged , COVID-19/blood , COVID-19/physiopathology , Cohort Studies , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/physiopathology , Fatty Liver/blood , Fatty Liver/diagnosis , Fatty Liver/physiopathology , Female , Humans , Insulin Resistance/physiology , Liver/diagnostic imaging , Magnetic Resonance Imaging , Male , Middle Aged , Protein C/analysis , Protein C/metabolism , Protein S/analysis , Protein S/metabolism , Randomized Controlled Trials as Topic , Risk Factors , SARS-CoV-2/pathogenicity
7.
J Heart Lung Transplant ; 40(7): 631-641, 2021 07.
Article in English | MEDLINE | ID: covidwho-1157308

ABSTRACT

BACKGROUND: The shortage of blood products has become a worldwide problem, especially during the COVID-19 Pandemic. Here, we investigated whether a point of care (POC) approach to perioperative bleeding and coagulopathy based on rotational thromboelastometry (ROTEM) results could decrease perioperative blood loss and the perioperative consumption of blood products during lung transplantation. METHODS: Patients undergoing bilateral lung transplantation were randomized into two groups: In the first group, designated the "non POC" group, the management of perioperative bleeding and coagulopathy was based on the clinical experience of the anesthesiologist; in the second group, designated the "POC" group, the management of perioperative bleeding, and coagulopathy was based on the ROTEM results. RESULTS: After performing an interim statistical analysis, the project was prematurely terminated as the results were significantly in favor of the POC approach. Data were analyzed for the period January 2018 until June 2020 when 67 patients were recruited into the study. There was significantly decreased perioperative blood loss in the POC group (n = 31 patients) with p = 0.013, decreased perioperative consumption of RBC with p = 0.009, and decreased perioperative consumption of fresh frozen plasma with p < 0.0001 (practically no fresh frozen plasma was used in the POC group) without deteriorating clot formation in secondary and primary hemostasis as compared to the non POC group (n = 36). CONCLUSION: POC management of perioperative bleeding and coagulopathy based on ROTEM results is a promising strategy to decrease perioperative blood loss and the consumption of blood products in lung transplantation.


Subject(s)
Blood Coagulation Disorders/diagnosis , COVID-19/epidemiology , Hemostasis/physiology , Lung Transplantation/adverse effects , Pandemics , Thrombelastography/methods , Blood Coagulation Disorders/etiology , Blood Coagulation Disorders/therapy , Blood Transfusion/methods , Female , Humans , Male , Middle Aged , SARS-CoV-2
10.
Ann Biol Clin (Paris) ; 78(5): 471-481, 2020 10 01.
Article in French | MEDLINE | ID: covidwho-836030

ABSTRACT

COVID-19 is associated with disturbances of hemostasis in the laboratory and an increased thrombotic risk. Routine laboratory tests - activated partial thromboplastin time (aPTT), prothrombin time, Clauss fibrinogen and D-dimers levels measurement - are used for the evaluation of the thrombotic risk and the monitoring of hemostasis, but are subject to several drawbacks that may affect the reliability and clinical relevance of the delivered results. Another challenge for the hemostasis laboratory is the monitoring of heparin treatment. For instance, the issue of the monitoring of unfractionated heparin remains debated, the more so when there is a tremendous inflammatory response. This brief review considers the role of laboratory tests of hemostasis in the management of COVID-19 and discusses their main limitations to be kept in mind.


Subject(s)
Coronavirus Infections/blood , Coronavirus Infections/therapy , Hemostasis/physiology , Pneumonia, Viral/blood , Pneumonia, Viral/therapy , Thrombosis/diagnosis , Thrombosis/etiology , Thrombosis/prevention & control , Anticoagulants/therapeutic use , Betacoronavirus/physiology , Blood Coagulation Tests , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/epidemiology , Drug Monitoring/methods , Hemostasis/drug effects , Humans , Laboratories, Hospital , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/epidemiology , Risk Factors , SARS-CoV-2 , Thrombosis/epidemiology
11.
Thromb Haemost ; 120(12): 1716-1719, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-735592

ABSTRACT

This is the first study to show a stepwise increase in venous thrombotic events according to COVID-19 coagulopathy (COVID-19-associated hemostatic abnormalities [CAHA]) staging and lung injuries assessed by chest computed tomography. Excess mortality and/or transfer to intensive care unit according to CAHA staging.


Subject(s)
COVID-19/blood , Hemostasis/physiology , Lung/diagnostic imaging , SARS-CoV-2/physiology , Venous Thromboembolism/blood , Adult , Aged , COVID-19/diagnosis , COVID-19/epidemiology , Disease Progression , Female , France/epidemiology , Hospitalization/statistics & numerical data , Humans , Intensive Care Units , Male , Middle Aged , Severity of Illness Index , Tomography, X-Ray Computed , Venous Thromboembolism/diagnosis , Venous Thromboembolism/epidemiology
14.
Crit Care ; 24(1): 364, 2020 06 19.
Article in English | MEDLINE | ID: covidwho-608390

ABSTRACT

COVID-19 is an infection induced by the SARS-CoV-2 coronavirus, and severe forms can lead to acute respiratory distress syndrome (ARDS) requiring intensive care unit (ICU) management. Severe forms are associated with coagulation changes, mainly characterized by an increase in D-dimer and fibrinogen levels, with a higher risk of thrombosis, particularly pulmonary embolism. The impact of obesity in severe COVID-19 has also been highlighted.In this context, standard doses of low molecular weight heparin (LMWH) may be inadequate in ICU patients, with obesity, major inflammation, and hypercoagulability. We therefore urgently developed proposals on the prevention of thromboembolism and monitoring of hemostasis in hospitalized patients with COVID-19.Four levels of thromboembolic risk were defined according to the severity of COVID-19 reflected by oxygen requirement and treatment, the body mass index, and other risk factors. Monitoring of hemostasis (including fibrinogen and D-dimer levels) every 48 h is proposed. Standard doses of LMWH (e.g., enoxaparin 4000 IU/24 h SC) are proposed in case of intermediate thrombotic risk (BMI < 30 kg/m2, no other risk factors and no ARDS). In all obese patients (high thrombotic risk), adjusted prophylaxis with intermediate doses of LMWH (e.g., enoxaparin 4000 IU/12 h SC or 6000 IU/12 h SC if weight > 120 kg), or unfractionated heparin (UFH) if renal insufficiency (200 IU/kg/24 h, IV), is proposed. The thrombotic risk was defined as very high in obese patients with ARDS and added risk factors for thromboembolism, and also in case of extracorporeal membrane oxygenation (ECMO), unexplained catheter thrombosis, dialysis filter thrombosis, or marked inflammatory syndrome and/or hypercoagulability (e.g., fibrinogen > 8 g/l and/or D-dimers > 3 µg/ml). In ICU patients, it is sometimes difficult to confirm a diagnosis of thrombosis, and curative anticoagulant treatment may also be discussed on a probabilistic basis. In all these situations, therapeutic doses of LMWH, or UFH in case of renal insufficiency with monitoring of anti-Xa activity, are proposed.In conclusion, intensification of heparin treatment should be considered in the context of COVID-19 on the basis of clinical and biological criteria of severity, especially in severely ill ventilated patients, for whom the diagnosis of pulmonary embolism cannot be easily confirmed.


Subject(s)
Coronavirus Infections/therapy , Hemostasis/physiology , Hospitalization , Pneumonia, Viral/therapy , Thrombosis/prevention & control , COVID-19 , Coronavirus Infections/physiopathology , Humans , Monitoring, Physiologic , Pandemics , Pneumonia, Viral/physiopathology , Risk
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