Type and dose of heparin in Covid‐19: Reply

We thank the authors for their comments and feedback on the ISTH interim guidance. Hyper-coagulability is indeed a significant issue in COVID-19 and the haemostatic system is shifted markedly towards the procoagulant side in these patients. However, we cannot yet be certain that unfractionated heparin (UFH) is better than low molecular weight heparin (LMWH) in this scenario. Although UFH has been used for several years, it does have practical issues, mainly with respect to the need for frequent monitoring using the activated partial thromboplastin times (aPTT).

[1]  Feng Li,et al.  Risk assessment of venous thromboembolism and bleeding in COVID-19 patients , 2020 .

[2]  R. McIntyre,et al.  Tissue plasminogen activator (tPA) treatment for COVID‐19 associated acute respiratory distress syndrome (ARDS): A case series , 2020, Journal of Thrombosis and Haemostasis.

[3]  G. Danzi,et al.  Acute pulmonary embolism and COVID-19 pneumonia: a random association? , 2020, European heart journal.

[4]  Dengju Li,et al.  Anticoagulant treatment is associated with decreased mortality in severe coronavirus disease 2019 patients with coagulopathy , 2020, Journal of Thrombosis and Haemostasis.

[5]  Edward Livingston,et al.  Coronavirus Disease 2019 (COVID-19) in Italy. , 2020, JAMA.

[6]  V. Jha,et al.  The Novel Coronavirus 2019 epidemic and kidneys , 2020, Kidney International.

[7]  Lei Liu,et al.  Clinical Pathology of Critical Patient with Novel Coronavirus Pneumonia (COVID-19) , 2020 .

[8]  Dengju Li,et al.  Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia , 2020, Journal of Thrombosis and Haemostasis.

[9]  D. Talmor,et al.  Is there a role for tissue plasminogen activator as a novel treatment for refractory COVID-19 associated acute respiratory distress syndrome? , 2020, Journal of Trauma and Acute Care Surgery.

[10]  M. Matthay,et al.  Meta-Analysis of Preclinical Studies of Fibrinolytic Therapy for Acute Lung Injury , 2018, Front. Immunol..

[11]  M. Balaan,et al.  Acute Respiratory Distress Syndrome , 2016, Critical care nursing quarterly.

[12]  A. Sauaia,et al.  Postinjury Hyperfibrinogenemia Compromises Efficacy of Heparin-Based Venous Thromboembolism Prophylaxis , 2014, Shock.

[13]  B. Nordestgaard,et al.  Elevated fibrinogen levels are associated with risk of pulmonary embolism, but not with deep venous thrombosis. , 2013, American journal of respiratory and critical care medicine.

[14]  T. Baglin,et al.  Parenteral anticoagulants: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. , 2012, Chest.

[15]  Christopher P Cannon,et al.  The use and limitations of unfractionated heparin. , 2010, Critical pathways in cardiology.

[16]  L. Ware.  Pathophysiology of acute lung injury and the acute respiratory distress syndrome. , 2006, Seminars in respiratory and critical care medicine.

[17]  B. Bosch,et al.  Murine Coronavirus with an Extended Host Range Uses Heparan Sulfate as an Entry Receptor , 2005, Journal of Virology.

[18]  F. Rosendaal,et al.  High levels of fibrinogen are associated with the risk of deep venous thrombosis mainly in the elderly , 2003, Journal of thrombosis and haemostasis : JTH.

[19]  E. Ohman,et al.  Heparin and low-molecular-weight heparin: mechanisms of action, pharmacokinetics, dosing, monitoring, efficacy, and safety. , 2001, Chest.

[20]  F. Rosendaal,et al.  Increased Levels of Factor VIII and Fibrinogen in Patients with Venous Thrombosis Are not Caused by Acute Phase Reactions , 1999, Thrombosis and Haemostasis.

[21]  K. Stringer,et al.  Tissue plasminogen activator (tPA) inhibits interleukin-1 induced acute lung leak. , 1998, Free radical biology & medicine.

[22]  P. Reitsma,et al.  Factor VII and Fibrinogen Levels as Risk Factors for Venous Thrombosis , 1994, Thrombosis and Haemostasis.

[23]  J. Navar,et al.  Prevention of adult respiratory distress syndrome with plasminogen activator in pigs. , 1990, Critical care medicine.

[24]  R. Bone,et al.  Intravascular coagulation associated with the adult respiratory distress syndrome. , 1976, The American journal of medicine.

[25]  T. Matsuda,et al.  Relationship between fibrinogen and blood viscosity. , 1976, Thrombosis research.

[26]  S. Lewis.  British Committee for Standards in Haematology , 1969 .

[27]  R. C. Cotton,et al.  Heparin resistance and plasma fibrinogen in elderly subjects with and without occlusive vascular disease. , 1968, Journal of atherosclerosis research.

[28]  E. Geever,et al.  Studies on the Role of Intravascular Coagulation in Irreversible Hemorrhagic Shock , 1962, Annals of surgery.

[29]  R. Hardaway,et al.  Disseminated Intravascular Coagulation: A Cause of Shock , 1959, Annals of surgery.