key: cord-0736123-521ly4mb
authors: Ciavarella, Alessandro; Peyvandi, Flora; Martinelli, Ida
title: Where do we stand with antithrombotic prophylaxis in patients with COVID-19?
date: 2020-04-20
journal: Thromb Res
DOI: 10.1016/j.thromres.2020.04.023
sha: b474f9bee005c10021ee5bd7976b615812a18041
doc_id: 736123
cord_uid: 521ly4mb

nan

J o u r n a l P r e -p r o o f From Dec 2019 onwards, an outbreak of cases of pneumonia associated with novel Coronavirus (SARS-CoV2) has been reported in China. The disease, defined 'COVID-19', since Jan 2020 has spread in Italy, particularly in Milan and other cities in Northern Italy. On March 11, the WHO declared COVID-19 a pandemic. The mortality rate in Italy exceeds 12% and is up to 26% in intensive care units (ICUs) [1] . After an early phase characterized by mild symptoms, patients with COVID-19 infection may develop an interstitial pneumonia associated with an acute inflammatory state [2] . Autopsy findings showed the occlusion on the small vessels of the lungs (and also other organs) [3] , possibly because of an intense cytokines secretion associated to an endothelial impairment bringing to the activation of the coagulation cascade.

An interim guidance on COVID-19 coagulopathy released on Mar 25 by experts of the International Society of Thrombosis and Haemostasis (ISTH) suggests a conventional prophylactic dose of enoxaparin 4000 U (or equivalent dose of another low molecular weight heparin) once daily [4] .

However, the same prophylactic dose is insufficient to prevent venous thromboembolism in non-COVID-19 ICU patients, who develop pulmonary embolism 10% of cases [5] . This figure was perceived even higher since the beginning of epidemic in many ICUs, and Klok and colleagues confirmed a 31% cumulative incidence of thrombosis in a cohort of 184 ICU patients with COVID-19, despite antithrombotic prophylaxis at least at the conventional doses. The vast majority of the events (81%) were pulmonary emboli [6] . It is easy to imagine how pulmonary embolism can dramatically worsen the respiratory function of COVID-19 patients and increase their mortality.

Baseline Characteristics and Outcomes of 1591 Patients Infected With SARS-CoV-2 Admitted to ICUs of the Lombardy Region

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19): The epidemic and the challenges

Comparison of clinical and pathological features between severe acute respiratory syndrome and coronavirus disease

ISTH interim guidance on recognition and management of coagulopathy in COVID-19

Pulmonary embolism in intensive care units: More frequent or more known