Role of LMWH in ARDS

Primary Indication: VTE Prophylaxis

The American Society of Hematology recommends that all hospitalized patients with ARDS should receive thromboprophylaxis with either LMWH or unfractionated heparin as a universal strategy, rather than using individualized risk assessment, to prevent venous thromboembolism 1, 2
Critically ill ICU patients with ARDS face high rates of VTE, with incidence rates of up to 26% in severe cases, and mortality rates approaching 42%, highlighting the importance of prophylaxis 3

For most ARDS patients, the standard prophylactic dose is Enoxaparin 40 mg subcutaneously once daily, according to the International Society on Thrombosis and Haemostasis 4
In patients with severe renal impairment, UFH may be preferred over LMWH, as recommended by the American College of Chest Physicians 1, 4
Intermediate-dose LMWH regimens, such as Enoxaparin 40-60 mg daily or 40 mg twice daily, should be considered for high-risk patients with D-dimer levels >6 times the upper limit of normal, sepsis-induced coagulopathy score ≥4, or obesity with BMI >30 kg/m², as suggested by the European Society of Intensive Care Medicine 1, 2, 5, 6

LMWH should be started within 24-36 hours of ICU admission for ARDS patients, according to the Society of Critical Care Medicine 4

Active bleeding or high bleeding risk must be carefully evaluated before initiating LMWH, as recommended by the American Heart Association 2, 5
Absolute contraindications to anticoagulation, such as active bleeding, should be assessed before initiating LMWH, as recommended by the International Society on Thrombosis and Haemostasis 1, 2

When anticoagulation is contraindicated, mechanical thromboprophylaxis with intermittent pneumatic compression devices should be used, as recommended by the American College of Chest Physicians 1, 2
Combining mechanical and pharmacological prophylaxis may be considered in completely immobile ARDS patients, as suggested by the European Society of Intensive Care Medicine 1, 2

For COVID-19-associated ARDS, a universal thromboprophylactic approach with particular attention to intermediate dosing in patients with elevated inflammatory markers is recommended by the International Society on Thrombosis and Haemostasis 4