Association of Anti-factor Xa Activity With Venous Thromboembolism in Critically Ill Patients

Association of Anti-factor Xa Activity With Venous Thromboembolism in Critically Ill Patients: a Prospective Multicentre Cohort Study

The goal of this observational study is to analyse the association between anti-factor Xa activity (antiXa) and the occurence of venous thromboembolism (VTE; either deep vein thrombosis and/or pulmonary embolism) in critically ill patients who are admitted to an intensive care unit. The main questions it aims to answer are:

• What is the association between antiXa and VTE?
• What is the association between antiXa and symptomatic, respectively incidental, VTE?
• How is pharmacological anticoagulation with enoxaparin related to measured antiXa?
• What is the association between antiXa and bleeding complications.
• What is the incidence of venous thromboembolism in patients treated at an intensive care unit?
• How is the occurence of VTE related to patient-centred outcomes such as mortality, quality of life, length of stay and days outside of the intensive care unit/hospital.

Inclusion Criteria:

• Age over 18 years at the time of intensive care unit admission
• Admission to a participating intensive care unit within the last 24 hours
• Expected discharge is later than 48 hours after enrolment

Exclusion Criteria:

• Therapeutic anticoagulation, defined as enoxaparin dose of at least 100 IE/kg when given twice daily or of at least 150 IE/kg when given once daily
• Extracorporeal membrane oxygenation in place or planned within 48 hours of study enrolment
• Planned regular administration of vitamin K antagonists, unfractionated heparin, low molecular weight heparin other than enoxaparin, thrombin inhibitors or factor X inhibitors within the observation period
• Estimated life expectancy below 48 hours or comfort terminal care order in place
• Previously diagnosed heparin-induced thrombocytopenia
• Pre-operative admission for elective surgery
• Previous enrolment in the study