The Use of Thrombin Generation Assay in Detection of Central Line Related Thrombosis (CRT) in Critically Ill Patients

Inclusion Criteria: * Age ≧ 18; AND * Admitted to the mixed medical-surgical intensive care units of Queen Mary Hospital in Hong Kong; AND * Clinically indicated for central catheter insertion, which includes central venous catheters and dialysis catheters; AND * Expected to have the central catheter in place for at least 5 days in their ICU stay. Exclusion Criteria: * Patients known to have active venous thromboembolism including deep venous thrombosis or pulmonary embolism; * Patients known to have hypercoagulable states, e.g., hereditary thrombophilia, antiphospholipid syndrome; OR * Patients with active solid organ or hematological malignancies; OR * Patients already receiving therapeutic anticoagulation prior to study recruitment; OR * Patients with thrombosis detected in the insertion site before central catheter insertion; OR * Patients with a central venous catheter already in place prior to ICU admission; OR * Patients admitted to the ICU for post-operative care; OR * Patients admitted to the ICU for trauma care; OR * Patients requiring extra-corporeal life support (ECLS); OR * Patients with poor window or inaccessible for ultrasonographic examination; OR * Pregnancy/post-partum within 6 weeks