Utility of coagulation analyses to assess thromboprophylaxis with dalteparin in intensive care unit patients.

BACKGROUND: The aim of this study was to evaluate the utility of coagulation analyses to assess thromboprophylaxis with dalteparin in intensive care unit (ICU) patients.

METHODS: Prospective observational study of ICU patients receiving dalteparin prophylaxis at Oslo University Hospital in Norway. Trough and peak antithrombin, protein C, anti-factor Xa activity (aFXa), d-dimer, thromboelastography, calibrated automated thrombogram and microparticles were analysed. Levels were compared in patients with and without venous thromboembolism (VTE), major bleeding, acute kidney injury (AKI) with use of renal replacement therapy (RRT) and variable dalteparin dose.

RESULTS: Among 50 included patients (76% male, mean age 62 years) five (10%) developed VTE and eight (16%) major bleeding. Median through aFXa level was 0.03 (0.02-0.05) IU/mL, and 48 (96%) of patients were within and two (4%) above target range. Peak aFXa level was 0.21 (0.13-0.29) IU/mL, the number of patients below, within and above prophylactic range were 21 (42%), 25 (50%) and four (8%). Peak aFXa levels were similar in patients with and without VTE (0.18 vs 0.21 IU/L, P = .72), major bleeding (0.22 vs 0.21 IU/mL, P = .38) and AKI with RRT (0.18 vs 0.24, P = .13), but lower in patients receiving dalteparin 5000 IU od compared to 7500 IU od (0.19 vs 0.30 IU/mL, P < .01).

CONCLUSIONS: Intensive care unit patients receiving dalteparin prophylaxis had half of patients within prophylactic peak aFXa target range. Peak aFXa levels was affected by administered dalteparin dose, but not presence of VTE, major bleeding or AKI with RRT.