Retrospective Study of Venous Thromboembolism Prophylaxis Dosing of Heparin in Adult Patients receiving Continuous Renal Replacement Therapy

Background: Appropriate chemical and/or mechanical venous thromboembolism prophylaxis is a high priority for clinicians. Unfortunately, there is little evidence-based guidance for clinical decision making for patients requiring both renal replacement therapy and VTE prophylaxis. The package insert for unfractionated heparin recommends 5000 units subcutaneously every 8 to 12 hours for VTE prophylaxis. Objective: The purpose of this study was to assess the two recommended dosing intervals and determine if there is a difference in terms of incidence of clotting or bleeding events. Methods: 159 patients were admitted to the UNC Health Care system between March 2014 and November 2019 and retrospectively screened for incidence of both the primary composite efficacy outcome (symptomatic or asymptomatic vascular event (VTE [DVT and PE]), ischemic event (stroke, TIA, or myocardial infarction), or death related to coagulopathy), the individual components of the composite outcome and the primary safety outcome. The results of the outcomes were then compared and analyzed using Fischer’s Exact test. Results: The two tailed p-values of the primary composite efficacy outcome (0.3517), the primary safety outcome (0.1571) and each of the composite outcomes (0.1556, 1.0000, 0.2297, respectively) showed no statistically significant difference. Conclusion: Results of this study show that there is no statistical difference between the dosing intervals of prophylactic UFH of every 8 to 12 hours, in terms of the incidence of VTE and major bleed events, for patients requiring CRRT. Suggesting that either interval is both efficacious and safe for the use of VTE prophylaxis.