Evaluation of Unfractionated Heparin Dosing for Thromboprophylaxis Using Anti-Xa Levels in Obese Critically Ill Patients: A Retrospective Study

Purpose: This study aims to evaluate whether current dosing recommendations of UFH for the prevention of thromboembolism is appropriate in obese critically ill patients utilizing Anti-Xa levels. Materials and methods:A pilot, observational and retrospective chart review of critically ill patients was evaluated.Patients aged ≥ 18 years were included if they received subcutaneous UFH for thromboprophylaxis and had a recorded Anti-Xa level taken four to five h after the administration of UFH.Identified patients were categorized into two groups: BMI<30 kg/m 2 or BMI ≥ 30 kg/m 2 .Anti-Xa heparin activity levels were then compared.Statistical analysis was performed using Student's t-test.Results: A total of 130 adult ICU patients were included in this study.For all critically ill patients receiving 5,000 units of subcutaneous heparin every 8 h, there was no statistically significant difference in Anti-Xa levels between the groups (p=0.287).There was no incidence of DVT/ PE reported from either group. Conclusion:This study suggests that there is no significant difference in Anti-Xa levels between obese critically ill patients and non-obese patients receiving traditional UFH dosing for thromboprophylaxis.