Enoxaparin Venous Thromboembolism Prophylaxis Dosing in Critically Ill Underweight Patients.

Optimal dosing of VTE prophylaxis for specific patient populations remains an area of concern as insufficient evidence exists regarding dosing for underweight patients. The purpose of this study is to compare the incidence of major bleeding events in underweight patients given different prophylactic doses of enoxaparin. This is a retrospective analysis performed at multiple hospitals within a single health care system. Patients with a BMI < 18.5 kg/m were divided into 2 groups depending on whether they received at least 1 prophylactic dose of enoxaparin 30 mg subcutaneously once daily or enoxaparin 40 mg subcutaneously once daily. Underweight adult patients were included if they were admitted to an ICU for at least 48 hours and received at least 1 dose of enoxaparin for VTE prophylaxis during their ICU admission. The primary aim was to compare the incidence of clinically significant bleeding between dosing strategies. Secondary aims included the incidence of VTE during admission, ICU length of stay, overall hospital length of stay, and all-cause mortality 30 days post-discharge. A total of 310 patients met inclusion criteria for this study, with 80 patients in the 30 mg group and 230 patients in the 40 mg group. There was no significant difference in major bleeding events between the 2 groups ( = .61). No significant differences in incidence of VTE ( = .455 ), ICU length of stay ( = .466), overall hospital stay ( = .502), or all-cause mortality ( = .925) were found between groups. No difference was found in clinically significant bleeding between underweight critically ill patients receiving VTE prophylaxis with enoxaparin 30 mg once daily or 40 mg once daily. Further studies are needed to evaluate the optimal dosing of VTE prophylaxis with enoxaparin in underweight patients.