Efficacy of standard dose unfractionated heparin for venous thromboembolism prophylaxis in morbidly obese and non-morbidly obese critically Ill patients

Abstract

To determine the efficacy of standard dose unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in critically ill morbidly obese patients. Retrospective single-center observational cohort study in a single tertiary teaching hospital intensive care units (ICUs) in Multiparameter Intelligent Monitoring in Intensive Care II Clinical Database. Patients 18 years or older, admitted to the ICU, and received either UFH 5000 units subcutaneously twice daily or UFH 5000 units three times daily for VTE prophylaxis between 2001 and 2008 were included. Total 243 patients in the BMI ≥ 40 kg/m group and 2813 patients in the BMI < 40 kg/m group were identified. There was no difference in VTE incidence between the two groups. However, a strong linear association was found showing as BMI increased so did the rate of VTE incidence. Morbidly obese patients had longer hospital (17 vs. 14 days, P = 0.016) and ICU length of stay (10 vs. 8 days, P = 0.007). After controlling Padua score, logistic regression analysis revealed the odds of VTE increased by a factor of 1.026 for each one-unit increase in BMI. Additionally, having a BMI ≥ 40 kg/m was associated with a greater likelihood of VTE incidence in males (OR 3.92) but not in females. In patients treated with standard dose UFH, morbid obesity does not increase VTE risk overall. However, BMI has a strong linear relationship with VTE incidence and morbid obesity is more likely associated with greater hospital and ICU length of stay.

Comparative effectiveness and safety of direct oral anticoagulants compared to warfarin in morbidly obese patients with acute venous thromboembolism: systematic review and a meta-analysis

“…Obesity is an independent risk factor for the acquisition of VTE. Extremely high BMI has been shown to be correlated with an increased incidence of VTE; this correlation is more apparent with a BMI of 30 kg/m 2 or more [33,34]. The increased risk of VTE in this cohort is likely due to the increased abdominal pressure and the mechanical effect it exerts on the veins [35,36].…”

Evaluation of unmet clinical needs in prophylaxis and treatment of venous thromboembolism in at-risk patient groups: pregnancy, elderly and obese patients

“…Adult obesity is classified into three categories: class I obesity is defined by a body mass index (BMI) of 30.0–34.9 kg/m 2 ; class II obesity by a BMI of 35.0–39.9 kg/m 2 ; and class III obesity, or severe obesity, by a BMI ≥40.0 kg/m 2 [69]. Weight is a VTE risk factor when a BMI exceeds 30 kg/m 2 [68], and BMI has a strong linear relationship with the incidence of VTE [4]. The inflammatory and metabolic perturbations associated with obesity are thought to provoke a hypercoagulability state in these patients, and central obesity plus high fibrinogen levels may be considered as clinical markers [70].…”

“…Acute VTE is linked to substantial long-term mortality in the elderly (21% of 991 patients in a Swiss cohort study with a median follow-up time of 30 months) [3]. Patients with VTE who are morbidly obese are more likely to have extended hospital and intensive care unit stays [4]. Thus, the suboptimal use of anticoagulants in these patients and the increased cost burden related to longer hospital stays needs to be addressed.…”

Thromboprophylaxis in Intensive Care Unit Patients: A Literature Review

“…However, in patients who were given a standard dose UFH, morbid obesity did not increase VTE risk overall. Also, morbid obesity was more likely associated with greater hospital and ICU length of stay [ 34 ].…”