Prevention of venous thromboembolism in obesity

Abstract

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in hospitalized patients. Where appropriate, evidence-based methods of prophylaxis are implemented and the burden of VTE can be reduced substantially. Obesity, including morbid obesity, is associated with a high risk of VTE and, unfortunately, fixed doses of US FDA-approved anticoagulant regimens, including unfractionated heparins, low-molecular-weight heparins and factor Xa inhibitors, may not provide optimal VTE prophylaxis in these patients. Although the data are still limited, a rapidly growing body of literature and cumulative evidence suggests that anticoagulant dose adjustments in morbidly obese patients may optimize pharmacodynamic activity and reduce VTE risk. With the prevalence of morbid obesity continuing to rise, more high-quality clinical data are needed to better understand the pathobiology of VTE in obesity and provide effective, yet safe, prevention strategies.

Venous thromboembolism: a role for weight-stratified thromboprophylaxis?

“…1,2 In the UK, fixed doses of low molecular weight heparin (LMWH) are used for VTE prophylaxis regardless of patient weight. 3 While the effects of LMWHs are not usually routinely monitored, levels of anti-Xa have been used to determine if standard prophylactic doses of LMWH provide adequate prophylactic cover to obese patients. An inverse correlation between anti-Xa levels in the first 10 hours and body weight with fixed prophylactic doses of 40 mg enoxaparin has been demonstrated, which suggests that current fixed-dose thromboprophylaxis is likely inadequate in heavier patients.…”

“…An inverse correlation between anti-Xa levels in the first 10 hours and body weight with fixed prophylactic doses of 40 mg enoxaparin has been demonstrated, which suggests that current fixed-dose thromboprophylaxis is likely inadequate in heavier patients. 3,4 A review of observational studies suggests that with fixed dose thromboprophylaxis, VTE rates in the obese are twice that of the non-obese, with a subgroup analysis of the PREVENT trial demonstrating no benefit of standard-dose dalteparin over placebo in the morbidly obese population. 3 Randomised control trials involving bariatric surgery groups have demonstrated lower rates of VTE with higher doses of LMWH, with no associated increase in bleeding events.…”

“…This has prompted a move by the UK Department of Health towards encouraging innovations that promote early diagnosis such as the Be Clear on Cancer campaign. [1][2][3] Endoscopy remains the gold-standard investigation for the diagnosis of gastro-oesophageal cancer. Unlike colonoscopy, where there are standardised key performance indicators and audits of all colonoscopists' practice, no parallel standards are currently in use in upper GI endoscopy.…”

Prevention of venous thromboembolism in the Enhanced Recovery After Surgery (ERAS) setting: an evidence-based review

“…Nevertheless, since LMWH accumulates almost entirely in the vascular space, which does not correlate linearly with total body weight, there is concern for overdosing LMWH by using dosing adjustments based on total weight. 23 Expert consensus recommends intensifying the dose of LMWH in obese patients undergoing surgery in a fixed manner (Table 4). 23 A systematic approach is needed to identify at-risk obese patients (BMI [ 30 kgÁm -2 ); this would entail the use of institutional VTE policies and pre-specified order sets that incorporate preoperative BMI measurements.…”

“…23 Expert consensus recommends intensifying the dose of LMWH in obese patients undergoing surgery in a fixed manner (Table 4). 23 A systematic approach is needed to identify at-risk obese patients (BMI [ 30 kgÁm -2 ); this would entail the use of institutional VTE policies and pre-specified order sets that incorporate preoperative BMI measurements.…”