Evaluation of Anti-Xa Activity in Patients With Severe Obesity After Subcutaneous Injection of Enoxaparin for Antithrombotic Prophylaxis at Two Different Sites.

Inclusion Criteria:• age \>18 years, * BMI \>40 kg/m2 * indication to primary or secondary thromboprophylaxis (Padua Score \> 4), as clinical practice Exclusion Criteria:• indication to full dose anticoagulant, * creatinine clearance \<30 mL/min (based on Cockcroft-Gault equation using adjusted body weight), * pregnant women, * low platelet count (\<50.000/microL or \<100.000/microL plus additional risk factors for bleeding), * active bleeding, * active gastroduodenal ulcer, * severe bleeding diathesis, * recent/planned/emergency high bleeding-risk surgery/procedure, * major trauma, * acute intracranial hemorrhage, * bleeding within the three months prior to admission, * known hypersensitivity to enoxaparin (e.g. pruritus, urticaria, anaphylactic/anaphylactoid reactions), * history of immune mediated heparin-induced thrombocytopenia (HIT), * severe uncontrolled hypertension, * diabetic or hemorrhagic retinopathy, * concurrent administration of subcutaneous drugs (i.e. insulin, GLP-1 receptor agonists, etc.).