- patients with life expectancy less than 48hrs - patients who require ventilatory support upon admission - age over 75 years or with a history of atrial fibrillation - history of venous or arterial thrombosis - severe neurological impairment - absence of a primary caregiver to supervise the administration of medication - history of cerebral hemorrhage - history of previous use of oral anticoagulants - history of major surgery 30 days prior to admission - uncontrolled systemic arterial hypertension - kdigo stage iii chronic kidney disease or less - hemodialysis or peritoneal dialysis treatment - history of active or inactive cancer - pregnant or postpartum patients

- patients with life expectancy less than 48hrs - patients who require ventilatory support upon admission - age over 75 years or with a history of atrial fibrillation - history of venous or arterial thrombosis - severe neurological impairment - absence of a primary caregiver to supervise the administration of medication - history of cerebral hemorrhage - history of previous use of oral anticoagulants - history of major surgery 30 days prior to admission - uncontrolled systemic arterial hypertension - kdigo stage iii chronic kidney disease or less - hemodialysis or peritoneal dialysis treatment - history of active or inactive cancer - pregnant or postpartum patients