* 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

- 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