Please select the eligibility criteria that correspond to the clinical trial below.
Title: BARIVA:Short Versus Extended Prophylaxis of Rivaroxaban for Venous Thromboembolism After Bariatric Surgery
Brief Summary: The aim of this study is to investigate the efficacy and safety of rivaroxaban in obese patients undergoing bariatric surgery.

The objectives are to assess the safety and feasibility of venous thromboembolism (VTE) prophylaxis and lung embolism with Rivaroxaban 10mg as an oral anticoagulant. After bariatric surgery patients receive the study medication Xarelto 10mg QD for 7, resp. 28 days.

All clinically thromboembolic events will be assessed by ultrasound or CT, respectively, as soon as apparent. In addition, patients are screened for VTE at day 28 by ultrasound to detect clinically inapparent thromboses.

In a subgroup of study patients (patients from the University Hospital Inselspital, Bern) PK/PD parameters are assessed following the last intake of rivaroxaban at day 28.


Options:
A: Inclusion Criteria:

* Age (equal or more than 18 yo)
* Hospitalization at conventional wards due to COVID-19 related mild or moderate pneumonia (CURB65\<3 points; Sat. O2\>90%)
* 3-4 points according to the WHO ordinal scale.
* Confirmed COVID-19 (PCR or other validated test)
* D-dimer \>500 ng/mL
* Sign of informed consent
* The patient is able, according to investigator's opinion, to deal with all the requirements of the clinical trial.

Exclusion Criteria:
B: Inclusion Criteria:

* Patients with scheduled elective bariatric surgery or redo surgery after bariatric interventions
* Written informed consent

Exclusion Criteria:

* DVT and/or PE in the patient history
* Myocardial infarction, transient ischemic attack or stroke within 6 months of study entry
* Uncontrolled hypertension
C: Inclusion Criteria:

* Hospitalized, COVID-19 positive, between 18 and ≤ 85 years of age;
* Signed Inform Consent Form;
* Body temperature \> 37.3 ℃;
* Oxygenation criterion (any of the following): i) Oxygen saturation ≤94% on Room Air; ii) PaO2/FiO2 ratio ≤300 mmHg but \> 100 mmHg, if patient on supplemental oxygen; iii) SpO2/FiO2\<200 if no arterial blood gas available;
* Respiratory rate (RR) ≥ 25 beats/min.

Exclusion Criteria:

* Pregnant or lactating females;
* Unwillingness or inability to complete the study.
* Rapidly deteriorating clinical condition or low likelihood to complete the study according to the investigator;
* eGFR \< 30 ml/min/m2 assessed with CKD EPI formula;
* Current or chronic history of liver disease (Child Pugh score ≥ 10), or known hepatic or biliary abnormalities;
* Participation in a clinical trial with an investigational product within the following time period prior to the first dosing day in the current study: 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer);
* Patients requiring high doses of loop diuretics (i.e. \> 240 mg furosemide daily) with significant intravascular volume depletion, as assessed clinically;
* History of allergy;
* History of sensitivity to heparin or heparin-induced thrombocytopenia;
* Unstable hemodynamics in the preceding 4 hours (SBP \< 90 mmHg, and/or vasoactive agents required);
* Hemoglobin \< 7 at time of drug infusion. Transfusion is allowed to increase hemoglobin levels before entry into the study;
* Malignancy or any other condition for which estimated 6-month mortality \>50%;
* Arterial blood pH less than 7.2;
* Known evidence of chronic interstitial infiltration at imaging;
* Known hospitalization within the past six months for respiratory failure (PaCO2 \> 50 mmHg or PaO2 \< 55 mmHg, or oxygen saturation \<88% on FiO2 = 0.21);
* Known chronic vascular disease resulting in severe exercise restriction (i.e. unable to perform household duties);
* Known secondary polycythemia, severe pulmonary hypertension, or ventilator dependency;
* Known vasculitis with diffuse alveolar hemorrhage;.
* Pre-existing renal failure on hemodialysis or peritoneal dialysis requiring renal replacement therapy;
* Extracorporeal membrane oxygenation (ECMO);
* Immunosuppressive treatment;
* Patient in trials for COVID-19 within 30 days before;
* Unstable hemodynamics in the preceding 4 hours (MAP ≤ 65 mmHg, or SAP \< 90 mmHg, DAP \< 60 mmHg, and vasoactive agents required);
* Hyperkalemia , i.e. serum K+ levels \> 5.0 mEq/L;
* Severe active bleeding;
* Any other uncontrolled comorbidities that increase the risks associated with the study drug administration, as assessed by the medical expert team.
D: Inclusion Criteria (all required):

* Positive SARS-CoV-2 diagnostic (on pharyngeal swab of deep airways material)
* Severe pneumonia defined by the presence of at least one of the following criteria:

  1. Respiratory Rate ≥25 breaths /min
  2. Arterial oxygen saturation≤93% at rest on ambient air
  3. PaO2/FiO2 ≤300 mmHg
* Coagulopathy, defined by the presence of at least one of the following criteria:

  1. D-dimer \>4 times the upper level of normal reference range
  2. Sepsis-Induced Coagulopathy (SIC) score \>4
* No need for invasive mechanical ventilation

Exclusion Criteria:

* Invasive mechanical ventilation
* Thrombocytopenia (platelet count \< 80.000 mm3)
* Coagulopathy: INR \>1.5, aPTT ratio \> 1.4
* Impaired renal function (eGFR calculated by CKD-EPI Creatinine equation \< 30 ml/min)
* Known hypersensitivity to enoxaparin
* History of heparin induced thrombocytopenia
* Presence of an active bleeding or a pathology susceptible of bleeding in presence of anticoagulation (e.g. recent haemorrhagic stroke, peptic ulcer, malignant cancer at high risk of haemorrhage, recent neurosurgery or ophthalmic surgery, vascular aneurysms, arteriovenous malformations)
* Concomitant anticoagulant treatment for other indications (e.g. atrial fibrillation, venous thromboembolism, prosthetic heart valves).
* Concomitant double antiplatelet therapy
* Administration of therapeutic doses of LMWH, fondaparinux, or unfractionated heparin (UFH) for more than 72 hours before randomization; prophylactic doses are allowed
* Pregnancy or breastfeeding or positive pregnancy test
* Presence of other severe diseases impairing life expectancy (e.g. patients are not expected to survive 28 days given their pre-existing medical condition)
* Lack or withdrawal of informed consent

Answer: B