The main aim is to demonstrate whether reintubation rate is lower with preventive conditioned noninvasive ventilation (NIV) rather than with High-flow oxygen therapy (HFOT) in obese intermediate-risk patients and in high-risk patients.

Inclusion Criteria:

1. High-Risk Patients: Patients under mechanical ventilation for more than 24 hours considered at high risk according to the presence of more than 3 of the following risk factors:

   • >65 years.
   • Cardiac failure as the primary indication of mechanical ventilation.
   • Moderate to severe chronic obstructive pulmonary disease.
   • APACHE II >12 points the extubation day.
   • Body mass index >30.
   • Inability to manage respiratory secretions.
   • Not simple weaning.
   • More than 1 comorbidity.
   • More than 7 days under mechanical ventilation.
   • Hypercapnia during the spontaneous breathing trial.
   • Airway patency problems.

2. Obese Intermediate Risk Patients: Patients under mechanical ventilation for more than 24 hours with a Body mass index >30 and considered at intermediate risk according to the presence of less than 3 of the following risk factors:

   • >65 years.
   • Cardiac failure as the primary indication of mechanical ventilation.
   • Moderate to severe chronic obstructive pulmonary disease.
   • APACHE II >12 points the extubation day.
   • Inability to manage respiratory secretions.
   • Not simple weaning.
   • More than 1 comorbidity.
   • More than 7 days under mechanical ventilation.
   • Airway patency problems.

Exclusion Criteria:

• <18 years.
• Thacheotomized patients.
• Contraindications for NIV (recent facial or cervical trauma/surgery, active gastro-intestinal bleeding, lack of cooperation).
• Unscheduled extubation.
• Do not reintubate orders.
• No informed consent.