Effect of High-Flow Humidified Oxygen on Ventilatory Work During the Spontaneous Breathing Trial

Inclusion Criteria: * Adult patient, of legal age * On invasive mechanical ventilation for more than 48 hours * With at least one criterion indicating a high risk of extubation failure: * Age \> 65 years * Chronic respiratory disease * Chronic cardiac disease * Capable of undergoing a mechanical ventilation weaning test ("weaning criterion"): * Respiratory rate \< 35 bpm * Adequate oxygenation: * SpO₂ ≥ 90% with FiO₂ ≤ 40% and PEEP ≤ 8 cm H₂O * Or PaO₂/FiO₂ ≥ 150 with PEEP ≤ 8 cm H₂O * Effective cough * Patient is alert (RASS score -2 to +1), without sedation * Hemodynamically stable or on the minimum effective dose * Patient has an invasive arterial pressure catheter for arterial blood sampling * Informed consent signed by a family member * Patient is enrolled in or eligible for a social security program Exclusion Criteria: * Resuscitation-associated neuromyopathy * History of neuromuscular disease * Admission for a neurological condition * Subjects currently excluded from another study, * Persons referred to in Articles L1121-5 through L1121-8 of the CSP (corresponding to all protected persons: pregnant women, women in labor, breastfeeding mothers, persons deprived of liberty by judicial or administrative decision, persons receiving psychiatric care pursuant to Articles L. 3212-1 and L. 3213-1 who are not covered by the provisions of Article L. 1121-8, persons admitted to a health or social care facility for purposes other than research, minors, and persons subject to a legal protection order or unable to give informed consent). * Staff members who report to the principal investigator