Time-controlled Adaptive Ventilation (TCAV) Compared With Conventional Ventilation in Patients With Moderate-to-severe Acute Respiratory Distress Syndrome (ARDS) Secondary to Community-acquired Pneumonia

Efficacy and Safety of Time-controlled Adaptive Ventilation (TCAV) Compared With Conventional Ventilation in Patients Requiring Invasive Ventilation for Moderate-to-severe Acute Respiratory Distress Syndrome (ARDS) Secondary to Community-acquired Pneumonia

ARDS is a pathology with mortality rates reaching 40%. Invasive ventilation, the cornerstone of ARDS management, leads to "ventilation-induced lung injury" (VILI). An approach based on pressure-controlled ventilation with unassisted spontaneous respirations (PC-SV or APRV) can limit the occurrence of VILI. Time-controlled adaptive ventilation (TCAV) is based on high mean inspiratory airway pressure, while limiting expiratory time at low pressure. TCAV has shown positive effects in experimental and observational studies. However, its efficacy and safety in patients with moderate-to-severe ARDS remains to be evaluated.

Evaluation of the efficacy of early application of TCAV compared to standard ventilation on the severity of alveolar damage leading to injury-related pulmonary edema in patients with moderate to severe ARDS After obtaining patient's consent, eligible patients will be included in this open-label, randomized controlled pilot study with stratification by minimization based on initial severity. The experimental group will be the TCAV group, where ventilator settings will be standardized. The ventilator in the standard care group will be set to volumetric mode with positive end-expiratory pressure according to the EXPRESS protocol.

The measurement of extravascular lung water will be compared on day 2 between the TCAV settings group and the standard care settings group using the PICCO system.

The TCAV setting is simple and inexpensive. In ARDS patients, the increase in injury-related pulmonary edema is a relevant marker of mortality, and its reduction could improve patients' outcomes. Our study aims to evaluate the efficacy and safety of these settings to justify a future large-scale, multicenter randomized trial.

Inclusion Criteria:

• Intensive care unit hospitalisation for ARDS with a PaO₂/FiO₂ ratio ≤ 200 mmHg and PEEP ≥ 5 cmH₂O under invasive ventilation
• Criteria for community-acquired pneumonia, 2 of the following: cough, purulent sputum, chest pain, dyspnea
• Onset of symptoms ≤ 7 days
• Invasive ventilation initiated ≤ 24 hours
• Affiliation to a social security program
• Patient for whom written consent has been obtained from a trusted person or a family member, or inclusion in a situation of immediate life-threatening emergency

Exclusion Criteria:

• Focal ARDS defined as unilateral involvement (1 out of 4 quadrants or 2 on the same side) on imaging (chest X-ray or CT scan)
• Right heart failure not related to acute pulmonary heart disease secondary to ARDS (pulmonary embolism, myocarditis, ischemic cause)
• Pneumothorax, drained or undrained, with a persistent pleural air leak
• COPD with significant obstructive impairment defined by the presence of chronic respiratory disease and oxygen therapy or non-invasive ventilation at home
• Circulatory support via VV-ECMO or VA-ECMO
• Presence of a patent foramen ovale
• Active limitation of therapies
• Increased intracranial pressure
• Sickle cell disease
• Burns > 30%
• Expected invasive mechanical ventilation for less than 48 hours
• A person covered by Articles L. 1121-5, L. 1121-7, and L. 1121-8 of the French Public Health Code
• Pregnant or breastfeeding women
• A not emancipated minor
• Adults subject to legal protective measures (guardianship, conservatorship, judicial protection) or inability to give consent
• Persons deprived of liberty by a judicial or administrative decision, persons receiving psychiatric care pursuant to Articles L. 3212-1 and L. 3213-1