Ventilator Lung clinical trials

Sigh in Acute Hypoxemic Respiratory Failure

Mortality of intubated acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) patients remains considerably high (around 40%) (Bellani 2016). Early implementation of a specific mechanical ventilation mode that enhances lung protection in patients with mild to moderate AHRF and ARDS on spontaneous breathing may have a tremendous impact on clinical practice. Previous studies showed that the addition of cyclic short recruitment maneuvers (Sigh) to assisted mechanical ventilation: improves oxygenation without increasing ventilation pressures and FiO2; decreases the tidal volumes by decreasing the patient's inspiratory drive; increases the EELV by regional alveolar recruitment; decreases regional heterogeneity of lung parenchyma; decreases patients' inspiratory efforts limiting transpulmonary pressure; improves regional compliances. Thus, physiologic studies generated the hypothesis that addition of Sigh to pressure support ventilation (PSV, the most common assisted mechanical ventilation mode) might decrease ventilation pressures and FiO2, and limit regional lung strain and stress through various synergic mechanisms potentially yielding decreased risk of VILI, faster weaning and improved clinical outcomes. The investigators conceived a pilot RCT to verify clinical feasibility of the addition of Sigh to PSV in comparison to standard PSV. The investigators will enrol 258 intubated spontaneously breathing patients with mild to moderate AHRF and ARDS admitted to the ICU. Patients will be randomized through an online automatic centralized and computerized system to the following study groups (1:1 ratio): - PSV group: will be treated by protective PSV settings until day 28 or death or performance of spontaneous breathing trial (SBT); - PSV+Sigh group: will be treated by protective PSV settings with the addition of Sigh until day 28 or death or performance of spontaneous breathing trial (SBT). Indications on ventilation settings, weaning, spontaneous breathing trial and rescue treatment will be specified.