Reverse Trigger Phenotypification and Response to Ventilatory Adjustments

Measurements:

An esophageal catheter for manometry will be placed as usual practice with confirmation of adequate position with the Baydur's occlusion test before recordings. An independent flow sensor and pressure transducer will be placed and connected to a laptop computer to obtain real-time monitoring along with continuous recordings, which then will be off-line analyzed by two experts, for confirmation of RT and characterization.

Data collection:

Main cause of the acute respiratory failure and days on mechanical ventilation until enrollment will be collected as well as demographic characteristics, including APACHE II, SOFA and the previous requirement of prone positioning therapy.

At identification of the RT, drugs for sedation and analgesia, time from initiation of mechanical ventilation to RT identification and blood gas analysis will be recorded. Ventilatory settings will also be collected, including the control variable of the ventilatory mode (volume or pressure), respiratory rate, received tidal volume in ml/kg of predicted body weight, maximum inspiratory flow, ratio of partial arterial oxygen pressure (pO2) to fraction of inspired oxygen (FiO2), driving pressure and (positive end-expiratory pressure (PEEP). Data about esophageal pressure related to RT will also be recorded, including the magnitude of pressure swing, phase angle, coefficient of variation, RT phenotype, entrainment ratio and the presence of breath stacking.

Patient-centered outcomes including length of mechanical ventilation, intensive care and hospital length of stay, and mortality will be followed-up until 60 days.

Inclusion criteria

• Diagnosis of ARDS according to the Berlin criteria and added New Global Definition 2023
• Mechanical ventilation

Exclusion criteria

• <18 years
• Tracheostomy status
• Pneumothorax
• Tube thoracostomy with air leaks