Observational StudyIncidence of Dyssynchronies in Early ARDS

Patients sedated under mechanical ventilation with acute hypoxemic respiratory failure with a PaO2/FiO2 equal or less than 200mmHg (Acute Respiratory Distress Syndrome, ARDS and non-ARDS) will be included in the study early in the course of the disease (first week of mechanical ventilation). At enrollment, data on the clinical condition of the patient will be recorded together with ventilation settings: ventilation mode, the fraction of inspired oxygen (FiO2), PEEP, tidal volume, set pressure, respiratory rate, time of the respiratory cycle, recent blood gas parameters.

Airway pressure, flow, and esophageal pressure (or alternatively electrical activity of the diaphragm, Eadi) will be recorded 3 times a day for 7 days:

1. Period 1 (morning): duration 20-30 minutes
2. Period 2 (afternoon): duration 20-30 minutes
3. Period 3 (evening / night): duration 20-30 minutes

Registration will be ended at extubation, death or at eight days from the first recording.

Monitoring of vital parameters (hemodynamic and respiratory) will be continuous throughout the duration of the study, as per normal clinical practice. All drugs used during the day of the measurements will be recorded. The patient will then be followed until discharge from the ICU and after 60 days of discharge to evaluate mortality.

As an ancillary study, in a subgroup of patients continuous simplified measurement of respiratory recordings together with hourly clinical data on sedation and extended simplified polysomnography recordings will be performed within the first 7 days from inclusion.

The analysis of the recorded waveforms will be performed in a single center by a centralized system that will quantify dyssynchrony and its intensity, calculate pressure time product, collect clinical and physiological data and outcome, and investigate possible correlations.