All patients admitted in St John’s Medical College Hospital ICU who are intubated and mechanically ventilated will be assessed for inclusion in the study within the first 24 hours of initiation of mechanical ventilation. For Consenting patients, Identification number and basic details - demographics will be entered in the Proforma. Comorbidities, reason for intubation, hemodynamic parameters will be noted.   

        All evaluations of ventilatory parameters and Ultrasound based evaluations shall be performed by principal investigator under supervision.

•      For patients who have been intubated, sedated and paralysed, on volume controlled ventilation the following parameters shall be noted down – respiratory rate (breaths/min) set, tidal volume (ml) set, minute volume set, PEEP (cm H2O) levels set and the inspiratory expiratory ratio set.

•      Peak pressure(PIP), plateau pressure (by applying inspiratory hold for 3-5 seconds), mean airway pressure, Total positive end expiratory pressure- PEEP ( by applying expiratory hold for 3 seconds) and hence auto PEEP, driving pressure ( plateau pressure – PEEP), (all in units of cm H2O) dynamic compliance (Vt/PIP-PEEP), static compliance (Vt/Plateau-PEEP), resistance  will also be noted down.

•      Mechanical power will be calculated according to the following equation as per the comprehensive equation for mechanical ventilation defined by gattinoni et al.

MP=0.098 * RR * Vt * [ PIP -0.5(Pplat-PEEP)]

·         Lung ultrasound will be done with a curved array transducer of 2-5MHz as per blue protocol and a composite lung aeration score will be calculated.

This score is computed in six regions per hemithorax: anterior, lateral, and posterior fields are identified by sternum, anterior, and posterior axillary lines; each field is divided into superior and inferior regions