This study aims to compare epidemiology, management of invasive ventilation and outcomes in critically ill patients with COVID-19 ARDS and ARDS from another pulmonary infection. The investigators will use individual patient data from four recently published large observational COVID-9 studies, including the 'Practice of VENTilation in COVID-19 patients' (PRoVENT-COVID) study, the 'Epidemiology of COVID-19 patients in the ICU' (EPICCoV) study, the 'SATI-COVID-19 - Clinical Characteristics and Outcomes of Patients With COVID-19 on Mechanical Ventilation in Argentina: a Prospective, Multicenter Cohort Study' and the CIBERESUCICOVID - Personalized Risk and Prognosis Factors and Follow-up at One Year of the Patients Hospitalized in the Spanish Intensive Care Units Infected with COVID -19' study. The investigators will use the individual patient data from ARDS patients with another pulmonary infection from the 'LUNG -SAFE - Large Observational Study to UNderstand the Global Impact of Severe Acute Respiratory FailurE' study and the 'ERICC - Epidemiology of Respiratory Insufficiency in Critical Care' study.

Early on in the pandemic, it was frequently proposed that ARDS caused by COVID-19 and ARDS caused by another cause were distinct in a number of ways. COVID-19 related ARDS phenotypes have been suggested, based on differences in respiratory system compliance (Crs) and the severity of the hypoxemia. Other reports have even suggested that lung-protective ventilation strategies for patients with ARDS caused by COVID-19 should differ from those used before the pandemic.

The use of low tidal volumes (VT) and prone positioning, which have been shown to be useful in reducing death in patients with ARDS prior to the pandemic, were also shown to be effective in patients with COVID-19 related ARDS, according to several reports. In the discussion of how to ventilate patients with COVID-19 related ARDS, the disagreement over other ventilatory settings, such as the best positive end-expiratory pressure (PEEP) and the use of recruitment manoeuvres, remains remarkably lively.

To compare epidemiology, management of invasive ventilation and outcomes in critically ill patients with COVID-19 ARDS and ARDS from another pulmonary infection, the investigators will use individual patient data from PRoVENT-COVID, EPICCoV, SATI-COVID-19, CIBERESUCICOVID, LUNG-SAFE and ERICC.

Inclusion Criteria:

1. Cause for ARDS is COVID -19 (confirmed with polymerase chain reaction (PCR) and/or presence of typical abnormalities on chest computer tomography (CT) and/or X-ray) or a pulmonary infection from another origen
2. Meeting a Berlin criteria for ARDS
3. Invasive ventilation

Exclusion Criteria:

1. Age < 18 years
2. Any form of non-invasive ventilation

Adult critically ill patients receiving invasive ventilation due to ARDS caused by COVID -19 or a pulmonary infection from another origen.

The database will be available after publication of the main publication upon reasonable request after consent of the steering committee. Request must be accompanied by a statistical analysis plan.

One year after publication of the main publication

All requests must be accompanied by a statistical analysis plan