Third International Study on Mechanical Ventilation

The objective of this study is to obtain a better understanding of the spectrum of use of mechanical ventilation in intensive care units: 1. Main analysis: To know the all-cause mortality rate in mechanically ventilated patients 2. Secondary analyses: * To know the current status of mechanical ventilation in the intensive care unit and determine the number and percentage of patients who are admitted to an intensive care unit and require mechanical ventilation. * To compare the results with prior data collected in previous observational studies (1998 and 2004) * Non-invasive positive pressure ventilation * Weaning * Use of adjuvant therapies as steroids or selective digestive decontamination * Sedation including prevalence of delirium in mechanically ventilated patients * Prediction of the duration of mechanical ventilation * Other