The goal of this observational study is to learn about the influence of mechanical ventilation on the right ventricular (RV) function. The primary focus is on methods which are routinely used to improve gas exchange in ventilated patients (positive end expiratory pressure [PEEP], inhalation of NO, prone positioning). The main questions it aims to answer are:1) Effects of prone positioning, PEEP and inhalation of NO on RV-function Are there determinants (clinical, laboratory, demographic, echocardiographic) for the right ventricular response to the above?
