After surgery all patients were admitted at the intensive care unit (ICU) following the institutional mechanical ventilation protocol. Immediately after admission heart rate, mean arterial pressure, and oxygen pulse saturation (SpO2) were measured with a Dixtal monitor (DX 2010). After ICU admission all participants were followed up for main outcomes: hospital discharge, stroke, infection or death. In addition the investigators also measured length of stay, the duration of mechanical ventilation, vasopressors usage and the needed of physiotherapy indication after hospital discharge. All study participants receive medical and physiotherapy care according to the routine of the institution.