Patients will be monitored with three-lead ECG, heart rate, oxygen saturation, as measured by pulse oximeter (SpO2) and invasive arterial blood pressure (Solar 8000, General Electric Medical System, Milwaukee, WI, USA). SV and CO were assessed with a LIDCO Rapid® via the arterial catheter. Inspiratory and expiratory oxygen partial pressure (FiO2, PETO2), sevoflurane inspiratory and expiratory partial pressure (Fisevo, PETsevo) and carbon dioxide inspiratory and expiratory partial pressure (FiCO2, PETCO2) will be analysed by the ventilator. Total ventilation per minute, tidal volumes and airway pressures as peak pressure, plateau pressure and mean pressure were measured and documented at the same intervals. Static compliance of the respiratory system will be calculated as tidal volume divided by the inspiratory plateau pressure minus PEEP.