Cardiac output (CO) and volumetric pulmonary variables will be obtained by the simple transpulmonary indicator dilution technique. Three consecutive measurements with less than 10% variations will be averaged. A fifteen milliliters bolus of 0.9% saline at 4°C will be injected through the central venous catheter into the right atrium and the change in temperature will be measured with the femoral artery thermistor tipped catheter. Using the mean transit time methods, intrathoracic blood volume, extravascular lung water and global end-diastolic volume will be calculated and indexed for the patient body weight (ITBVI, EVLWI and GEDVI, respectively). Heart rate (HR), stroke volume (SV) and maximal change in arterial pressure will be determined by beat-to-beat analysis of the arterial pressure wave. The systemic vascular resistance index (SVRI) will be calculated using standard formula. The ratio of EVLWI to ITBVI will be calculated as an index reflecting the permeability of the alveolar–capillary barrier.