Pressure-controlled vs Volume Controlled Ventilation on RV Function During OLV

The use of pressure controlled ventilation (TV) during one lung ventilation (OLV) for thoracic surgery is associated with comparable oxygenation with volume controlled ventilation (VCV) with added benefits of decreasing airway pressures and shunt fraction. The later may improve the right ventricular (RV) function during OLV. We postulate that the use of PCV during OLV for thoracic surgery would preserve RV function than during VCV. After local ethics committee approval and informed consent, we will randomly allocate 28 patients scheduled for elective thoracic surgery OLV to randomly crossed from PCV to VCV mode (n= 14 for each) during with VT of 6 mL/kg, I: E ratio 1: 2.5, PEEP of 5 cm H2O, recruitment maneuvers and respiratory rate will be adjusted to maintain normocapnia. Intraoperative changes in the right ventricular function (peak systolic and diastolic tricuspid annular velocity (TAV), end-diastolic volume (EDV), end-systolic volume (ESV), and RV fractional area changes (RV-FAC)), hemodynamic and oxygenation parameters, peak and plateau airway pressures, compliance will be recorded.