Effects Of Lung Protective Ventilation Strategy With Different Peep On Lung Function And Haemodynamics In Patients Undergoing Cardiac Valve Replacement With Cadiopulmonary Bypass

Objective:To evaluate the effects of lung protective ventilation strategy with different PEEP on lung function and haemodynamics in patients undergoing cardiac valve replacement with cadiopulmonary bypass(CPB).Methods:Sixty patients undergoing elective cardiac valve replacement with CPB were randomly divided into 3 groups(n=20 each):Conventional ventilation group(group C:VT 10～12ml/kg, PEEP 0cmH2O), Lung protective ventilation group (group P Ⅰ:VT 6～8ml/kg, PEEP 5cmH2O; group PⅡ:VT 6～8ml/kg, PEEP 10cmH2O). According to grouping, adjust respiratory parameters after tracheal intubation general anesthesia. Observation time points:5 min after endotracheal intubation(T1)、5 min after extracorporeal circulation downtime(T2) and the moment of surgery end(T3). compare three groups of patients with oxygenation index、the dynamic lung compliance、the changes of heart rate and mean arterial pressure at different time points.Result:Comparison between the three groups, in T1 time point, there was no significant change in OI and Cdyn (P>0.05). In T2 and T3 time points, significant change was found in OI and Cydn (P<0.05), and group P I more than group C (P<0.05), groupP Ⅱ more than group P I and group C (P<0.05). Comparison within the three groups, OI and Cydn at T1 time point were significant higher than T2 and T3 time points (P<0.05). At any time point, comparison between the three groups of patients, HR and MAP were no significant change (P>0.05)Conclusions:lung protective ventilation with 10cmH2O can better improve OI and Cydn than 5cmH2O in patients undergoing cardiac valve replacement with CPB.