Comparison Of The Effects Of Methyl Prednisolone And Dexamethasone On Lung Function In Patients Undergoing Heart Valve Replacement With Cardiopulmonary Bypass

Objective:To compare the effects of Methyl prednisolone and dexamethasone on lung function in patients undergoing heart valve replacement with cardiopulmonary bypass.Methods:Sixty patients undergoing heart valve replacement with CPB were investigated. The patients were randomly divided into two groups, dexamethasone group(A group), thirty patients and Methyl prednisolone group(B group), thirty patients. Those patients in the dexamethasone group were recieved dexamethasone0.5mg/kg.iv. after induction of anesthesia. In the Methyl prednisolone group, those patients were received Methyl prednisolone10mg/kg.iv. after induction of anesthesia. Blood gas analysis was performed at pre CPB (Ti),30min after the injection of protamine (T2), the end of the surgery (T3), two hours after the surgery (T4), before pulling out the endotracheal tube (T5), recording PaO2、PaCO2and FiO2. The alveolar arterial oxygen pressure difference [A-aDO2], respiratory index (RI) and Oxygenation index (OI) was measured according to the formula. The time with the endotracheal tube, the time staying CCU and pulmonary complications after surgery will be recorded.Results:The values of PaO2at T1point were not statistically significant between the two groups(P>0.05);The values of PaO2at T2-5point were statistically significant between the two groups, The values of PaO2in the B group was significantly lower than A group(P<0.05). The values of A-aDO2、 RI and OI at T1point were not statistically significant between the two groups(P>0.05);The values of A-aDO2、RI、OI at T2～5point were statistically significant between the two groups, The values of A-aDO2、 RI in the B group was significantly lower than A group(P<0.05), The values of OI in the B group was significantly higher than A group(P<0.05)(P<0.05); The values of A-aDO2and RI in two groups increased firstly and then decreased; The values of OI in two groups decreased firstly and then increased; The time with the endotracheal tube and the incidence of pulmonary complications was statistically significant between the two groups(P<0.05), The B group was significantly lower than A group. The time in the CCU were not statistically significant between the two groups(P>0.05).Conclusions:1、The pulmonary diffusion function and the oxygen exchange function is impaired After CPB, It is shown as A-aDO2, RI increased, OI decreased After CPB;2、Methyl prednisolone has better Protective effect on lung function in patients undergoing heart valve replacement with cardiopulmonary bypass than dexamethasone.