ABSTRACT
Objective To explore the influence of different blood gas strategies on cerebral protection and blood gas analysis during moderate hypothermic cardiopulmonar.Methods Patients under cardiac valve replacement with extracorporeal circulation (ECC) were performed in this study.The cerebral blood flow (CBF) and regional cerebral oxygen saturation (rSO2) were monitored at 5 points:(1)Induction of anesthesia (T1),(2) after 10 min of the beginning of cardiopulmonary bypass (T2),(3) during the moderate hypothermic phase of CBP managed by the alpha-stat after calibrate blood gas 15 min (T3),(4) pH-stat followed,after calibrate blood gas 15 min (T4),and (5) 10 min after CBP (T5).pH and pCO2 in patients were recorded and analyzed at T3 and T4.Results The CBF of T2 and T3 was lower than that of T1,but the difference was not significant (t =2.841,2.711;P =0.062,0.080).The CBF of T4 and T5 was higher than that of T3,but the difference was not significant (t =1.793,2.135;P =0.119,0.066).The CBF of T5 resumed to before operation.The rSO2 of T2 and T3 was lower than that of T1,but the difference was not significant (t =1.821,2.032;P =0.132,0.267),the rSO2 ofT4 and T5 was higher than that ofT3,but the difference was not significant (t =1.879,2.021;P =0.312,0.075).The rSO2 of T5 resumed to before operation.However,the pH was much lower in pH-stat than alpha-stat (t =17.541,P =0.000) and the pCO2 was much higher than alpha-stat (t =13.914,P =0.000).Conclusions Both pH-stat and alpha-stat have cerebral protection effects.However,compared to pH-stat,alpha-stat could reduce the possibility of acidosis,and maintain the acid-base equilibrium.