不同呼气末二氧化碳分压对室间隔缺损修补术患儿脑氧合及脑血流的影响

目的探讨不同P_(ET)CO_2对室间隔缺损修补术患儿脑氧合及脑血流的影响。方法择期行室间隔缺损修补术患儿60例,随机分为两组,每组30例。低通气组(L组):调控V_T和RR,以维持P_(ET)CO_2在40～45 mmHg;高通气组(H组):调控V_T和RR,以维持P_(ET)CO_2在35～40 mmHg。记录麻醉诱导后(T_0)、开心包(T_1)、CPB结束(T_2)、改良超滤结束(T_3)、术毕(T_4)时的局部脑氧饱和度(rScO_2)以及右侧大脑中动脉血流平均速度(V_(MCA))、搏动指数(PI)和阻力指数(RI)。结果与T_2时比较,T_0、T_1、T_3、T_4时两组患儿rScO_2和V_(MCA)明显升高(P0.05),PI和RI明显降低(P0.05)。T_0、T_1、T_3、T_4时L组rScO_2和V_(MCA)明显高于H组(P0.05)。结论 P_(ET)CO_2在40～45 mmHg时,患儿rScO_2和V_(MCA)高于P_(ET)CO_2在35～40 mmHg时,可改善脑氧供需平衡。

Effect of different end-tidal carbon dioxide partial pressure on cerebral oxygenation and cerebral blood flow in infants with ventricular septal defect repair

Ojective To analyze the change of different PETCO2 on regional cerebral oxygen saturation (rScO2) and cerebral blood flow in infants with ventricular septal defect repair.
Methods In this study, 60 infants with VSD were randomly divided into high ventilation group (group H, 30 cases) and low ventilation group (group L, 30 cases). PETCO2 was maintained at 40 - 45 mmHg by regulating VT and RR in group L. PETCO2 was maintained at 35 - 40 mmHg by regulating VT and RR in group H. The values of rScO2, flow velocity of middle cerebral artery (VMCA) at the right side, pulse index (PI) and resistance index(RI) were recorded respectively after anesthesia (T0), cut pericardium (T1), the end of CPB (T2), the end of modified ultrafiltration (T3), after operation (T4).
Results Compared with T2, the values of rScO2 and VMCA were significantly increased while the levels of PI and RI were decreased at T0, T1, T3, T4 (P<0.05). Meanwhile, the levels of rScO2 and VMCA in group L were higher than those in group H (P<0.05).
Conclusion The infants'' rScO2 and VMCA performed better when PETCO2 is 40-45 mmHg versus 35-40 mmHg, which could improve the balance of cerebral oxygen supply and demand.