婴儿心脏手术中脑氧饱和度的监测：与手术后早期预后的关系

背景我们对婴儿心脏手术中脑氧饱和度的变化及其与解剖学诊断和早期预后的关系进行了研究。方法将104例接受双心室修补无主动脉弓缩窄手术的先心病患儿随机分成两组，两组的红细胞比容分别稀释至25％和35％。用近红外光谱仪监测各时点每例患儿的局部脑氧饱和度（rSO2）。结果在心肺转流前，与右位型大动脉转位（D-TGA）和室间隔缺损患儿相比，法洛氏四联症（TOF）患儿局部脑氧饱和度较高（P〈0．001）。在心肺转流降温、低流量转流及心肺转流结束时，右位型大动脉转位患儿的局部脑氧饱和度最高（P〈0．001）。但各组间手术中局部脑氧饱和度和早期预后经校正诊断后并没有明显关系。39例接受≥5分钟深低温停循环[deephypothermiccirculatoryarrest（DHCA）]的右位型大动脉转位患儿中，停循环开始时的局部脑氧饱和度（91％±6％）及红细胞比容（29．2％±5．5％）与停循环中的局部脑氧饱和度下降速率没有明显关系。结论手术中局部脑氧饱和度随解剖学诊断不同而变化，但是与手术后早期预后无明显关系。正如使用额叶近红外线光谱探头测量局部脑氧饱和度所示，高红细胞比容与当今的灌注技术似乎可为深低温停循环在短期内提供足够的氧储备。

BACKGROUND： We examined changes in cerebral oxygen saturation during infant heart surgery and its relationship to anatomic diagnosis and early outcome. METHODS： Regional cerebral oxygen saturation （rSO2） was measured by nearinfrared spectroscopy in 104 infants undergoing biventricu/ar repair without aortic arch obstruction as part of a randomized trial of hemodilufion to a hematocrit of 25% vs 35%. RESULTS： Before cardiopulmonary bypass （CPB）, infants with tetralogy of Fallot had higher rSO2 values compared to those with D-transposition of the great arteries （D-TGA） or ventricular septal defect （P 〈 0. 001 ）. During CPB cooling, low flow, and at the termination of CPB, D-TGA subiects had the highest rSO2 values （P 〈 0.001 ）. There were no significant associations between intraoperative rSO2 and early postoperative outcomes after adiustment for diagnosis. In 39 D-TGA subiects with ≥5 min of deep hypothermic circulatory arrest （DHCA）, there was no correlation between the rSO2 （91% ± 6%） or hematocrit （29.2% ± 5.5%） at the onset of arrest and the rate of decline in rSO2 during arrest. CONCLUSIONS： Intraoperative rSO2 varies according to anatomic diagnosis but accounts for very tittle of the variance in early outcome. As measured by frontal near-infrared spectroscopy, higher levels of hematocrit and current perfusion techniques appear to provide an adequate oxygen reservoir prior to relatively short periods of DHCA.