目的 探究婴儿先天性心脏病（先心病）术后中心静脉血氧饱和度（ScvO₂）与血乳酸（Lac）、动脉血氧饱和度（SaO₂）及机械通气时间的关联性。 方法 将2020年1月至2024年12月于遵义市第一人民医院接受先心病手术治疗的84例患儿纳入研究。根据患儿术后机械通气时间分为延长组（28例，机械通气时长≥ 72 h）和未延长组（56例，机械通气时长< 72 h）。对比不同机械通气时间患儿的临床资料、先心病手术风险分级评分（RACHS-1）及ScvO₂、Lac、SaO₂水平，使用多因素logistic回归分析影响患儿术后机械通气时间的危险因素，使用ROC分析ScvO₂、Lac、SaO₂对患儿术后机械通气延长的预测价值，记录两组患儿的临床结局。 结果 不同机械通气时间患儿的年龄、术前合并肺炎、RACHS-1分级、ScvO₂、Lac、SaO₂水平之间差异有统计学意义（P < 0.05）；经多因素logistic回归分析，ScvO₂、Lac、SaO₂水平是影响患儿术后机械通气时间的独立危险因素（P < 0.05）；经ROC分析，ScvO₂、Lac、SaO₂水平及联合检测预测患儿术后机械通气延长的曲线下面积分别为0.846、0.863、0.839、0.917，最佳截断值分别为67.64%、1.51 mmol/L、96.06%（P < 0.05）。延长组脱机失败率高于未延长组，PICU停留时间和实际住院时间均长于未延长组（P < 0.05）。 结论 婴儿先心病术后的ScvO₂、Lac、SaO₂水平与患儿机械通气时间有关，是影响机械通气延长的独立危险因素，可作为临床上预测术后机械通气延长的辅助性检测指标。

Objective To explore the correlation between central venous oxygen saturation （ScvO₂）， blood lactate （Lac）， arterial oxygen saturation （SaO2） and mechanical ventilation time in infants with congenital heart disease （CHD）. Methods Eighty?four CHD children treated in the First People's Hospital of Zunyi were enrolled between January 2020 and December 2024. According to postoperative mechanical ventilation time， they were divided into prolongation group （28 cases， mechanical ventilation time ≥ 72 h） and non?prolongation group （56 cases， mechanical ventilation time < 72 h）. The clinical data， score of risk adjustment for congenital heart surgery （RACHS?1）， levels of ScvO₂， and Lac and SaO₂ in the two groups were compared. The risk factors of postoperative mechanical ventilation time were analyzed by multivariate logistic regression analysis， and predictive value of ScvO₂， Lac and SaO₂ for prolonged mechanical ventilation time was analyzed by ROC curves. The clinical outcomes in the two groups were recorded. Results There were significant differences in age， preoperative pneumonia， RACHS?1 grading， and levels of ScvO₂， Lac and SaO₂ among children with different mechanical ventilation time （P < 0.05）. Multivariate logistic regression analysis showed that ScvO₂， Lac and SaO₂ were independent influencing factors of postoperative mechanical ventilation time （P < 0.05）. ROC curves analysis showed that area under the curve （AUC） values of ScvO₂， Lac， SaO₂ and combined detection for predicting prolonged postoperative mechanical ventilation were 0.846， 0.863， 0.839 and 0.917， and the best cut?off values were 67.64%， 1.51mmol/L and 96.06%， respectively （P < 0.05）. The failure rate of weaning in the prolongation group was higher， and stay time in PICU and actual length of hospital stay were longer than those in non?prolongation group （P < 0.05）. Conclusion The levels of ScvO₂， Lac and SaO₂ are related to mechanical ventilation time in CHD infants. They are all independent risk factors affecting prolonged mechanical ventilation and can be applied as auxiliary detection indexes to predict the prolongation of mechanical ventilation in clinical practice.