目的 ·评价更新版小儿死亡风险评分（pediatric risk of mortality score，PRISM）Ⅳ应用于先天性心脏病术后机械通气患儿病情评估的效果。方法 ·采用 t检验、 ROC曲线下面积、 Hosmer-Lemeshow拟合优度检验等方法验证新版 PRISM Ⅳ的临床应用效果，同时比较其与 PRISM Ⅲ以及特异性评分的效果差异。结果 ·纳入 230例患儿，评定者间信度可靠。 PRISM Ⅳ、PRISM Ⅲ、小儿先天性心脏病术后危重程度评分对死亡与存活结局的区分能力（ AUC>0.75）、预测校准能力（ P>0.05）、预测百分比均较好。 PRISM Ⅳ在评估患儿术后 4 h内状况及 12 h内状况的效应方面与其他工具相比无显著差异（ P>0.05）。结论 · PRISM Ⅳ经更新后，缩短了评估时间，与其他工具相比具有一定应用价值。建议护理人员根据临床现况及实践需求，可将其纳入危重患儿预后预测系统，以早期发现高风险患儿，及早干预，降低患儿并发症及死亡率。

Objective · To evaluate the application effect of the newly updated pediatric critical illness score PRISM Ⅳ on assessing the condition of children with mechanical ventilation after congenital heart disease (CHD). Methods · T test, area under ROC curve and Hosmer-Lemeshow goodness of fit test were used to assess the performance of PRISM Ⅳ . The performance of PRISM Ⅳ was also compared with PRISM Ⅲ and specific severity of illness scoring system for CHD. Results · 230 children with CHD were included. Reliability among evaluators was good. The discriminatory power (AUC>0.75) and calibration capability (P>0.05) of PRISM Ⅳ , PRISM Ⅲ and specific score for CHD were tolerable. The results of PRISM Ⅳ evaluation were similar to specific scores for CHDT0-4 and CHDT0-12 (P>0.05). Conclusion · PRISM Ⅳ has been updated to shorten the assessment time and has certain advantages over other tools. It is recommended that nursing staff take it in the prognosis prediction system for critically ill children based on clinical status and practical needs, to detect high-risk children early, and to intervene early to reduce the complications and mortality of children.