Mycoplasma pneumoniae pneumonia (MPP) can cause a variety of intrapulmonary and extrapulmonary injuries, including thrombotic diseases, which seriously endanger the health of children. And for assessing the coagulation status, routine coagulation parameters has great limitations, while thromboelastography (TEG) can be comprehensively and rapidly, but there are few data on TEG used in condition evaluation in children with MPP.

To explore the value of TEG in condition assessment of children with MPP.

Two hundred and twelve MPP children were recruited from the Affiliated Changzhou No.2 People's Hospital of Nanjing Medical University from July 2019 to July 2021, including 52 with severe condition and 160 with non-severe condition. Comparisons were made between two groups in terms of demographics, platelet count, routine coagulation parameters, and TEG parameters. The association of TEG parameters with platelet count and routine coagulation parameters was assessed. Multivariate Logistic regression analysis was used to explore influence factors for the condition of MPP. ROC analysis was used for assess the value of those identified risk factors for predicting the condition of MPP.

Both groups had no significant differences in sex ratio and mean age (P>0.05) . Compared with children with non-severe condition, those with severe conditionhad shortened reaction time (R) and kinetic time (K) , and elevated maximum amplitude (MA) , α-angle, clotting index (CI) , fibrinogen (FIB) , prothrombin time (PT) , international normalized ratio (INR) , D-dimer (D-D) (P<0.05) . Correlation analysis showed that MA was moderately positively associated with PLT and FIB (P<0.001) ; R was weakly positively associated with activated partial thromboplastin time (P<0.001) ; K was weakly negatively associated with PLT and FIB (P<0.001) ; α-angle was weakly positively correlated with PLT and FIB (P<0.001) . Multivariate Logistic regression analysis showed that CI〔OR=5.698, 95%CI (3.329, 9.753) , P<0.05〕, and D-D〔OR=5.061, 95%CI (1.724, 14.859) , P<0.05〕were influence associated with MPP, and the prediction algorithm based on them for MPP is CI+D-D: Y=1.777CI+1.624D-D-5.264. ROC analysis indicated that the area under the ROC curve of CI was 0.885〔95%CI (0.830, 0.941) 〕with 0.750 sensitivity and 0.907 specificity when the cut-off value was determined as 2.05, and that of D-D was 0.716〔95%CI (0.632, 0.799) 〕with 0.615 sensitivity and 0.784 specificity when the cut-off value was determined as 0.545, and that of CI in combination with D-D was 0.901〔95%CI (0.850, 0.952) 〕with 0.769 sensitivity and 0.914 specificity when the cut-off value was determined as -0.65.

TEG could partially predict the condition of children with MPP, but could not replace the routine coagulation parameters, and the combined predictive value of the two may be higher.

肺炎支原体肺炎（MPP）可导致多种肺内外损伤，包括血栓性疾病，严重危害患儿健康，对其凝血状态的评估，常规凝血检测局限性大，血栓弹力图（TEG）可全面快速评估儿童凝血状态，但有关TEG在肺炎支原体肺炎患儿病情评估中应用的相关研究较少。

探讨TEG在MPP患儿病情评估中的应用价值。

选取2019年7月至2021年7月南京医科大学附属常州市第二人民医院收治的212例MPP患儿，根据病情严重程度将其分为重症MPP（SMPP）组（n=52）、非SMPP组（n=160），比较两组患儿的一般资料、血小板计数（PLT）、常规凝血参数、TEG参数，分析TEG参数与常规凝血参数、PLT的相关性，采用多因素Logistic回归分析探讨MPP患儿病情的影响因素，应用受试者工作特征（ROC）曲线分析影响因素对MPP患儿病情的预测价值。

两组患儿性别、年龄比较，差异无统计学意义（P>0.05）。与非SMPP组相比，SMPP组的反应时间（R）和凝血形成时间（K）缩短，最大振幅（MA）、凝固角（α角）、凝血综合指数（CI）、纤维蛋白原（FIB）、凝血酶原时间（PT）、国际标准化比值（INR）、D-二聚体（D-D）升高（P<0.05）。相关性分析显示，MA与PLT、FIB呈中度正相关（P<0.001）；R与活化部分凝血活酶时间呈弱正相关（P<0.001）；K与PLT、FIB呈弱负相关（P<0.001）；α角与PLT、FIB呈弱正相关（P<0.001）。多因素Logistic回归分析显示，CI〔OR=5.698，95%CI（3.329，9.753），P<0.05〕、D-D〔OR=5.061，95%CI（1.724，14.859），P<0.05〕是MPP患儿病情的影响因素，两者联合所得的MPP病情影响因素预测模型CI+D-D为：Y=1.777CI+1.624D-D-5.264。CI、D-D、CI+D-D预测MPP病情的ROC曲线下面积分别为0.885〔95%CI（0.830，0.941）〕、0.716〔95%CI（0.632，0.799）〕、0.901〔95%CI（0.850，0.952）〕；最佳截断值分别为2.05、0.545、-0.65；灵敏度分别为0.750、0.615、0.769；特异度分别为0.907、0.784、0.914。

TEG对MPP患儿病情有一定预测价值，但不能取代常规凝血参数。TEG与常规凝血联合，可进一步提高对MPP患儿病情评估的准确性。