探讨重症胎粪吸入综合征(MAS)的临床分型指标，为按病情分类救治该病提供理论依据。

选取2008年1月至2011年12月于随州市妇幼保健院住院治疗的因羊水胎粪污染被诊断为重症MAS的236例患儿作为研究对象，按照本研究自行拟定的重症MAS分型标准将研究对象分为重型重症MAS组(n＝158)和危重型重症MAS组(n＝78)。两组重症MAS患儿性别构成比、胎龄、出生体质量等一般情况比较，差异无统计学意义(P>0.05)。选取2012年1月至2013年12月于本院住院的127例重症MAS患儿作为危重型重症MAS预判指标的验证对象，也按照本研究自行拟定的重症MAS分型标准将其分为重型重症MAS验证组(n＝88)和危重型重症MAS验证组(n＝39)。两验证组重症MAS患儿年龄、性别构成比等一般临床资料比较，差异也无统计学意义(P>0.05)。对两组患儿临床表现、实验室检查结果、辅助检查结果、并发症及预后情况进行比较，再对有统计学意义的观察指标进行多因素非条件logistic回归分析，并对两验证组患儿的重症MAS分型结果进行验证。本研究遵循的程序符合湖北省随州市妇幼保健院人体试验委员会所制定的伦理学标准，得到该委员会批准，分组征得受试对象监护人的知情同意，并与之签署临床研究知情同意书。

两组患儿昏迷、惊厥、呼吸困难和紫绀持续时间≥3 d等9项临床表现比较，差异有统计学意义(P<0.05)；两组患儿动脉血氧分压(PaO₂)<50 mmHg(1 mmHg＝0.133 kPa)、二氧化碳分压(PaCO₂)>60 mmHg、pH值<7.25和剩余碱<－5发生率比较，差异有统计学意义(P<0.05)；两组患儿胸部X射线摄片结果示肺不张、肺气肿和肺气漏发生率比较，差异有统计学意义(P<0.01)；缺氧缺血性脑病(HIE)、肺动脉高压(PPHN)和心力衰竭等7种MAS并发症发生率比较，差异有统计学意义(P<0.05)；两组痊愈率和死亡率比较，差异也有统计学意义(P<0.05)。上述有统计学意义观察指标的多因素非条件logistic回归分析和受试者工作特征(ROC)曲线修正的结果示，呼吸困难和紫绀持续时间≥3 d、动脉血PaCO₂>65 mmHg、胸部X射线摄片结果示肺气漏是危重型重症MAS的独立预判指标。两验证组患儿进行前瞻性Kappa检验结果示，约登指数为0.95，Kappa值为0.945，其灵敏度达0.97，特异度达0.98。

对于呼吸困难和紫绀持续时间≥3 d、动脉血PaCO₂>65 mmHg、胸部X射线摄片结果示肺气漏的重症MAS患儿，可诊断为危重型重症MAS。

To investigate the characteristics of different clinical types of severe meconium aspiration syndrome (MAS), and provide a scientific basis for classification of severe MAS by the disease treatment.

From January 2008 to December 2011, a total of 236 hospitalized cases who were diagnosed with severe MAS in Suizhou Maternal and Child Health Hospital Center were included in the study.They were divided into heavy MAS group(n=158) and critical MAS group(n=78). There were no statistically significant differences in gender constituent ratio, gestational age, birth weight between two groups(P>0.05). With the same method, another 127 hospitalized case were also chosen in the study from January 2012 to December 2013, and they were divided into verification of heavy MAS group(n=88) and verification of critical MAS group(n=39). There were no statistically significant differences in gender constituent ratio, gestational age between two groups either(P>0.05). The clinical manifestations, laboratory examination results, auxiliary examination results, complications and prognosis were observed.The results of single factor analysis was statistically significant for multi-factor unconditioned logistic regression analysis. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Suizhou Maternal and Child Health Hospital. Informed consent was obtained from each participants' parents.

There were significant differences in 7 kinds of clinical manifestations such as coma, convulsions, breathing difficulties, the duration of cyanosis ≥3 d and so on between two groups(P<0.05); The differences in incidence rates of partial pressure of oxygen (PaO₂)<50 mmHg (1 mmHg=0.133 kPa), partial pressure of carbon dioxide (PaCO₂)>60 mmHg, pH value<7.25 and base excess <-5 were significant between two groups(P<0.05). The incidence rates of atelectasis, pulmonary emphysema and pulmonary gas leakage in critical MAS group were significant higher than those of heavy MAS group(P<0.05). There were significant differences in 7 kinds of complications between two groups(P<0.01), and the differences in cure rate and mortality between two groups had statistical significance(P<0.05). Multiple logistic regression analysis and receiver operating characteristics (ROC) curve showed that the duration of breathing difficulties and cyanosis ≥3 d, arterial blood PaCO₂>65 mmHg, lung gas leakage were the independent forecasts determine index of critical intensive MAS .The results of prospective Kappa test in two verification groups showed that Youden index was 0.95, Kappa value was 0.945, and its sensitivity was 0.97, specificity was 0.98.

The children with the duration of breathing difficulties and cyanosis ≥3 days, arterial blood PaCO₂>65 mmHg, lung gas leakage can be diagnosed as critical intensive MAS.