目的：早产儿呼吸窘迫综合征(RDS)需要做出早期诊断才能指导呼吸机和肺表面活性物质的及时使用。该研究的目的是明确胃液稳定微泡实验(stab le m icrobubb le test,SMT)早期诊断早产儿RDS的价值,为预防性使用肺表面活性物质提供指导。方法：对101例收治于日本岩手医科大学新生儿重症监护室的早产儿,胎龄31±3.5周,(24~35周,)生后30 m in内取胃液做SMT,低倍镜下数出每mm2中直径<15μm的稳定微泡数;1 h内拍胸片,以临床表现及X线结果作为诊断早产儿RDS的金标准。计算SMT早期诊断早产儿RDS的敏感度、特异度及阳性、阴性预测值,观察以SMT结果指导肺表面活性物质使用的临床价值。结果：101例早产儿中诊断为RDS者31例,其中微泡数<10个/mm2者22例,10~20个/mm2者7例,>20个mm2者2例;非RDS者共70例,其中<10个/mm2者仅1例,10~20个/mm2者2例,>20个mm2者67例。以胃液微泡数<10个/mm2作为界值,SMT预测并早期诊断RDS的敏感度及特异度分别为70.97%和98.57%,阳性预测值及阴性预测值分别为95.65%和88.46%;以胃液微泡数<20个/mm2作为界值,SMT预测并早期诊断RDS的敏感度及特异度分别为93.55%和95.71%,阳性预测值及阴性预测值分别为90.63%和97.10%。微泡数<10个/mm2者均接受肺表面活性物质替代治疗,临床效果显著。结论：SMT法简便、快速、经济,敏感度高,特异性好,能预测并早期诊断早产儿RDS,有助于指导肺表面活性物质的预防性使用,有极高的临床应用价值,值得在国内推广。

OBJECTIVE: Neonatal respiratory distress syndrome (RDS)is an acute clinical neonatal disorder that requires prompt management. This study aimed to evaluate the usefulness of the stable microbubble test (SMT) on gastric aspirates in the early diagnosis of RDS in premature infants. METHODS: One hundred and one samples of gastric aspirates obtained within half an hr of delivery from premature neonates born at the Iwate Medical University, Japan, with gestational ages between 24 and 35 weeks (mean 30.1 ±3.5 weeks) were detected by the SMT. The stable microbubles per mm~2 were counted. Chest X-rays were taken within 1 hr of delivery. The clinical characteristics and X-ray results were used as the gold standard for the diagnosis of RDS. The sensitivity,specificity and positive and negative values of the SMT to predict and make an early diagnosis of RDS were evaluated. RESULTS: Of the 101 premature infants, 31 were diagnosed as RDS by the gold standard.Twenty-two infants had stable microbubbles less than 10 bubbles/mm~2,7 had stable microbubbles between 10 and 20 bubbles/mm~2,and 2 had stable microbubbles more than 20 bubbles/mm~2.In the 70 non-RDS infants,only 1 had stable microbubbles less than 10 bubbles/mm~2,2 had stable microbubbles between 10 and 20 bubbles/mm~2,and the rest had stable microbubbles more than 20 bubbles/mm~2.The sensitivity and specificity of the SMT with a cut-off value of less than 10 bubbles/mm~2 to predict RDS were 70.97% and 98.57%,respectively,with positive and negative predictive values of 95.65% and 88.46%,respectively.With a cutoff value of less than 20 bubbles/mm~2,the sensitivity,specificity and positive and negative values were 93.55%,95.71%,90.63% and 97.10% respectively. The patients with bubbles less than 10/mm~2 (whose chest X-ray showed moderate RDS) were administered with surfactant replacement.As a result the patients' symptoms were significantly improved. CONCLUSIONS: The SMT on gastric aspirates is a rapid, simple and reliable procedure to predict and make an early diagnosis of neonatal RDS. It is helpful to the prophylactic exogenous surfactant replacement.