氮末端脑钠肽前体对机械通气撤机的预测价值

Predictive value of plasma N-terminal-pro-brain natriuretic peptide in weaning patients from mechanical ventilation

目的评价氮末端脑钠肽前体（NT-proBNP）水平对机械通气患者撤机结局的预测价值。方法回顾性分析2014年1月～2014年12月收治于瑞金医院EICU的机械通气患者42例，统计其病因构成。根据自主呼吸试验（spontaneous breathing trial，SBT）后48h的撤机结局，将患者分为撤机成功组和撤机失败组。比较两组患者入院时基础NT-proBNP1、SBT前NT-proBNP2、SBT后48h的NT-proBNP3水平及SBT前72h液体平衡的差异、并通过绘制受试者工作特征曲线（ROC曲线），分析NT-proBNP2预测撤机失败的截点值。结果42例患者中，27例撤机成功，15例失败。两组患者既往心功能不全病史及基础NT．proBNP，水平差异无统计学意义（P=0．121）；撤机失败组患者NT-proBNP2及NT-proBNP，水平均大于成功组（P=0．01，0．003）；NT-proBNP2预测撤机失败的ROC曲线下面积为0．862（95％讲：0．753-0．971），其预测撤机失败的截点为715．5pg／mL，在此截点下敏感度93．3％，特异度74．1％。结论患者SBT前的NT-proBNP：水平在预测撤机结局中具有一定参考价值，可作为撤机筛查指标之一。

Objective To evaluate the predictive value of N-terminal-pro-brain natriuretic peptide （NT-proBNP） in weaning patients from mechanical ventilation （MV）. Methods Data of 42 patients supported with MV in intensive care unit （ ICU ） admitted to the Rui Jin Hospital from January through December in 2014 were retrospectively analyzed, and the causes for MV were recorded. According to the outcomes of weaning from MV after 48 hours, the patients were divided into two groups namely success group and failure group. Comparisons of fluid balance in 72 hours before spontaneous breathing trial （SBT） , and comparisons of NT-proBNP1 levels at admission, NT-proBNP2 levels before SBT, NT-proBNP3 levels after 48 hours after SBT between two groups were carried out. And the receiver operating characteristic （ ROC ） curve for predicting weaning rate was plotted to find the optimal cut-off point of NT-proBNP2. Results In the total of 42 patients, there were 27 cases in success group and 15 cases in failure group. There were not statistically differences of NT-proBNPl levels between success group and failure group （ P = 0. 121 ）. However, the NT-proBNP2 levels and NT-proBNP3 levels in failure group were significantly higher than those in success group （P = 0. 01, 0. 003）. The area under curve （AUC） of the ROC curve of NT-proBNP2 levels to predict the failure of weaning was 0. 862 （95% CI： 0. 753 - 0.971 ）. When the optimal cut-off point of NT-proBNP2 was 715.5 pg/mL, the sensitivity and specificity were 93.3% and 74. 1%,respectively. Conclusion The NT-proBNP2 levels before SBT have predictive value in weaning rate, and it can be used as one of the screening indicators for weaning.