D-二聚体对老年重症社区获得性肺炎30天死亡率的预测价值

目的探讨D-二聚体水平对住院老年重症社区获得性肺炎（CAP）患者30d死亡率的预测价值。方法152例符合诊断标准的老年重症CAP患者纳入研究，人院后即进行D-二聚体、c-反应蛋白（CRP）检测及肺炎严重度指数（PSI）评分，记录患者30d死亡率。采用受试者工作特征曲线（ROC）分析D-二聚体对30d死亡率的预测价值，计算曲线下面积（AUC）。结果PSI评分Ⅳ级患者的D-二聚体水平为（961．55±186．49）μg／L，V级为（1122．53±197．98）μg／L，两者差异有明显统计学意义（t=5．159，P〈0．001）；死亡患者的D-二聚体水平（1112．59±215．25）μg／L明显高于存活患者的D-二聚体水平（920．46±126．89）μg／L（t=6．239，P〈0．001）。Pearson相关性分析显示，D-二聚体和PSI有明显相关性（r=0．47，P〈0．0001）；ROC分析表明D-二聚体的AUC为：0．79（95％CI：O．72～0．85），和PSI的AUC相比差异无统计学意义（0．85，95％CI：0．78～0．91，P=0．095）。结论D-二聚体水平对住院老年重症CAP患者30d死亡率有较好预测价值。

Predictive value of D-dimer in 30-day mortality of elderly patients with severe community-acquired pneumonia

Objective To investigate the value of plasma D-dimer level in predicting 30-day mortality for the elderly patients with severe community-acquired pneumonia （CAP）. Methods A total of 152 elderly inpatients （over 60 years old） with identified severe CAP admitted in our department from August 2009 to August 2011 were enrolled in this study. Immediately after admission, their blood samples were obtained for plasma levels of D-dimer and C-reactive protein （CRP）, and pneumonia severity index （PSI） was calculated. Clinical and laboratory variables and 30-day mortality were recorded. Receiver operating characteristic （ROC） curve was used to assess the value of D-dimer for predicting 30-day mortality, and the area under curve （AUC） was calculated. Results The D-dimer levels were （961.55± 186.49）μg/L in the patients with PSI score in class IV, and （1 122.53 ±197.98）μg/L for those with score in class V, respectively, with significant difference between them （t=5.159, P 〈 0.001）. The levels were significantly higher in non-survivors than in survivors （1 112.59 ± 215.25） vs （920.46 ± 126.89）μg/L, t=6.239, P〈 0.001]. Pearson correlation analysis indicated that D-dimer level was significantly correlated with PSI score （r = 0.47, P 〈 0.0001）. ROC curve showed that the AUC for D-dimer predictive value was 0.79 （95% CI= 0.72 to 0.85）, having no significant difference with that of PSI score （0.85, 95% CI= 0.78 to 0.91, P = 0.095）. Conclusion D-dimer level is of great value for predicting 30-day mortality in the elderly patients with severe CAP.