早期血小板变化在预测老年重症肺炎患者预后中的价值

摘要

目的 探讨早期血小板变化对老年重症肺炎患者预后的预测价值. 方法 采用回顾性研究方法,选择2014年1月至2018年1月常州市第二人民医院重症加强治疗病房(ICU)收治年龄≥65岁、住院时间≥72 h的重症肺炎患者,根据28 d预后将患者分为存活组和死亡组.收集患者基本资料,入ICU时,入ICU24、48和72 h血清血小板数据,以血小板计数(PLT)、血小板变化值(△PLT)及血小板变化率(△PLT％)绘制受试者工作特征曲线(ROC),评估其对28 d预后的预测价值.分别以入ICU时血小板,入ICU72 h血小板、血小板变化值及血小板变化率的临界值将患者分组,采用Kaplan-Meier生存曲线分析患者28 d累积存活率. 结果 (1)入选100例老年重症肺炎患者,28 d死亡41例,病死率41.0％.死亡组入ICU后24 h急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分、序贯器官衰竭评估(SOFA)评分、C反应蛋白(CRP)、降钙素原(PCT)均明显高于生存组.(2)入ICU后两组血小板均呈下降趋势,尤其入ICU 72 h时死亡组血小板明显低于生存组(80.00×109/L比171.00×109/L,Z=5.786,P＜0.05),同时死亡组血小板变化值、变化率明显高于生存组,尤其以入ICU72 h时最显著(△PLT 72:-79.00×109/L比-38.00×109/L,Z=4.938,P＜0.05;△PLT 72％:-43.6％比-17.7％,Z=6.816,P＜0.05).(3)ROC曲线分析显示,血小板、血小板变化值及变化率对老年重症肺炎患者28 d死亡均有较好的预测价值,其中以入ICU72 h血小板变化率的ROC曲线下面积(AUC)最大,为0.902,以入ICU72 h血小板下降率＞-36.14％作为预测28 d死亡的临界点,敏感度为89.8％,特异度为75.6％.(4)Kaplan-Meier生存曲线分析显示,以入ICU和入ICU72 h血小板、血小板变化值及变化率相应的临界值将患者分组,高于相应临界值患者28 d存活率明显高于低于相应临界值者,且生存期较长. 结论 血清血小板的持续下降提示老年重症肺炎患者预后不良,结合72 h血小板计数、血小板变化幅度及血小板变化率更能预测老年重症肺炎患者不良预后.%Objective To explore the predictive value of early changes in platelet counts in the prognosis of severe pneumonia in aged patients.Methods This retrospective study included elderly patients with severe pneumonia,who were ≥65 years old and whose length of ICU stay ≥72 hours,admitted to the intensive care unit(ICU)of NO.2 People's Hospital of Changzhou from January 2014 to January 2017.They were divided into a survival group and a death group according to the 28-day outcome.General information and serum platelet levels at 0,24,36,and 72 hours after admission were collected.Receiver operating characteristic curve (ROC)was plotted according to platelet counts,changes in platelet counts and rates of change in platelet counts to evaluate their predictive value for 28-day prognosis.Kaplan-Meier survival curve was used to analyze the 28-day cumulative survival rate between different groups of patients,who were further divided according to platelet counts at 0 and 72 hours after admission to ICU,changes in platelet counts and rates of change in platelet counts at 72 hours after admission.Results (1)One hundred elderly patients with severe pneumonia were enrolled,among whom 41 cases were in the death group,thus with a mortality of 41.0％.The acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ),sequential organ failure assessment (SOFA),C-reactive protein (CRP),and procalcitonin(PCT)in the death group were significantly higher than those in the survival group.2)Serum platelet levels showed a downward trend in both the death group and the survival group.The level of serum platelets at 72 hours after admission to ICU in the death group was significantly lower than that in the survival group(80.00 × 109/L vs.171.00 × 109/L,Z=5.786,P＜0.05);changes in platelet counts and rates of change in platelet counts in the death group were significantly higher than those in the survival group,especially at 72 hours after admission to ICU(/△PLT72:-79.00 × 109/L vs.-38.00 × 109/L,Z =4.938,P ＜0.05;△PLT 72％:43.6％ vs.-17.7％,Z=6.816,P＜0.05).(3)ROC curve analysis showed that platelet levels,changes in platelet counts,and rates of change in platelet counts could predict 28-day mortality in aged patients with severe pneumonia.The largest area under ROC curve was 0.902 when plotted with the rate of platelet counts at 72 hours after admission to ICU.Using the cut-off value of-36.14％ in the rate of change at 72 hours after admission to evaluate the predictive value in 28 day mortality,the sensitivity and specificity were 89.8％ and 75.6％,respectively.(4)Kaplan-Meier survival analysis showed that the 28 day survival rate was significantly higher and the length of survival was significantly greater when platelet counts at 0 and 72 hours after admission to ICU were higher than the cut-off value,and this also occurred in changes in platelet count and rates of change at 72 hours after admission to ICU.Conclusions Continuous decline in serum p[atelet levels indicates poor prognosis.When combined with platelet counts,changes in platelet counts and rates of change in platelet counts at 72 hours after admission to ICU,it may play an important role in assessing the prognosis of aged patients with severe pneumonia.