多种评分系统对体外膜肺氧合支持下重症急性呼吸衰竭患者病死率的预测价值

Predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure supported by extracorporeal membrane oxygenation

目的 探讨多种危重症评分系统对静脉-静脉体外膜肺氧合(VV-ECMO)支持的重症急性呼吸衰竭(ARF)患者预后的评估作用.方法 纳入2009年11月至2015年7月收治的接受VV-ECMO支持的重症ARF患者共42例,其中男性25例,女性17例,年龄18～69岁,平均(44±18)岁.计算患者建立ECMO时急性生理学及慢性健康状况评分(APACHE)Ⅱ、APACHEⅢ、APACHEⅣ、简化急性生理学评分(SAPS)Ⅱ、序贯器官衰竭评分(SOFA)、体外膜肺氧合协作网评分(ECMOnet)、体外膜肺氧合支持的重度急性呼吸窘迫综合征病死率预测评分(PRESERVE)和体外膜肺氧合支持的呼吸系统疾病生存率预测评分(RESP).以接受ECMO支持后180 d为研究终点,将患者分为存活组(17例)和病死组(25例),比较两组患者的病例资料和上述评分系统的结果.采用受试者工作特征曲线(ROC曲线)分析各评分系统对患者预后的评估价值.采用Kaplan-Meier法绘制患者的生存曲线,Log-rank法分析患者生存情况.多因素Logistic回归分析影响患者预后的危险因素.结果 (1)存活组ECMO支持前6h内PEEP设置水平[(9.7±5.0)cmH2O(1 cmH2O =0.098 kPa)]低于病死组[(13.2±5.4) cmH2O,t=-2.134,P=0.039].病死组ECMO运行过程中联合肾脏替代治疗(CRRT)比例(32％)多于存活组(6％,x2=4.100,P=0.043),并且接受ECMO支持的时间[(15±13)d]长于存活组[(12±11)d,t=-2.123,P=0.041].存活组APACHEⅡ、APACHEⅢ、APACHEⅣ、SAPSⅡ、ECMOnet、PRESERVE和RESP评分均优于病死组(均P＜0.05).(2)APACHEⅣ评分预测患者180 d死亡的ROC曲线下面积最大,为0.792±0.076(95％ CI:0.643 ～0.940,P＜0.05),以≥48为最佳界值点,敏感度和特异度分别为92.0％和64.7％,正确率为81％.(3)Kaplan-Meier生存曲线分析显示,低APACHEⅣ评分(＜48)患者生存率高于高APACHEⅣ评分(≥48)患者(X2=11.331,P＜0.05).(4)多因素Logistic回归分析显示,PEEP(OR=1.555,95％ CI:1.097 ～2.204,P＜0.05)、APACHEⅣ评分(OR=1.152,95％CI:1.021 ～1.301,P＜0.05)和PRESERVE评分(OR=4.984,95％ CI:1.531 ～ 16.227,P＜0.05)均为患者180 d死亡的独立危险因素.结论 目前临床应用的多种危重症评分系统均能较好地预测VV-ECMO支持的严重呼吸衰竭患者的病死率,其中APACHEⅣ评分更为准确,而几项专门针对ECMO患者预后的评分系统并无优势.

Objective To investigate the predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure (ARF) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO).Methods Forty-two patients with severe ARF supported by VV-ECMO were enrolled from November 2009 to July 2015.There were 25 males and 17 females.The mean age was (44 ± 18) years (rang 18-69 years).Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ],Ⅲ,Ⅳ,Simplified Acute Physiology Score Ⅱ (SAPS) Ⅱ,Sequential Organ Failure Assessment (SOFA),ECMO net,PRedicting dEath for SEvere ARDS on VVECMO (PRESERVE),and Respiratory ECMO Survival Prediction (RESP) scores were collected within 6 hours before VV-ECMO support.The patients were divided into the survivors group (n =17) and the nonsurvivors group (n =25) by survival at 180 d after receiving VV-ECMO.The patient clinical characteristics and aforementioned scoring systems were compared between groups.Scoring systems for predicting prognosis were assessed using the area under the receiver-operating characteristic (ROC) curve.The Kaplan-Meier method was used to draw the surviving curve,and the survival of the patients was analyzed by the Log-rank test.The risk factors were assessed for prognosis by multiple logistic regression analysis.Results (1) Positive end expiratory pressure (PEEP) 6 hours prior to VV-ECMO support in the survivors group [(9.7 ±5.0)cmH2O,(1 cmH2O =0.098 kPa)] was lower than that in the nonsurvivors group [(13.2 ± 5.4)cmH2 O,t =-2.134,P =0.039].VV-ECMO combination with continuous renal replacement therapy(CRRT) in the nonsurvivors group (32％) was used more than in the survivors group (6％,x2 =4.100,P =0.043).Duration of VV-ECMO support in the nonsurvivors group [(15 ± 13) d] was longer than that in the survivors group [(12 ± 11) d,t =-2.123,P=0.041].APACHE]Ⅱ,APACHE Ⅲ,APACHE Ⅳ,ECMO net,PRESERVE,and RESP scores in the survivors group were superior to the nonsurvivors group (all P ＜ 0.05).(2) The areas under the ROC curve of APACHE Ⅳ score for predicting death were largest (0.792 ± 0.076,95％ CI:0.643-0.940,P ＜ 0.05).The best cutoff point was 48 for APACHE Ⅳ score with a sensitivity of 92.0％,specificity of 64.7％,and overall accuracy of 81％.(3) Kaplan-Meier survival analysis showed that 180 d survival rate of the low APACHE Ⅳ score group was higher than the high APACHE Ⅳ score group (x2 =11.331,P ＜ 0.05).(4) Multiple logistic rcgression analysis showed that PEEP (OR =1.555,95％ CI:1.097-2.204,P ＜ 0.05),APACHE Ⅳ score (OR =1.152,95 ％ CI:1.021-1.301,P ＜ 0.05),and PRESERVE score (OR =4.984,95％ CI:1.531-16.227,P ＜ 0.05) were independent risk factors associated with mortality of patients supported by VV-ECMO.Conclusion The critical scoring systems proved to have good prognostic ability in predicting hospital mortality for severe ARF patients supported by VV-ECMO.Compared to other scoring systems,APACHE Ⅳ score system predicted more accurately,while specific scoring systems in predicting hospital mortality showed no advantage.