预后营养指数对重症慢性阻塞性肺疾病患者短期预后的影响

The impact of prognostic nutritional index on short-term prognosis in critically chronic obstructive pulmonary disease patients

目的探究重症监护病房(intensive care unit,ICU)慢性阻塞性肺疾病(简称慢阻肺)患者的预后营养指数(prognostic nutritional index,PNI)对其28天全因死亡率的预测价值。方法通过COX比例风险模型与限制性立方样条(restricted cubic spline,RCS)模型分析PNI与慢阻肺患者短期病死率的关系。绘制受试者操作特征曲线(receiver operating characteristic curve,ROC曲线),并计算曲线下面积(area under ROC curve,AUC)评价PNI的预测性能。利用约登指数确定PNI最佳临界值并将数据划分为低PNI和高PNI两组,绘制Kaplan-Meier曲线,通过Log-Rank检验评价两组生存时间是否存在差异。结果共纳入980名慢阻肺患者,多因素COX回归分析显示PNI是重症慢阻肺患者短期死亡的独立影响因素(风险比=0.972,95%置信区间0.948~0.995,P=0.019)。RCS曲线结果显示PNI与重症慢阻肺患者短期病死率呈非线性关系(非线性P=0.032),随着PNI增大死亡风险逐渐下降。ROC曲线表明PNI具有一定预测性能,与序贯器官衰竭评分预测性能相近[(AUC_(PNI)=0.693)比(AUC_(SOFA)=0.672)]。Kaplan-Meier曲线分析显示低PNI(≤38.3)与高PNI(>38.3)组的生存时间有明显差异(P<0.05)。结论PNI对重症慢阻肺患者短期全因死亡具有一定的预测作用。入住ICU时低PNI患者具有较高的短期死亡风险。

Objective To investigate the predictive value of the prognostic nutritional index(PNI)for 28-day all-cause mortality in patients with chronic obstructive pulmonary disease(COPD)in intensive care unit(ICU).Methods The relationship between PNI and short-term mortality in COPD patients was analysed using COX proportional hazards and restricted cubic spline(RCS)models.Receiver operating characteristic(ROC)curves were plotted and area under the ROC curve(AUC)was calculated to assess the predictive performance of PNI.The optimal cut-off value for PNI was determined using the Youden index,and the data were divided into a low PNI group and a high PNI group.Kaplan-Meier curves were then constructed and the log-rank test was used to assess differences in survival between the two groups.Results A total of 980 COPD patients were included in the study.Multivariable COX regression analysis showed that PNI was an independent factor influencing short-term mortality in the severe COPD patients(HR=0.972,95%CI 0.948-0.995,P=0.019).RCS curve results showed a non-linear relationship between PNI and short-term mortality in the severe COPD patients(P for non-linear=0.032),with the risk of death gradually decreasing as PNI increased.The ROC curve indicated that PNI had some predictive power,comparable to that of SOFA score[(AUC_(PNI)=0.693)vs.(AUC_(SOFA)=0.672)].Kaplan-Meier curve analysis showed a significant difference in survival time between the low(≤38.3)PNI group and the high(>38.3)PNI group(P<0.05).Conclusions PNI has a certain predictive role for short-term all-cause mortality in patients with severe COPD.Patients with low PNI at ICU admission have a higher risk of short-term mortality.