摘要目的:建立SAP患者肺炎克雷伯杆菌(KP)感染风险列线图预测模型。方法:回顾性分析2016年3月至2021年12月间上海市第一人民医院收治的109例SAP患者的临床资料，根据是否发生KP感染将患者分为感染组(25例)和非感染组(84例)，比较两组患者的临床特征。对单因素分析有统计学意义的变量采用最小绝对值收敛和选择算子算法(LASSO)进行降维处理，将LASSO回归模型优化后得到的特征纳入多变量logistic回归分析并建立列线图预测模型。绘制列线图的受试者工作特征曲线(ROC)，计算曲线下面积(AUC)，使用一致性指数(C-index)评估预测模型的诊断能力。结果:109例SAP患者分离出KP 25株，其中21株(84.0%)显示出泛耐药、多重耐药现象。单因素分析结果显示，20个风险因素(SOFA评分、APECHEⅡ评分、Ranson评分、MCTSI评分、机械通气时间、禁食时间、腹腔引流管留置时间、深静脉置管留置时间、侵袭性操作次数、是否有外科干预、是否行ERCP术、高级别抗生素使用种类、胃肠功能障碍、凝血异常、代谢性酸中毒、胰腺坏死、腹腔出血、腹腔高压、ICU住院时间、住院总时间)与SAP患者发生KP感染相关。应用LASSO回归对上述20个因素降维处理后得到4个变量，分别为APACHEⅡ评分、腹腔引流管留置时间、高级别抗生素使用种类、住院总时间。多因素logistic回归分析结果显示，上述4个变量为影响SAP患者发生KP感染的风险因素( P值均<0.05)。基于以上4项变量建立SAP患者KP感染列线图预测模型，经评估显示该模型的C-index为0.939，AUC值为0.939(95% CI0.888~0.991)，提示该列线图模型具有较精准的预测能力。 结论:本研究建立的预测模型结合患者的基本临床数据，可以方便临床工作中对SAP患者发生KP感染的风险预测，从而为患者制定更优的治疗方案。

abstractsObjective:To construct a risk prediction model for infection with Klebsiella pneumonia (KP) for patients with severe acute pancreatitis (SAP).Methods:Retrospective analysis was done on the clinical data of 109 SAP patients who were admitted to Shanghai General Hospital, between March 2016 and December 2021. Patients were classified into infection group ( n=25) and non-infection group ( n=84) based on the presence or absence of KP infection, and the clinical characteristics of the two groups were compared. The least absolute shrinkage and selection operator (LASSO) algorithm was used to reduce the dimension of the variables with statistical significance in univariate analysis. A nomogram prediction model was created by incorporating the optimized features from the LASSO regression model into the multivariate logistic regression analysis. Receiver operating characteristic curve (ROC) was drawn and the area under curve (AUC) was calculated; and consistency index (C-index) were used to assess the prediction model's diagnostic ability. Results:A total of 25 strains of KP were isolated from 109 patients with SAP, of which 21(84.0%) had multi-drug resistance. 20 risk factors (SOFA score, APACHEⅡ score, Ranson score, MCTSI score, mechanical ventilation time, fasting time, duration of indwelling of the peritoneal drainage tube, duration of deep vein indwelling, number of invasive procedures, without or with surgical intervention, without or with endoscopic retrograde cholangiopancreatography (ERCP), types of high-level antibiotics used, digestion disorders, abnormalities in blood coagulation, metabolic acidosis, pancreatic necrosis, intra-abdominal hemorrhage, intra-abdominal hypertension, length of ICU stay and total length of hospital stay) were found to be associated with KP infection in SAP patients by univariate analysis. The four variables (APACHEⅡ score, duration of indwelling of the peritoneal drainage tube, types of high-level antibiotics used, and total length of hospital stay) were extracted after reduced by LASSO regression. These four variables were found to be risk factors for KP infection in SAP patients by multiple logistic regression analysis (all P value <0.05). Nomogram prediction model for KP infection in SAP was established based on the four variables above. The verification results of the model showed that the C-index of the model was 0.939, and the AUC was 0.939 (95% CI 0.888-0.991), indicating that the nomogram model had relatively accurate prediction ability. Conclusions:This prediction model establishes integrated the basic clinical data of patients, which could facilitate the risk prediction for KP infection in patients with SAP and thus help to formulate better therapeutic plans for patients.