Sepsis is a systemic inflammatory response caused by an imbalance of the host immune response to infectious factors, potentially leading to life-threatening organ dysfunction. The application of immature platelet fraction (IPF) to assessing the severity and prognosis of sepsis has been previously analyzed. However, the application of IPF combined with other biomarkers to predict sepsis has been rarely reported.

To explore the predictive value of IPF combined with other biomarkers in the severity and prognosis of sepsis.

A total of 60 sepsis patients admitted to the Department of Critical Care Medicine, Zhongshan Hospital, Fudan University (Xiamen Branch) from November 2020 to November 2022 were retrospectively recruited for analyzing their clinical data. Patients were classified into the severe sepsis group (n=24) and septic shock group (n=36) based on the severity of sepsis. Divided by the Sequential Organ Failure Assessment (SOFA) score, 60 sepsis patients were assigned into the low SOFA group (SOFA score<6 points, n=26) and high SOFA group (SOFA score ≥6 points, n=34). According to the outcome, there were 39 cases in the survival group and 21 cases in the death group. IPF and other blood indicators, including neutrophil to albumin ratio (NAR), platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), and lactate to albumin ratio (LAR) were compared. The receiver operating characteristic (ROC) curves of IPF combined with other biomarkers for predicting the severity and prognosis of sepsis were plotted, and the area under the curve (AUC) was calculated.

The proportion of lung diseases, baseline Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) scores and baseline SOFA scores were significantly higher in the death group compared to those of the survival group (P<0.05). Similarly, the proportion of lung diseases, baseline APACHE II scores and mortality were significantly higher in the high SOFA group compared to those of the low SOFA group (P<0.05). IPF at 48 hours of treatment was significantly higher in the septic shock group than that of the severe sepsis group, which was significantly higher in the high SOFA group compared to that of the low SOFA group, and significantly higher in the death group compared to that of the survival group (P<0.05). Given the significant difference in 48 h IPF between groups, the laboratory indicators at this time point were selected for further research and analysis. The AUC of IPF in predicting septic shock, a high SOFA score and death was 0.70 (95%CI=0.55 to 0.83, cut-off value 3.95%) and 0.72 (95%CI=0.60 to 0.86, cut-off value 7.70%), 0.73 (95%CI=0.58 to 0.89, cut-off value 6.10%), respectively. The AUC of IPF + baseline APACHE Ⅱscore + NLR, and IPF + baseline APACHE Ⅱ score + LAR in predicting a high SOFA score was 0.91 (95%CI=0.84 to 0.98) and 0.93 (95%CI=0.84 to 0.99), respectively. The AUC of IPF + NAR + PLR in predicting the death in sepsis patients was 0.90 (95%CI=0.81 to 0.98) .

IPF combined with different blood indicators can improve the ability to assess the severity and prognosis of sepsis in clinical practice. Specifically, 48 h IPF + baseline APACHE Ⅱ score+48 h NLR and 48 h IPF + baseline APACHE Ⅱscore+48 h LAR have high efficacy in predicting the severity of sepsis; whereas 48 h IPF+NAR+PLR shows a superior efficacy in predicting the prognosis of sepsis.

脓毒症是由感染因素引发机体免疫反应失调而导致的全身炎症反应，可能会导致潜在的危及生命的器官功能障碍。目前对于未成熟血小板比率（IPF）在脓毒症严重程度及预后方面已有一些研究，但关于IPF联合其他指标在脓毒症中应用的研究较少。

探讨IPF联合其他指标在脓毒症严重程度及其预后中的预测价值。

收集2020年11月—2022年11月复旦大学附属中山医院厦门医院重症医学科收治的60例脓毒症患者的临床资料进行回顾性分析。分组情况：严重程度按定义划分，可分为严重脓毒症组24例与脓毒性休克组36例；严重程度按序贯器官衰竭评估（SOFA）评分划分，可分为低SOFA组26例（SOFA评分<6分）与高SOFA组34例（SOFA评分≥6分）；按预后划分，可分为生存组39例与死亡组21例。对比不同分组患者IPF及其他血液指标[中性粒细胞与白蛋白比值（NAR）、血小板与淋巴细胞比值（PLR）、中性粒细胞与淋巴细胞比值（NLR）、乳酸与白蛋白比值（LAR）]的差异，绘制不同联合指标评估脓毒症严重程度和预后的受试者工作特征（ROC）曲线，计算ROC曲线下面积（AUC）并比较其评估价值。

死亡组患者肺部疾病所占比例、基线急性生理学与慢性健康状况量表系统Ⅱ（APACHEⅡ）评分、基线SOFA评分高于生存组（P<0.05）。高SOFA组患者肺部疾病所占比例、基线APACHEⅡ评分、死亡所占比例高于低SOFA组（P<0.05）。对于治疗开始48 h IPF，脓毒性休克组患者高于严重脓毒症组，高SOFA组患者高于低SOFA组，死亡组患者高于生存组（P<0.05）。因不同组患者治疗开始48 h IPF均存在统计学差异，故截取48 h各实验室检查指标进行进一步研究分析：IPF在预测脓毒性休克及高SOFA评分的AUC分别为0.70（95%CI=0.55~0.83，截断值为3.95%）、0.72（95%CI=0.60~0.86，截断值7.70%），预测死亡的AUC为0.73（95%CI=0.58~0.89，截断值为6.10%）。IPF+基线APACHEⅡ评分+NLR、IPF+基线APACHEⅡ评分+LAR预测高SOFA评分的AUC分别为0.91（95%CI=0.84~0.98）和0.93（95%CI=0.84~0.99）；IPF+NAR+PLR预测脓毒症患者死亡的AUC为0.90（95%CI=0.81~0.98）。

IPF联合不同血液指标能够提高临床实践中对脓毒症患者病情严重程度及预后的评估能力，治疗开始48 h IPF+基线APACHEⅡ评分+治疗开始48 h NLR及治疗开始48 h IPF+基线APACHEⅡ评分+治疗开始48 h LAR在脓毒症严重程度预测中具有较高效能；而治疗开始48 h的IPF+NAR+PLR在预测脓毒症患者预后方面效能较好。