■血清阴离子间隙(AG)可以潜在地应用于各种代谢性酸中毒的诊断,最近的一项研究报告了AG与2019年冠状病毒病患者(COVID-19)死亡率的相关性。然而,AG与呼吸机相关性肺炎(VAP)患者短期死亡率的关系尚不清楚.在这里,我们旨在调查AG与VAP患者30天死亡率之间的关系,并构建和评估VAP30天死亡风险的多变量预测模型。
这项回顾性队列研究从重症监护医学信息集市III(MIMIC-III)数据库中提取了477例VAP患者的数据。将患者的数据分为训练集和测试集,比率为7:3。在训练集中,通过单变量Cox回归和逐步回归分析,将与VAP患者30日死亡率显著相关的变量纳入多变量预测模型.然后,在训练集和测试集中评估了多变量预测模型的预测性能,并与单个AG和其他评分系统(包括顺序器官衰竭评估(SOFA)评分)进行比较,混乱,尿素,呼吸频率(RR),血压,年龄(≥65岁)(CURB-65)评分,和血尿素氮(BUN),精神状态改变,脉搏,年龄(>65岁)(BAP-65)评分。此外,在性别亚组中探讨了AG与VAP患者30天死亡率的关系,年龄,和感染状况。评价指标为危害比(HR)、C指数,和95%置信区间(CI)。
■共有70名患者在30天内死亡。多变量预测模型由AG组成(HR=1.052,95%CI:1.008-1.098),年龄(HR=1.037,95%CI:1.019-1.055),机械通气的持续时间(HR=0.998,95%CI:0.996-0.999),和血管升压药的使用(HR=1.795,95%CI:1.066-3.023)。在训练集(C指数=0.725,95%CI:0.670-0.780)和测试集(C指数=0.717,95%CI:0.637-0.797)中,多变量模型的预测性能优于单个AG值。此外,在男性患者中也发现了AG与30天死亡率的关联(HR=1.088,95%CI:1.029-1.150),无论感染何种病原体(细菌感染:HR=1.059,95%CI:1.011-1.109;真菌感染:HR=1.057,95%CI:1.002-1.115)。
■AG相关的多变量模型对VAP患者的30天死亡率具有潜在的预测价值。这些发现可能为进一步探索简单、可靠的VAP短期死亡风险预测因子提供一定的参考。这可能进一步帮助临床医生在重症监护病房(ICU)的早期阶段识别具有高死亡风险的患者。
UNASSIGNED: Serum anion gap (AG) can potentially be applied to the diagnosis of various metabolic acidosis, and a recent study has reported the association of AG with the mortality of patients with coronavirus disease 2019 (COVID-19). However, the relationship of AG with the short-term mortality of patients with ventilator-associated pneumonia (VAP) is still unclear. Herein, we aimed to investigate the association between AG and the 30-day mortality of VAP patients, and construct and assess a multivariate predictive model for the 30-day mortality risk of VAP.
UNASSIGNED: This retrospective cohort study extracted data of 477 patients with VAP from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Data of patients were divided into a training set and a testing set with a ratio of 7:3. In the training set, variables significantly associated with the 30-day mortality of VAP patients were included in the multivariate predictive model through univariate Cox regression and stepwise regression analyses. Then, the predictive performance of the multivariate predictive model was assessed in both training set and testing set, and compared with the single AG and other scoring systems including the Sequential Organ Failure Assessment (SOFA) score, the confusion, urea, respiratory rate (RR), blood pressure, and age (≥65 years old) (CURB-65) score, and the blood urea nitrogen (BUN), altered mental status, pulse, and age (>65 years old) (BAP-65) score. In addition, the association of AG with the 30-day mortality of VAP patients was explored in subgroups of gender, age, and infection status. The evaluation indexes were hazard ratios (HRs), C-index, and 95% confidence intervals (CIs).
UNASSIGNED: A total of 70 patients died within 30 days. The multivariate predictive model consisted of AG (HR =1.052, 95% CI: 1.008-1.098), age (HR =1.037, 95% CI: 1.019-1.055), duration of mechanical ventilation (HR =0.998, 95% CI: 0.996-0.999), and vasopressors use (HR =1.795, 95% CI: 1.066-3.023). In both training set (C-index =0.725, 95% CI: 0.670-0.780) and testing set (C-index =0.717, 95% CI: 0.637-0.797), the multivariate model had a relatively superior predictive performance to the single AG value. Moreover, the association of AG with the 30-day mortality was also found in patients who were male (HR =1.088, 95% CI: 1.029-1.150), and whatever the pathogens they infected (bacterial infection: HR =1.059, 95% CI: 1.011-1.109; fungal infection: HR =1.057, 95% CI: 1.002-1.115).
UNASSIGNED: The AG-related multivariate model had a potential predictive value for the 30-day mortality of patients with VAP. These findings may provide some references for further exploration on simple and robust predictors of the short-term mortality risk of VAP, which may further help clinicians to identify patients with high risk of mortality in an early stage in the intensive care units (ICUs).