CADFlow超声血流监测技术对脓毒性休克患者死亡风险的预测价值研究

Predictive Value of CADFlow Ultrasound Blood Flow Monitoring Technology for Mortality Risk in Patients with Septic Shock

摘要: 目的：脓毒性休克患者早期血流动力学状态与预后密切相关，但传统有创监测实施复杂，常规经胸超声受声窗限制。因此，本研究旨在探讨基于CADFlow技术的无创颈动脉血流监测参数，特别是颈动脉速度–时间积分(cVTI)，对脓毒性休克患者ICU死亡风险的预测价值。方法：采用单中心前瞻性观察研究设计，纳入96例脓毒性休克患者。根据28天临床结局分为生存组(n = 59)和死亡组(n = 37)。应用CADFlow超声监测仪采集入室即刻的血流动力学参数。通过单因素及多因素Cox比例风险回归模型筛选预后独立危险因素；绘制受试者工作特征(ROC)曲线评估cVTI及联合模型的预测效能，计算曲线下面积(AUC)及最佳截断值；采用Kaplan-Meier法绘制生存曲线，通过Log-rank检验比较不同cVTI水平组间的生存率差异。并通过Bootstrap自助法(n = 1000次)验证模型效能。结果：与生存组相比，死亡组患者在0 h的cVTI水平显著降低(28.57 ± 5.65 vs 34.86 ± 7.66, P <0.001)。多因素Cox回归分析证实，0 h cVTI是患者ICU的独立危险因素(HR = 0.916, 95%CI: 0.869~0.965, P = 0.001)。ROC曲线分析显示，基于0 h cVTI构建的联合预测模型AUC为0.87 (95%CI: 0.80~0.95)，其预测死亡的最佳截断值为33.5 cm。Kaplan-Meier生存分析显示，低cVTI组(<33.5 cm)患者的ICU累积死亡率显著高于高cVTI组(Log-rank P < 0.0001)。结论：入室早期cVTI < 33.5 cm是识别脓毒性休克患者高死亡风险的独立预警信号，“低流速”状态可能提示隐匿性低灌注，具有重要的临床分层与预后评估价值。

Abstract: Objective: The early hemodynamic status of patients with septic shock is closely correlated with prognosis. However, traditional invasive monitoring is complex to implement, while conventional transthoracic echocardiography is limited by acoustic windows. This study aims to evaluate the reliability of non-invasive carotid hemodynamic parameters based on CADFlow technology—Particularly, the Carotid Velocity-Time Integral (cVTI) demonstrates significant predictive value for ICU mortality risk in patients with septic shock. Methods: A single-center, prospective observational study was conducted involving 96 patients with septic shock. Patients were stratified into a survivor group (n = 59) and a non-survivor group (n = 37) based on 28-day clinical outcomes. Hemodynamic parameters were acquired immediately upon ICU admission using a CADFlow ultrasound monitor. Univariate and multivariate Cox proportional hazards regression models were utilized to identify independent prognostic risk factors. Receiver Operating Characteristic (ROC) curves were plotted to assess the predictive efficacy of cVTI and a combined model, calculating the Area Under the Curve (AUC) and the optimal cut-off value. Survival curves were generated using the Kaplan-Meier method, and the Log-rank test was employed to compare survival differences between cVTI groups. The model performance was validated through the bootstrap resampling method (with 1000 repetitions). Results: Compared with the survivor group, the 0h cVTI levels in the non-survivor group were significantly lower (28.57 ± 5.65 cm vs. 34.86±7.66 cm, P < 0.001). Multivariate Cox regression analysis confirmed that 0h cVTI is an independent risk factor for ICU mortality (HR = 0.916, 95% CI: 0.869~0.965, P = 0.001). ROC curve analysis indicated that the combined predictive model constructed based on 0 h cVTI achieved an AUC of 0.87 (95% CI: 0.80~0.95), with an optimal cut-off value for mortality prediction of 33.5 cm. Kaplan-Meier survival analysis demonstrated that the cumulative survival rate of patients in the low cVTI group (<33.5 cm) was significantly lower than that of the high cVTI group (Log-rank P < 0.0001). Conclusion: An early admission cVTI < 33.5 cm serves as an independent warning signal for high mortality risk in patients with septic shock. This “low flow velocity” state may suggest occult hypoperfusion and holds significant value for clinical stratification and prognostic assessment.