Background: Measurement of general microcirculation remains difficult in septic shock patients. The peripheral perfusion index (PI) and sublingual microcirculation monitoring are thought to be possible methods. This study was performed to determine whether assessing microcirculation by PI and a new parameter, proportion of perfusion vessel change rate (△PPV) from sublingual microcirculation monitoring, can be associated with patients' outcome.
Methods: A prospective observational study was carried out, including 74 patients with septic shock in a mixed intensive care unit. Systemic hemodynamic variables were obtained at T0 and 6 h after (T6). PI and sublingual microcirculation indicators were obtained using a bedside monitor and a sidestream dark-field device, respectively. The t-test, analysis of variance, Mann-Whitney U-test, Kruskal-Wallis test, receiver operating characteristic curve analysis with the Hanley-McNeil test, survival curves using the Kaplan-Meier method, and the log-rank (Mantel-Cox) test were used to statistical analysis.
Results: Systemic hemodynamics and microcirculation data were obtained and analyzed. Patients were divided into two groups based on whether the first 6 h lactate clearance (LC) was ≥20%; PI and △PPV were lower at T6 in the LC <20% group compared with LC ≥20% (PI: 1.52 [0.89, 1.98] vs. 0.79 [0.44, 1,81], Z = -2.514, P = 0.012; △PPV: 5.9 ± 15.2 vs. 17.9 ± 20.0, t = -2.914, P = 0.005). The cutoff values of PI and △PPV were 1.41% and 12.1%, respectively. The cutoff value of the combined indicators was 1.379 according to logistic regression. Area under the curve demonstrated 0.709 (P < 0.05), and the sensitivity and specificity of using combined indicators were 0.622 and 0.757, respectively. Based on the PI and △PPV cutoff, all the participants were divided into the following groups: (1) high PI and high △PPV group, (2) high PI and low △PPV group, (3) low PI and high △PPV group, and (4) low PI and low △PPV group. The highest Sequential Organ Failure Assessment score (14.5 ± 2.9) was in the low PI and low △PPV group (F = 13.7, P < 0.001). Post hoc tests showed significant differences in 28-day survival rates among these four groups (log rank [Mantel-Cox], 20.931; P < 0.05).
Conclusion: PI and △PPV in septic shock patients are related to 6 h LC, and combining these two parameters to assess microcirculation can predict organ dysfunction and 28-day mortality in patients with septic shock.
联合外周灌注指数与舌下微循环监测脓毒症休克微循环障碍与预后摘要背景：对于脓毒症休克患者而言，休克时微循环的变化与监测至关重要。外周灌注指数（peripheral perfusion index，PI）及舌下微循环监测是目前临床上较为直接且便捷的监测手段。本研究通过联合外周灌注指数（PI）及舌下微循环监测衍生指标灌注血管比例变化率（proportion of perfusion vessel change rate，△PPV）对脓毒症休克患者器官损伤情况及28天病死率进行预测。 方法：本研究为前瞻性观察性研究，采用t检验, 方程分析(ANOVA), Mann-Whitney U 检验, Kruskal-Wallis检验, ROC曲线, Kaplan-Meier生存曲线结合Mantel-Cox检验。本实验中共纳入74名脓毒症休克患者。于收入重症医学科时（T0）及第6小时（T6）分别监测患者大循环血流动力学参数、舌下微循环相关参数及外周灌注指数（PI）。 结果：根据患者6h乳酸清除率（lactate clearance，LC）是否≥20%，将入组病人分为两组，分别为LC＜20%组与LC≥20%组。LC＜20%组患者T6时刻的PI及6小时后△PPV均低于LC≥20%组(PI: 1.52 [0.89, 1.98] vs. 0.79 [0.44, 1,81], Z=-2.514, P = 0.012; △PPV: 5.9 ± 15.2 vs. 17.9 ± 20.0, t =-2.914, P = 0.005)。因此根据6h的LC是否 ≥20%，分别得到PI临界值1.41与△PPV临界值12.1%。通过逻辑回归分析可得联合应用两个指标的临界值为1.379，曲线下面积为0.709，敏感性和特异性分别为0.622及0.757（P＜0.05）。根据PI及△PPV的临界值，我们将入组病人分为四组。组1：PI ≥1.4且△PPV ≥12.1%，组2：PI ≥1.4且△PPV ＜12.1%，组3：PI ＜1.4且△PPV ≥12.1%，组4：PI ＜1.4且△PPV ＜12.1%。其中，组4 患者SOFA评分最高（14.5 ± 2.9），Post hoc分析显示组1患者生存率最高，而组4患者生存率最低（log rank [Mantel-Cox], 20.931; P ＜ 0.05）。 结论：PI和△PPV与脓毒症休克患者6小时乳酸清除率相关，联合应用两个指标可早期预测患者病情危重程度（器官功能异常情况）与28天病死率。.
Keywords: Microcirculation; Sepsis; Shock.