1st Department of Critical Care, School of Medicine, National and Kapodistrian University of Athens, "Evangelismos" Hospital, Athens, Greece.
Nephrology Department and Renal Transplantation Unit, National and Kapodistrian University of Athens, School of Medicine, "Laiko" Hospital, Athens, Greece.
Shock. 2022 Apr 1;57(4):501-507. doi: 10.1097/SHK.0000000000001896.
Renal resistive index (RRI) has been used to evaluate renal blood flow. Our aim was to investigate the relation between RRI and global tissue hypoperfusion indices and their association with clinical outcome, in intensive care unit (ICU) patients.
RRI was measured within 24 h of ICU admission. Gas exchange and routine hemodynamic variables at the time of RRI assessment were recorded. An elevated RRI was defined as >0.7. The ratio of central venous-to-arterial carbon dioxide partial pressure difference by arterial-to-central venous oxygen content difference (P(cv-a)CO2/C(a-cv)O2) and lactate were used as global tissue hypoperfusion indices.
A total of 126 patients were included [median age 61 (IQR 28) years, 74% males]. P(cv-a)CO2/C(a-cv)O2 ratio and arterial lactate were significantly higher in patients with RRI >0.7 compared with those with RRI ≤0.7 [2.88 (3.39) vs. 0.62 (0.57) mmol/L and 2.4 (2.2) vs. 1.2 (0.6)] respectively, both P < 0.001)]. RRI was significantly correlated with P(cv-a)CO2/C(a-cv)O2 ratio and arterial lactate for the whole patient population (rho = 0.64, both P < 0.0001) and for the subset of patients with shock (rho = 0.47, P = 0.001; and r = 0.64, P < 0.0001 respectively). Logistic regression models showed a significant association between RRI and P(cv-a)CO2/C(a-cv)O2 ratio with clinical outcome. The combination of RRI with P(cv-a)CO2)/(C(a-cv)O2 ratio and lactate better predicted mortality than RRI alone [AUC 84.8% (95% CI 5.1% -94.4%)] vs. [AUC 74.9% (95% CI 61%-88.8%)] respectively, P < 0.001.
Renal blood flow assessed by RRI, on ICU admission, correlates with global tissue hypoperfusion indices. In addition, RRI in combination with tissue perfusion estimation better predicts clinical outcome than RRI alone.
肾阻力指数（RRI）已被用于评估肾血流量。我们的目的是探讨 RRI 与全身组织低灌注指数的关系及其与重症监护病房（ICU）患者临床结局的关联。
在 ICU 入院后 24 小时内测量 RRI。记录 RRI 评估时的气体交换和常规血流动力学变量。定义 RRI 升高为>0.7。中心静脉-动脉二氧化碳分压差与动脉-中心静脉氧含量差（P(cv-a)CO2/C(a-cv)O2）和乳酸的比值用作全身组织低灌注指数。
共纳入 126 例患者[中位年龄 61（IQR 28）岁，74%为男性]。与 RRI≤0.7 的患者相比，RRI>0.7 的患者的 P(cv-a)CO2/C(a-cv)O2 比值和动脉乳酸明显更高[分别为 2.88（3.39）与 0.62（0.57）mmol/L 和 2.4（2.2）与 1.2（0.6），均 P<0.001]。RRI 与 P(cv-a)CO2/C(a-cv)O2 比值和动脉乳酸在整个患者人群中呈显著相关（rho=0.64，均 P<0.0001），在休克患者亚组中也呈显著相关（rho=0.47，P=0.001；r=0.64，P<0.0001）。Logistic 回归模型显示 RRI 与 P(cv-a)CO2/C(a-cv)O2 比值与临床结局之间存在显著关联。与单独使用 RRI 相比，RRI 与 P(cv-a)CO2/C(a-cv)O2 比值和乳酸的组合更好地预测死亡率[AUC 84.8%（95%CI 5.1%-94.4%）] vs. [AUC 74.9%（95%CI 61%-88.8%）]，均 P<0.001。
ICU 入院时通过 RRI 评估的肾血流量与全身组织低灌注指数相关。此外，与单独使用 RRI 相比，RRI 与组织灌注评估的组合能更好地预测临床结局。
