Value of the combination of renal resistive index and central venous pressure to predict septic shock induced acute kidney injury / 中华危重病急救医学

ABSTRACT

Objective:To explore a better indicator that can predict septic shock induced acute kidney injury (AKI) by combining renal resistive index (RRI) and central venous pressure (CVP).Methods:A prospective observational study was conducted. Patients with septic shock admitted to department of critical care medicine of Hebei General Hospital from November 2017 to October 2018 were enrolled. Baseline characteristics such as age, gender, underlying diseases, infection sites, acute physiology and chronic health evaluation Ⅱ(APACHEⅡ) in the first 24-hour, sequential organ failure assessment (SOFA) were recorded; Doppler-based RRI was obtained on the first day when hemodynamics was relatively stable, meanwhile the dose of norepinephrine and hemodynamic parameters were assessed. Urine output per hour, the total duration of mechanical ventilation, the length of intensive care unit (ICU) stay and 28-day mortality were also collected. Observational end point was death at discharge or the 28th day after ICU admission, whenever which came first. The patients were divided into AKI and non-AKI groups according to the 2012 Kidney Disease Improving Global Organization (KDIGO) clinical practice guideline. The baseline and prognostic indicators, variables potentially associated with AKI were compared between the two groups. The variables independently associated with septic shock induced AKI were identified using multivariable Logistic regression. The predictive value of RRI and RRI combining CVP for AKI were analyzed by the receiver operating characteristic (ROC) curve.Results:A total of 107 patients were enrolled, with 59 patients in AKI group and 48 patients in non-AKI group. There was significant difference in RRI, CVP, percentage of norepinephrine dosage ≥0.5 μg·kg -1·min -1, procalcitonin (PCT), lactate (Lac), and serum creatinine (SCr) between the two groups. Logistic regression analysis showed that high CVP, RRI, Lac and PCT were independent risk factors for septic shock induced AKI [CVP odds ratio ( OR) = 1.20, 95% confidence interval (95% CI) was 1.03-1.40, P = 0.022; RRI OR = 3.02, 95% CI was 2.64-3.48, P = 0.006; Lac OR = 2.43, 95% CI was 1.32-4.50, P = 0.005; PCT OR = 1.20, 95% CI was 1.05-1.38, P = 0.009]. ROC curve analysis showed that the area under ROC curve (AUC) values of CVP≥9.5 mmHg (1 mmHg = 0.133 kPa) and RRI≥0.695 for predicting septic shock induced AKI were 0.656 and 0.662 respectively. The AUC value of the combination of RRI and CVP was greater compared with either RRI or CVP alone in predicting septic shock induced AKI, which AUC value was 0.712, 95% CI was 0.615-0.809, the sensitivity was 59% and the specificity was 75%. Conclusions:High CVP and RRI were independent risk factors for septic shock induced AKI. The combination of RRI and CVP performs poorly in predicting septic shock induced AKI. Further studies are needed to describe factors influencing Doppler-based assessment of RRI, which may help clinicians to prevent AKI early.