Predictors of Augmented Renal Clearance in a Heterogeneous ICU Population as Defined by Creatinine and Cystatin C

Nephron. 2020;144(7):313-320. doi: 10.1159/000507255. Epub 2020 May 19.

Abstract

Introduction: The incidence of augmented renal clearance (ARC) in the intensive care unit (ICU) is highly variable, and identification of these patients remains challenging.

Objective: The objective of this study was to define the incidence of ARC in a cohort of critically ill adults, using serum Cr and cystatin C, and to identify factors associated with its development.

Methods: This is a retrospective cohort study of critically ill patients without stage 2 or 3 acute kidney injury with both serum Cr and cystatin C available. The incidence of ARC was defined as a Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)Cr-cystatin C-estimated glomerular filtration rate >130 mL/min. A multivariable logistic regression model using a penalized Lasso method was fit to identify independent predictors of ARC.

Results: Among the 368 patients included in the study, indication for ICU admission was nonoperative in 55% of patients, and 9% of patients were admitted for major trauma. The overall incidence of ARC was low at 4.1%. In a multivariable logistic regression model, Charlson comorbidity index, major trauma, intracerebral hemorrhage, age, and Sequential Organ Failure Assessment score were found to predict ARC.

Conclusion: The incidence of ARC in this study was low, but prediction models identified several factors for early identification of patients with risk factors for or who develop ARC, particularly in a cohort with a low baseline risk of ARC. These factors could be used to help identify patients who may develop ARC.

Keywords: Augmented renal clearance; Biomarker; Critical care; Cystatin C; Nephrology.

MeSH terms

  • Acute Kidney Injury / blood*
  • Acute Kidney Injury / epidemiology
  • Adult
  • Aged
  • Biomarkers
  • Cohort Studies
  • Creatinine / blood*
  • Critical Care
  • Cystatin C / blood*
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Kaplan-Meier Estimate
  • Kidney / metabolism*
  • Kidney Function Tests*
  • Male
  • Middle Aged
  • Multiple Organ Failure
  • Patient Admission
  • Retrospective Studies
  • Survival Analysis

Substances

  • Biomarkers
  • CST3 protein, human
  • Cystatin C
  • Creatinine