Laboratory Investigation of Acute Kidney Injury

Patient Guideline Summary

Publication Date: May 11, 2021
Last Updated: November 21, 2023

Objective

Objective

This patient summary means to discuss key recommendations from the American Association for Clinical Chemistry (AACC) for Laboratory Investigation of Acute Kidney Injury. It is limited to adults 18 years of age and older and should not be used as a reference for children.

Overview

Overview

  • Acute kidney injury is a rapid decrease in kidney function.
  • We will use the abbreviation AKI throughout this summary to refer to acute kidney injury.
  • Causes for acute kidney injury include trauma, surgery, poisoning from certain drugs, heart failure, liver failure, and severe infections.
  • Symptoms are not diagnostic, largely because AKI usually occurs in the midst of serious illness with its own set of similar symptoms.
  • This patient summary focuses on early laboratory diagnosis of AKI.

Diagnosis

Diagnosis

  • Accurate early identification is critical to a good outcome from treatment.
  • Diagnosis can also identify the cause of AKI, greatly aiding proper treatment.
  • The standard method for assessing kidney function is blood creatinine levels and the speed with which the kidneys pass creatinine into the urine, known as creatinine clearance (ClCr) or glomerular filtration rate (GFR).
  • All patients with any elevated risk for AKI should be closely monitored for early signs of kidney injury.
  • A few other kidney tests, notably a microscopic urine analysis, may help identify some causes of AKI.
  • Recently FDA-approved tests of blood cystatin C and urinary insulin-like growth factor binding protein 7 (IGFBP7) plus tissue inhibitor of metalloproteinases 2 (TIMP2) are approved by the Food and Drug Administration (FDA) in the US for the assessment of risk for moderate or severe AKI. These tests may prove useful when they are further refined and evaluated.

Abbreviations

  • AACC: American Association For Clinical Chemistry
  • AKI: Acute Kidney Injury
  • ClCr: Creatinine Clearance
  • FDA: Food And Drug Administration
  • GFR: Glomerular Filtration Rate
  • IGFBP7: Insulin-like Growth Factor Binding Protein 7 

Source Citation

El-Khoury JM, Hoenig MP, Jones GRD, Lamb EJ, Parikh CR, Tolan NV, Wilson FP. AACC Guidance Document on Laboratory Investigation of Acute Kidney Injury. J Appl Lab Med. 2021 Sep 1;6(5):1316-1337. doi: 10.1093/jalm/jfab020. PMID: 33973621.

Disclaimer

The information in this patient summary should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.