Definitions, Risk Factors and Symptoms – Section Summary

Lesson Summary

AKI is a common condition that affects children and adults and is defined as the presence of any of the following:

  • Increase in SCr by ≥0.3 mg/dL (≥26.5 µmol/L) within 48 hours
  • Increase in SCr to ≥1.5 times baseline within the prior 7 days (ie, known or presumed to have occurred within this period)
  • Urine volume <0.5 mL/kg/h for 6 hours

Risk factors for AKI include trauma, infection, older age, heart failure, and causes of AKI can be classified as pre-renal, intra-renal, or post-renal.

Symptoms of AKI can vary depending on the underlying cause.

AKI is associated with a high rate of complications and requires immediate treatment. 

Without treatment, progression to multiple organ dysfunction results in an increased risk of mortality.

Mayo Clinic. Acute kidney failure. Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/kidney-failure/symptoms-causes/syc-20369048  

Oxford Medical Education. Acute Kidney Injury (AKI)/Acute Renal Failure (ARF). https://oxfordmedicaleducation.com/renal/acute-kidney-injury-aki/  

Oxford Medical Education. Definition of acute kidney injury. https://oxfordmedicaleducation.com/renal/acute-kidney-injury/  

Penn Medicine. What is Acute Kidney Injury? https://www.pennmedicine.org/for-patients-and-visitors/patient-information/conditions-treated-a-to-z/acute-kidney-injury  

Rudd KE, Cizmeci EA, Galli GM, et al; COVID-LMIC Task Force and Mahidol-Oxford Research Unit. Pragmatic recommendations for the prevention and treatment of acute kidney injury in patients with COVID-19 in low- and middle-income countries. Am J Trop Med Hyg. 2021;104(Suppl 3):87-98. doi:10.4269/ajtmh.20-1242