Clinical investigations from the RACP

Investigating patients with impaired renal function

Chii Yeat Yeap, Randall Faull



Impairment of renal function is associated with high rates of adverse outcomes. The optimal approach to investigation depends on whether the impairment is acute, chronic or acute on chronic. Diagnostic evaluation is further guided by whether the kidney injury is due to prerenal, intrinsic renal or postrenal causes.

Key Points

  • The use of age-specific cut-off points of estimated glomerular filtration rate in the diagnosis of renal disease is not currently recommended.
  • All patients with acute kidney injury or increases of more than 1.5 times baseline serum creatinine levels should receive appropriate medical attention and treatment.
  • Rapid progression of renal impairment or the presence of active urine sediments should prompt urgent referral of the patient to a nephrologist or renal unit.
  • Urinalysis and urine microscopy is an essential component in any work-up of a patient with kidney impairment.
  • A thorough history and examination supported by additional blood tests are likely to identify the underlying aetiology.

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