If newly diagnosed GFR <60 ml/min/1.73 m2

If newly diagnosed GFR <60 ml/min/1.73 m2

• all patients with newly detected abnormal kidney function should be assumed to have acute renal failure (ARF) until proven otherwise, although the majority will turn out to have chronic kidney disease (CKD). In patients with newly diagnosed stage 3, 4 or 5 CKD, clinicians should obtain all previous measurements of serum creatinine and estimate GFR to assess the rate of progression to date. A blood test showing a GFR < 60 ml/min/1.73 m2 in a patient who is not known to have established CKD with abnormal GFR should prompt:
  • medication review, especially recent additions (e.g. diuretics, non-steroidal antiinflammatory drugs (NSAIDs), any drug capable of causing interstitial nephritis)
  • clinical examination for enlarged bladder (bladder outflow obstruction)
  • urinalysis: haematuria and proteinuria suggest the possibility of glomerulonephritis, which may be rapidly progressive
  • clinical assessment, looking for underlying conditions such as sepsis, heart failure, hypovolaemia
  • arrange a repeat measurement of serum creatinine concentration within a maximum of 5 days

Notes:

• ARF is a clinical syndrome characterised by a rapid decline in excretory function occurring over a period of hours or day
  • should be suspected if there is a >1.5-fold rise in serum creatinine concentration, or a fall in estimated GFR of >25%, or oliguria (defined as urine output <0.5 ml/kg/h), in the context of an acute illness
    • if baseline serum creatinine concentration or GFR is not known, it should be assumed that baseline GFR was 75 ml/min/1.73 m2
    • if a patient has suspected ARF the s/he should be referred to a nephrologist
    • formula-based estimated GFR should be interpreted with caution in ARF - this is because the formulae rely on a stable serum creatinine concentration

Reference:

1. The Renal Association (May 2006).UK CKD Guidelines