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Investigations prior to nephrology referral

Tests and investigations

  • Kidney failure risk equation (KFRE) % at five years if referral for chronic kidney disease (CKD)
  • Estimated glomerular filtration rate (eGFR), repeated if evidence of acute change in renal function
  • Urinalysis
  • Urine albumin to creatinine ratio (ACR)/ protein to creatinine ratio (PCR)
  • Blood pressure
  • Albumin

Renal ultrasound requesting

NICE recommend offering a renal ultrasound to all adults with chronic kidney disease (CKD) who:

  • have accelerated progression of CKD
  • have visible or persistent invisible haematuria
  • have symptoms of urinary tract obstruction
  • have a family history of polycystic kidney disease and are older than 20
  • have a glomerular filtration rate of less than 30 ml/min/1.73 m2 (GFR category G4 or G5)
  • are considered by a nephrologist to need a renal biopsy

The result of renal imaging will determine the most appropriate specialty referral in some cases and negate the need for referral in others.

For direct access referrals, please use the renal ultrasound referral form which is available for you to complete electronically on your practice management system.

Learn more about direct access renal ultrasound referrals on the link below:

NICE guidance

Utilising the current NICE guidance, the following indications for renal ultrasound are available from primary care:

Patients with accelerated progression of chronic kidney disease (CKD)

US to be reported within two weeks of request from primary care:

  • estimated glomerular filtration rate (eGFR) <30ml/min and rapid decline in renal function defined as sustained decrease in eGFR of 25% or more AND a change in CKD category within 12 months OR sustained decrease in eGFR of 15ml/min/1.73m2 or more per year
  • if evidence of obstruction, primary care to contact on call urology registrar for immediate referral to surgical assessment unit
  • if no evidence of renal obstruction referral to nephrology services

Patients with an eGFR of less than 30 ml/min/1.73 m2 and no accelerated change in renal function (eGFR shows <25% decrease or <15ml/min/1.73m2 per year)

Primary care to request renal US to be reported within 6 weeks of request, (request only if no prior renal imaging):

  • evidence of obstruction on US requires urgent referral to urology services
  • assess kidney failure risk equation (KFRE) if >5% at 5 years refer to nephrology services

Patients with visible or persistent invisible haematuria

Two-week cancer referral to urology services required (US request should not delay referral for cancer assessment and should be requested at secondary care triage) in:

  • age >45 years with unexplained visible haematuria without urinary tract infection
  • age >45 years with persistent visible haematuria that persists or recurs after successful treatment of urinary tract infection
  • age >60 and unexplained non-visible haematuria and dysuria or raised white cell count on a blood test

Patients with a family history of polycystic kidney disease and older than 20

  • primary care to request a non urgent renal ultrasound to be reported within 12 weeks of request
  • evidence of at least one cyst requires routine referral to nephrology services
  • no cysts on scan reassure patient. No referral required

What to do with incidental ultrasound findings

  • Evidence of bladder outflow obstruction requires urgent catheterization and immediate referral to local urology services
  • Evidence of dilated renal pelvis (unilateral or bilateral) requires urgent referral to urology services
  • Simple renal cysts do not require follow-up or referral to secondary care unless causing significant pain where a routine urology referral may be required
  • Complex cysts (thick septae, solid component, significant calcification or radiological concern) requires two-week cancer pathway to urology for CT imaging
  • Multi-cystic kidneys, check eGFR and urine ACR, optimize BP to <130/80. Monitor and refer to nephrology as per CKD guidelines
  • Polycystic kidneys (hereditary condition causing enlarged cystic kidneys), control blood pressure <130/80, take family history. Refer to renal services urgency dependent on rate of decline in renal function
  • Incidental asymptomatic stones >6mm or multiple stones requires routine referral to urology services
  • Incidental asymptomatic non obstructing stone <6mm no referral required
  • Renal mass on ultrasound requires referral to urology services as two-week cancer pathway referral
  • Angiomyolipomata: monitoring or these is done via urology clinic. These do not require referral to nephrology unless there is a requirement for investigation and management of tuberous sclerosis (TS). This may be required if there are multiple angiomyolipomas or other clinical features of TS

Last reviewed: 23 November 2023