Renal Medicine

Some referral criteria are given below; these are consistent with NICE CKD guidelines.

NB The advice below is for adults.  For children and young people, it is usually appropriate to refer if ANY albuminuria, haematuria, decreased GFR or hypertension (and to the paediatric renal team).

Who to refer:

Immediate referral

• AKI (i.e. a new acute kidney injury or an acute-on-chronic kidney injury): refer to renal if the cause is not obvious or “intrinsic” renal disease suspected (e.g. blood and protein on urine dip; features of a multi-system disease)
  • if the AKI is mild and likely to be reversible (e.g. in context of diarrhoea and vomiting) then community management may be most appropriate
  • if the AKI is in the context of a medical illness, then it may be more appropriate to refer to acute medicine or the relevant specialty (e.g. refer to cardiology if AKI associated with heart failure; refer to GI if in the context of decompensated cirrhosis)
  • if the AKI is due to renal tract obstruction, then refer to urology (unless there is a life-threatening biochemical disturbance or fluid overload that could need immediate renal replacement therapy)
• new, very advanced chronic renal failure (eGFR < 15)
• hypertensive emergency with renal involvement

Urgent referral

• hyperkalaemia
  • acute or dangerous hyperkalaemia is usually referred to the general medical take for same-day assessment (unless patient known to renal services)
  • chronic hyperkalaemia may be referred to renal (especially if associated with CKD) or endocrinology

• nephrotic syndrome (oedema, hypoalbuminaemia, heavy proteinuria)
  • nephrotic-range proteinuria is uPCR > 300 mg/mmol or uACR > 220 mg/mmol
  • most individuals with nephrotic syndrome should be seen by renal urgently
  • if this is chronic and in the context of longstanding diabetes then a routine referral is appropriate

• multi-system disease with evidence of renal involvement (which may be blood and protein on a urine dip and / or a climbing serum creatinine)

Routine referral

• declining eGFR:
  • a sustained decrease in eGFR of >25% and a change in eGFR category within 12 months
  • a sustained decrease in eGFR of >15 ml/min per year

• heavy proteinuria:
  • uACR > 70 mg/mmol (or uPCR > 100 mg/mmol), unless known to be caused by diabetes and already appropriately treated
  • uACR > 30 mg/mmol (or uPCR > 50 mg/mmol) with haematuria

• high absolute risk of progressing to end-stage kidney disease:
  • this will depend on age, eGFR (ideally viewed over time on a graph), proteinuria and co-morbidities
  • NICE recommend referral if 5-year risk of needing renal replacement therapy >5% (measured using the 4-variable Kidney Failure Risk Equation); we have not noticed widespread use of this tool in NHS Lothian yet…

• haematuria if unexplained by urological causes:
  • refer all visible and symptomatic haematuria to urology in the first instance
  • refer persistent asymptomatic haematuria in patients aged over 40 to urology in the first instance
  • refer to renal if features to suggest a likely intrinsic renal cause (e.g. associated proteinuria or “synpharyngitic” haematuria at time of upper respiratory tract infection)

• diabetes:
  • the vast majority of patients with CKD and diabetes are managed in the community
  • refer if progression (in GFR or proteinuria) is disproportionate to the duration / severity of diabetes (because non-diabetic renal disease likely)
  • refer early if intensive multi-factorial intervention may help to prevent progression to stage 4 CKD (i.e. if not meeting blood pressure and glycaemic targets despite best management in primary care; may benefit from the joint-renal diabetic clinic)

• suspected renal artery stenosis:
  • refer young patients (may have fibromuscular dysplasia which is amenable to angioplasty)
  • most patients with atherosclerotic renal artery stenosis are managed conservatively these days, but we are always happy to discuss

• recurrent kidney stones
• known or suspected rare or genetic causes of CKD (e.g. family history, young patient, extra-renal syndrome)

Who not to refer:

Nephrologists do not usually offer particularly useful insights into the management of:

• early-stage CKD (e.g. GFR > 60; uPCR <50) – particularly if stable and likely due to common risk factors (e.g. hypertension, diabetes) – the focus here should be on cardiovascular risk reduction in the community but we are always happy to discuss
• CKD in the context of advanced frailty / multi-morbidity – often the CKD is largely irrelevant but again we are always happy to discuss
• UTIs (better to refer to the recurrent UTI service within infectious diseases for difficult cases)
• kidney or urological cancers (managed by urology / oncology)

How to refer:

See information above under “options for obtaining renal advice”.

Patient Information  
Handbook for Clinicians looking after Renal Patients 
www.cancerreferral.scot.nhs.uk