When to refer to the renal unit
These guidelines have been developed in the Edinburgh renal unit, based on review of evidence in CKD guidelines and from other sources. This guide is ordered by urgency. To read guidance ordered by problem, see the menu on the left or GPinfo home. Questions not answered? GPs local to Edinburgh can use our email advice service.
|Suspected acute renal failure (ARF)
Acute renal failure superimposed on chronic renal failure – as for ARF
Malignant hypertension – severe hypertension with retinal haemorrhages/ exudates; often with renal impairment and dipstick urine abnormalities. More info on malignant hypertension (patient information from EdRenINFO).
Urgent outpatient referral
|Nephrotic syndrome – urinary protein/creatinine >300mg/mmol with low serum albumin and oedema.
New advanced renal failure – GFR <15mls/min and asymptomatic, or GFR 15-30mls/min. Explain how to estimate GFR
Multisystem disease with evidence of progressive renal involvement
Common diseases here include very treatable conditions such as systemic vasculitis (more info) and renal lupus (more info), though the differential diagnosis is wide and can include infections and malignancies.
Haematuria with proteinuria and worsening renal function – high probability of inflammatory and potentially treatable disease. Some instances will be unrecognised systemic disease.
Hyperkalaemia – dangerous hyperkalaemia in a patient not known to renal services should usually be acutely managed by acute medical team. If severe hyperkalaemia is persistent, renal or endocrine review may be appropriate.
Routine outpatient referral
|Declining renal function – e.g. 20% rise in serum creatinine or 15% fall in GFR over 6-12 months or longer, without obvious reversible features.
Known multisystem disease with minor and/or stable renal involvement
Suspected renal artery stenosis – for example,
Stable, severe renal impairment with GFR 15-30mls (Stage 4 – explain stages – explain how to estimate GFR) – unless it is clear that the prognosis from other disease is short. A GFR of 30 corresponds to creatinine approx 240 micromol/l in a 30y man, but 160 in a 70y woman.
Moderately severe renal impairment with complications: (stage 3, GFR 30-60) with severe acidosis, disturbances of calcium, phosphate, or high parathyroid hormone. See guideline on management of CKD – stage 3Moderately severe renal impairment with haematuria – GFR 30-60mls/min, (Stage 3 – explain stages – explain how to estimate GFR) – increased likelihood of inflammatory disease. Haematuria 2+ or more.
Proteinuria with haematuria – high probability of underlying renal disease. See guideline on proteinuria.
Isolated proteinuria – if protein/creatinine ratio >200mg/mmol, approx equivalent to 2g/day, without nephrotic syndrome. See guideline on proteinuria.
Macroscopic haematuria that is urologically unexplained. See guideline on macroscopic haematuria
Diabetes where progression out of keeping with disease (rapidity; no other microvascular complications, particularly retinopathy). Otherwise refer to nephrologist as for other patients with renal disease. See guideline on management of CKD – diabetes
Possible familial renal disease – for diagnosis or advice. Subsequent monitoring may not need to be at a renal unit.
Recurrent renal stones – nephrological and specialist dietetic review is valuable for multiple stone formers. More (brief) info from the EdRen Handbook.
Refractory hypertension (e.g. >150/90 despite agents from 4 complementary classes) if renal disease or renal artery stenosis is suspected.
Management in general practice
|GP care, with nephrological advice by email or telephone if necessary, is entirely appropriate for:
Isolated microscopic haematuria (no hypertension or proteinuria) – see guideline on microscopic haematuria.
Isolated proteinuria – protein creatinine ratio <100mg/mmol in the absence of renal impairment or severe hypertension. See guideline on proteinuria.
Mild to moderately reduced GFR – stages 1 to 3 without other features above. Common but important – see guideline on management of patients with reduced GFR
Urinary tract infections without chronic kidney disease. UTIs are very common. Nephrologists rarely have unusual insights into the management of recurrent uncomplicated UTI. See teaching information on UTI and related topics; and patient information on UTIs.
Helpful and essential information when referring
|The kidney problem
Urine dipstick results