Signs and Symptoms

The two common methods for detecting CKD are:

• Estimated glomerular filtration rate (eGFR) - see caveats for eGFR
• Urinalysis (see investigations for information)

A low eGFR result should prompt a repeat request depending on the clinical context the repeat sample may be within 2 days or 2 weeks.

The diagnosis of CKD requires at least 2 eGFR measurements separated by 90 days.

Acute kidney injury (AKI) needs to be considered in the context of a rapidly rising creatinine the exact value remains to be debated as it depends on the clinical context, but an example may be an increase of 30μmol/L or 1.5 fold above baseline within 48 hours.

Renal association - acute kidney injury guideline

Do NOT use CKD pathway for AKI.

• Indications for urgent referral (telephone secondary care):
  • Suspected vasculitis causing AKI
  • Severe hyperkalaemia (K more than 7mmol/L)
  • Severe hypertension (more than 180/110mmHg) with renal disease or AKI
  • Severe fluid overload, i.e. peripheral or pulmonary oedema
  • Advanced CKD 5 with uraemic symptoms

Primary Care Action

Complete urinalysis and/or eGFR (estimated glomerular filtration rate)

Urinalysis should be performed alongside measurement of creatinine and eGFR in anyone being evaluated for CKD. A positive urinalysis, defined as:

• Asymptomatic microscopic haematuria (AMH) (2+ on urine dipstick)
• Proteinuria with AMH (1+ on urine dipstick) or
• Isolated proteinuria

All the above may be indicators of CKD and should prompt further investigation with an eGFR.

The eGFR is estimated from the serum creatinine, gender and age. It should be multiplied by a correction factor of 1.2 for African-Caribbean patients. In broad terms, the eGFR equates to the "percentage" of normal kidney function that someone has.

The eGFR is not validated in the following patient groups, in whom results should be interpreted with caution:

• Patients with acute kidney injury (AKI)
• Patients aged below 18 years of age
• During pregnancy
• Patients with extremes of muscle mass e.g. malnutrition or muscle wasting disorders, amputees, body builders
• Oedematous states e.g. congestive cardiac failure, chronic liver disease
• Certain ethnic groups e.g. Asians and Chinese:
  • Allow for biological and analytical variability of serum creatinine (± 5%) when interpreting changes in the eGFR over time.

Consider using cystatinC at initial diagnosis to confirm or rule out CKD in people with:

• an eGFRcreatinine of 45-59ml/min/1.73m2, sustained for at least 90 days and
• no proteinuria (albumin:creatinine ratio (ACR less than 3mg/mmol) or other marker of kidney disease
• Please liaise with Pathology before requesting eGFRcystatinC

Urinalysis result

A negative urinalysis is defined as:

• Absence or trace of blood
• Absence of proteinuria (This does NOT exclude microalbuminuria, and an ACR should be requested in all patients with diabetes, even when the urine dip is negative for protein)

A positive urinalysis may be any of the following and should prompt further investigations:

• Isolated asymptomatic microscopic haematuria (AMH) (2+ has been locally agreed)
• Proteinuria (1+) with AMH (2+)
• Isolated proteinuria (1+)
• eGFR should be measured in anyone being evaluated for Chronic Kidney Disease, regardless of the urinalysis result, to determine whether nephrology referral is indicated. See eGFR results in management section.

Screening for CKD in high risk groups:

• Screen for occult CKD (eGFR and urinalysis) at least annually in all adult patients with:
  • Conditions associated with a high risk of development of CKD, e.g.
    • Hypertension
    • Diabetes mellitus
    • CV disease and heart failure
  • Conditions requiring long-term treatment with recognised nephrotoxins, e.g.
    • ACE inhibitors (ACEIs) and angiotensin-II receptor blockers (ARBs)
    • Non-steroidal anti-inflammatory drugs (NSAIDS)
    • Lithium
    • Mesalazine
    • Calcineurin inhibitors such as cyclosporine or tacrolimus
  • Multisystem diseases with potential kidney involvement, e.g.
    • SLE
    • Vasculitis
    • Myeloma
    • Rheumatoid arthritis
  • Family history of hereditary renal disease, e.g.
    • Autosomal Dominant Polycystic Kidney Disease (ADPKD)
    • Stage 5 CKD
  • Urological conditions including:
    • Neurogenic bladder (e.g. spina bifida)
    • Surgical urinary diversion
    • Renal stone disease
    • Benign prostatic hypertrophy
    • Lower urinary tract symptoms including recurrent UTIs
  • History of "nephritis" in childhood

Assessment of isolated Asymptomatic Microscopic Haematuria (AMH)

Isolated asymptomatic microscopic haematuria (AMH) (2+):

• Exclude menstruation and UTI (by dipstick)
• Repeat urinalysis by dipstick on 3 separate occasions
• Persistent AMH (2 out of 3 positive results), with or without proteinuria should prompt investigation for urinary tract malignancy in appropriate age groups (aged over 50 - see urology guideline)
• Persistent invisible haematuria in the under 50's, in the absence of proteinuria should be followed up annually with repeat testing for haematuria, proteinuria or albuminuria, GFR and blood pressure monitoring as long as the haematuria persists.

Assessment of proteinuria with Asymptomatic Microscopic Haematuria (AMH)

Proteinuria (1+) with asymptomatic microscopic haematuria (AMH) (2+):

• Exclude menstruation and UTI (by dipstick)
• If persistent AMH (2 out of 3 positive results) and see referral criteria
• If persistent proteinuria (2 out of 3 positive results), send spot urine for PCR and see referral criteria

Points to note:

• PCR should be measured preferably on an early morning mid-stream urine sample
• PCR is the better (and cheaper) test for monitoring patients with proteinuria as well as detecting proteinuria in non-diabetic patients
• Dividing the PCR by 100 approximates to the amount of protein per day e.g. PCR 100mg/mmol=proteinuria of 1g/24hr
• ACR is the test of choice in patients with diabetes with dipstick negative proteinuria
• For a diagnosis of microalbuminuria 2 abnormal results from 3 specimens are required
• Intercurrent illness such as sore throat, may give positive urine dipstick or high ACR, so these should be repeated 2 weeks after recovery from the illness.

Assessment of isolated proteinuria

Isolated proteinuria (1+):

• Exclude UTI by dipstick
• Repeat urinalysis
• If persistent proteinuria, send spot urine for PCR and see referral criteria

Points to note:

• PCR (or ACR) should be measured preferably on an early morning mid-stream urine sample
• PCR is the better (and cheaper) test for monitoring patients with proteinuria as well as detecting proteinuria in non-diabetic patients
• Dividing the PCR by 100 approximates to the amount of protein per day e.g. PCR 100mg/mmol=proteinuria of 1g/24hr)
• ACR is the test of choice in patients with diabetes with dipstick negative proteinuria
• For a diagnosis of microalbuminuria 2 abnormal results from 3 specimens are required
• Intercurrent illness such as sore throat, may give positive urine dipstick or high ACR, so these should be repeated 2 weeks after recovery from the illness.

eGFR result

eGFR should be measured in anyone being evaluated for CKD even if the urinalysis is negative.

CKD was classified into 5 stages of severity, based on the eGFR and the presence or absence of other markers of kidney damage. There is now a new classification of CKD using GFR and ACR categories from Improving Global Outcomes (KDIGO) CKD Work Group (2013). "G" is used to denote the GFR category (G1-G5, which have the same GFR thresholds as the CKD stages 1-5 recommended previously) and "A" for the ACR category (A1-A3).

Points to note:

• Patients with eGFR more than 60mls/min/1.73 m² without other evidence of kidney damage do not have CKD and should not be subjected to further investigation
• Patients with stable eGFR between 45 - 59mls/min/1.73 m² (CKD3A) and a normal urine dip do not usually need an ultrasound scan unless there is a family history of renal disease (e.g. ADPKD), or a history of reflux nephropathy or a suspected anatomical abnormality
• Patients older than 70 years with Stage 3A CKD (eGFR 45-59mls/min/1.73m²), stable renal function and no other evidence of kidney damage are unlikely to develop CKD-related complications
• Patients with Stage 3B CKD (eGFR 30-44mls/min/1.73m²) are at far higher risk of CV disease and end-stage kidney disease than those with Stage 3A disease and should therefore be regarded as an important target group, particularly if there are risk factors for progression e.g.
  • Hypertension
  • Diabetes
  • significant proteinuria or
  • inherited kidney disease

If eGFR less than 60 ml/min: Manage in primary care:

• Review all previous creatinine/eGFR results to assess rate of deterioration
• Review medication, particularly recent additions e.g. non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, mesalazine, diuretics, ACEIs/ARBs
• Test urine for haematuria and proteinuria. If protein present request urine protein/creatine ratio
• Assess clinically: for urine symptoms, palpable bladder, BP, sepsis, heart failure, hypovolaemia
• Repeat serum creatinine measurement within 5 days to exclude rapid progression, if new finding.

Check referral criteria: ensure entry into a chronic disease management programme is not indicated

Referral Criteria

Who should be referred?

1. All patients with new or previously undiagnosed CKD 4 (eGFR 15-29 ml/min/1.73 m²)
2. All patients with new CKD 5 (eGFR less than -15 ml/min/1.73 m²) – Refer URGENTLY
3. Sustained decrease in GFR of 25% or more, and a change in GFR category or sustained decrease in GFR of 15ml/min /1.73m² or more within 12 months
4. Acute deterioration in kidney function after starting an ACEi or ARB suggesting possible renal artery stenosis. (A fall in eGFR of more than 25% within 2 weeks of starting ACEI/ARB or dose increase)
5. Refractory hypertension (BP not to target on 3 or more agents) and an eGFR less than 45ml/min/1.73 m²
6. Hypertension that remains poorly controlled despite the use of at least 4 BP agents at therapeutic dose
7. Haemoglobin less than 11gd/L and eGFR less than 45 ml/min/1.73 m² (non-renal causes should have been excluded)
8. Known or suspected genetic cause of renal disease e.g. ADPKD
9. Proteinuria (PCR more than 100 mg/mmol or ACR more than 70 mg/mmol) irrespective of eGFR, unless known to be caused by diabetes and already appropriately treated)
10. Proteinuria (PCR more than 50 mg/mmol or ACR more than 30 mg/mmol) with persistent asymptomatic microscopic haematuria (= or greater) irrespective of eGFR
11. Any patient with a K+ more than 7.0mmol/L (Refer URGENTLY to local medical department for urgent assessment)
12. Patients with a K+ more than 6 mmol/L and an eGFR less than 60ml/min/1.73 m²

• Persistent AMH (2 out of 3 positive results), with or without proteinuria should prompt investigation for urinary tract malignancy in appropriate age groups (aged over 50 - see urology guideline)

• Persistent invisible haematuria in the under 50's, in the absence of proteinuria should be followed up annually with repeat testing for haematuria, proteinuria or albuminuria, GFR and blood pressure monitoring as long as the haematuria persists.

Referral Requirements

• Full medical history including relevant renal history
• Current (and recently changed) medications - 4-6 weeks
• Examination including blood pressures (last 3 months) oedema etc.
• Urinalysis results
• A list of the dates and results of previous measurements of serum creatinine / eGFR
• Recent renal function and FBC (if available also: calcium, phosphate, bicarbonate, CRP, albumin, glucose, lipid profile, haemoglobin and haematinics)
• Results of ultrasound scan, if available

Please note pre-referral criteria are applicable in this referral and referrals may be returned if this information is not contained within the referral letter.

Referral Instructions

e-Referral service selection.

• Specialty: Nephrology
• Clinic Type: Nephrology
• Service: DRSS-Eastern-Nephrology-Devon ICB -15N

Referral Form

DRSS Referral Form

Patient Information

MyHealth Patient Information - Chronic Kidney Disease

Evidence

NICE Guidance (CG182) - early identification and management of chronic kidney disease in adults in primary and secondary care

Pathway Group

This pathway was signed off by the NHS Devon.

Publication date: February 2016