Chronic Kidney Disease

• CKD is defined as abnormalities of kidney structure or function present for >3 months with implications for health.
• 3% of the Scottish population were classified as having chronic kidney disease grades 3-5 in 2016 (Grading defined below) which carries with it an increased incidence of vascular disease and a risk of progression to end-stage kidney disease (ESKD).
• For most patients the risk of vascular disease outweighs the risk of renal progression (<2% of all cases of CKD will progress to ESKD), though the latter is increased with proteinuria and uncontrolled hypertension.

Arrange investigations for patients with:

• Raised creatinine and/or eGFR < 60
• Proteinuria (ACR > 3)
• Persistent haematuria (follow visible or non-visible haematuria pathways)
• Urine sediment abnormalities (RBC - may indicate glomerular disease, WBC - may indicate pyelonephritis/interstitial nephritis, casts/epithelial cells - may indicate renal parenchymal disease)

Initial investigations

• Check blood pressure
• Review recent medications (e.g. Trimethoprim)
• Exclude urinary retention
• Identify cardiovascular risk factors
• Arrange:
  • Repeat eGFR within 2 weeks
  • ACR if not already done
  • FBC
  • HbA1c
  • Fasting Lipids
  • Urinalysis
• Arrange renal USS where:
  • there is a family history of polycystic kidneys and patient is age >20
  • eGFR < 30ml/min/1.73m²
  • eGFR has dropped by 15ml/min/1.73m² or more or 25% over the past year
  • there is visible or persistent non-visible haematuria
  • there are symptoms of urinary obstruction

If repeat eGFR < 60, repeat again within 3 months

If ACR between 3 and 70 repeat within 3 months (ACR > 70 indicates significant proteinuria and repeat is not needed to confirm)

Note transient rise in ACR is seen with menstruation, UTI, strenuous exercise.

If eGFR < 30 arrange blood for calcium, phosphate, vitamin D and parathyroid hormone, (and ferritin and iron studies if anaemia) at time of referral.

Management of CKD is essentially the management of cardiovascular risk and should be holistic, taking into account other risk factors and patient factors (following the House of Care model).

• All patients over 50 with confirmed CKD should be treated as high risk for cardiovascular disease (CV risk calculation is not required)
• Patients under 50 or post transplant should have CV risk assessment (QRisk takes CKD into account)
• Offer statin (atorvastatin 20mg), taking into account patient's preferences, polypharmacy, general frailty and life expectancy. Titrate dose aiming for 40% reduction cholesterol but caution with higher doses if eGFR < 30.
• Offer lifestyle advice, in particular smoking and limiting salt intake to less than 6g per day
• Manage co-existing hypertension but consider ACR in treatment choices:
  • ACR < 30 - manage as normal
  • ACR 30-70 - Use ACEI or ARB if possible aiming for BP < 140/90
  • ACR > 70 - Prescribe maximum tolerated dose of ACEI or ARB regardless of blood pressure. If hypertensive aim for BP < 130/80
• Patients with co-existing diabetes should be on Dapagliflozin and, if ACR > 3mg/mmol, ACEI or ARB at maximum tolerated dose.
• Consider adding dapagliflozin 10mg OD to non-diabetic patients with CKD as an add-on to ACEI or ARB where the patient has ACR > 22. Note contra-indicated in polycystic kidney disease, ANCA vasculitis and lupus nephritis)
• The use of the Kidney Failure Risk Equation can be useful in quantifying risk of renal replacement with patients
• Arrange regular follow-up

Immediate referral (admission or discussion with on-call physician)

• Malignant hypertension
• Hyperkalaemia (Potassium 6.5 mmol/l or greater)
• New eGFR < 15 (unless further investigation and management clearly inappropriate)

Urgent referral

• CKD 4 unless known to be stable in which case routine referral appropriate
• Nephrotic syndrome - ACR > 250mg/mmol, Albumin < 25g/l and oedema
• Acute glomerulonephritis/vasculitis suspected - multisystem symptoms with blood and protein in urine and acute renal impairment

Routine referral

• Stable CKD 4
• ACR > 70 regardless of eGFR
• Polycystic kidney disease
• CKD 3 where:
  • there is a progressive fall in eGFR (sustained drop of 15 within 12 months)
  • uncontrolled BP on three drugs
  • unexplained anaemia < 110g/l /abnormal potassium, calcium or phosphate
  • suspected systemic illness - (e.g. SLE)
  • A 5 year risk of > 5% of requiring renal replacement using Kidney Failure Risk Equation
  • suspected renal artery stenosis - should be suspected if  >25% reduction eGFR within 3 months of starting or increasing ACEI/ARB
  • there is haematuria but urology urgent suspicion of cancer referral may be more appropriate. See visible and non-visible haematuria pathways

Note renal mass/cysts identified on USS should be referred to Urology not Renal.