Chronic Kidney Disease

Classification – Green, Yellow, Orange, Red Criteria

Remember: Each column (normal urine ACR, microalbuminuria, macroalbuminuria) has six rows corresponding to different eGFR ranges (first row = eGFR >90).

Below each number corresponds to number of rows it occupies:

• Left (normal urine ACR) column - 2, 1, 1, 2 (green, yellow, orange, red)

• Middle (microalbuminuria) column - 2, 2, 2 (yellow, orange, red)

• Right (macroalbuminuria) column - 1 (red)

CKD Yellow & Orange Categories

Yellow (Moderate Risk CKD)

Criteria:

• eGFR 45-59 (normal ACR)

• eGFR 60-90 (microalbuminuria)

Review & Investigations (Every 12 Months):

• Kidney health check: Urine ACR, eGFR, BP

• Add-on tests: Weight, lipid profile

• HbA1c (if diabetic)

• Assess cardiovascular risk

• Optimise BP, lipid profile, glycaemic control

• Avoid nephrotoxic medications

Orange (High-Risk CKD)

Criteria:

• eGFR 30-44 (normal ACR)

• eGFR 30-59 (microalbuminuria)

Review & Investigations (Every 3-6 Months):

• Yellow category tests +

• Calcium & phosphate

• FBC (for EPO deficiency, anaemia)

• PTH (if eGFR <45)

• Check medication doses appropriate for eGFR

• Monitor for CKD complications

• Note: Red Category CKD requires 1-3 monthly review

Risk Factors & Screening

Risk Factors:

• Age >60

• Hypertension

• Diabetes

• Smoking

• Obesity

• Previous cardiovascular disease

• ATSI >30 (or >18 if CKD risk factors present)

• Family history of kidney disease

How Often to Screen:

• Annual screening (eGFR, BP, urine ACR) if diabetes or hypertension

• 1-2 yearly kidney check for other high-risk individuals

Medications

Medications to Withhold When Unwell (SADMANS)

• Sulfonylureas

• ACE inhibitors

• Diuretics (safe if eGFR <30, but adjust doses)

• Metformin (CI if eGFR <30)

• ARBs

• NSAIDs (except low-dose aspirin)

• SGLT2 inhibitors (CI if eGFR <45)

Initiating ACE/ARB Therapy

• Acceptable eGFR drop <25% within 2 months

• If >25% decline → Nephrology referral

• Caution if K >5.5 before starting (as it will increase ~0.5, risk hyperkalaemia)

• If K >6.5 → Requires urgent ED referral

Best Diabetic Medications for CKD

• SGLT2 Inhibitors (Preferred if eGFR >45 for renal & CV protection)

• DPP-4 Inhibitors (Preferred if eGFR <30, as they require minimal dose adjustment)

Symptoms, Diagnosis, and Investigations

Symptoms:

• Anaemia (Fatigue, dyspnoea from EPO deficiency)

• Uraemia (Pruritus, encephalopathy, nausea, restless legs, anorexia)

• Hypoalbuminaemia (Peripheral oedema)

Diagnosis:

• eGFR <60 on at least 3 readings over >3 months

• Urine ACR >2.5 (men) or >3.5 (women) on at least 2 out of 3 tests over 3 months

• Persistent haematuria (after excluding urological causes)

• Structural kidney abnormalities (e.g., single kidney, PCKD, hydronephrosis)

• Pathological abnormalities (nephritic or nephrotic features)

Investigations:

• FBC, UEC

• ESR/CRP (if considering inflammatory cause)

• Lipid profile, glucose (diabetes assessment)

• Urine microscopy (Look for dysmorphic RBCs or casts)

• Renal ultrasound

Consider Further Testing If:

• Rash, arthralgia, pulmonary symptoms (SLE, vasculitis): Anti-GBM, ANCA, ANA, ENA, complement

• Risk factors for infection: HIV, Hep B/C serology

• >40 years old with possible myeloma: Serum and urine protein electrophoresis

Management

Lifestyle Modifications:

• Smoking cessation

• Alcohol <2 standard drinks/day (max 4 per occasion)

• Avoid nephrotoxic medications (even if not on NSAIDs)

• Monitor BP (target <140/90, or <130/80 if diabetes/microalbuminuria/high CVD risk)

• Reduce salt intake <6g/day

• 150 min of moderate-intensity exercise per week

• Maintain BMI <25

• Drink fluids to satisfy thirst (no need to increase fluid intake)

Pharmacological Management:

• ACE/ARB:

  • BP targets:

    • <140/90 (standard CKD)

    • <130/80 (diabetes, microalbuminuria, high CVD risk)

  • Essential for all except eGFR 45-60 and normotensive patients

• Statins:

  • All CKD patients >50 years

  • If <50 years, only if high CVD risk or diabetic

  • Use atorvastatin or pravastatin (no dose adjustment needed)

• Diabetes control:

  • Metformin 500 mg (if eGFR >30, dose-adjust below 60)

Additional Notes:

• Request "RBC morphology" on pathology form when assessing haematuria

• No need for routine urine MCS in CKD unless infection suspected

Causes of False eGFR & Urine ACR Readings

eGFR False Readings (Creatinine-Based Formula)

• Extremes of body mass (underweight = overestimation, very muscular = underestimation)

• Strict vegetarian or high-protein diet (affects creatinine production)

• AKI, dialysis, immobilisation, pregnancy

Urine ACR False Readings

• UTI, febrile illness

• Heavy exercise (if done within 24 hours before testing)

• High protein intake

• Congestive heart failure (CCF)

Notes:

• eGFR drop >25% after starting ACEI/ARB → Nephrology referral

• Urine ACR >2.5-3.5 is abnormal, even if eGFR >60

• Screen annually in diabetes, hypertension, or ATSI >30 years old

• CKD is an independent risk factor for cardiovascular disease

• SGLT2 inhibitors are first-line in CKD with diabetes, provided eGFR >45

• NSAIDs are a major cause of AKI in CKD – avoid chronic use

• Severe hyperkalaemia (>6.5) requires urgent ED review