Chronic Kidney Disease (CKD)

Clinical assessment

Suspect in patients with risk factors, especially those with long-standing diabetes or hypertension. Often detected via screening (urine dipstick, serum creatinine). Assess for symptoms/signs of uraemia and complications. Differentiate from AKI (duration >3 months needed for CKD diagnosis).

Investigations

• Serum Creatinine: Calculate estimated Glomerular Filtration Rate (eGFR) using formulas (e.g., CKD-EPI, MDRD). GFR determines CKD stage (Stage 1: ≥90 + kidney damage; Stage 2: 60-89 + damage; Stage 3a: 45-59; Stage 3b: 30-44; Stage 4: 15-29; Stage 5: <15 or dialysis).
• Urinalysis: Dipstick for protein, blood. Microscopy for cells, casts.
• Urine Albumin-to-Creatinine Ratio (ACR) or Protein-to-Creatinine Ratio (PCR): Quantify proteinuria/albuminuria (key marker of kidney damage and progression risk).
• Kidney Ultrasound: Assess kidney size (typically small/echogenic in CKD, except in PCKD/diabetic nephropathy), rule out obstruction, assess structure.
• Blood tests: Urea, Electrolytes (check K+, bicarbonate - acidosis), Calcium, Phosphate, Parathyroid Hormone (PTH) (assess bone mineral disease), CBC (anaemia), HbA1c (diabetes control), Lipid profile.
• Investigations for underlying cause: e.g., Viral serology (HBV, HCV, HIV), Autoimmune screen, Protein electrophoresis.

Diagnostic criteria

Presence of kidney damage (e.g., albuminuria ≥30mg/day or ACR ≥3mg/mmol) OR GFR <60 ml/min/1.73m² for ≥3 months.

Non-pharmacological management

• Slowing Progression & Managing Co-morbidities:
• - Blood Pressure Control: Crucial. Target typically <130/80 mmHg (or per specific guidelines). ACE inhibitors or ARBs are first-line, especially if proteinuria/diabetes.
• - Glycaemic Control (Diabetes): Target HbA1c <7% (or individualized target).
• - Lifestyle Modifications: Weight loss, smoking cessation, regular exercise, low salt diet (<2g/day).
• - Dietary Protein Restriction: Moderate restriction may be beneficial in later stages (specialist guidance).
• - Avoid Nephrotoxins: NSAIDs, aminoglycosides, IV contrast (use cautiously).
• Management of Complications:
• - Anaemia: Iron supplements (oral/IV), Erythropoiesis-Stimulating Agents (ESAs - e.g., Epoetin alfa, Darbepoetin alfa) if Hb <10-11 g/dL (Target Hb 10-12 g/dL). Requires specialist initiation/monitoring.
• - Mineral and Bone Disorder (CKD-MBD): Phosphate binders (e.g., Calcium carbonate/acetate), Vitamin D analogues (e.g., Calcitriol, Alfacalcidol), Calcimimetics (specialist). Control phosphate, calcium, PTH levels.
• - Fluid Overload: Sodium/fluid restriction, Loop diuretics (Furosemide - often requires high doses).
• - Metabolic Acidosis: Oral sodium bicarbonate.
• - Hyperkalaemia: Dietary potassium restriction, review medications, potentially potassium binders.
• Renal Replacement Therapy (RRT) Planning (Stage 4/5):
• - Education about options: Haemodialysis, Peritoneal dialysis, Kidney transplantation.
• - Vascular access creation (AV fistula/graft) well in advance of needing haemodialysis.
• - Referral for transplant evaluation.

Pharmacological treatment

• Antihypertensives: ACE inhibitors (e.g., Enalapril, Lisinopril) or ARBs (e.g., Losartan, Valsartan) preferred, especially with proteinuria/diabetes. Add other agents (CCBs, diuretics, beta-blockers) as needed to reach target BP. Adjust doses for GFR.
• Diuretics: Loop diuretics (Furosemide) for fluid overload (Thiazides generally ineffective if GFR <30).
• Medications for Complications: Iron, ESAs, Phosphate binders, Vitamin D analogues, Sodium bicarbonate (as above).
• Dosage Adjustment: Many drugs require dose adjustment based on eGFR. Consult drug information resources.

Monitoring

Regular monitoring (e.g., 3-12 monthly depending on stage/stability) of: GFR/Creatinine, Electrolytes (esp. K+), Bicarbonate, Calcium, Phosphate, PTH, Hb, BP control, Albuminuria/Proteinuria, Volume status, Nutritional status.