Chronic Kidney Disease (CKD)

Related Subjects: |Metabolic acidosis |Lactic acidosis |Acute Kidney Injury (AKI) / Acute Renal Failure |Renal/Kidney Physiology |Chronic Kidney Disease (CKD) |Anaemia in Chronic Kidney Disease |Analgesic Nephropathy |Medullary Sponge kidney |IgA Nephropathy (Berger's disease) |HIV associated nephropathy (HIVAN) |Balkan endemic nephropathy (BEN) |Autosomal Dominant Polycystic kidney disease

📖 About (NICE-aligned)

• Chronic Kidney Disease (CKD): abnormalities of kidney structure or function present for ≥3 months with implications for health.
• CKD includes: eGFR <60 mL/min/1.73m² on ≥2 occasions ≥90 days apart (with or without markers), or markers of kidney damage (e.g. albuminuria, haematuria of renal origin, structural disease) even if eGFR is ≥60.
• Why it matters: increasing ACR and falling eGFR predict higher risk of CKD progression, AKI, and cardiovascular events.

📊 CKD Classification (use GFR + ACR)

• GFR categories (G):
  • G1: ≥90 (CKD only if markers present)
  • G2: 60–89 (CKD only if markers present)
  • G3a: 45–59
  • G3b: 30–44
  • G4: 15–29
  • G5: <15 (kidney failure)
• Albuminuria categories (A, by urine ACR):
  • A1: <3 mg/mmol
  • A2: 3–30 mg/mmol
  • A3: >30 mg/mmol

🔖 Practical suffixes

• T = transplant recipient (e.g. CKD G3bA2T)
• D = dialysis (e.g. CKD G5D)
• Tip: NICE uses A1–A3 (ACR categories) rather than a “P” suffix; record the A category and the ACR value.

🧬 Aetiology (common)

• Diabetes mellitus
• Hypertension/vascular disease
• Glomerulonephritis.
• Polycystic kidney disease
• Reflux/tubulointerstitial disease
• Obstructive uropathy.
• Systemic disease (e.g. lupus, vasculitis)
• Medicines (e.g. NSAIDs, lithium)
• Myeloma (when suggested by phenotype).

🧠 Pathophysiology hook: falling eGFR reflects nephron loss; rising ACR reflects glomerular/endothelial injury. Albuminuria is a powerful “vascular damage” marker, so NICE stratifies BP targets and referral thresholds by ACR as well as GFR.

🧪 Diagnosis (NICE)

• Confirm chronicity: in a new reduced eGFR, repeat within 2 weeks to exclude AKI/acute deterioration; define progression using multiple readings over ≥90 days.
• Urine ACR: use ACR (more sensitive than PCR). If initial ACR 3–70, confirm on a repeat early-morning sample; no repeat needed if ACR ≥70.
• Urinalysis: haematuria/protein; consider renal-origin haematuria implications.
• Bloods: U&E/eGFR, potassium, bicarbonate, FBC, HbA1c (if diabetes), lipids; calcium/phosphate/PTH if advanced CKD or symptoms.
• Renal ultrasound if accelerated progression, persistent haematuria, obstruction symptoms, FHx ADPKD >20y, or eGFR <30 (G4–G5).

📉 Monitoring frequency (minimum eGFR checks per year – NICE Table 2)

• G1–G2: A1 = 0–1; A2 = 1; A3 = 1+
• G3a: A1 = 1; A2 = 1; A3 = 2
• G3b: A1 = 1–2; A2 = 2; A3 = 2+
• G4: A1 = 2; A2 = 2; A3 = 3
• G5: A1 = 4; A2 = 4+; A3 = 4+
• ACR monitoring: individualise based on risk and whether a change would alter management.

🎯 Blood pressure targets (NICE NG203)

• ACR <70 mg/mmol: aim clinic BP <140/90 (systolic target range 120–139).
• ACR ≥70 mg/mmol: aim clinic BP <130/80 (systolic target range 120–129).
• Frailty/multimorbidity: individualise (see NICE hypertension guidance).

💊 Proteinuria-lowering / kidney-protective therapy (NICE)

• Diabetes + ACR ≥3: offer ACEi or ARB titrated to the highest licensed tolerated dose.
• Hypertension + ACR >30 (A3): offer ACEi or ARB titrated to highest tolerated dose.
• No diabetes + ACR ≥70: refer and offer ACEi or ARB.
• RAAS safety: check eGFR and potassium before starting; repeat 1–2 weeks after starting and after each dose increase; avoid routine start if baseline K⁺ >5.0 mmol/L.

💔 CV risk reduction

• Statin: offer atorvastatin 20 mg as preferred initial high-intensity statin for people with CKD (unless contraindicated/not appropriate).
• Smoking cessation, exercise, weight and dietary salt reduction are core interventions.
• Antiplatelet therapy is for secondary prevention when indicated, balancing bleeding risk.

🩸 Anaemia of CKD (NICE)

• Investigate/manage if Hb ≤110 g/L (or symptomatic).
• Diagnostic clue: if eGFR >60, anaemia is unlikely due to CKD; if eGFR <30, CKD is often contributory but still consider other causes.
• ESA targets: do not correct to normal; typically maintain Hb 100–120 g/L in adults; avoid Hb >120 g/L (CV risk).

🦴 CKD-MBD / phosphate

• Monitor calcium/phosphate/PTH as CKD advances; manage persistent hyperphosphataemia (often in CKD 4–5) with diet and binders per local renal pathways.

🧯 Metabolic acidosis (NICE)

• Consider oral sodium bicarbonate if eGFR <30 (G4–G5) and serum bicarbonate <20 mmol/L.

🚑 When to refer (NICE NG203)

• KFRE: 5-year risk of needing RRT >5% (4-variable KFRE).
• ACR ≥70 mg/mmol (unless due to diabetes and already appropriately treated).
• ACR >30 with haematuria.
• Progression: sustained eGFR drop ≥25% with category change in 12 months, or ≥15 mL/min/1.73m² per year.
• Resistant hypertension despite ≥4 agents, suspected genetic/rare CKD, suspected renal artery stenosis.

📚 References

• NICE NG203: Chronic kidney disease: assessment and management (Published 25 Aug 2021; last updated 24 Nov 2021)
• NICE NG203 Recommendations (BP targets, ACR confirmation, referral criteria, RAAS monitoring, anaemia, bicarbonate)
• NICE CKS: Chronic kidney disease
• NICE QS5: Statins for people with CKD (atorvastatin 20 mg)