chronic kidney disease

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staging

GFR categories

albuminuria categories

KDIGO risk heat map

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renoprotective strategies

RAS blockade

ACEi or ARB — first-line for CKD with albuminuria (A2–A3). Titrate to maximum tolerated dose. Accept up to 30% rise in creatinine after initiation; beyond that, investigate renal artery stenosis.

• Hold in AKI, volume depletion, hyperkalaemia >5.5 mmol/L
• Do not combine ACEi + ARB (ONTARGET — no benefit, more hyperkalaemia and AKI)

SGLT2 inhibitors

Add regardless of diabetes status if eGFR ≥20 mL/min/1.73 m² and ACR ≥20 mg/mmol (or eGFR 20–45 even without significant albuminuria per EMPA-KIDNEY).

• DAPA-CKD (2020) — dapagliflozin reduced sustained ≥50% eGFR decline, ESKD, or renal/CV death by 39% vs placebo; benefit in diabetic and non-diabetic CKD
• EMPA-KIDNEY (2023) — empagliflozin reduced progression or CV death by 28%; included patients with eGFR 20–45 without significant albuminuria
• CREDENCE (2019) — canagliflozin in diabetic nephropathy; 30% reduction in primary renal composite

Expect an initial eGFR dip of 3–5 mL/min (haemodynamic, not injury) — do not stop for this. Withhold perioperatively and in acute illness (sick-day rules).

finerenone (non-steroidal MRA)

Add in type 2 diabetes with CKD (eGFR ≥25, K⁺ ≤5.0 mmol/L, ACR ≥3 mg/mmol) already on maximised RAS blockade. Note: trial entry criterion was K⁺ ≤4.8 mmol/L.

• FIDELIO-DKD (2020) — 18% reduction in kidney composite endpoint
• Monitor K⁺ at 1 month and regularly; hold if K⁺ >5.5 mmol/L; restart at 10 mg once K⁺ ≤5.0

BP targets

<120 mmHg systolic (KDIGO 2024, standardised office measurement). CSN recommends a less aggressive target of <140/90 mmHg — reasonable in older or frail patients. Tolerate higher targets if symptomatic hypotension or eGFR declining with lower BP.

other measures

• Statin (or statin/ezetimibe) if age ≥50 with eGFR <60 (KDIGO). Age <50 with CKD: statin if other CV risk factors. Not initiated in dialysis-dependent patients (SHARP, AURORA, 4D)
• Sodium restriction <2 g/d (≈5 g NaCl) — potentiates RAS blockade
• Protein: avoid high-protein diets; 0.8 g/kg/d in G4–G5 (controversial, modest benefit)
• Glycaemic control in diabetes — HbA1c ≤53 mmol/mol (≤7%); individualise in advanced CKD (hypoglycaemia risk rises as renal insulin clearance falls)
• Avoid nephrotoxins: NSAIDs, aminoglycosides, iodinated contrast without hydration

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outpatient assessment framework

history — nephrology-specific

• Creatinine and ACR trend — start with a one-line trajectory summary
• Duration and control of diabetes (HbA1c, microvascular complications) and hypertension (home readings)
• NSAID use — ask by brand name; PPI use (AIN risk)
• Lower urinary tract symptoms, UTI history
• Vasculitic screen: joint pain, rashes, oral ulcers, haematuria
• Volume status: dyspnoea, orthopnoea, PND, peripheral oedema
• Previous AKI episodes and circumstances

examination

• BP both arms (sitting) + standing — retake elevated readings after settling
• Volume status: JVP, lung crackles, peripheral oedema; weight trend

investigations

• Trend creatinine and ACR; urinalysis (blood, protein); HbA1c in diabetes
• Renal US if not done — size, echogenicity, obstruction
• Consider: calcium, phosphate, PTH, vitamin D (G3b+); haemoglobin and iron studies (G3a+)

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nephrology referral indications

• eGFR <30 (G4–G5) or declining rapidly (>5 mL/min/yr sustained, or ≥25% decline from baseline)
• Kidney Failure Risk Equation (KFRE) 5-year risk ≥3–5% (KDIGO 2024) — developed in Canada (Tangri et al.); uses age, sex, eGFR, and ACR. Available at kidneyfailurerisk.com
• ACR >60 mg/mmol (A3) or nephrotic-range proteinuria
• Persistent haematuria with proteinuria (glomerular disease likely)
• Refractory hypertension despite ≥3 agents
• Refractory hyperkalaemia or metabolic acidosis
• AKI-on-CKD or unexplained anaemia requiring ESA consideration
• Suspected systemic disease affecting kidneys (vasculitis, myeloma, amyloid)

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CKD complications

anaemia

Screen haemoglobin from G3a onward. Target Hb 100–115 g/L — do not exceed 115 (↑ stroke and thromboembolism risk).

• Iron first: trial of IV or oral iron when TSAT ≤20% and ferritin ≤500 µg/L (KDIGO). Do not routinely give iron if ferritin >500. IV iron preferred in haemodialysis; oral or IV in non-dialysis CKD. Non-dialysis CKD thresholds for deficiency: ferritin <100 µg/L or TSAT <20%
• ESA (epoetin, darbepoetin): consider if Hb 90–100 g/L and iron replete. Titrate to avoid Hb >115
• ESA hyporesponsiveness → reassess iron stores, occult blood loss, infection, hyperparathyroidism, malignancy

CKD–mineral bone disease

Check calcium, phosphate, PTH, 25-OH vitamin D from G3b onward. Replete 25-OH vitamin D if deficient. Key principles:

• Hyperphosphataemia — dietary restriction first (processed foods, dairy, cola); phosphate binders with meals if persistent (calcium carbonate first-line; sevelamer/lanthanum if vascular calcification or hypercalcaemia)
• Secondary hyperparathyroidism — calcitriol/alfacalcidol only once phosphate controlled (risk of metastatic calcification); cinacalcet if refractory; parathyroidectomy rarely needed
• PTH target in dialysis: 2–9× upper limit of normal (KDIGO) — most titration is nephrologist-managed

metabolic acidosis

Oral NaHCO₃ (sodium bicarbonate) 500–1000 mg TDS once serum HCO₃⁻ <22 mmol/L (KDIGO 2024 target: maintain ≥22). Slows CKD progression and mitigates muscle wasting. Monitor volume and sodium load.

sick-day rules — SADMANS

Hold during acute dehydrating illness (vomiting, diarrhoea, febrile illness):

• Sulfonylureas
• ACEi
• Diuretics
• Metformin (some versions add MRAs — non-standard but clinically reasonable)
• ARBs
• NSAIDs
• SGLT2 inhibitors

urgent dialysis indications

AEIOU: refractory Acidosis, Electrolytes (hyperkalaemia), Ingestions (toxic alcohols, lithium, salicylates), fluid Overload, Uraemia (pericarditis, encephalopathy, bleeding) — see dialysis overview.

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traps

• Stopping ACEi/ARB for a modest creatinine rise — up to 30% increase is expected and acceptable. Stopping prematurely removes long-term renoprotection.
• Ignoring albuminuria when eGFR is normal — A3 albuminuria with G1 eGFR is still high-risk CKD. ACR drives prognosis independently of GFR.
• Attributing all CKD to diabetes/hypertension without confirmation — atypical features (active sediment, rapid decline, no retinopathy in a diabetic with advanced nephropathy) warrant biopsy consideration.
• NSAIDs in CKD — patients self-medicate without mentioning it. Ask by brand name every visit.

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related: acute kidney injury · nephrotic syndrome · hyponatraemia · hyperkalaemia · acid-base disorders · dialysis overview