Chronic Kidney Disease — SAQ

Stem A (outpatient CKD staging and disease-modifying therapy)

A 58-year-old man with type 2 diabetes (12 years) and hypertension is reviewed. Creatinine 168 µmol/L (eGFR 38 mL/min/1.73 m² by CKD-EPI), stable over 8 months. Urine ACR 420 mg/g. BP 148/88 on amlodipine 10 mg OD. HbA1c 7.8%. K⁺ 4.6 mmol/L. No oedema. Hb 112 g/L, ferritin 95 µg/L, transferrin saturation 22%. Bicarbonate 22 mmol/L, phosphate 1.5 mmol/L, PTH 11 pmol/L (mildly raised).^[1][2]

Stem B (complication — for part d)

Separately, a patient with eGFR 12 mL/min/1.73 m² presents with K⁺ 7.1 mmol/L, peaked T waves, and mild weakness.^[1][2]

Questions

a) Stem A — define CKD and give the KDIGO stage (G and A categories). (3 marks)^[1][2]

CKD = abnormalities of kidney structure or function present for >3 months with health implications (KDIGO). Markers include eGFR <60 or markers of damage (albuminuria UACR ≥30 mg/g, urine sediment, imaging, histology, transplant history).^[1][2]

This patient: G3b (eGFR 30–44) A3 (UACR >300 mg/g — severely increased). Heat-map risk is very high.^[1][2]

b) List disease-modifying drug therapy with agent, dose, and trial evidence relevant to this diabetic CKD patient. (5 marks)^[1][2]

1. ACEI or ARB to maximally tolerated dose for albuminuric CKD — e.g. ramipril titrate toward 10 mg OD or losartan 50–100 mg OD. Expect creatinine rise; stop if hyperkalaemia severe or creatinine rises >30%. Never combine ACEI+ARB.^[3]
2. SGLT2 inhibitor independent of glycaemic need if eGFR allows label: dapagliflozin 10 mg OD (DAPA-CKD) or empagliflozin 10 mg OD (EMPA-KIDNEY) — reduce CKD progression and HF hospitalisation.^[1][2]
3. If residual albuminuria on ACEI/ARB and T2DM: consider finerenone (non-steroidal MRA) per FIDELIO/FIGARO pathway if K⁺ controlled (start when K⁺ allows; monitor closely).^[1][2]
4. Statin for CV risk (e.g. atorvastatin 20 mg OD — SHARP used simvastatin+ezetimibe in advanced CKD).^[1][2]
5. Optimise glycaemia (prefer agents with CV/renal benefit); BP target typically <130/80 if tolerated.^[1][2]
6. Lifestyle: salt restriction, smoking cessation, avoid NSAIDs, dose-adjust renally cleared drugs.^[1][2]

c) Outline monitoring and management of anaemia and mineral-bone disorder at this stage. (3 marks)^[1][2]

Anaemia of CKD: investigate iron first. Absolute iron deficiency if ferritin <100 and TSAT <20% (thresholds vary by dialysis status). Correct iron (oral or IV) before escalating ESA. ESA target Hb usually 100–120 g/L — avoid Hb >130 (TREAT/CHOIR risk of stroke/CV events with normalisation).^[3]

CKD-MBD: check Ca, PO₄, PTH, 25-OH vitamin D. Dietary phosphate advice; phosphate binders if hyperphosphataemia; vitamin D analogues/calcimimetics later; avoid oversuppression of PTH.^[1][2]

d) Stem B — immediate management of severe hyperkalaemia with ECG changes (drug, dose, route, sequence). (4 marks)^[3]

Protect heart → shift K⁺ → remove K⁺:

1. Calcium gluconate 10 mL of 10% IV over 5–10 min (membrane stabilisation; repeat if ECG persists).^[3]
2. Insulin–glucose: soluble insulin 10 units IV in 25–50 g glucose (e.g. 50 mL 50% or 125 mL 20%); monitor glucose.^[3]
3. Salbutamol 10–20 mg nebulised as adjunct shift.
4. Consider sodium bicarbonate only if severe metabolic acidosis and volume allows.^[1][2]
5. Remove K⁺: potassium binders (e.g. sodium zirconium cyclosilicate / patiromer where available) and urgent dialysis if anuric/oliguric advanced CKD, refractory hyperkalaemia, or fluid overload. Stop ACEI/ARB/spironolactone temporarily.^[3]

Additional teaching points

When to refer nephrology: eGFR <30, rapid decline, ACR >70 mg/mmol (~700 mg/g) or nephrotic, resistant HTN, active urine sediment, uncertain diagnosis, preparation for RRT.^[1][2]

Indications for dialysis (AEIOU): Acidosis refractory, Electrolytes (refractory hyperK), Intoxications, Overload (pulmonary oedema), Uraemic symptoms (pericarditis, encephalopathy).^[1][2]

Pregnancy: pregnancy may be high risk if baseline creatinine elevated; ACEI/ARB contraindicated; pre-pregnancy counselling essential.^[1][2]

References3ShowHide

1. [1]Levin A, Ahmed SB, Carrero JJ, et al. Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknowns Kidney Int, 2024.PMID 38519239
2. [2]Perkovic V, Jardine MJ, Neal B, et al. Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy N Engl J Med, 2019.PMID 30990260
3. [3]Heerspink HJL, Stefánsson BV, Correa-Rotter R, et al. Dapagliflozin in Patients with Chronic Kidney Disease N Engl J Med, 2020.PMID 32970396