Chronic kidney disease management accounts for approximately 14 per cent of the SCE Nephrology exam. KDIGO (Kidney Disease: Improving Global Outcomes) guidelines are the primary international reference, supplemented by UK Kidney Association (UKKA) clinical practice guidelines for UK-specific management. This page covers the high-yield content.
Classification
CKD is classified by GFR category and albuminuria category using the KDIGO heat map. GFR categories run from G1 (normal, GFR 90 or above) through G5 (kidney failure, GFR below 15). Albuminuria categories are A1 (normal to mildly increased, ACR below 3 mg/mmol), A2 (moderately increased, ACR 3 to 30 mg/mmol), and A3 (severely increased, ACR above 30 mg/mmol).
The combination of GFR and albuminuria categories determines the risk stratum — green (low risk), yellow (moderately increased), orange (high), and red (very high). The risk stratum drives monitoring frequency and referral decisions.
The exam tests your ability to classify a patient using both GFR and albuminuria — not GFR alone. A patient with GFR 55 (G3a) and ACR 35 (A3) is at higher risk than a patient with GFR 35 (G3b) and ACR 2 (A1), despite having a better GFR. Questions that present both values and ask about management or referral are testing whether you use the full classification.
Referral to nephrology
KDIGO and UKKA recommend referral to specialist nephrology services for patients with GFR below 30 (G4-G5), persistent significant albuminuria (ACR 70 mg/mmol or above, or ACR 30 to 70 with haematuria), a sustained decrease in GFR of 25 per cent or more within 12 months or a sustained decrease of 15 mL/min/1.73m² or more within 12 months, uncontrolled hypertension despite four or more antihypertensive agents, suspected renal artery stenosis, and suspected genetic kidney disease.
The referral criteria are frequently tested. Know the specific GFR threshold (below 30) and the albuminuria threshold (ACR 70 or above) — these are precise and the exam expects precise answers.
Pharmacotherapy — the SGLT2 inhibitor revolution
The 2024 KDIGO guideline update positions SGLT2 inhibitors (dapagliflozin, empagliflozin) as a foundational therapy for CKD alongside RAS blockade. SGLT2 inhibitors are recommended for patients with CKD and eGFR 20 to 45 (regardless of diabetes status) or eGFR 45 to 90 with uACR 20 mg/mmol or above.
The evidence base comes from DAPA-CKD, EMPA-KIDNEY, and CREDENCE trials, which demonstrated reduced risk of kidney disease progression, cardiovascular events, and hospitalisation for heart failure across diabetic and non-diabetic CKD populations.
The exam tests SGLT2 inhibitor eligibility — which patients qualify, at what eGFR they can be started (down to 20), and that they should be continued even if eGFR falls below 20 after initiation (do not stop for declining GFR once started). The initial eGFR dip of 10 to 15 per cent seen in the first few weeks is expected and should not prompt discontinuation — this is a haemodynamic effect of reduced intraglomerular pressure and is analogous to the initial creatinine rise seen with ACE inhibitor initiation.
RAS blockade (ACE inhibitor or ARB) remains the first-line pharmacotherapy for CKD with albuminuria. ACR 3 mg/mmol or above is the threshold for starting RAS blockade in CKD. Titrate to maximum tolerated dose. Do not combine ACE inhibitor with ARB — dual RAS blockade increases the risk of hyperkalaemia and AKI without additional benefit.
Anaemia management
Renal anaemia is managed with iron replacement (targeting transferrin saturation above 20 per cent and ferritin above 100 in non-dialysis CKD, higher targets in dialysis patients) and erythropoiesis-stimulating agents (ESAs — epoetin, darbepoetin). The target haemoglobin is 100 to 120 g/L — overshooting above 130 g/L increases cardiovascular risk (CREATE and TREAT trials).
HIF-PHI (hypoxia-inducible factor prolyl hydroxylase inhibitors) such as roxadustat represent a newer oral alternative to injectable ESAs. NICE has appraised several HIF-PHIs for CKD anaemia. The mechanism — stabilising HIF to increase endogenous erythropoietin production and improve iron utilisation — is testable at SCE level.
Iron replacement before ESA initiation is important — ESAs are less effective in iron-deficient patients. The exam may present a patient with renal anaemia and ask for the first step — the correct answer is iron studies and iron replacement if deficient, not immediate ESA initiation.
CKD-mineral bone disease
CKD-MBD is managed by controlling phosphate (dietary restriction plus phosphate binders — calcium-based or non-calcium-based such as sevelamer or lanthanum), treating vitamin D deficiency (cholecalciferol for deficiency, alfacalcidol or calcitriol for CKD G4-G5 with secondary hyperparathyroidism), and monitoring PTH.
The target PTH range for dialysis patients is 2 to 9 times the upper limit of normal — not normalisation. Over-suppression of PTH increases the risk of adynamic bone disease.
Cinacalcet (calcimimetic) is used for secondary hyperparathyroidism in dialysis patients who do not respond to standard measures. Parathyroidectomy is reserved for severe refractory hyperparathyroidism.
Dialysis and transplant planning
KDIGO recommends that dialysis planning (including vascular access creation or peritoneal dialysis catheter insertion) should begin when eGFR falls below 15 to 20, or earlier if the rate of decline suggests imminent need. The decision to start dialysis is based on symptoms, not a fixed GFR threshold — there is no evidence that starting dialysis at a higher GFR improves outcomes (IDEAL trial).
Pre-emptive transplantation (transplant before starting dialysis) is the preferred modality for eligible patients. Transplant assessment should begin when eGFR falls below 20.
iatroX's SCE Nephrology bank includes comprehensive CKD content aligned to KDIGO and UKKA guidelines — classification, referral criteria, SGLT2 inhibitor eligibility, anaemia management, CKD-MBD, and dialysis planning. All included at £29 per month or £99 per year.