Dialysis replaces two of the kidney's five functions: waste removal and fluid balance. It does not replace hormone production (erythropoietin, active Vitamin D) or precise blood pressure regulation. KDIGO 2024 recommends symptom-driven dialysis initiation — not a fixed eGFR threshold. The IDEAL trial proved early-start dialysis (eGFR 10–14) offers no survival advantage over late-start (eGFR 5–7 with symptoms).
A common misconception is that dialysis must start at a specific eGFR. KDIGO 2024 guidelines are explicit: dialysis initiation should be symptom-driven, not eGFR-driven. Symptoms that trigger dialysis evaluation:
| Nutrient | Pre-Dialysis G4–G5 | Haemodialysis | Peritoneal Dialysis |
|---|---|---|---|
| Protein | 0.6–0.8 g/kg/day | 1.1–1.4 g/kg/day ↑ | 1.2–1.5 g/kg/day ↑↑ |
| Sodium | <2,000 mg/day | <2,000 mg/day | <2,000 mg/day |
| Potassium | <2,000 mg/day | <2,000 mg/day (sessions only remove K+ 3x/wk) | ~2,500–3,000 mg/day (continuous removal) |
| Phosphorus | <1,000 mg + restriction | <800 mg + binder with every meal | <800 mg + binder with every meal |
| Fluid | Normal to mild restriction | 500–700 mL + residual urine output per day | Less restrictive — depends on peritoneal removal |
For elderly patients or those with significant comorbidities (advanced cancer, severe heart failure, frailty), conservative kidney management (CKM) — also called supportive care — is a valid and evidence-backed alternative to dialysis. Studies show that frail elderly patients with G5 CKD sometimes have equivalent or better quality of life and survival on optimised conservative care compared to dialysis.
Conservative management includes: maximum medical therapy (diuretics, RAASi, SGLT2i), dietary and symptom management, and hospice-level palliative care when appropriate. KDIGO 2024 mandates that CKM must be discussed with every G5 patient as an equal option alongside dialysis.
When should dialysis be started in CKD?
KDIGO 2024: symptom-driven, not eGFR-driven. Initiate when uraemic symptoms appear — fluid overload, refractory hyperkalemia, acidosis, malnutrition, pericarditis. The IDEAL trial showed no survival benefit from early-start (eGFR 10–14) vs late-start (eGFR 5–7 with symptoms).
What is the difference between haemodialysis and peritoneal dialysis?
HD: machine filters blood 3x/week at a centre (or at home). Requires AV fistula access. PD: peritoneal membrane filters continuously at home via a catheter. Both have similar survival outcomes. PD offers more independence; HD offers professional monitoring.
Does diet change on dialysis?
Yes — protein intake reverses from restriction to increase (1.1–1.4 g/kg/day) because dialysis removes amino acids. Fluid restriction becomes strict on HD (500–700 mL/day + residual urine). Phosphorus restriction with binders at every meal continues. Potassium restriction continues but may be slightly more liberal on PD (continuous removal).
What is an AV fistula and when should it be created?
An AV fistula is a surgically created artery-vein connection in the arm that provides high-flow blood access for HD. It requires 3–6 months to mature. Create when eGFR reaches 15–20 mL/min to have it ready when needed. Protect the arm: no BP measurements, IVs, or blood draws on the fistula arm.