Indications for Renal Replacement Therapy According to KDIGO
KDIGO recommends initiating dialysis when one or more of the following are present: symptoms or signs attributable to kidney failure (serositis, acid-base or electrolyte abnormalities, pruritus); inability to control volume status or blood pressure; progressive deterioration in nutritional status refractory to dietary intervention; or cognitive impairment, which typically occurs in the GFR range between 5 and 10 ml/min per 1.73 m². 1
Clinical Context and Disease Duration
The indications differ based on whether the kidney failure is acute or chronic:
For Chronic Kidney Disease (CKD)
- Absolute indications include uremic symptoms (serositis, bleeding, encephalopathy), refractory hyperkalemia or metabolic acidosis, volume overload unresponsive to diuretics, and malnutrition despite dietary intervention 1
- These manifestations typically emerge when GFR falls between 5-10 ml/min per 1.73 m², though this is not invariable 1
- Timely referral for RRT planning should occur when the risk of kidney failure within 1 year is 10-20% or higher based on validated risk prediction tools 1
For Acute Kidney Injury (AKI)
- Immediate initiation is warranted for life-threatening complications: severe hyperkalemia, metabolic acidosis, pulmonary edema refractory to medical management, or uremic complications 1
- The 2012 KDIGO AKI guideline states RRT should be discontinued "when it is no longer required, either because intrinsic kidney function has recovered to the point that it is adequate to meet patient needs, or because RRT is no longer consistent with the goals of care" 1
Specific Clinical Indicators
Metabolic and Electrolyte Abnormalities
- Severe hyperkalemia unresponsive to medical therapy 1
- Refractory metabolic acidosis 1
- Persistent abnormalities of serum potassium requiring specialist referral 1
Volume and Hemodynamic Status
- Inability to control volume status despite optimal diuretic therapy 1
- Hypertension refractory to treatment with 4 or more antihypertensive agents (warrants specialist referral) 1
Uremic Manifestations
- Serositis (pericarditis, pleuritis) 1
- Uremic bleeding 1
- Pruritus attributable to kidney failure 1
- Cognitive impairment related to uremia 1
Nutritional Status
- Progressive deterioration in nutritional status that is refractory to dietary intervention 1
Important Caveats
The GFR threshold of 5-10 ml/min per 1.73 m² is not absolute—clinical symptoms and signs should drive the decision rather than GFR alone 1. Some patients may require earlier initiation if symptomatic, while others with comprehensive conservative care may defer or avoid RRT entirely 1.
For ECMO patients specifically, fluid overload becomes a particularly important indication, and earlier RRT initiation may be required compared to non-ECMO patients 2.
Conservative management remains a valid option for patients who choose not to pursue RRT, and this should be supported by a comprehensive management program including symptom control, psychological care, and advance care planning 1.
The timing controversy persists in the absence of absolute indications—there is no consensus on initiating RRT based solely on progressive azotemia without overt uremic symptoms 3, 4. The decision integrates multiple clinical variables and should account for trajectory of kidney function, comorbidities, and patient goals of care 4.