What are the stages of renal failure and their corresponding treatments?

Stages of Renal Failure and Their Treatments

Chronic kidney disease is classified into five stages based on glomerular filtration rate (GFR), with Stage 1 representing the mildest form (GFR ≥90 mL/min/1.73 m²) and Stage 5 representing kidney failure (GFR <15 mL/min/1.73 m²), requiring dialysis or transplantation when uremic symptoms develop. 1, 2

CKD Staging System

The staging system requires abnormalities to persist for at least 3 months to distinguish chronic from acute kidney disease 1, 3:

Stage 1: GFR ≥90 mL/min/1.73 m²

• Requires evidence of kidney damage (albuminuria, proteinuria, or structural abnormalities on imaging) since GFR alone is insufficient for diagnosis 1, 2
• Treatment focus: Diagnose and treat underlying conditions, slow progression, and reduce cardiovascular disease risk 2
• Monitor annually 1

Stage 2: GFR 60-89 mL/min/1.73 m²

• Requires evidence of kidney damage 1, 2
• Treatment focus: Estimate progression rate and continue treating comorbid conditions 2
• Monitor annually 1

Stage 3: GFR 30-59 mL/min/1.73 m²

This stage is subdivided based on significantly different mortality and cardiovascular risk profiles 1, 2:

• Stage 3a: GFR 45-59 mL/min/1.73 m² 4, 1
• Stage 3b: GFR 30-44 mL/min/1.73 m² 4, 1
• Treatment focus: Evaluate and treat complications (hypertension, anemia, hyperphosphatemia) 2
• Monitor with biological control 2-4 times per year based on severity 1
• Risk of complications increases significantly below GFR of 60 mL/min/1.73 m² 2

Stage 4: GFR 15-29 mL/min/1.73 m²

• Treatment focus: Intensive management of complications and preparation for kidney replacement therapy 1, 2
• Refer to nephrologist for consultation and co-management 2
• Begin planning for dialysis access and modality selection 5
• Monitor monthly for clinical status with GFR assessment every 3 months 5

Stage 5: GFR <15 mL/min/1.73 m² or on dialysis

• Represents end-stage renal failure or kidney failure 4, 1, 2
• Treatment focus: Kidney replacement therapy (dialysis or transplantation) if uremic symptoms develop 1, 2
• Approximately 98% of patients with kidney failure in the United States begin dialysis when GFR falls below 15 mL/min/1.73 m² 5

Complete Risk Stratification

Use the CGA classification system (Cause, GFR category, Albuminuria category), not GFR alone, to avoid incomplete staging 1:

Albuminuria Categories

• A1: <30 mg/g (normal to mildly increased) 1
• A2: 30-300 mg/g (moderately increased) 1
• A3: >300 mg/g (severely increased) 1

Measure albumin-to-creatinine ratio (ACR) on a single urine sample rather than 24-hour urine collection, and perform at least 2-3 measurements over 6 months to confirm diagnosis 1. An albuminuria level of 30 mg/g represents more than 3 times the normal value and independently predicts increased risk for CKD complications, cardiovascular mortality, and progression to kidney failure 1.

Dialysis Initiation Criteria

Dialysis should be considered when GFR reaches 5-10 mL/min/1.73 m² in the presence of uremic symptoms 5:

Clinical Indicators for Dialysis

• Uremic symptoms: nausea, vomiting, encephalopathy, pruritus, or serositis 5
• Volume management failure 5
• Metabolic derangements 5
• Nutritional decline 5
• Cognitive impairment 5

Quantitative Thresholds

• Weekly renal Kt/Vurea falls below 2.0 (approximating GFR ~10.5 mL/min/1.73 m²) 5
• Most patients initiate dialysis when GFR <15 mL/min/1.73 m² 5

GFR Estimation Method

Use the CKD-EPI equation for reporting estimated GFR in adults from serum creatinine calibrated to isotope-dilution mass spectrometry reference method 1. The CKD-EPI equation demonstrates less bias than the MDRD equation, especially at GFR ≥60 mL/min/1.73 m², with improved precision and greater accuracy 1.

Critical Pitfalls to Avoid

• Do not rely solely on estimated GFR without considering clinical symptoms, as this can lead to premature or delayed dialysis initiation 5
• Do not delay nephrology consultation when GFR approaches 30 mL/min/1.73 m², as late referral compromises outcomes 5
• Do not assume all patients with GFR <15 mL/min/1.73 m² require immediate dialysis if they remain asymptomatic with stable nutritional status 5
• All GFR estimation formulas underestimate GFR for subnormal renal function (GFR <90 mL/min), and there is no correlation between GFR and albuminuria progression, so both parameters must be monitored independently 1
• Early nephrology referral (>1 year before anticipated dialysis) maximizes preparation and improves outcomes 5
• Conservative management without dialysis is an appropriate option for many older or more infirm individuals and should be discussed as part of shared decision-making 5