Stage 4 Chronic Kidney Disease (CKD)
With an eGFR of 27 mL/min/1.73 m², you have Stage 4 CKD, defined as severe decrease in kidney function with eGFR between 15-29 mL/min/1.73 m² 1, 2, 1, 2.
Understanding Your Lab Values
Your laboratory results indicate advanced kidney disease:
- eGFR 27 mL/min/1.73 m²: This is the most critical value for staging CKD and places you definitively in Stage 4
- Creatinine 2.36 mg/dL: Elevated, reflecting reduced kidney filtration capacity
- BUN 32 mg/dL: Elevated, indicating accumulation of nitrogenous waste products
The eGFR is the gold standard for CKD staging and classification 1. Your value of 27 falls squarely within the Stage 4 range (15-29 mL/min/1.73 m²), which represents severe kidney function impairment.
CKD Staging Framework
According to multiple international guidelines 1, 2, 1, 2:
- Stage 1: eGFR ≥90 with kidney damage
- Stage 2: eGFR 60-89 with kidney damage
- Stage 3a: eGFR 45-59
- Stage 3b: eGFR 30-44
- Stage 4: eGFR 15-29 (severe decrease) ← Your current stage
- Stage 5: eGFR <15 or on dialysis (kidney failure)
Critical Clinical Implications at Stage 4
At Stage 4 CKD, you should be preparing for renal replacement therapy and receiving intensive nephrology care 1, 2. This stage requires:
Immediate Actions Required:
- Nephrology referral is mandatory - Stage 4 CKD with eGFR <30 mL/min/1.73 m² requires specialist management 1
- Preparation for renal replacement therapy (dialysis or transplantation) should begin 1, 2
- Evaluation and treatment of CKD complications including anemia, mineral bone disease, metabolic acidosis, and cardiovascular risk 1
Key Management Priorities:
Blood pressure control: Target management to slow progression, particularly with ACE inhibitors or ARBs if you have diabetes or proteinuria 2
Protein intake restriction: Approximately 0.8 g/kg/day is recommended to reduce metabolic burden on remaining kidney function 2
Medication review: All nephrotoxic drugs must be avoided, and all medications require dose adjustment for reduced kidney function 3
Monitoring frequency: More intensive follow-up is needed at this stage, with regular assessment of electrolytes, acid-base status, anemia, and bone metabolism 1
Important Caveats
Your elevated BUN relative to creatinine (BUN/Cr ratio of approximately 13.6) suggests possible prerenal factors or increased protein catabolism may be contributing 4. However, this does not change your CKD stage, which is determined solely by eGFR.
The distinction between Stage 4 and Stage 5 is clinically crucial: Stage 5 (eGFR <15) represents kidney failure requiring dialysis or transplantation 1, 2. You are approaching this threshold and need urgent nephrology involvement to plan for renal replacement therapy before reaching Stage 5.
Stage 4 CKD carries significantly increased risks of cardiovascular disease, mortality, and progression to end-stage renal disease 3, 5. The focus at this stage shifts from slowing progression to preparing for kidney replacement therapy while managing complications that substantially impact quality of life and survival.