eGFR Calculation for 54-Year-Old Male with Creatinine 111 µmol/L
The eGFR for this patient is approximately 68 mL/min/1.73 m² using the CKD-EPI equation, which represents Stage 2 kidney function (mildly decreased GFR) if kidney damage markers are present, or normal age-appropriate kidney function if no damage markers exist. 1
Calculation Method
Use the CKD-EPI equation as the preferred method for estimating GFR in adults, as it demonstrates superior accuracy compared to MDRD and Cockcroft-Gault, particularly at GFR ≥60 mL/min/1.73 m². 1, 2
Step-by-Step Calculation:
- Convert creatinine: 111 µmol/L = 1.26 mg/dL (divide by 88.4)
- Apply CKD-EPI formula: GFR = 141 × min(SCr/0.9,1)^-0.411 × max(SCr/0.9,1)^-1.209 × 0.993^age 3, 1
- For this 54-year-old male with SCr 1.26 mg/dL:
- min(1.26/0.9,1) = 1
- max(1.26/0.9,1) = 1.4
- GFR = 141 × 1^-0.411 × 1.4^-1.209 × 0.993^54
- Result: ~68 mL/min/1.73 m² 1
Clinical Interpretation
This eGFR of 68 mL/min/1.73 m² places the patient just above the critical threshold of 60 mL/min/1.73 m², which is the cutoff for defining chronic kidney disease (CKD). 1, 4
- Stage classification: Stage 2 CKD (G2: 60-89 mL/min/1.73 m²) if kidney damage markers are present, or normal kidney function for age if no damage markers exist 1, 4
- Cardiovascular risk: eGFR ≥60 mL/min/1.73 m² carries no significantly increased cardiovascular or mortality risk from kidney function alone 4
- Age-adjusted context: Normal GFR declines physiologically by 1-2 mL/min per year beginning in the third or fourth decade, so this value represents retention of more than half of normal adult kidney function 4
Essential Next Steps
Measure urinary albumin-to-creatinine ratio (UACR) on a spot urine sample to determine if kidney damage is present (normal <30 mg/g). 1, 4
- The presence or absence of albuminuria is the critical determinant of whether this eGFR represents CKD requiring intervention 1
- Albuminuria (UACR ≥30 mg/g) dramatically increases cardiovascular and kidney disease progression risk even with preserved eGFR 4
Repeat creatinine measurement in 3-6 months to confirm stability, as single measurements can be affected by recent exercise, infection, or dietary protein intake. 1
Medication Management
At eGFR 68 mL/min/1.73 m², no routine medication dose adjustments are required for most renally-excreted drugs. 1
- Continue standard dosing unless specific medications have adjustment thresholds above 60 mL/min/1.73 m² 1
- Drug accumulation due to reduced renal excretion becomes clinically significant primarily when eGFR falls below 60 mL/min/1.73 m² 4
Monitoring Strategy
If no albuminuria is present, annual monitoring of creatinine and eGFR is sufficient. 1
If albuminuria is detected, increase monitoring frequency to 2-3 times yearly and optimize blood pressure control. 1
- Monitor for rate of eGFR decline: If declining >4-8 mL/min per year, this suggests accelerated kidney disease requiring intervention 4
- Serial eGFR measurements over time are more informative than a single value for risk stratification 4
Common Pitfalls to Avoid
Do not use the Cockcroft-Gault equation, as it is significantly less accurate than CKD-EPI and should not be preferred in modern clinical practice. 5
Do not assume normal kidney function based solely on creatinine being near the "normal range" (111 µmol/L is at the upper limit of normal), as 46.5% of patients with creatinine of 100 µmol/L have Stage 3 CKD when using MDRD eGFR. 6
Verify that the creatinine measurement is standardized and IDMS-traceable, as non-standardized measurements can lead to significant errors in eGFR calculation. 3