What does impaired renal function signify?

Understanding eGFR 67 with Creatinine 123 μmol/L

This represents Stage 2 chronic kidney disease (CKD) with mildly decreased kidney function, requiring evaluation for underlying kidney damage and cardiovascular risk stratification. 1

CKD Classification and Staging

Your laboratory values indicate:

• eGFR of 67 mL/min/1.73 m² falls into Stage 2 CKD (GFR 60-89 mL/min/1.73 m²), which represents mildly decreased kidney function 2, 1
• Creatinine of 123 μmol/L (approximately 1.4 mg/dL) is elevated above normal range, though serum creatinine alone should not be used to assess kidney function without calculating eGFR 2, 1
• Stage 2 CKD requires evidence of kidney damage (such as albuminuria, proteinuria, hematuria, or structural abnormalities on imaging) for formal diagnosis, as GFR alone is insufficient at this level 1, 3

Clinical Significance

The key distinction is that Stage 2 CKD indicates kidney damage is present, not just reduced filtration. 1

• At this GFR level, kidney function is only mildly impaired, but the presence of damage markers indicates progressive disease risk 2
• Cardiovascular disease risk begins to increase when eGFR falls below 60 mL/min/1.73 m², so at 67 mL/min/1.73 m², you are just above this threshold but warrant monitoring 2, 1
• The risk of progression to more severe CKD stages depends heavily on the underlying cause and presence of proteinuria 1, 3

Essential Next Steps

You must obtain a urine albumin-to-creatinine ratio (UACR) to confirm Stage 2 CKD diagnosis and assess progression risk. 1, 3

• If UACR >30 mg/g on two of three spot urine specimens, this confirms kidney damage and establishes Stage 2 CKD diagnosis 3
• Albuminuria categories (A1: <30 mg/g, A2: 30-300 mg/g, A3: >300 mg/g) combined with GFR provide complete risk stratification 1
• Repeat eGFR in 3 months to confirm chronicity, as CKD requires abnormalities persisting ≥90 days 2, 1, 3

Management Priorities for Stage 2 CKD

Focus on early detection of complications, CKD risk reduction, and aggressive treatment of comorbid conditions. 1

• Identify and treat the underlying cause of kidney disease (diabetes, hypertension, glomerulonephritis, etc.) 1
• Blood pressure control is critical: target <130/80 mmHg, particularly if proteinuria is present 2
• Screen for and manage cardiovascular risk factors aggressively, as cardiovascular disease is the leading cause of death in CKD patients 2, 4
• Avoid nephrotoxic medications including NSAIDs, which can reduce the effectiveness of ACE inhibitors and worsen kidney function 5

Monitoring Requirements

Serial monitoring of kidney function is essential to detect progression early. 2

• Repeat creatinine and eGFR every 3-6 months for Stage 2 CKD to assess stability versus progression 2, 1
• Monitor for worsening renal function (WRF), defined as ≥25% increase in creatinine, ≥26.5 μmol/L absolute increase, or ≥20% decrease in eGFR over 6-12 months 2
• Annual screening for complications including anemia, bone mineral disorders, and electrolyte abnormalities, though these typically emerge when eGFR falls below 60 mL/min/1.73 m² 1

Medication Considerations

If you are on ACE inhibitors or ARBs (common in CKD), close monitoring is required. 5

• ACE inhibitors like lisinopril can cause acute increases in creatinine, particularly in volume-depleted states or bilateral renal artery stenosis 5
• An acute rise in creatinine of up to 30% after starting ACE inhibitors/ARBs is acceptable and does not require discontinuation 5
• Monitor potassium levels, as ACE inhibitors increase hyperkalemia risk, especially with eGFR <60 mL/min/1.73 m² 5

Red Flags Requiring Urgent Evaluation

Certain findings mandate immediate nephrology referral: 2, 6

• Rapid decline in eGFR (>5 mL/min/1.73 m² per year or >10 mL/min/1.73 m² over 5 years) 2
• Heavy proteinuria (UACR >300 mg/g or protein excretion >0.5 g/day) 1
• Acute kidney injury superimposed on CKD: creatinine increase ≥26.5 μmol/L within 48 hours or ≥50% within 7 days 6
• Unexplained hematuria, rapidly progressive symptoms, or refractory hypertension 1

Common Pitfalls to Avoid

• Do not rely on creatinine alone to assess kidney function, as it varies with age, sex, muscle mass, and ethnicity 2, 1
• Do not assume Stage 2 CKD is benign without confirming the presence or absence of albuminuria, which dramatically affects prognosis 1, 3
• Do not use incomplete staging (GFR alone); always incorporate albuminuria category for complete CGA (Cause-GFR-Albuminuria) classification 1
• Ensure adequate hydration status before interpreting kidney function tests, as volume depletion can artificially elevate creatinine 6