What tests are included in a renal panel?

Components of a Renal Panel

A renal panel typically includes blood urea nitrogen (BUN), creatinine, electrolytes (sodium, potassium, chloride, bicarbonate), and estimated glomerular filtration rate (eGFR) as the core components for assessing kidney function. 1, 2

Core Components

• Blood Urea Nitrogen (BUN): Measures nitrogen in the form of urea, a waste product filtered by the kidneys 1, 3
• Creatinine: A waste product from muscle metabolism that is filtered by the kidneys; serves as the most reliable indicator of kidney function 2, 3
• Estimated Glomerular Filtration Rate (eGFR): Calculated value based on creatinine levels that estimates how well the kidneys filter blood 2
• Electrolytes:
  • Sodium: Essential for fluid balance and nerve/muscle function 1, 2
  • Potassium: Critical for heart, nerve, and muscle function 1, 2
  • Chloride: Helps maintain fluid and acid-base balance 2
  • Bicarbonate (CO2): Reflects acid-base balance in the body 2

Additional Components Often Included

• Calcium: Important for bone health and many cellular functions; levels can be affected by kidney disease 1
• Phosphorus: Works with calcium in bone formation; levels often rise in kidney disease 1
• Albumin: Major protein in blood that can indicate nutritional status and kidney function 1

Clinical Significance

• A renal panel is essential for:
  • Initial assessment of kidney function 1, 2
  • Monitoring chronic kidney disease progression 1
  • Evaluating electrolyte imbalances 1, 2
  • Assessing acid-base status 2

Interpretation Considerations

• The BUN-to-creatinine ratio provides valuable diagnostic information:

  • Normal ratio is typically 10-20:1 3
  • Elevated ratio may indicate pre-renal causes (dehydration, heart failure) 3
  • Decreased ratio may suggest liver disease or malnutrition 3

• eGFR is the preferred initial assessment of kidney function:

  • Normal is typically >60 mL/min/1.73m² 2
  • Values <60 mL/min/1.73m² may indicate chronic kidney disease 2

When Additional Testing May Be Needed

• If the basic renal panel shows abnormalities, additional tests may be warranted:

  • Urinalysis and urine protein studies 1
  • 24-hour urine collection for protein and creatinine clearance 1
  • Renal biopsy in cases of unexplained renal insufficiency 1

• For patients with monoclonal gammopathies or multiple myeloma, specialized renal assessment should include:

  • Serum free light chain measurement 1
  • Urine protein electrophoresis 1
  • Serum protein electrophoresis 1

Clinical Pearls

• Creatinine is less influenced by extra-renal factors than BUN, making it a more reliable indicator of kidney function 3
• Certain medications can affect renal panel results without actual kidney damage (e.g., trimethoprim raises creatinine) 3
• Hydration status significantly impacts BUN levels but has less effect on creatinine 3
• Regular monitoring of renal function with a renal panel is recommended for patients with chronic conditions like diabetes, hypertension, or heart failure 2