Normal Values for Basic Metabolic Panel (BMP)
The normal values for a Basic Metabolic Panel (BMP) include sodium 135-145 mEq/L, potassium 3.5-5.0 mEq/L, chloride 98-107 mEq/L, carbon dioxide 22-29 mEq/L, blood urea nitrogen (BUN) 7-20 mg/dL, creatinine 0.6-1.2 mg/dL, glucose 70-99 mg/dL, and calcium 8.5-10.5 mg/dL.
Components of a Basic Metabolic Panel
A Basic Metabolic Panel (BMP) is a group of 8 blood tests that provide important information about the body's chemical balance and metabolism. The components include:
Electrolytes
- Sodium: 135-145 mEq/L
- Potassium: 3.5-5.0 mEq/L
- Chloride: 98-107 mEq/L
- Carbon dioxide (CO2, bicarbonate): 22-29 mEq/L
Kidney Function Tests
- Blood Urea Nitrogen (BUN): 7-20 mg/dL
- Creatinine: 0.6-1.2 mg/dL (may vary slightly by gender)
Other Measurements
- Glucose (fasting): 70-99 mg/dL
- Calcium: 8.5-10.5 mg/dL
Clinical Significance
The BMP is frequently used in clinical practice to:
- Assess kidney function
- Monitor electrolyte balance
- Screen for diabetes and prediabetes
- Evaluate acid-base balance
- Monitor effects of medications
- Assess overall metabolic status
Important Considerations
Glucose interpretation: A single elevated fasting glucose reading should not be used alone to diagnose diabetes. Confirmation with repeat testing is necessary unless the patient has classic symptoms of hyperglycemia or hyperglycemic crisis with a random plasma glucose ≥200 mg/dL 1, 2.
Renal function: BUN and creatinine values should be interpreted together. An elevated creatinine (>1.2 mg/dL) may indicate impaired kidney function 1. For example, in case studies of patients with hip fractures, a creatinine of 1.42 mg/dL was noted as abnormal 1.
Electrolyte abnormalities: Deviations from normal ranges can indicate various conditions:
- Hyponatremia or hypernatremia (low or high sodium)
- Hypokalemia or hyperkalemia (low or high potassium)
- Metabolic acidosis or alkalosis (abnormal CO2 levels)
Sample handling: Proper sample handling is critical as glycolysis can falsely lower glucose values. Samples should be processed rapidly or collected in tubes with glycolytic inhibitors 2.
Common Pitfalls to Avoid
- Interpreting isolated abnormal values without clinical context
- Failing to consider the effects of medications on electrolyte levels
- Not accounting for age, gender, and other factors that may affect normal ranges
- Relying on a single abnormal test result for diagnosis without confirmation
- Overlooking the need to repeat testing for diagnostic confirmation of conditions like diabetes
By understanding the normal ranges and clinical significance of BMP components, healthcare providers can better interpret results and make appropriate clinical decisions for patient care.