What are the abnormal values on a Comprehensive Metabolic Panel (CMP) that may indicate kidney or Genitourinary (GU) tract problems?

From the Guidelines

Abnormal values on a Comprehensive Metabolic Panel (CMP) that may indicate kidney or genitourinary tract problems include elevated blood urea nitrogen (BUN) and creatinine levels, which are the primary markers of kidney function, with normal BUN ranging from 7-20 mg/dL and normal creatinine typically being 0.6-1.2 mg/dL for men and 0.5-1.1 mg/dL for women 1. These values are crucial as they reflect the kidney's ability to filter waste products from the blood.

• Elevated BUN and creatinine levels can indicate a decrease in kidney function, which may be due to various causes such as dehydration, kidney damage, or disease.
• Electrolyte imbalances, including high potassium (hyperkalemia), low sodium (hyponatremia), or elevated phosphorus, can also suggest kidney dysfunction, as the kidneys play a key role in maintaining electrolyte balance in the body.
• Metabolic acidosis, indicated by low bicarbonate (CO2) levels below 22 mEq/L, may occur when kidneys fail to properly excrete acid, leading to an accumulation of acid in the blood.
• Elevated glucose levels might indicate diabetic nephropathy, a common cause of kidney disease, as high blood sugar levels can damage the kidneys over time.
• Abnormal calcium levels can reflect kidney problems, as the kidneys help regulate calcium balance by activating vitamin D, which is essential for calcium absorption. The BUN-to-creatinine ratio is also important; a ratio exceeding 20:1 may suggest pre-renal issues like dehydration or heart failure, while a lower ratio might indicate intrinsic kidney damage 1. These abnormalities should prompt further investigation with urinalysis, imaging studies, or referral to a nephrologist, especially if values are significantly outside normal ranges or show a worsening trend over time. It is essential to consider the glomerular filtration rate (GFR) when evaluating kidney function, as a GFR level less than 60 mL/min per 1.73 m2 represents a loss of half or more of the adult level of normal kidney function, and below this level, the prevalence of complications of chronic kidney disease increases 1.

From the FDA Drug Label

Serum electrolytes (particularly potassium), CO2, creatinine and BUN should be determined frequently during the first few months of Furosemide tablets therapy and periodically thereafter. Reversible elevations of BUN may occur and are associated with dehydration, which should be avoided, particularly in patients with renal insufficiency

The abnormal values on a Comprehensive Metabolic Panel (CMP) that may indicate kidney or Genitourinary (GU) tract problems are:

• Elevated BUN (Blood Urea Nitrogen): associated with dehydration and renal insufficiency
• Elevated creatinine: indicates impaired renal function
• Electrolyte imbalances: such as hypokalemia (low potassium), hypochloremic alkalosis, and hypomagnesemia (low magnesium) These values should be monitored frequently, especially in patients receiving Furosemide tablets therapy 2, 2.

From the Research

Abnormal Values on a Comprehensive Metabolic Panel (CMP)

Abnormal values on a CMP that may indicate kidney or Genitourinary (GU) tract problems include:

• Elevated creatinine levels, which can indicate impaired kidney function or kidney disease 3
• Abnormal potassium levels, such as:
  • Hyperkalemia (elevated potassium levels), which can be a sign of kidney disease or acute kidney injury (AKI) 3
  • Hypokalemia (low potassium levels), which can also be associated with kidney disease or AKI 3
• Other abnormal electrolyte levels, such as elevated phosphorus or decreased calcium levels, which can also indicate kidney problems

Risk Factors for Abnormal Values

Certain factors can increase the risk of abnormal values on a CMP, including:

• Use of certain medications, such as:
  • Potassium-sparing diuretics, which can increase the risk of hyperkalemia 3
  • ACE inhibitors, which can also increase the risk of hyperkalemia 3
• Underlying medical conditions, such as:
  • Chronic kidney disease (CKD), which can increase the risk of hyperkalemia and other electrolyte imbalances 3
  • Acute kidney injury (AKI), which can cause a range of electrolyte imbalances and other abnormalities on a CMP 3