Laboratory Tests

Why Order a BMP?

  • Situations to consider ordering a BMP:
    • Emergency Room Treatment: To quickly assess metabolic conditions.
    • Kidney/Metabolism Issues: If experiencing related symptoms.
    • General Symptoms: Such as unexplained fatigue or vomiting.
    • Chronic Conditions Monitoring: Essential for high blood pressure or kidney disease.
    • Follow-up on Abnormal Results: To check if levels have improved or worsened.
    • Medication Effects: Starting medications that might affect kidney function.

Comprehensive Metabolic Panel (CMP)

  • Overview: Similar to BMP but includes additional tests.
  • Components of CMP:
    • Albumin: Small protein produced in the liver.
    • Total Protein: Measures albumin and all serum proteins.
    • Sodium: An electrolyte vital for numerous body processes.
    • Potassium: Another major electrolyte for bodily functions.
    • CO2: Assesses acid-base balance (pH levels).
    • Chloride: Maintains fluid levels in the body.
    • Blood Urea Nitrogen (BUN): Waste product filtered by kidneys.
    • Creatine: Good indicator of kidney function, a waste product from muscles.
    • Alkaline Phosphatase (ALP): Indicates liver or bone disease when elevated.
    • Alanine Transaminase (ALT or SGPT): Liver enzyme, rises with liver damage.
    • Aspartate Aminotransferase (AST or SGOT): Enzyme present in various tissues including liver and heart.
    • Bilirubin: Waste product from the breakdown of red blood cells, relevant for liver function assessment.

Prothrombin Time Test (PT/INR)

  • Purpose: Measures the time it takes for blood to clot.
  • Interpretation of Results:
    • High Reading: Indicates slow clotting.
    • Normal PT Range: 11 to 13.5 seconds.
    • Normal INR Range: 0.8 to 1.1; may be 2.0 to 3.0 for patients on warfarin.
    • Adjustment for Conditions: Some conditions may need different target PT levels.

Troponin Test

  • Function: Measures troponin proteins found in cardiac muscle.
  • Interpretation:
    • Normal Levels: Typically undetectable in healthy individuals.
    • Elevated Troponins: A sign of myocardial infarction (MI) indicating heart muscle damage.

B-Type Natriuretic Peptide (BNP) Test

  • Usage: Diagnoses heart failure.
  • Function of BNP: Peptide that regulates vasodilation and fluid/salt levels in the body.
  • Relation to Symptoms: Higher levels help identify whether symptoms are cardiac or respiratory in nature.

Rapid Platelet Function Assays (RPFA)

  • Types and Functions:
    • RPFA Assay: Measures platelet activity, important for therapies targeting GP IIb/IIIa.
    • RPFA-ASA: Assesses platelet dysfunction in patients on aspirin.
    • PFA-100 Analyzer: Rapid and accurate platelet adhesion and aggregation screening.
    • Ultegra-RPFA: Optical detection system measuring aggregation changes based on light transmittance.
  • Indications for Use: Recommended when there is bleeding, specific medication use, or certain surgical procedures.
  • Factors Affecting Results: Medications like aspirin, NSAIDs, tricyclic antidepressants can alter test results.

Arterial Blood Gas (ABG) Test

  • Purpose: Evaluates cardiac, respiratory, and metabolic conditions.
  • Main Function: Analyzes the regulation of oxygen and carbon dioxide in the blood.
  • Procedure: Blood drawn from an artery for lab testing.

Arterial Oxygen Saturation (SaO2)

  • Definition: Measures the percentage of oxygen bound to hemoglobin.
  • Measurement Methods: Can be measured non-invasively by oximetry.
  • Importance: Indicator of blood oxygen levels and capability of oxygen delivery.

Normal SaO2 Range

  • Typical Values: 95-100%.
  • Potential Causes for Decrease: Can drop in conditions like emphysema or COPD (Chronic Obstructive Pulmonary Disease).