clinical lab data

• What is the definition of a reference range in clinical data?

  It sets the boundaries for expected variability of any analyte in healthy subjects.
• What factors can affect the reference range of analytes?

  Age, gender, race, and ethnicity can affect the reference range.
• What is a critical test value?

  A result significantly outside the reference range that may represent a life-threatening situation.
• What does a complete blood count (CBC) measure?

  • Counts and examines leukocytes (white blood cells)
  • Evaluates erythrocytes (red blood cells) for size and hemoglobin content
  • Evaluates thrombocytes (platelets) by number present
• What is leukocytosis?

  It is a WBC count above normal, common with infection, stress, and trauma.
• What does severe leukocytosis indicate?

  It may represent a poor prognosis in severe infections.
• What is leukopenia?

  It is a WBC count below normal, occurring with overwhelming infections or immune system depression.
• What diseases can cause leukopenia?

  It can occur due to diseases of the bone marrow, such as leukemia.
• What does the differential of WBC count determine?

  • The number of each type of WBC present in the blood
  • Most circulating WBCs are either neutrophils or lymphocytes
  • Five varieties of WBCs: Neutrophils, Lymphocytes, Eosinophils, Basophils, Monocytes
• What causes neutrophilia?

  It is increased with bacterial infection and trauma.
• What are bands in the context of neutrophils?

  Bands are immature neutrophils found mostly in the bone marrow.
• What does an elevation of bands and segs indicate?

  It likely indicates a more severe bacterial infection.
• When are lymphocytes increased?

  They are increased with viral and other infections.
• What is the diagnostic threshold for lymphocytes in HIV disease?

  Less than 200 lymphocytes.
• When are eosinophils increased?

  They are increased with allergic reactions and parasitic infections.
• What causes an increase in basophils?

  They are increased with allergic reactions.
• When are monocytes increased?

  They are increased with the invasion of foreign material.
• What is anemia?

  It is a reduced RBC count due to blood loss or reduced RBC production.
• How does anemia affect the blood?

  It reduces the oxygen-carrying capacity of blood.
• What is polycythemia?

  It is an abnormal elevation of RBC count.
• What is secondary polycythemia?

  It occurs when bone marrow produces more RBCs in response to chronically low blood oxygen levels.
• What is the reference range for hemoglobin in men?

  13.3-17.7 g/dl.
• What is the reference range for hemoglobin in women?

  11.7-15.7 g/dl.
• What is the recommended threshold for blood transfusion based on hemoglobin?

  A hemoglobin of 7.0 g/dL or hematocrit of 21%.
• What does hematocrit measure?

  It measures the ratio of RBC volume to that of whole blood.
• What is the reference range for hematocrit in men?

  40%-52%.
• What is the reference range for hematocrit in women?

  35%-47%.
• What can low hematocrit levels indicate?

  They can occur with anemia or overhydration.
• What can high hematocrit levels indicate?

  They can occur with polycythemia and dehydration.
• What are the basic concepts of electrolyte tests?

  • Normal cellular function depends on homeostasis of fluid, electrolytes, and acid-base balance.
  • Electrolytes are ions influencing enzyme function.
  • Enzymes regulate all chemical reactions within cells.
• What is important when interpreting blood tests?

  Blood samples provide a one-time snapshot of constantly changing processes.
• What is a basic chemistry panel also called?

  A basic metabolic panel (BMP).
• What are the predominant electrolytes measured in a basic chemistry panel?

  • Sodium (Na+)
  • Potassium (K+)
  • Chloride (Cl-)
  • Total CO2 / bicarbonate (bicarb)
  • Glucose
• What is the reference range for sodium (Na+)?

  136-145 meq/L.
• What is the physiologic importance of sodium (Na+)?

  It is crucial for maintaining fluid balance and nerve impulse conduction.
• What is a critical test result for sodium (Na+)?

  Greater than 155 meq/L or less than 125 meq/L.
• What common condition is associated with hypernatremia?

  Dehydration from excessive water loss or fluid restriction.
• What common condition is associated with hyponatremia?

  Overhydration or abnormal secretion of antidiuretic hormone.
• What is the reference range for potassium (K+)?

  1. 5-5.0 meq/L.
• What is the physiologic importance of potassium (K+)?

  It is crucial for maintaining normal heart and kidney function and acid-base balance.