Custom Search

Our Products · On-Line Store

Hematocrit (Hct)

The hematocrit is a measure of the red blood cell mass, expressed as a percentage.

Blood is placed in a test tube and centrifuged to separate the heavier red blood cells from the lighter serum and plasma. The percentage of the blood volume occupied by the mass of red cells is the hematocrit.

Increased in the Presence of:

  • Hemoconcentration
  • COPD (chronic obstructive pulmonary disease)
  • CHF (congestive heart failure)
  • Smokers
  • Pre-eclampsia

Decreased in the Presence of:

  • Anemia
  • Leukemia
  • Hyperthryroidism
  • Chronic liver disease
  • Hemolysis:
    • Transfusion reaction
    • Drug/chemical reaction
    • Infection
    • Burns
    • Mechanical disruption (artificial heart valves)
  • Systemic Disease
    • Cancer
    • Lupus
    • Sardoidosis

Special Considerations

  • Smokers typically have elevated hematocrits in response to chronic, low-grade carbon monoxide poisoning and other mild respiratory ailments. Because of the carbon monoxide binding, they may still be functionally anemic, even though their hematocrit levels look good.
  • Adaptation to high altitudes includes moderate elevation of hematocrit.
  • During the initial phases of an acute hemorrhage, the hematocrit generally doesn't change very much. Later, as extracellular fluid is mobilized and IV fluids are incorporated, there is a dilutional effect that will lead to a reduced hematocrit. This fall in hematocrit may take several hours to develop.

 

Normal Values*

  Packed Cell Volume

Men

40%-54%
Women 37%-47%
Pregnancy 33%-44%
Newborn 50%-62%

*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.

 


 

 

Approved for public release; Distribution is unlimited.
The listing of any non-Federal product in this CD is not an endorsement of the product itself, but simply an acknowledgement of the source. 

Bureau of Medicine and Surgery
Department of the Navy
2300 E Street NW
Washington, D.C
20372-5300

Operational Medicine
 Health Care in Military Settings
CAPT Michael John Hughey, MC, USNR
NAVMED P-5139
  January 1, 2001

United States Special Operations Command
7701 Tampa Point Blvd.
MacDill AFB, Florida
33621-5323

*This web version is provided by The Brookside Associates Medical Education Division.  It contains original contents from the official US Navy NAVMED P-5139, but has been reformatted for web access and includes advertising and links that were not present in the original version. This web version has not been approved by the Department of the Navy or the Department of Defense. The presence of any advertising on these pages does not constitute an endorsement of that product or service by either the US Department of Defense or the Brookside Associates. The Brookside Associates is a private organization, not affiliated with the United States Department of Defense.

Contact Us  ·  ·  Other Brookside Products

Operational Medicine 2001
Contents

 

 

 

Advertise on this site