The trapping of blood in an extremity by compression of veins
Venostasis
A decrease in the fluid content of the blood with a subsequent increase in nonfilterable large molecule or protein-based blood components
Hemoconcentration
Increases due to hemoconcentration: Cholesterol (increases up to ___ after 2 minutes of tourniquet application and up to ___ after 5 minutes)
- 5%
- 15%
Changes that occur within 1 minutes of tourniquet application are ___; however prolonged tourniquet application can lead to marked changes
Slight
Vigorous hand pumping can
- increase potassium levels up to ___
- reported to be responsible for ___ of all elevated potassium and may also increase ___
- 20%
- A third
- Lactate and phosphate levels
Results when RBCs are damaged or destroyed and the hemoglobin they contain escapes into the fluid portion of the specimen
Hemolysis
Color of serum
Slight hemolysis
Pink
Color of serum
Moderate hemolysis
Dark pink to light red
Color of serum
Gross hemolysis
Dark red
Hemolysis can erroneously decrease:
RBC count
Short-draw serum tubes such as ___ are generally acceptable for testing as long as the specimen is not ___ and there is sufficient specimen to perform the test
- Red tops and SSTs
- Hemolyzed
Excess EDTA in underfilled lavender-top tubes can:
- ___ RBCs, causing erroneously low blood cell counts and hematocrits and negatively affecting the morphological examination of the RBCs on a blood smear
- can also alter the ___ of the cells on a blood smear
- shrink
- staining characteristics
Excess heparin in plasma from underfilled green-top tubes may interfere with the testing of some ___ analytes
Chemistry
Excess sodium fluoride in underfilled gray-top tubes can result in ___ of the specimen
Hemolysis
Some manufacturers’ short-draw tubes have a ___ on the label to indicate the proper fill level
Line or arrow
