5.1 Lab Ealuation of Primary Hemostasis Flashcards
On the average, if platelet cpunt is normal, there is at least 1 platelet in _______ RBCs or approx. ______ platelets per OIF
10-30
8-20
Specimen for enumeration of platelet?
Venous blood is preferred (EDTA)
Review of peripheral blood smear is advantageous in some points in detecting causes of low counts but it is not the preferred method for routine plt counts such as
- artificial due to clumping
- clotted specimen
- Giant platelets
T or F
T
Due to platelets clumps: In the machine this may cause:
Falsely ______ Platelet ct
Falsely ______ WBC ct
Decrease
Increase
If giant platelet is seen, Manual count is done
T or F
T
Manual platelet Count:
- Direct Method
Preferred method of microscopy
Phase contrast microscopy
Diluting fluid in phase-contrast microscopy?
Brecher-Cronkite method (1% ammonium oxalate
Manual platelet Count:
- Direct Method
- Lightmicroscope
What is the method and diluting fluid?
Rees-Exker method: Citrate-formaldehyde buffer with Brilliant Cresyl Blue
In light microscope, platelets appear refractile and bluish with BCB
T or F
T
In direct method: Platelets are counted in central small squares of Neubauer chamber
T or F
T
Indirect method:
Platelets estimation in peripheral smear using what Field?
OIO
Fator used in Indirect method?
20,000
In Indirect method:
Normally,________/ OIF are seen in healthy indiv.
8-20
Automated Platelet count
- Detect electrical resistance when particles stream through an aperture tube
Electrical impedance
Direct method uses Counting chamber
Indirect Method uses Blood smear
T or F
T
Indirect method is only use to verfy the analyzer
T or F
T
Automated Platelet count
- Particles that are in the range of 2-20 fL are counted as platelets
T or F
T
MPV is between 8-10 fL
T or F
T
Automated Platelet count:
Hemolysis
a. Spurious increase
b. Spurious decrease
a
Automated Platelet count:
Clotting
a. Spurious increase
b. Spurious decrease
b
