Sysmex/CBC Review Flashcards
The electronic impedance cell counter depends on:
The cell being less conductive than the isotonic diluent
What best describes the cell counting principle of Sysmex automated blood analyzers?
Direct current and hydrodynamic focused flow impedance
What is the type of measurement utilized by the Sysmex system for Hemoglobin?
measured photometrically & directly
What information does forward scatter provide about a cell?
Measures cell size
How is the MCH calculated?
HGB/RBC
How is the MCV calculated?
HCT X 1000/RBC
How is the MCHC calculated?
HGB/HCT
How is the HCT calculated?
MCV X RBC COUNT/1000
RULE OF 3, HCT FORMULA
HGB X 3/1000 = HCT +/- 0.03 L/L
RULE OF 3, HGB FORMULA
RBC X 30 = HGB +/- 15G/L
Why do laboratories subscribe to External Proficiency Testing?
It is further check of result accuracy
What best describes the method used to determine the total WBC counts on the Sysmex analyzers?
Fluorescence flow cytometry
What method is used to measure Hemoglobin on an automated cell analyzer?
Photometric method
What is the type of measurement utilized by the Sysmex system for WBC?
Measured directly using impedance technology
Drabkin’s reagent for the measurement of hemoglobin by the cyanmethemoglobin uses the following reagents.
Potassium ferricyanide and potassium cyanide
What best explains/demonstrates a QC “shift”?
A sudden change in QC values that are consecutive either above or below the mean
What information does Side scatter provide about a cell?
Cytoplasmic granularity and nuclear configuration
What is Low Voltage DC used to measure?
Total cell volume
What is the type of measurement utilized by the Sysmex system for Hematocrit?
Measured directly by rbc cumulative pulse height detection
What is the type of measurement utilized by the Sysmex system for RBC?
measured directly using impedance – DC detection
Automated differential analysis can be based on?
Granularity of WBC cytoplasm, conductivity, light scattering
What is the type of measurement utilized by the Sysmex system for MCH?
Calculated using directly measured or derived parameters
What method is used to measure RBC/ size and number on the Sysmex Cell analyzer?
Direct Current/ Hydrodynamic focusing
What best describes the method used to detect the presence of immature myeloid cells on the Sysmex cell analyzer?
Radio frequency / Direct current
Floating discriminators and/or thresholds (electronically set size limits) are used to
distinguish between RBC’s and platelets
The cyanmethemoglobin method of hemoglobin determination measures all forms of hemoglobin EXCEPT:
Sulfhemoglobin
What is laminar flow?
movement of two liquids past one another without mixing
What is the basis for the impedance principle of cell counting and sizing?
Cells create a resistance, when passed through an electrical current that is directly proportional to the volume or size of that cell
What action needs to be taken with a critical hemoglobin value?
Check for a clot and repeat the test
What action is recommended when platelet aggregates or platelet satellitosis are found on the peripheral blood smear?
Recollect specimen 4.5 ml whole blood in a 3.2% Sodium Citrate and multiple platelet results by 1.1
Which CBC parameters best indicate a possible iron deficiency?
↓HGB & ↓MCV & ↑RDW
How are CBC results affected by cold agglutinins?
Falsely decreasing the HCT
Under what conditions would an RBC histogram from an automated cell analyzer shift to the right?
Megaloblastic anemia
Which RBC parameters indicate normochromic RBCs?
MCHC, MCH
What parameter best indicates the presence of red cell agglutination?
MCHC
Which of the following would result in falsely high hemoglobin?
A greatly elevated WBC count
When examining the peripheral blood smear and Complete Blood count, which parameter should be examined after the hemoglobin and Hematocrit?
MCV
Under what conditions would an RBC histogram from an automated cell analyzer shift to the left?
Chronic blood loss
Which CBC parameters best indicate a possible thalassemia?
↑RBC,↓MCV, & HGB = N
When reviewing a CBC result with a normal MCV, which CBC parameter best alerts the operator that the results may not be accurate?
MCHC
