Csmls Heme Review Exam Questions With Correct Answers

CSMLS HEME REVIEW EXAM
QUESTIONS WITH CORRECT ANSWERS



Manual cell count calculation - Correct Answers -Average # of cells counted x dilution
factor
# of squares x Area of squares (LxW mm2)x Depth (0.1mm)

Then convert mm3 to x 109/ L - divide by 1000

Manual cell count sources of error: overfilling chamber - Correct Answers -- falsely low
count
- cells get pushed out of grid
- cells lost in moat

Manual cell count sources of error: angle of pipette - Correct Answers -- must be vertical
- angle will push cells out of grid
- falsely low count

Manual cell count sources of error: evaporation - Correct Answers -- chamber sits too
long before count results in lost cells
- falsely low count

Manual cell count sources of error: dirty chamber - Correct Answers -- falsely elevated
- dirt counted as cells

RBC indicies: MCV - Correct Answers -HCT X 1000
RBC

RBC indices: MCH - Correct Answers -HGB
RBC

RBC indices: MCHC - Correct Answers -HGB
HCT

NRBC correction calculation - Correct Answers -100 x automated total WBC/L
100 + NRBCs/ 100 WBCs

- change absolute count my multiplying relative by corrected WBC count

,greatly raised Hgb result on CBC - Correct Answers -- check history for recent
transfusion before proceeding

decreased Hgb result on CBC - Correct Answers -- check chemistry results for
suspected anemias

true hemorrhage vs bloody tap (CSF) - Correct Answers -- spin down CSF
- check supernatant: if clear= traumatic tap, or very recent hemorrhage (becomes
xanthochromic after 36 hrs)
- if xanthochromic: true hemorrhage

cytospin - Correct Answers -- concentrates cells for adequate analysis (body fluids)

what can you add to specimen to prevent cell smudging in body fluid analysis - Correct
Answers -- albumin
- prevents cells from being smudged or washed off
- PBF doesn't usually need addition of albumin due to proteins in whole blood

What component of the sickle reagent causes RBCs to form tactoid crystals? - Correct
Answers -sodium metabisulphite
- slide test

Most common deficiency in the Embden-Mayerhof pathway - Correct Answers -PK
deficiency

Cause of false (+) stomatocytosis - Correct Answers -- humidity introduced to slide
- stomatocytes a result of abnormal erythrocyte hydration

Reasons for MCHC to be > 360 - Correct Answers -- spherocytes
- agglutination
- lipemia
- hemolysis
- icterus

increased MCV - Correct Answers -macrocytes

decreased MCV - Correct Answers -microcytes

decreased MCH, MCHC - Correct Answers -- RBCs have less hgb
- increased central pallor
- hypochromasia

decreased HGB, MCH, MCHC - Correct Answers -- abnormal production
- anemias

MCV normal, increased RDW - Correct Answers -- dual pop

,- variation in cell size
- possible recent transfusion

Under-filling the EDTA blood collection tube - Correct Answers -- increased
anticoagulant
- Erroneous low blood cell counts & hematocrits
- Morphologic changes to RBCs and WBCs
- Staining alteration
- Excess EDTA can shrink red cells

Interstitial fluid from a skin puncture or the improper flushing of a catheter causes
_______________ Hct readings - Correct Answers -decreased

Blood smears should be prepared within __________ hours of collection - Correct
Answers -two

Evacuated EDTA specimens should be analyzed within _____ hours of collection, kept
at _______________ until analysis - Correct Answers -- six
- RT

Micro collection EDTA tube specimens should be stored at _____ and analyzed within
_____ hours. - Correct Answers -- RT
-4

Changes in Blood at Room Temperature - Correct Answers -- MCV: increased due to
cell swelling
- HCT: increased due to increased MCV
- WBC: decreased due to cell lysis
- WBC morph: increased necrotic cells, vacuolization

Over-filling the EDTA blood collection tube - Correct Answers -- Prevents proper mixing
- may lead to platelet clumping and clotting
- Clotted Specimen: Reject

NCCLS recommends the tube be filled to _______ of the stated draw volume - Correct
Answers -± 10%

MCV RI - Correct Answers -80-100 fl

MCH RI - Correct Answers -27-31 pg

MCHC RI - Correct Answers -320-360 g/L

RBC indices: HCT - Correct Answers -RBC x MCV
1000

, HCT RI - Correct Answers -M: O.40-0.54 L/L
F: 0.35-0.49 L/L

Absolute Diff calculation - Correct Answers -Analyzer WBC count x Relative Count (%)
- Reported in x 10^9/L

RBC RI - Correct Answers -M: 4.6 - 6.0 x 10^12/L
F: 4.0 - 5.4 x 10^12/L

HGB RI - Correct Answers -M:140 - 180 g/L
F: 120 - 150 g/L

RDW RI - Correct Answers -11.5 - 14.5 %

PLT RI - Correct Answers -150-450 x 10^9/L

WBC relative RI - Correct Answers -Neutrophils 0.50 - 0.70 Ratio
Bands 0.00 - 0.05 Ratio
Lymphocytes 0.18 - 0.42 Ratio
Monocytes 0.02 - 0.11 Ratio
Eosinophils 0.01 - 0.03 Ratio
Basophils 0.00 - 0.02 Ratio

automated cell counters: Hydraulics & Pneumatics - Correct Answers -vacuum &
pressure to 'pull' sample & diluent through tubing and baths

Automated Cell Counters: Cell Counts- optical light scatter - Correct Answers -- uses
laser light
- angle of light scatter correlates to cell size and complexity
- forward scatter= size
- side scatter= complexity

Automated Cell Counters: Cell Counts- electronic impedance - Correct Answers --
Blood is diluted in an isotonic electrolyte solution
- Cells passing through an aperture will displace its own volume of isotonic solution and
increase the resistance
- resistance is represented as a pulse
- sum of pulses= total cell count
- pulse height directly proportional to cell size

cause of right shift on RBC histogram - Correct Answers -- macrocytes
- WBCs counted as RBCs

causes of right shift of PLT histogram - Correct Answers -- small RBCs counted at plts
- giant plts
- RBC fragments