w8 hematology Flashcards
what does hematology study
blood and blood forming tissue
two devisions of hematology
- hematology- studies formed elements in blood and other body fluids. rbc wbc and platelets
- coagulation studies the process of clotting
what is primary hematology test
CBC- complete blood count
automated analyzers
help diagnose anemia, leukaemia and infection
-number of rbc, wbc, and platelets
-hemoglobin concentration
-leukocyte differential (percent count of each type of red blood cell)
EDTA
CBC collected in EDTA ethylenediaminetetraacetic acid
prevents clotting and preserves cell morphology
must be clot free and homogenous
other non-blood hematology specimens
bone marrow aspirates, cerebral spinal fluid, joint fluids, semen
pre-analytical hem prep by MLA
- check volume and quantity
- clotted specimens can’t be tested
- load onto rocker-mix
- load onto cassette analyzer
- PBS
- staining other body fluid
- coverslipping
what does coag do
investigates clotting and bleeding disorders: haemophilia and thromboembolisms
-sodium citrate tubes (prevent clotting)
pre analytical-centrifuge higher speeds for longer to ensure a platelet poor specimen, plasma aliquoted off
PBS, why is it used
peripheral blood smears used for the microscopic evaluation of morphology of blood cells- it depends highly on proper cell distribution
two ways to manually make smears
- specail spreader mounted in a smear making device=consistent smears but needs to be cleaned a lot
- use another hematology slide as spreader -once slide used to smear blood it can be used for the next specimen or discarded
factors that effect quality of smear (5)
- age of specimen- morphology changes within 2-4 hrs-fridge come to room temp, prepare slides with freshly collected specimen- no longer than 24 hrs
- very clean slides with edges free of nicks-inspect for damage
- correct size of drop from well mixed tube 3mm
- quick smearing action after drop -dry=abnormal cell distribution and streaks
- correct consistent technique
correct consistent PBS
30 degree angle
spreader drawn back slowly into drop of blood, entire drop is allowed to spread along the spreader edge almost to the width of the slide then spreader is pushed away in a quick and smooth and straight motion keeping 30 degree angle
monolayer
rbc are evenly spaced while being viewed microscopically.(not overlapping)- monolayer visible under fluorescent lights- it looks like a rainbow
what does a good smear look like
- 3-4 cm
- thick to thin
- bullet or rectangular shape
- adequate monolayer
- thin edge free of tails or nicks
- not to end of slide
- no ridges wavy lines holes
- have an even wbc distribution when brewed microscopically
smear too short and thick
caused from: spreader angler greater than 30
and pushed too fast
smear too long and thin
spreader angle less than 30
or pushed too slowly
tails or streaks in smear (3 reasons)
- drying of drop creates streaks
- tails caused from lifting spreader at end
- spreader has nicks on end
monolayer too narrow on smear
this results from a smear that is too short and thick
monolayer too wide on smear
this results from a smear too long and thin
smear with holes and lumps
dirty or greasy slide results in holes
lint creates lumps
waves on smear
uneven spreader motion
chatters on smear
uneven pressure when spreading