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Flashcards in Intro to Hematology Deck (48)
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What conditions may altered erythrocyte numbers show?

^ = erthyrocytosis v = aneamia


When may leukocytes be analysed/what can they show?

Inflammatory conditions Neoplastic conditions Chemotherapy (check for leukopenia)


What can platelets show?

Bleeding disorders DIC (Disseminated Intravascular Coagulopathy)


How is plasma assessed?

Colour - should be clear/straw - if pink = heamolysis - if yellow = icterus


What two aspects of blood cells are assessed?

Number (often by machine) Morphology in blood smears (should still be checked if only briefly to confirm machine findings)


What can PCV show?

Aneamia/Dehydration Buffy coat assessmnet Plasma colour Total protein measurement from plasma once layers have been measured [check these values against machine]


What form of RBCs may be released into the circulation if the BM is struggling to keep up with the demand for cells?

Reticulocytes/polychromatophils Still un-nucleated (pre-cursor to these has nucleus and is rarely released into bloodstream)


What is RBCC?

Red blood cell concentration


What is HGB?

Total heamoglobin - if RBCs are being lysed this Hgb is released and value ^ (?)


What is HCT?

Heamatocrit Equivalent to spun PCV but calculated differently - machine calculates by measuring size and number of RBCs.


What is MCV?

Mean Cell Volume Will be increased if blood cells are being produced at a rapid rate and immature cells released into circulation. Will be decreased if Hbg is low/being lost


What is MCH?

Mean Cell Heamoglobin Hbg per cell


What is MCHC?

Mean Cell Heamoglobin CONCENTRATION Amount of Hbg per unit VOLUME of blood - dependent on size of cell (larger cells will require more Hbg for same concentration per unit volume) This is associated with RBC maturation - will keep dividing until have sufficient Hbg concentration


What is RDW?

Redcell Distribution Width Shows uniformity/variability of cell sizes Will be greater if ^ demand for cells is meaning immature cells are released into the circulation


How is ameamia classified (3 stages) ?

1. Mild / Moderate / Severe [different differentials] 2. MCV - Normocytic / Microcytic / Macrocytic 3. MCHC - Normochromic / Hypochromic [Hyperchromia does not exist as a pathology as RBCs are released when sufficient Hbg has been added. Thus only an artifact of RBC lysing etc.]


What is the ultimate Q we try to answer when investigating aneamia?

Regenerative or non regenerative?


When are normocytic cells seen associated with aneamia? What will be noted about normocytic cells in anemic animals?

Mild, NON-regenerative - acute heamorrhage etc > will be ^ spacing between cells


When are microcytic cells seen?

Iron deficiency, PSS, Hepatic failure, AKITAS [congenital breed difference] - MCHC determines when division of immature RBCs stops - Fe deficiency allows more division -> smaller cells to maintain same concentration


When are macrocytic cells seen?

Regeneration - immature RBCs have not condensed, released as polychromatophils POODLES [congenital breed predisposition - still pathological]


When are hypochromic cells sen?

v Hbg concentration due to Fe deficiency or poor Fe incorporation (with microcytosis) Associated with MCHC/MCH on blood panel


Why may RBCs appear see through or just have an outline?

v thickness / v volume (not necessarily v diameter)


What are the 2 differentials for regenerative anaemia?

Heamolysis (eg. immune mediated) Heamorrhage


What are the most common differentials for non-regenerative?

Anaemia of chronic/inflammatory disease (mild) Chronic renal failure (severe) Decreased production in BM If acute stages of anaemia will appear non-regenerative as marrow still catching up


How can regenerative anaemia be distinguished?

^ no reticulocytes


How do reticulocytes and polychromatophils differ?

They are the same cell when prepared in different ways. IDed due to the cell still containing "machinery" that enables them to make Hbg. Should lose this before being released as fully mature cells. - Polychromatophil = Diff-Quick/Giemsa stain, immature cells show as LARGER and BLUER cells. - Reticulocytes = New Methylene Blue stain, which causes RNA to precipitate and form aggregates/reticulum.


Do polycromatophils continue to mature once released into the blood stream?



Which species have different reticulocytes? How do they differ? How does this affect analysis?

Cats Cat retics released as "aggregate retics" then mature to "punctate retics" over time When counting retics only these populations separately and not lumped together. If only one is counted this should be aggregate.


How is reticulocyte % calculated?

1000 red cells counted, retics expressed as a percentage Must be CORRECTED for PCV of the patient Retic % x patient's PCV/normal PCV (Otherwise same no. reticulocytes will give greater % in an anaemic animal)


What is the normal reticulocyte % in healthy dog/cats?

~45% dog ~35% cat


What difference in reticulocyte % is clinically significant?

>1% dogs >0.4% cats