Blood

Question 1

stats for:

how much rbc?

how effective?

how large

shape?

lifespan?

f?

Answer 1

• 4.4 -5.9x10^12/L
• Hb = 13.5-16.7 g/dL
• MCV mean corpuscular volume) 80-100fl
• biconcave flexible disc -~8microm diameter
• 120 days
• deliver oxygen to tissues , carry Hb, maintain Hb in its ferrous (reduced state), maintain osmotic equlibirum and generate energy

Question 2

what causes RBC shape changes? and what does this causes?

name 1 condition

Answer 2

• changes to the components of the membrane
• causes them to become more fragile and less deformable, so spleen recognises them as abnormal and takesn them up, which cancause haemolytic anemia
• spherocytosis

Question 3

what is the structure of erythrocyte structure?

Answer 3

• Ankyrin ; spectrin, band 3 and 4.2

Question 4

What are the instruments, and turn over time for UHL haem labs?

Answer 4

• 9 FBC analysers , 6 coagulation analysers
• URGENT (A&E) 1 hour
• Non-urgent (ward patients)

Question 5

normal vs abnormal results

what affect normal results

Answer 5

• normal ranges = 95% of healthy population levels, but not everyones falls into the catergory, what you do is multiple tests and see if theres a drop, that would be abnormal
• gender, sex, ethnicity, co-morbidities

Question 6

why do we get abnormal b results?

Answer 6

• due to issue or reactionof the blood (EDTA)

Question 7

what errors can occur in;

• specimen collection
• delivery of specimen to lab
• specimen analysis and result reporting
• responsive action

Answer 7

• specimen mix up/ Wrong blood in tube(WBIT) / pooling of sample (combinined fluids like urine and blood) / poor technique
• delayed specimen/not delievered/wrong delivery method
• specimen mix up/ incorrect clinical details/wrong test performed/inherent test variability/technical error
• result not reviewed/reflex tests not carried out(reflex tests =additional tests)/right result applied to wrong patient

Question 8

what are essential parameters of FBC?

what analysis techniques used?

Answer 8

• platelets / RBC /Hb/ WBC
• spectrophotometry ; (amount of light abosred by sample proportional to amount of absorbant compount within ite.g used to meaure Hb. it isues hypotonic solution to lysis cells and release Hb, then use light as the wavelength and use calibration curve to determine the sample concentration)
• Flow Cytometry ; involves cells in single line and light baem passing through, forward scatterng = size. and side scatter =whether mono/polymorphonuclear, or inreaceullar complexities like granules) can check myeloperoxidase activity = important in inflammation detection

Question 9

PCV?

why used?

why shouldnt you always trust polycythenia results?

Answer 9

• packed cell volume aka haematocrit (L) allows you to see what proportion of blood allows visualisation
• used to assess anaemia and polycythemia
• pseudo polycythenia due to less water = less plasma so higher haematocrit

Question 10

hb levels for

men

women

children 3-puberty

newborns

Answer 10

>135g/L

>115g/L

>110g/L

>150g/L

Question 11

whats in vitro vs in vivo haemolysis?

what do they cause

Answer 11

• in vitro= haemolysis due to cellulr damage
• in vivo = RBC haemolysis due to increase in erythrocyte destruction rate or decreased erythrocyte life span
• reduced Hb

Question 12

why do a RBC specifically? RCC of examples fo each

Answer 12

to test for anaemia and erythrocytosis (body makes ^RBC which can rsult in polycythesia)

• microcytic anaemia (RBCunsually small) ; iron deficiency anaemia = lower RBC because smaller RBC less Hb so less iron // thalassemia triat = higher RCC because lots of RBC but have defective hb

Question 13

how do we measure size of RBC?

Answer 13

lighter scattered as they pass in a single fine past a laser

Question 14

causes of anaemia

Answer 14

• megalablastic anaemia (vitB12, folate) = iron deficeny anaemia
• liver disease

Question 15

what’s increased mean cell haemoglobin conc (g/L)

and why do we do it?

Answer 15

^ = spherocytosis (mishaped RBC si bone marrow makes more ‘normal’RBCsooverall higher PCV and higher MCHC

• most important test to identify of cold aggultinins (antibodies produced by body that target RBC and aggregate them together increasing risk of them being destroyed so increased number od cold aggulins = decreased RBC = decreased MCHC) caused by viral/mycoplasma infections

Question 16

whast RCDW? ^ levels? why do we do it?

Answer 16

red cell distribution width = variation in sizeof RBC

anisocytosis (pateints RBC sized are unequal)

used to assess causes of anaemia = increased in iron deficiency especially in nutrients like folate, v12 deficeiency because they are larger) / usually ormal in thalassemia trait / increased flowing transfusion

Question 17

whast rc adn unit? how is it indentified?

Answer 17

reticulocyte count

measurement of the number of young erythrocytes

identified using size and RNA content

Question 18

what’s a blood film and why use it?

what do you need to consider with it?

Answer 18

• only do it if sample is plagged so if significant results or change really out of nomral range

takes longer to get results

Question 20

what is a blood sample placed in and why?

Answer 20

• blood tube containing EDTA because it contains ca2+ wc mixes with the blood and chelates it acting like an anticoagulant, without itthe blood would clot

Question 21

what should you do with a UE analysis of blood?

Answer 21

neverpour it from the FBC b test tube, because there’s k+salt in EDTA wc will c a high k+ reading

Question 22

How is WBC measured

Answer 22

-automatatic counting involved a ligth beam, but first it has to be lysed out from RBC sample

Question 23

how is RBC count done

Answer 23

-same as WBC so with autated interrupted beam of light or electrical current tht counts them as they move as a line through a narrow tube)

Question 24

how do you measure Hb conc

Answer 24

amount of Hb g/L

• lysis of RBC and then convert Hb to astable form then carry out spectrophotometry

Question 25

HCT

what has changed now?

Answer 25

haematocrit

• fraction of whole blood that consists of RBC only
• measured vi a centriduge, you would get the PCV (packed cell volume - so height of haematocrit, but that has been replaced by another calcualtion;

MCV (mean corpuscle volume; averagesize of RBC) x numer of RBC per litre to give haematocrit

Question 26

MCV

Answer 26

mean corpusclar volume

average red blood volume measured in femtolitres (10^15)

• useful in determining macrocytic and microcytic anaemia

Question 27

MCH

Answer 27

mean cell hb

• average amount of Hb (measured in pg (10^-15kg) in 1 RBC

so do this by ; Hb in given volume/ umberof rBC in given volume

Question 28

platelets count

Answer 28

• same analyser but smaller signal because its smaller

Question 29

Reticulocyte count

Answer 29

• immature RBc releaed into blood,
• reticulotey/Hct %
• good for distinugishingif the bone marrow is wrking or not

Question 30

what’s a blood film

Answer 30

blood smear to check the shape of RBC

• dropof blood, thinly then dispersed used a spreder slide to make sure ,onolayer of cells then viewed under microscope, dried in methanol
• used for aprastites, shapes of RBC, count physical WBC/RBC adn for cell abnormlaits like membrane defects, thrombotic thrbocytopenic purpura

Question 31

Answer 31

thrombotic thrombocytopenia purpura

-b clots in small vessels c thrombocytopenia

Question 32

low MCV?

Answer 32

microcytic anaemia ( TAILS)

<80fl (10^-15 litres)

Question 33

high MCV

Answer 33

macrocytic (nomegaloblastic ; liver disease, alcoholism, diamond-blackfan anaemia ) OR megaloblastic ;Vit B12/ folate deficency , or orotic anaemia (orotic acid is a mineral carrier),or defective DNa repair (Fanconi aneamia ; cant repair damagedDNA)

Question 34

low MCH

Answer 34

• microcytic (TAILS)
• dont do this for macro nomegaloblastic anaemic b it has normal hb just ^ cell d ^ lipid in mitochondira