Haematology Flashcards
What are the 3 components of whole blood
Red Cells
Platelets
Plasma
What are the 3 types of plasma used for blood transfusions
Fresh Frozen Plasma (FFP)
Cryoprecipitate
Plasma for fractionation
What 3 components can be collected from plasma fractionation
Albumin
Coagulation factors
Antibodies
What are the 3 cellular components of blood
Red Cells
White Cells
Platelets
Where are the cellular components of blood mainly produced
Bone Marrow
How many ml of RBC are in a unit for blood transfusions
280ml
What temperature are RBC stored at
4 degrees C
How long can RBCs be stored for
35 days
What is the name of the fluid medium used to store RBCs
Additive fluid
What are is the alternative name for Red Blood Cells
Eurythrocytes
What is the alternative name for platelets
Thrombocytes
How are thrombocytes obtained
From pooling platelets extracted from whole blood donations
How many Donors = 1 Pool
4 Donors
What is aphaeresis
Cell Separator machine used to obtain thrombocytes
What temperature are platelets stored at
room temperature
What is done to prevent platelets from clumping together
They are agitated on a plate
How long do platelets last, and why not longer
7 days, due to risk of bacterial infection
What is required and not required when transiting platelets
Correct blood group, no crossmatching required
Where are the plasma components of the blood made
liver
What are the 3 plasma components of blood
clotting factors
albumin
immunoglobin
What is FFP used for
Good source of coagulation factors
What is required and not required when administering FFP
Same blood group, no cross-match required
How much is one unit from one donor
300ml
what temperature is FFP stored at
-30 degrees C
how long can FFP be stored for
up to 1 year
How long does it take to thaw FFP
20-30 minutes
FFP must be given ASAP, why
coagulation factors degenerate over time
What is the average dose of FFP in ml/kg
12-15ml/kg
How is cryoprecipitate obtained, and why is it obtained in this way
by thawing plasma slowly to precipitate out the higher molecular weight proteins in the plasma
what temperature is FFP defrosted to obtain cryoprecipitate, and for how long
4-8 degrees C overnight
What are 2 examples of higher molecular weight proteins in plasma
Fibrinogen
Factor VIII
What are Cryoprecipitate a source for during haemorrhage
Fibrinogen
What temperature is cryoprecipitate stored at
-30 degrees C
How long is Cryoprecipitate stored for
1 Year
What is the standard dose of cryoprecipitate
10 donors
What are the 2 indications where cryoprecipitate should be used
Massive bleeding, where fibrinogen is low
Hypofibrinogenaemia (Rare)
What are the three blood groups
A
B
O
Blood groups are …… on the blood cell surface
antigens
What type of inheritance are blood groups A and B
Co-dominant
What type of inheritance is Blood group O
Recessive
What determines the antigens on the red cell surface
Genetically determined, occur through the presence/absence of certain enzymes acting on the O antigen
What blood group does a person with only the Gal Transferase enzyme have
B
What blood group does a person with the GalNAc Transferase enzyme have
A
What blood group does a person with both GalNAc and Gal Transferase enzymes have
AB
What blood group does a person with neither the GalNAc and Gal transferase enzymes have
O
How how long before birth do ABO antibodies form
3-6 months
What type of antigen are the ABO antibodies, and what 2 things can they do
IgM
Agglutinate
Activate compliment
What 2 things are unusual about the ABO antibodies
They are naturally occurring
Develop antibodies to antigens you don’t have
What are the antigens on Red cells in blood group A
A
What are the antigens on Red cells in blood group B
B
What are the antigens on Red cells in blood group AB
A and B
What are the antigens on Red cells in blood group O
None
What antibodies are present in plasma for those with blood group A
Anti-B
What antibodies are present in plasma for those with blood group B
Anti-A
What antibodies are present in plasma for those with blood group AB
None
What antibodies are present in plasma for those with blood group O
Anti-A and Anti-B
Which blood group is the universal recipient
AB
Which blood group is the universal donor
O
What percentage of people are Rhesus positive
85%
What percentage of people are Rhesus negative
15%
What determines Rhesus positive/negative
Two Genes, D and d
Which alleles code for Rhesus positive
DD or Dd
Which alleles code for Rhesus negative
dd
What 2 things are anti globulin tests used for
Cross-matching to ensure donor compatibility
Investigate haemolysis
What two things are a Direct Antiglobulin Test (DAT) used for
To detect the cause of haemolytic anaemia investigator transfusion reaction
Diagnose haemolytic disease in a newborn
What is a Direct Antiglobiuin test also know as
Coombs Test
What does the DAT determine
If there are any antibodies on the red cell surface
What happens during a DAT
Anti-globulin is added to the patient red cells
Red cell aggregation occurs is antibodies are present on the red cell surface
What is the Indirect Antiglobulin test used to detect
Antibodies directed against red blood cell antigens
What 2 things is an Indirect Antiglobulin test used in preparation for
Blood Transfusion
Pregnancy
What temperature are the test RBC incubated at during an IAT
37 Degrees C
Why is Antiglobulin added during a DAT or IAT
To detect any antibody present on the red cell surface
How is the Indirect Antiglobulin test performed
Patient serum containing antibody is added to test RBCs
These are incubated at 37 Degrees C
Antiglobulin is added to see for agglutination
During an DAT or IAT, what does agglutination mean
Red Cells are coated with a particular antibody
What are the 2 main functions of the coagulation system
Control of bleeding
Allow vessels to be repaired
What is primary Haemostasis
Formation of platelet plug and vasoconstriction
What is secondary haemostasis
Coagulation factors are activated, and thrombin in generated
What does thrombin convert fibrinogen into
fibrin
What stabilises the soluble clot formed by fibrin
Factor XIII (8)
What process breaks down fibrin
fibrinolysis
What are the 5 steps in primary haemostasis, starting from injured blood vessel
Injured Blood Vessel Exposure of collagen Platelet adhesion Activation and degranulation of platelets aggregation of platelets
What is von Willebrand factor used for
Platelet adhesion
What are the 3 stages of secondary haemostasis
Initiation
Propagation
Amplification
What 3 conversions happen during initiation
Factor VIIa and Tissue Factor combine to form TF-VIIa complex
TF-VIIa complex converts IX to IXa
TF-VIIa complex converts X to Xa
What 3 conversions happen during propagation
Factor XI converted to XIa
XIa converts IX to IXa
IXa and VIIIa convert X to Xa
What 2 conversions happen during amplification
Xa converts II to IIa
IIa converts fibrinogen to soluble fibrin
What is an alternative name for Factor II
Prothrombin
What is an alternative name for Factor IIa
Thrombin
Which factor converts Soluble fibrin into insoluble cross-linked fibrin
Factor XIIIa (8a)
During secondary haemostasis, which 3 stages require Calcium 2+ ions
Conversion of IX to IXa
Conversion of X to Xa
Conversion of II to IIa
During secondary haemostasis, which 2 stages require Platelet phospholipid
Conversion of X to Xa
Conversion of II to IIa
What are 3 examples of natural anticoagulants
Antithrombin
Protein C
Protein S
How is the coagulation system controlled
Inhibition on thrombin formation and breakdown of fibrin clots
What 2 factors does antithrombin inhibit
Factor Xa and Thrombin
What 2 factors does protein S and activated protein C inhibit
Factors V and VIII
During fibrinolysis, what is plasminogen converted into
plasmin
What does plasmin do during fibrinolysis
converts fibrin into fibrin degradation products
What does Alteplase (t-Pa) do
thrmobolyse (break down) the patient clot
Which test would be used to investigate possible defects in primary haemostasis
PFA-100
What 3 things usually causes defects in primary haemostasis
Platelet number
Platelet function
von Willebrand disease
What is thrombocytopenia
Low platelets
What characterises primary haemostasis defects
muco-cutaneous bleeding
What are 9 examples of muco-cutaneous bleeding
Easy/spontaneous blruising Petechiae/purpura Epistaxis (Nose Bleeds) Menorrhagia (heavy periods) Prolonged bleeding following minor trauma Operative bleeding Intramuscular haematoma (rare) Intracranial haemorrhage (rare) Join bleeds (very rare)
What are 4 examples of causes for acquired secondary haemostasis
Liver Disease
drugs
Vitamin K deficiency
Consumption
What is an example of a Vitamin K dependant factor
VII
How does warfare act in treating Vitamin K Deficiency
Prevents Vitamin K recycling
What are 2 examples of deficient factors causing inherited haemophilia
Factor VII and IX deficiency
Which Factor deficiency causes Haemophilia A deficiency
Factor VIII (8)
Which factor deficiency causes Haemophilia B
Factor IX Deficiency
How is Haemophilia inherited
Sex Linkage
Which chromosome is haemophilia carried on
X chromosome
Which type of haemophilia is more common
Haemophilia A
Which pathway are Factors VIII and IX involved in
Intrinsic pathway
What do deficiencies in factors VIII and IX result in, with respect to the intrinsic pathway
Prolonged activated partial thromboplastin time
What is given to severe haemophiliacs prophylactically
Regular coagulation factors
What 3 things constitute an abnormal coagulation screening
APTT prolonged
PT Normal
TT Normal
What pathway is APTT
Intrinsic Pathway
What pathway is PT
Extrinsic Pathway
What pathway is TT
Final Common Pathway
What does APTT stand for
Activated Partial Thromboplastin Time
What does PT stand for
Prothrombin Time
What does TT stand for
Thrombin Time
What is used to treat Bleeding Disorders as a general measure
Tranexamic Acid
What does tranexamic acid do
Inhibit break down of blood clots (fibrinolysis)
What is Venous Thromboembolism (VTE)
When Thrombosis blood clots affect the arterial system
What are 5 risk factors for VTE
Increasing age Obesity Dehydration Significantly reduced mobility Abnormal clotting conditions
What is thrombophilia
tendency to thrombosis
What is the name given to the administration of drugs to prevent VTE
Thromboprophylaxis
What e the 3 categories in Virchrow’s Triad
Blood Hypercoagulability
Venous Stasis/Abnormal Flow
Injury to the Vessel Wall
Where is the most common location for a VTE
Lower limb in the legs
What are the 3 most common symptoms of Deep Vein Thrombosis (DVT)
Pain
Swelling
Erythema
What is the most serious for of VTE
Pulmonary Embolism
What are 3 common symptoms of Pulmonary Embolisms
Shortness of Breath
Chest Pain
Haemoptysis (coughing up blood)
How do Pulmonary Embolisms form
Clot forms, usually in a deep vein
Clot becomes dislodged and moves to the pulmonary arteries
After 2 years, what are the chances of a recurrent VTE
20%
After 10 Years, what are the chances of recurrent VTE
30%
What are the chances of post-thrombotic syndrome aft DVT
Around 20%
What are the chances of pulmonary hypertension after Pulmonary Embolism
up to 4%
What are the 2 broad goals of treating VTE
Stop the Thrombus getting worse
Prevent the recurrence of the thrombus
What is used mainly to treat VTE
Anticoagulant
What is given to treat VTE in selected scenarios
Thrombolysis
What are anticoagulants and thrombolysis associated with
Bleeding
Name 3 examples of anticoagulants
Heparin
Direct Oral Anticoagulants (DOACs)
Warfarin
What are two ways of thromboprophylaxis, giving an example for each
Drugs - Heparin
Mechanical - Compression Stockings
What is Anaemia
The number of red blood cells, or their oxygen-carrying capacity is insufficient to meet physiological needs
What is the commonest cause of anaemia worldwide
Iron Deficiency
What is the daily production of RBCs
200 billion
What is the lifespan of a RBC
120 days
How many RBCs are destroyed each second
2.5 million
What is a reticulocyte
immature RBC
What is the 1 main difference between the reticulocyte and the mature RBC
Reticulocyte has RNA
What is the name of the Blood Stem Cell
Hemoatopoic Stem Cell
What is the major function of the RBC
Oxygen Carrier
What is the structure of haemoglobin (4)
Tetramer of 4 global folded proteins
2x alpha chains
2x beta chains
4 Haem groups
What 2 components make up the Haem group
Iron
Porphyrin Ring
What is the oxygen delivery equation
DO2 = Q x (Hb x SaO2 x 1.34 +(PaO2 x 0.003))
DO2 = Oxygen Delivery Q = Cardiac Output Hb = Haemoglobin SaO2 = Arterial O2 Saturation (PaO2 x 0.003) = Amount of O2 dissolved in the blood
What is erythropoiesis
The generation of Red Blood Cells
What are the 3 stages to recover from Low blood O2 Level
Kidneys increase production of erythropoietin
Stem Cells increase Red Cell production
O2 blood levels return to normal
Where is erythropoietin produced
Kindeys
What disease can impact the levels of erythropoietin
Chronic Kidney Disease
What is Normoxia
Normal Blood Oxygen Levels
What is Hypoxia
Low Blood Oxygen Levels
Which transcription factor increases the production of erythropoietin
HIF-1a (alpha)
Which protein is the signal transducer for erythropoietin
JAK2
What breaks down RBCs
Mcrophages
Where are RBCs broken down (3)
Spleen
Liver
Red Bone Marrow
What are RBCs broken down into
Haem
Globin
What happens to the broken down Globin
Broken down further into amino acids, which are then re-used for protein synthesis
What happens to the broken down haem
Fe3+ extracted
What protein transfers the iron from the haem
Transferrin
What does Fe3+ and Transferrin become in the liver
Ferratin
Where does Transferrin transport Fe3+
Back to the Red Bone Marrow
What 5 ingredients are required for erythropoiesis in the Red Bone Marrow
Fe3+ Globin Vitamin B12 Folic Acid Erythropoitin
What is billirubin fromed from
broken down haem
Where is bilirubin formed
Liver
What issue can stimulate the production of erythropoietin
Hypoxia
What is the average range of Hb levels in adult males
135-170 g/l
What is the average range of Hb levels in adult females
115-150 g/l
In Anaemia, what component of blood is at the highest proportions
Plasma
In Polycythemia, what component of blood is at the highest proportions
Haemocrit
What are the components measured in a full blood count
Haemoglobin
White Cell Count
Platelet Count
What are the 4 Red Cell Indicies
Mean Cell Volume
Red Cell Distribution Width
Packed Cell Volume
Red Cell Count
How is the Haemoglobin levels measured and expressed
Photometric method
expressed as a concentration g/L
How are white cells identified and expressed
Any cell with a nucleus is assumed to be a white blood cell
Expressed as n x10^9 /L
How are red cells and platelets identified, differentiated and expressed
Cells without a nucleus are considered Red Cells or Platelets
Differentiated by Size
RBC Expressed as n x10^12/L
Plts expressed as n x10^9/L
What are the three MCV subclasses of anaemia
Microcytic
Normocytic
Macrocytic
What is the MCV of microcytic cells
MCV <80fl
What is the MCV of normocytic cells
MCV 80-100fl
What is the MCV of macrocytic cells
MCV >100fl
What does a normal Red Cell distribution width mean (within the reference range of 11-15%)
There is a uniform cell population (all the cells are a similar size)
What does an abnormal Red Cell Distribution width mean
Both large and small cells are present
What 3 things is the packed Cell Volume derived from
Haemoglobin
Red Cell Count
Mean Cell Volume
What is used to differentiate Reticulocyte from an erythrocyte
Reticulocytes have RNA
What are 2 typical identifiers of iron deficiency anaemia blood films
Pencil Cell
Hypochromic Cell
What is typical of sickle cell anaemia blood films
Notable sickle-shaped red cells
What is typical of megaloblastic anaemia blood films
Hypersegmented nucleophile (due to B12 deficiency)
What is typical of haemolytic anaemia (G6PD deficiency)
Cytoplasm pertrusion
What is typical of Autoimmune Haemolytic anaemia blood films
Darker, solid RBCs
What is typical of thalassaemia blood films
Pale RBCs with ringed cytoplasm
What are 5 examples of inadequate RBC production
Haematinic Deficiency Reduced Globin Chain Production Bone Marrow Failure Inability to utilize Iron Insufficient EPO Production
What is Iron required for
Haem production
What is B12 and Folate required for
DNA production
Which compounds are deficient in Haematinic deficiency
Fe and B12/Folate
What si reduced globin chain production
Problem with the globin genes, leading to thalassaemias
What are the 13 Common symptoms for anaemia
Yellowing Eyes Paleness Cold Skin Yellowing Skin Shortness of Breath Weakness Changed stool colour Fatigue Dizziness Low Blood Pressure Heart Palpitations Rapid Heart Rate Enlarged Spleen
What are the 4 symptoms of sever anaemia
Fainting
Chest Pain
Angina
Heart Attack
What are the changes in Full Blood count and Red Cell Indices in Iron Deficiency Anaemia
Lowered Haemoglobin Increased Platelet Count decreased MCV (microcytic) increased Red Cell Distribution Width Decreased PCV Decreased Red Cell Count
What is anisopoikilocytosis
shape variation
What is anisocytosis
Size Variation
What are the changes in Full Blood count and Red Cell Indices in B12 or Folate Deficiency
Reduced Haemoglobin Normal/Lower Platelet Count Increased MCV (Macrocytic) Increased Red Cell Distribution Volume Reduced PCV Reduced Red Cell Count
What are the changes in Full Blood count and Red Cell Indices in Acute and Chronic Haemorrhage
Reduced haemoglobin Normal/raised platelets Increased Red Cell Distribution Width Reduced PCV Reduced Red Cell Count
What are the differences between Acute and Chronic Haemorrage
Normal MCV in Acute
Lowered MCV in Chronic
What can Chronic Blood Loss Lead to
Iron Deficiency
What are the changes in Full Blood count and Red Cell Indices in Haemolysis
Lowered Haemoglobin
Normal or Lowered Platelet count
Lowered/Normal/Raised MCV
Raised RCDW
What causes the Sickle Cell Shape in sickle cell anaemia
Single base substitution causes the Beta Subunit of haemoglobin to have a different shape, leading to polymerisation of the Haem, and the sickle-cell shape
What are the changes in Full Blood count and Red Cell Indices in Anaemia of Chronic Diseas
Lowered Haemoglobin
