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Flashcards in Haematology Deck (50):
1

Four factors that natural haemostasis relies on?

Vascular endothelium

Platelets

Coagulation factors

Fibrinolysis

2

What platelets formed from, what protein stimulates that?

Formed from megakaryocytes. Stimulated by thrombopoietin.

3

What organ mostly produces thrombopoeitin?

The Liver

4

Lifecycle of a platelet?

Circulate for 6-8days and are then destroyed in the spleen.

5

What will a blood film and a blood count tell you about platelets?

Number and shape of platelets

Can reveal different disorders such as leukaemia

6

Examples of coagulation tests?

PT (prothrombin time)
APTT (Activated Partial Thromboplastin Time)
PTTK
Thrombin Time

7

Prothrombin time is elongated in what disorders?

- Abnormal factor II, V, VII, X
- Liver disease
- Warfarin
- Vit K deficiency
- DIC (disseminated intravascular coagulation)

8

What is Disseminated intravascular coagulation? (DIC)

Pathological condition in which there is abnormal activation of the clotting cascade and blood clots form in small vessels around the body.

9

What is INR?

Special Prothrombin time - used for monitoring warfarin.

10

Activated Partial Thromboplastin Time (APTT) is prolonged in what?

- Deficiency/ inhibition of II, V, VIII, IX, X, XI, XII (not VII) – NB XII deficiency can be asymptomatic
- Unfractionated heparin therapy (not LMW heparins)
- Liver disease
- Vit K deficiency
- DIC

11

How does a correction test work?

Adds normal plasma to patients plasma and if that corrects the clotting time there is a deficiency. If not it is likely there is an inhibitor present.

12

Different types of purpura?

Senile - associated with old age and small trauma (benign)

Henoch-schonlein - associated with children following infection, mostly harmless, can lead to CKD

Steroid induced

Infection associated purpura

Thrombotic thrombocytopenic purpura

13

What is purpura?

A rash of purple spots on the skin caused by internal bleeding from small blood vessels.

14

Causes of thrombocytopenia?

Drugs, chemicals and viral infections - lead to megakaryocyte depression

Leukaemia, lymphoma, aplastic anaemia. HIV - bone marrow failure

DIC, Thrombotic thrombocytopenic purpura (TTP), Heparin - increased platelet production leads to splenomegaly.

15

Congenital causes of platelet disorders?

Bernard-soulier

Glazmanns

16

Acquired causes of platelet disorders?

NSAIDs
Renal Failure
Cardiopulmonary bypass (the pump in surgery)
Myeloproliferative disorders

17

Examples of coagulation disorders?

Congenital:

- Haemophilia (A and B)

- Von-willibrand disease (deficiency in von-willibrand factor)

- Factor XI deficiency

Acquired:

- Vit K deficiency
- Liver disease
- DIC
- Anticoagulant drugs

18

What is the diagnosis?

- 4 year old boy with increased bleeding tendency
- No FHx
- Prolonged APTT, other clotting times are normal
Corrects with normal plasma
- Factor VIII assay is low

Haemophilia A

19

Types of Haemophilia, what are they lacking in each?

A - lacking factor VIII (8)

B - lacking factor IX (9)

20

Management of haemophilia?

Refer to a haemophilia centre - screen mother and siblings

Mild haemophilia treated with tranexamic acid and desmopressin

Severe will require factor VIII replacement

Avoid use of NSAIDS and injections if at all possible

21

Symptoms of anaemia?

Lethargy

SOB

Angina

headache

22

Causes of anaemia?

Bleeding

Iron, B12, Folate deficiency

Malabsorption

Systemic illness

Haemolysis

Inherited RBC disorders

Bone marrow failure

23

Causes of microcytic anaemia?

iron deficiency, haemoglobinopathies (including thalassaemias)

24

Causes of normocytic anaemia

Anaemia of chronic disease

25

causes of macrocytic anaemia

B12/Folate deficiency

26

Features of B12 deficiency anaemias?

Hypersegmented neutrophils

Macrocytic and oval red cells

Mild Jaundice

Peripheral neuropathy

27

What is pancytopaenia?

deficiency of white cells red cells and platelets in the blood

28

Causes of pancytopaenia?

- Bone marrow failure/infiltration (leukaemia, lymphoma, carcinomas, myelofibrosis)
- Septicaemia
- Splenomegaly
- Immune-mediated destruction

29

Types of leukaemia?

Acute - myeloid (AML) or lymphoblastic (ALL)

Chronic - myeloid (CML) or lymphocytic (CLL)

30

What is acute leukaemia defined as?

>20% of nucleated bone marrow cells are blasts

31

Causes of leukaemia?

- Ionising radiation
- Viruses
- Chemicals
- Congenital factors
- - Acquired haematological disorders

32

Most common type of cancer in pts below 15 yrs

ALL

33

Most common type of cancer in pts above 50 yrs

AML

34

Clinical features of leukaemia (ALL and AML)?

Anaemia
Neutropenia
Thrombocytopenia

35

Clinical features of CML?

• Fatigue
• Malaise
• Anorexia
• Abdominal discomfort (splenomegaly/ splenic infarction)
• Excessive sweating from hypermetabolism
• Pallor
• XS WBC breakdown = gout
• Priapism (painful persistent erection from hypercoagulation)

36

Most common type of leukaemia overall?

CLL

37

Triphasic course of CML?

1) Chronic
2) Accelerated course

38

Features of CLL?

• Insidious onset
• Proliferation and accumulation of immune incompetent B-lymphocytes
• Associated with infiltration of lymph nodes, spleen and liver
• Infection is common due to neutropenia, hypogammaglobulinaemia, impaired immunity
• Can lead to diffuse lymphoma/Richter’s syndrome or PLL

39

Role of von willibrands factor?

Helps Platelets stick to the endothelium

40

Basic coagulation cascade?

Prothrombin --- Thrombin

Fibrinogen --- fibrin

Fibrin goes on to form a fibrin polymer and then with factor XIIIa forms stable fibrin.

41

The anti coagulation cascade basic steps?

Plasminogen --- plasmin

Plasmin converts fibrin to soluble products

42

What is idiopathic acquired aplastic anaemia?

Intrinsic stem cell defect, where your bone marrow no longer produces cells, due to:

- Failure of stromal microenvironment

- Growth factor defect or deficiency

- Immune suppression of the marrow

43

Symptoms of idiopathic acquired aplastic anaemia?

Fatigue
Bleeding
Infections

44

Lab investigations for anaemia?

Blood count and film

Haematinics

B12, folate, ferritin

Inflammatory indices

Reticulocytes

Special tests:

- Bone marrow biopsy
- Special tests for haemolysis

45

Lab features of iron deficiency?

Low haemoglobin

Low ferritin (low iron stores)

Blood film appearances:

- Hypochromic, microcytic cells,
- Pencil shaped cells
- Target cells
- Increased variation in red cell shape

46

Lab features of folate deficiency?

Hypersegmented neutrophils (same as b12)

Macrocytic and oval red cells (same as b12)

Low serum folate

Low red cell folate

47

Lab findings for anaemia of chronic disease?

Most are normal

48

Lab findings in haemolytic anaemia?

Decreased Hb

Raised reticulocyte (immature red cell without a nucleus) count

Red cells show altered red cell shape and colour

(depending on underlying cause of haemolysis)

Serum bilirubin raised
Serum haptoglobins low or absent

49

Tests to diagnose leukaemia?

Examination of blood and bone marrow

Cell morphology

Flow cytometry to detect antigens and cell surface molecules

Cytogenetic studies

50

Lab findings for idiopathic acquired aplastic anaemia?

Pancytopenia
Low reticulocyte count; red cells may be macrocytic
Marrow markedly low in cells
Neutrophil count low
No abnormal cells in the peripheral blood
Normal cytogenetics