Session 5-Haemostasis, Thrombosis And Embolism

Question 1

Define thrombosis

Answer 1

Formation of solid mass of blood within circulatory system

Question 2

Why does thrombosis occur? (3)

Answer 2

1) abnormalities of vessel wall
2) abnormalities of blood flow
3) abnormalities of blood components

Question 3

What vessel wall abnormalities can lead to thrombosis?

Answer 3

Atheroma (more important in arterial, not venous, thrombosis)
Direct injury
Inflammation

Question 4

What blood flow abnormalities can lead to thrombosis?

Answer 4

Stagnation

Turbulence

Question 5

Describe the appearance of arterial thrombi (4)

Answer 5

1) pale
2) granular
3) lines of Zahn
4) lower cell content

Question 6

Describe the appearance of venous thrombi (4)

Answer 6

1) soft
2) gelatinous
3) deep red
4) higher cell content

Question 7

Why are arterial thrombi paler than venous thrombi?

Answer 7

RBC content is lower in arterial thrombi

Question 8

What are the outcomes of thrombosis? (5)

Answer 8

1) Lysis
2) Propagation
3) Organisation
4) Recanalisation
5) Embolism

Question 9

What happens in lysis?

Answer 9

1) Complete dissolution of thrombus
2) Fibrinolytic system is active
3) Blood flow is re-established

Question 10

When is lysis most likely?

Answer 10

When thrombi are small

Question 11

What happens in propagation?

Answer 11

Progressive spread and enlargement of thrombosis

Question 12

In which direction do thrombi propagate in:

1) arteries
2) veins?

Answer 12

1) dismally

2) proximally

Question 13

True or false: turbulence causes more thrombi to form

Answer 13

TRUE

Question 14

What happens in organisation of thrombosis?

Answer 14

Ingrowth of fibroblasts and capillaries (replace the thrombus)
Lumen remains obstructed

Question 15

What happens in recanalisation?

Answer 15

Blood flow is re-established but usually incompletely

One or more channels formed through organising thrombus

Question 16

What happens in embolism?

Answer 16

Part of thrombus breaks off and travels through blood stream and lodges at distant site

Question 17

What are the effects of arterial thrombus?

Answer 17

Ischaemia

Infarction

Question 18

What are the effects of venous thrombus?

Answer 18

Congestion
Oedema
Ischaemia
Infarction

Question 19

Define embolism

Answer 19

Blockage of blood vessel by solid, liquid or gas at site distant from its origin

Question 20

What are 90% of emboli?

Answer 20

Thrombo-emboli

Question 21

What are other types of embolism?

Answer 21

Air
Amniotic fluid 
Nitrogen
Medical equipment 
Tumour cells
Septic emboli

Question 22

What is pulmonary emboli?

Answer 22

From systemic veins to lungs

Question 23

What are the predisposing factors of deep vein thrombosis? (7)

Answer 23

1) immobility/bed rest
2) post-op
3) pregnancy
4) oral contraceptives
5) severe burns
6) cardiac failure
7) disseminated cancer

Question 24

What are flowtron boots?

Answer 24

Inflate and mimic muscle pump of calf to assist venous return

Question 25

How can DVT be treated?

Answer 25

1) intravenous heparin type drugs (prevents propagation)

2) oral warfarin (anticoagulant)

Question 26

What happens in a massive pulmonary embolism?

Answer 26

> 60% reduction in blood flow is rapidly fatal

Question 27

What happens in a major pulmonary embolism?

Answer 27

Medium sized vessels blocked
Patients are short of breath
Cough and blood stained sputum

Question 28

What happens in a minor pulmonary embolism?

Answer 28

Small peripheral pulmonary arteries blocked

Asymptomatic or minor shortness of breath

Question 29

What do recurrent minor pulmonary embolisms lead to?

Answer 29

Pulmonary hypertension

Question 30

When does fat embolism occur?

Answer 30

When long bone fractures, fracture leads to release of bone and marrow which enters blood stream and can enter brain