Haemostasis, thrombosis, coagulation, fibrinolysis and platelets lecture

Question 1

What is the balance of Haemotasis?

Answer 1

Regulating the balance between Blood clotting and blood fluidity

Question 2

What controls Haemotasis?

Answer 2

Balance of pro and anti-thrombotic mediators.

Question 3

At normal conditions, what happens to Haemostasis

Answer 3

It is inhibited at normal conditions.

Question 4

What is Haemotasis?

Answer 4

the normal response of the vessel to injury by forming a clot that serves to limit haemorrhage.

Question 5

What is Thrombosis?

Answer 5

Thrombosis is the unwanted pathological clot formation that results when haemostasis is excessively activated in the absence of bleeding (haemotasis when not necessary)

Question 6

Give examples of inhibitors of Haemotasis: (7)

Answer 6

Prostacyclin, Nitric Oxide, Plasminogen activator, Thrombomodulin protein, Endothelium, Antithrmbin III, Heparin Sulphate

Question 7

Give examples of Thromboembolic diseases:

Answer 7

Deep Vein Thrombosis
Pulmonary embolism
Transient Ishaemic attack
Attack coronary syndrome
Atrial fibrilation

Question 8

What are the 5 components of Haemostasis?

Answer 8

Blood vessels
Platelets
Plasma coagulation factors
Fibrinolytic system
Inhibitors

Question 9

What are the pathways of normal Haemostastis?

Answer 9

Intrinsic and Extrinsic pathway joining to form the final common pathway

Question 10

What is the Extrinsic pathway?

Answer 10

Also known as the tissue factor pathway is the primary response to trauma

Question 11

What is the important co-factor in many of the steps of the pathway?

Answer 11

Calcium

Question 12

What promotes further thrombin production?

Answer 12

The cascade is amplified by the production of thrombin- thrombin promotes more thrombin production

Question 13

What else does thrombin activate

Answer 13

Thrombin activates the platelet plug, ultimately forming a clot

Question 14

Thrombosis can occur in what circulation?

Answer 14

Arterial or venous circulation, presenting with different pathophysiology.

Question 15

What is Venous Thrombosis associated and not associated with?

Answer 15

Associated with stasis (slow down) of the blood flow and or damage to the veins.
It is not assocaited with endothelial damage- atherosclerosis

Question 16

What is in the blood count when Venous thrombosis is occuring?

Answer 16

High red blood cell and fibrin content, low platelet count

Question 17

Why is venous thrombosis a risk during pregancy?

Answer 17

with venous thrombosis, a embolus is formed, and will travel to the right side of the heart, and possibly reach the lungs - a pulmonary embolism - and it is the highest cause of maternal death - mothers dying during or soon after pregnancy.

Question 18

What is Deep Vein Thrombosis?

Answer 18

A vorm of Venous thrombosis seen more often in the legs than the arm. In itself, it is not life threatning, but it is the risk of an embolism that is the danger.

Question 19

What are the symptoms of DVT?

Answer 19

Oedema (tissue swelling), pain and tenderness, increased temperature

Question 20

When is the risk of a pulmonary embolism at its highest?

Answer 20

If above the knee, the risk of embolism is >5%

Question 21

What are the risk factors of DVT?

Answer 21

Obeisity, age (>40), varicose veins (structural change in the veins promoting stasis of blood), immobility, post-surgery (esp knee or hip), oral contraceptives (esp with oestrogen), long flights- lack of mobility

Question 22

What are the possible ways of diagnosing DVT?

Answer 22

Venography - inject a dye
Doppler ultrasound- sound waves
D-dimer blood tests - measures fibrin breakdown products
General blood tests

Question 23

Pulmonary Embolism: Definition

Answer 23

blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream

Question 24

What are the Symptoms?

Answer 24

It can occur in the absence of clinical signs, and is difficult to diagnose.
If an Acute PE: acute breathlessness, pain in the chest, coughing, tachycardia, collapse, death

Question 25

What are the methods of diagnosing PE?

Answer 25

Physical examination
Wells Two-level PE test = a score over 4 means highly likely to be a pulmonary embolism
blood tests
Chest - X ray

Question 26

Arterial Thrombosis: related to what syndrome?

What is the difference in relation to Venous Thrombosis?

Answer 26

Acute Coronary Syndrome

THis is more likely to be related to Atherosclerosis.

Question 27

When does Arterial Thrombosis usually form?

Answer 27

Ususally forms at the site of atherosclerosis following a plaque rupture

Question 28

What is seen in a blood count of Arterial Thrombosis?

Answer 28

Low fibrin content, very high platelet content.

Question 29

How would an Arterial Thrombosis look in formation compared to a Venous Thrombosis?

Answer 29

Much more irregular formation

Question 30

Cardiogenic Embolism often as a result of

Answer 30

Atrial Fibrilation resulting in a thrombus formation which may occlude vessels in the legs, arms, or brain and less frequetly in other interanl organs. e.g. kidney

Question 31

What is a Cardiac Embolsim?

Answer 31

An embolism caused due to a cardiac source that travells to another organ

Question 32

Why is there high platelet count where the arterial thrombosis would form?

Answer 32

Due to the high turbulent flow of blood in the arteries.

Question 33

What happens if an arterial thrombus travels to the coronary circulation

Answer 33

COuld cause Acute Coronary Syndrome

Question 34

What happens if an arterial thrombus travels to the brain

Answer 34

COuld cause a stroke or TIA - Transient Ischaemic Attack

Question 35

A stroke has a same underlying mechanism as TIA which is:

Answer 35

Transient Ischaemic Attack - both involve the occlusion of a major cerebral (brain) Vessel

Question 36

What are the two different types of strokes?

Answer 36

Cerebral Infarction And Cerebral Haemorrhage.

Question 37

What are the differnece between Cerebral Infarction And Cerebral Haemorrhage. ?

Answer 37

Cerebral Infarction: the occlusion of a major cerebral vessel either by blockage or narrowing - if not treated will lead to brain damage and function loss. much more common
Cerebral Haemorrhage: Due to a massive bleed (anuerism) - not much can be done, less common

Question 38

What are the symptoms of a stroke?

Answer 38

FAST
FACE dropped, can’t smile
Can’t raise their their ARMS due to numbness or weakness
slurred SPEECH
cannot talk at all even though they are concious
TIME to call 999

Question 39

What is the difference between a Stroke and a TIA?

Answer 39

A stroke can be a cerebral infarction or a cerebral haemorrhage, and is when the blood supply to a part of the brain is interupted.
A TIA is transient - the blockage is only temporary and blood flow is restored on its own. Normally lasts for a few minutes.

Question 40

What is the only symptom clinical distinction between a Cerebral Infarction and a TIA?

Answer 40

The time that the symptoms last for = A transient Ishcaemic Attack’s symptoms are normally gone within 24 hours. They may not even experience any symptoms
But the symptoms of a stroke will last much longer, and can have lasting damage.

Question 41

WHat is the other name fot TIA?

Answer 41

mini-stroke.

Question 42

What are the risk factors for stroke/ TIA?

Answer 42

age, gender, family history, ethnicity, genetics, Hypertension, Atrial Fibrillation, Diabetic, Smoking, Ischaemic HEart Disease.