Lecture 6 Thrombosis, embolism and shock Flashcards Preview

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Flashcards in Lecture 6 Thrombosis, embolism and shock Deck (39)
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1
Q

Define thrombosis?

A

Formation of a solid or semi-solid mass from blood constituents which moves within vascular system.

2
Q

Where may thrombi form?

A

1) lumen of heart 2) arteries 3) veins 4) capillaries.

3
Q

What may aortic thrombus cause?

A

Ischaemia and emolism to the leg

4
Q

What may vein thrombus cause?

A

Oedematous right leg. Deep vein thrombosis. ?after abdo surgery.

5
Q

What do capillary thrombi cause?

A

(involves both thrombus formation and haemorrhage). Minute thrombi may cause scattered ischaemic lesions.

6
Q

Factors that promote thrombosis

A

Virchow’s triad. Abnormalities of 1) vessel wall 2) Blood flow 3) blood constituents

7
Q

Factors affecting vessel wall in arteries?

A

Atheroma, inflammation

8
Q

Factors affecting vessel wall in heart?

A

Myocardial infarction, rheumatic endocarditis.

9
Q

Factors affecting vessel wall in veins?

A

1) Trauma, inflammation. 2) Chemicals (sclerosants - irritant substances injected to remove varicose veins). 3) Glucose (atheroma in diabetes)

10
Q

Factors affecting vessel wall in capillaries?

A

Inflammation

11
Q

General factors affecting blood flow?

A

Heart failure or circulatory shock.

12
Q

Factors affecting blood constituents?

A

Polycythaemia, hyperproteinaemia, abnormalities of clotting

13
Q

What is polycythaemia

A

abnormally ^ haemoglobin

14
Q

What can make someone have polycythaemia?

A

Dehydration, polycythaemia rubra vera or chronic hypoxia.

15
Q

What can lead to hyperptoteinaemia?

A

Multiple myeloma (tumour of plasma cells in bone marrow with accumulation of immunoglobins in plasma)

16
Q

What can cause abnormalities of clotting?

A

Pregnancy (Xbleeding when placenta detaches). Older contraceptive pills, following trauma (liver produces more clotting factors). Thrombocythaemia.

17
Q

Define thrombocythaemia

A

High platelet count in blood

18
Q

What are the three thrombi fates?

A

Resolution (fibrinolysis), Organisation (incorporated into scar by macrophages/fibroblasts), Detachment (thromboembolism)

19
Q

Define embolism

A

The transport of abnormal material (solid,liquid or gas) by the blood stream and its impacting in a blood vessel.

20
Q

Types of emboli

A

Thrombi, fat (from multiple bone #), gas (infusion/vascular surgery).

21
Q

What is caisson disease?

A

When ascending from the depths too rapidly, bubbles of N2 form in blood -> enters bones and joints -> pain known as bends.

22
Q

How can an air embolus from IV therapy be found?

A

filled pericardium with water, cut into ventricular cavity, can see bubbles.

23
Q

Types of emboli? (5)

A

Tumour material, infective agents, aheroma, amnootic fluid, foreign bodies.

24
Q

Define shock

A

A physiological state. Systemic ↓ in tissue perfusion, ↓ oxygen delivery and insufficient removal of metabolic waste -> tissue injury

25
Q

What causes hypovolaemic shock

A

Haemorrhage - internal or external. Severe burns.

26
Q

What causes cardiogenic shock

A

Large acute myocardial infarction, other acute cardiac disease.

27
Q

What causes neurogenic shock

A

Spinal cord trauma, regional anaesthesia.

28
Q

What causes obstructive shock

A

Cardiac tamponade, tension pneumothorax, massive pulmonary embolism

29
Q

Define cardiac tamponade

A
30
Q

Define tension pneumothorax

A

build-up of air in pleural space. Due to lung laceration -> allows air into the pleural space.

31
Q

What causes septic shock

A

Endotoxins (gram negative), exotoxins (gram positive). Both -> blood vessels dilating

32
Q

What causes anaphylactic shock?

A

Severe form of allergic reaction

33
Q

Clinical features of shock: BP?

A

↓BP

34
Q

Clinical features of shock: HR?

A

Tachy >90bpm

35
Q

Clinical features of shock: RR?

A

29 breaths per minute

36
Q

Clinical features of shock: Urine output?

A

Low

37
Q

Clinical features of shock: blood vessels?

A

Cutaneous vasoconstriction/vasodilation

38
Q

Clinical features of shock: feelings?

A

anxiety, agitation OR indifference, lethargy, obtunded.

39
Q

Clinical features of shock: Additional?

A

Hypoxia, metabolic acidosis.