Thrombosis, Embolism and Shock

Question 1

What is a thrombosis?

Answer 1

• The formation of a solid or semi-solid mass from the constituents of the blood while moving within the vascular system during life.

Question 2

Where do thombi form?

Answer 2

• Lumen of the heart (after MI) - Arteries (causing ischaemia) - Veins (DVT and oedema) - Capillaries (coagulation)

Question 3

What factors promote thrombosis?

Answer 3

• Abnormalities of the vessel wall - Abnormalities of blood flow - Abnormalities of the blood constituents - Abnormalities of clotting

Question 4

What is an embolism?

Answer 4

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

Question 5

What are the types of embolism?

Answer 5

• Thrombi (dislodged thrombus) - Fat (usually caused by bone fractures) - Gas (infusions, vascular surgery). - Tumour material (metastases) - Infective agents (vegetations growing in heart valves) - Atheroma (fragments of atheroma plaques break off) - Amniotic fluid (forced from uterus) - Foreign bodies (IV drug abuse)

Question 6

What is shock?

Answer 6

A physiological state characterised y a significant, systemic reduction in tissue perfusion, resulting in decreased tissue oxygen delivery and insufficient removal of cellular metabolic products, resulting in tissue injury.

Question 7

What is hypovolaemic shock?

Answer 7

• Haemorrhage - internal or external - Severe burns

Question 8

What is cardiogenic shock?

Answer 8

• Large acute MI - Other acute cardiac diseases

Question 9

What is septic shock?

Answer 9

• Endotoxins from gram negative bacteria - Exotoxins from gram positive bacteria

Question 10

What is anaphylactic shock?

Answer 10

• Severe form of allergic reaction.

Question 11

What is neurogenic shock?

Answer 11

• Spinal cord trauma - Regional anaesthesia

Question 12

What is obstructive shock?

Answer 12

• Cardiac tamponade - Tension pneumothorax - Massive pulmonary embolism.

Question 13

What are the clinical features of shock?

Answer 13

• Low systolic BP (90bpm) - Respiratory rate (29 breaths/min) - Low urine output - Metabolic acidosis - Hypoxia - Cutaneous vasoconstriction or vasodilation - Anxiety, agitation, indifference, lethargy, obtunded.