thrombosis, embolism and shock

Question 1

what is blood clotting?

Answer 1

the rapid and localised haemostatic plug at site of vascular injury, to maintain tissue preservation

Question 2

what happens immediately after injury?

Answer 2

reflex vasoconstriction of arterioles - blood vessels constrict, which reduces blood flow and therefore blood loss to that area

Question 3

what is meant by international normalised ratio (INR) ?

Answer 3

this is the measure of prothrombin time - how long it takes the blood to clot. normal is 1-1.5

Question 4

define thrombosis?

Answer 4

the inappropriate activation of blood clotting in vessels, resulting in the formation of a solid or semi-solid mass from the constituents of blood.

Question 5

define thrombus and embolus

Answer 5

thrombus - blood clot. embolus - fragment of a blood clot

Question 6

what is meant by the term embolism?

Answer 6

this is the detached intravascular solid, liquid or gas mass that is carried by the blood stream to a site distant to its origin.

Question 7

what is the Virchow’s triad?

Answer 7

Factors promoting coagulation - abnormalities of blood vessel wall, abnormalities of blood flow, abnormalities of bloods constituents

Question 8

what is shock and when does it occur?

Answer 8

when organs and tissues are not receiving an adequate flow of blood. this deprives the organs and tissues of oxygen and allows build up of waste products

Question 9

clinical features of shock?

Answer 9

low systolic BP <110mmHg, tachycardia, RR <7 or >29, low PU, metabolic acidosis, hypoxia, cutaneous vasoconstriction or vasodilation, anxiety, agitation, indifference, lethargy, obtunded

Question 10

stages of shock?

Answer 10

compensated 15-25% blood loss, non-compensated; blood volume loss >25%, irreversible; failure to restore circulation, critical organ damage

Question 11

describe hypovolemic shock

Answer 11

caused by haemorrhage - internal or external

Question 12

describe cardiogenic shock?

Answer 12

large acute myocardia infarction and other acute cardiac diseases

Question 13

describe septic shock?

Answer 13

triggered by systemic infection. endotoxins from gram negative bacteria, and exotoxins from gram positive bacteria

Question 14

describe anaphylactic shock?

Answer 14

severe form of allergic reaction from food, antibiotics, insect stings etc

Question 15

describe neurogenic shock?

Answer 15

caused by spinal cord trauma, regional anaesthesia, or spinal cord damage

Question 16

describe obstructive shock?

Answer 16

cardiac tamponade, tension pneumothorax, pulmonary embolism