Cardiovascular Response to Shock

Question 1

what are the 6 types of shock?

Answer 1

1) hypovolaemic
2) cardiogenic
3) obstructive
4) disruptive;
- neurogenic
- vasoactive shock

Question 2

What may hypovolaemic shock involve?

Answer 2

• haemorrhage

- non-haemorrhage

Question 3

what may cardiogenic shock involve?

Answer 3

• acute myocardial infarction

Question 4

what may obstructive shock involve?

Answer 4

• cardiac tamponade
• tension pneumothorax
• pulmonary embolism
• severe aortic stenosis

Question 5

what may disruptive shock involve?

Answer 5

• neurogenic e.g. spinal cord injury

- vasoactive e.g. septic shock, anaphylactic shock

Question 6

what is shock?

Answer 6

an abnormality of the circulatory system resulting in inadequate tissue perfusion & oxygenation

Question 7

what are the 4 steps in-between shock and cellular failure?

Answer 7

1) inadequate tissue perfusion
2) inadequate tissue oxygenation
3) anaerobic metabolism
4) accumulation of metabolic waste products

Question 8

What 2 things does adequate tissue perfusion depend on?

Answer 8

1) adequate blood pressure

2) adequate cardiac output

Question 9

what 3 things affect stroke volume?

Answer 9

1) pre-load
2) myocardial contractility
3) afterload

Question 10

what effects preload?

Answer 10

= venous return

Question 11

what is hypovolaemic shock?

Answer 11

when you lose more than 20% of your body’s blood supply or body’s fluid

Question 12

in hypovolaemic shock, what does loss of blood volume cause? (6)

Answer 12

1) decreased blood volume
2) decreased venous return
3) decreased end diastolic volume
4) decreased stroke volume
5) decreased cardiac output & blood pressure
6) inadequate tissue perfusion

Question 13

what is cardiogenic shock?

Answer 13

sustained hypotension caused by decreased cardiac contractility

Question 14

what is cardiogenic shock caused by?

Answer 14

= the inability of the heart to pump sufficient blood for the needs of the body.

Question 15

in cardiogenic shock, what 3 things happen after decreased cardiac contractility?

Answer 15

1) decreased stroke volume
2) decreased cardiac output & blood pressure
6) inadequate tissue perfusion

Question 16

what happens to the frank starlings curve

Answer 16

• unable to sustain blood pressure

= moving frank starlings curve to the right

Question 17

what is obstructive shock?

Answer 17

form of shock associated with physical obstruction of the great vessels or the heart itself.

Question 18

what is a primary example of obstructive shock?

Answer 18

= tension pneumothorax

Question 19

in a tension pneumothorax in obstructive shock, what 5 events happen after increased intra-thoracic pressure?

Answer 19

1) decreased venous return
2) decreased end diastolic volume
3) decreased stroke volume
4) decreased CO & blood pressure
5) inadequate tissue perfusion

Question 20

what is neurogenic shock?

Answer 20

= attributed to the disruption of the autonomic pathways within the spinal cord

Question 21

in neurogenic shock, what 4 things happen after loss of sympathetic tone to blood vessels and heart?

Answer 21

1) massive venous & arterial vasodilation
- effect on heart rate

2) decreased venous return & SVR
- decreased HR

3) decreased cardiac output & blood pressure
4) inadequate tissue perfusion

Question 22

what happens to the heart rate in neurogenic shock that is unlike other types of shock?

Answer 22

= decreased heart rate

Question 23

in vasoactive shock, what 4 events happen after the release of vasoactive mediators?

Answer 23

1) massive venous & arterial vasodilation
= increased capillary permeability

2) decreased venous return & SVR
3) decreased CO & BP
4) inadequate tissue perfusion

Question 24

in vasoactive shock, what 4 events happen after the release of vasoactive mediators?

Answer 24

1) massive venous & arterial vasodilation
= increased capillary permeability

2) decreased venous return & SVR
3) decreased CO & BP
4) inadequate tissue perfusion

Question 25

what sort of approach should be taken to treat shock?

Answer 25

= ABCDE

Question 26

what 2 things should be given to treat shock?

Answer 26

1) hig flow oxygen | 2) volume replacement

Question 27

in what type if shock would you NOT give volume placement for?

Answer 27

cardiogenic shock

Question 28

in cardiogenic shock, what should be given?

Answer 28

inotropes

Question 29

in a tension pneumothorax, what should immediately be done too avoid obstructive shock?

Answer 29

- chest drain

Question 30

in anaphylactic shock what should be given?

Answer 30

adrenaline

Question 31

in septic shock, what should be give?

Answer 31

vasopressors

Question 32

what are 3 possible causes of hypovolaemic shock?

Answer 32

1) haemorrhage (e.g. trauma, surgery, GI haemorrhage) 2) vomiting or diarrhoea 3) excessive sweating

Question 33

what effect does vomiting, diarrhoea or excessive sweating have on ECFV?

Answer 33

= decreases ECFV

Question 34

what happens to blood volume, cardiac output and MAP after a decreased ECFV and what does this cause?

Answer 34

they all decreases = circulatory shock = hypovolaemic shock

Question 35

in haemorrhagic shock, after what percentage of blood volume loss will compensatory mechanisms that are maintaining blood pressure fail?

Answer 35

> 30%

Question 36

what are the 4 types of haemorrhagic shock?

Answer 36

I II III IV

Question 37

in haemorrhagic shock, what happens to the heart rate and stroke volume?

Answer 37

= tachycardia (increased heart rate) = decreased stroke volume

Question 38

what is the volume pulse like in haemorrhagic shock?

Answer 38

small volume pulse

Question 39

what does an increased HR and decreased SV have on cardiac output and SVR?

Answer 39

= decreased cardiac output | = increased systemic vascular resistance

Question 40

what effect does decreased cardiac output & increased SVR have on temperature of peripheries?

Answer 40

cool peripheries

Question 41

what do all of these things do to MAP?

Answer 41

decreased MAP