Cardiovascular Response to Shock

Question 1

What is shock

Answer 1

circulatory system abnormality = inadequate tissue perfusion and oxygenation

Question 2

How does shock cause cellular failure

Answer 2

inadequate tissue perfusion
inadequate tissue oxygenation
anaerobic metabolism
accumulation of metabolic waste 
= Cellular failure

Question 3

what causes inadequate tissue perfusion

Answer 3

inadequate blood pressure and inadequate CO

Question 4

3 factors affecting Stroke Volume

Answer 4

Preload (influenced by venous return)
Myocardial contractility
after load

Question 5

what are the 4 different types of shock

Answer 5

cariogenic
obstructive
distributive
hypovolaemic

Question 6

what is hypovolaemic shock

Answer 6

loss of blood volume -> decreased blood volume -> decreased venous return -> decreased end diastolic volume -> decreased stroke volume -> decreased CO and BP -> inadequate tissue perfusion

Question 7

what is cardiogenic shock

Answer 7

sustained hypotension caused by decreased cardiac contractility

Question 8

what causes cariogenic shock

Answer 8

decreased cardiac contractility -> decreased SV -> decreased CO and BP -> inadequate tissue perfusion

Question 9

what is a type of obstructive shock

Answer 9

tension pneumothorax

Question 10

what is obstructive shock and how does it cause inadequate tissue perfusion

Answer 10

increased intrathoracic pressure -> decreased venous return -> decreased EDV -> decreased SV -> decreased CO and BP -> inadequate tissue perfusion

Question 11

how does neurogenic shock cause inadequate tissue perfusion

Answer 11

loss of sympathetic tone to Blood Vessels & heart ->
massive venous and arterial vasodilation, effects HR –> decreased venous return, Decreased SVR, decreased HR –> decreased CO and BP -> inadequate tissue perfusion

Question 12

how does vasoactive shock cause inadequate tissue perfusion

Answer 12

release of vasoactive mediators -> massive venous & arterial vasodilation + increased capillary permeability -> decreased venous return and SVR -> decreased CO and SVC -> inadequate tissue perfusion

Question 13

what is the treatment of any shock patient

Answer 13

ABCDE
High flow oxygen
Volume replacement (not in cariogenic shock)
call for help easy

Question 14

what is used to treat cariogenic shock

Answer 14

inotropes

Question 15

what is used to treat obstructive shock (tension pneumothorax)

Answer 15

immediate chest drain

Question 16

what is used to treat anaphylactic shock

Answer 16

adrenaline

Question 17

what is used to treat septic shock

Answer 17

vasporessors

Question 18

what causes hypovolaemic shock

Answer 18

haemorrhage (trauma, surgery, GI) decreases Blood volume directly
Vomiting, diarrhoea, excessive sweating decreased ECFV (+plasma) which decreases blood volume

Question 19

in haemorrhagic shock how long can compensatory mechanism maintain blood pressure for

Answer 19

until >30% of blood volume is lost

Question 20

how is MAP decreased in haemorrhagic shock

Answer 20

tachycardia (increased HR by baroreceptor reflex) +
Small Volume Pulse (decreased SV) = CO may be decreased + cool peripheries (increased SVR via baroreceptor reflex) = decreased MAP if >30% blood loss

Question 21

what is the name given to auto regulation of cerebral blood flow

Answer 21

myogenic response