Shock

Question 1

Define shock

Answer 1

inadequate blood flow to the tissue to meet demands

Question 2

What are the types of shock

Answer 2

Septic
Haemorrhagic
Neurogenic
Cardiogenic
Anaphylactic

Question 3

How is MAP calculated

Answer 3

Mean arterial pressure = CO x TPR
CO = HR x SV

Question 4

What are the classes of shock

Answer 4

Class 1 – compensated
- Blood loss <750/<15% CV
- HR/SBP/PP/CRT/RR normal
Class 2 – tachycardia
- Blood loss 640-1500ml
- HR >100
- CRT >2s
- Narrow PP
- RR 20-30
- Reduced UO
Class 3 – hypotension
- 1500-2000mL
- HR 120-140
- Low SBP
- RR >30
Class 4 – LoC
- >2000
- HR >140
- SBP unrecordable
- absent CRT
- RR >35
- Confused/unresponsive

Question 5

Describe hypovolaemic shock

Answer 5

Reduced pre-load and cardiac output
Intravascular volume depletion
HR raised, JVP N, cool tissue perfusion

Caused by:
Blood loss
Third space loss
GI loss (D&V)
Renal loss
Skin loss

Question 6

Management of hypovolaemic shock

Answer 6

Treat the cause e.g. stop bleeding
Fluid replacement
Blood
Crystalloid (solutions with ions)
Colloids e.g. albumin

Question 7

Describe distributive shock

Answer 7

Vascular dilatation → reduced TPR
HR raised, JVP N, warm perfusion

Caused by:
Sepsis
Anaphylaxis

Question 8

Management for distributive shock

Answer 8

Treat the cause, sepsis 6
Abx
Remove allergen
Fluid replacement
Vasopressors

Question 9

Describe cardiogenic shock

Answer 9

Reduced pump failure → reduced CO
HR deranged, JVP raised, cool peripheries

MI
Arrhythmia
Endocarditis/valve disease
Myocarditis

Question 10

Management for cardiogenic shock

Answer 10

Treat the cause e.g. PCI, cardioversion, pacemaker, valve repair
Inotropes

Question 11

Describe obstructive shock

Answer 11

Obstruction preventing complete cardiac filling
Compression of the right atria (sensitive to pressure changes due to lack of muscle)
HR raised, JVP raised, cool peripheries

Large pulmonary embolus
Tension pneumothorax
Tamponade

Question 12

Describe neurogenic shock

Answer 12

A type of distributive shock
(NOT the same as spinal shock)
Disruption to autonomic pathways following spinal injury → either decreased sympathetic tone or increased parasympathetic tone, the effect of which is a decrease in peripheral vascular resistance mediated by marked vasodilation

HR deranged, JVP N, warm peripheries

Question 13

How do you interpret pulmonary artery occlusion pressure monitoring

Answer 13

Low <5 = Hypovolaemia

Low with pulmonary oedema <5 = ARDS

Normal 8-12

High >18 = Overload/cardiogenic shock