Shock

Question 1

Define shock

Answer 1

A life-threatening, generalised form of acute circulatory failure with inadequate O2 delivery to, and consequently O2 utilisation by, the cells.

Question 2

What are the 4 types of shock?

Answer 2

1) Hypovolaemic

2) Distributive

3) Obstructive

4) Cardiogenic

Question 3

Underlying mechanism in hypovolaemic shock?

Answer 3

Inadequate circulating volume 2ary to fluid loss

• haemorrhage e.g. trauma, AAA, obstetric haemorrhage
• D&V
• DKA
• burns

Question 4

Underlying mechanism in distributive shock?

Answer 4

Inadequate perfusion 2ary to maldistribution:

• sepsis
• neurogenic shock
• anaphylactic

Question 5

Underlying mechanism in obstructive shock?

Answer 5

Inadequate cardiac output as a result of mechanical obstruction:

• PE
• tension pnuemothorax
• cardiac tamponade
• acute IVC or SVC obstruction

Question 6

Underlying mechanism in cardiogenic shock?

Answer 6

Inadequate cardiac output as a result of cardiac failure:

• myocardial infarction
• myocardial contusion
• myocarditis
• late sepsis
• overdose (e.g. beta blockers)
• complete heart block

Question 7

General presentation of shock?

Answer 7

Very unwell:

• hypotension
• tachycardia
• tachypnoea
• reduced GCS
• possible cardiac arrest

Question 8

Presentation of patients in hypovolaemic shock?

Answer 8

‘Cold’ shock

• Cold peripheries due to vasoconstriction
• Increased CRT
• May have dry mucous membranes (e.g. if due to dehydration)

Question 9

Presentation of patients in distributive shock?

Answer 9

‘Warm’ shock

• These patients vasodilate as oppose to vasoconstrict, and are hence often warm with normal CRT
• If infection (sepsis): underlying signs of infection, rigors, high temp, muscle aches, lethargy, drowsiness, reduced GCS

Question 10

2 key causes of distributive shock?

Answer 10

1) Anaphylaxis

2) Sepsis