Shock**** Flashcards

1
Q

Shock definition

A

Shock (or cardiovascular collapse) is the ter given to any process that results in reduced blood flow through microcirculatory beds. Regardless of the underlying pathology, shock gives rise to systemic hypoperfusion caused by reduction either in CO or in the effective circulating blood volume.

This causes hypotension, followed by impaired tissue perfusion and cellular hypoxia. Multiple organ failure results with death or significant tissue and organ damage as the sequelae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Classification of shock

A

Major causes of shock

  • Cardiogenic shock
  • Hypovolaemic shock
  • Septic shock

Less common causes of shock

  • Neurogenic shock
  • Anaphylactic shock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mechanisms of cardiogenic shock

A

Failure of the myyocardial pump owing to intrinic myocardial damage, extrinsic pressure, or obstruction to outflow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Causes of cardiogenic shock

A
  1. MI
  2. Ventricular rupture
  3. Arrhythmia
  4. Cardiac tamponade
  5. Pulmonary embolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mechanisms of hypovolaemic shock

A

Inadequate blood or plasma volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Causes of hypovolaemic shock

A

Fluid loss e.g. vomiting, diarrhoea burns or trauma, haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mechanisms of septic shock

A

Overwhelming microbial infection activates cytokine cascades (TNF, IL-1 and IL-6) which cause systemic vasodilaton, hypotension, widespread endothelial damage (DIC and ARDS) ad reduced myocardiac contractility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Causes of septic shock

A

Endotoxic shock (caused by LPS toxin from GN organisms), gram positive septicaemia, fungal sepsis, superantigens (e.g. TSS).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Neurogenic shock

A

Spinal injury ot neurotoxin/anaesthic agent that causes loss of vascular tone and subsequent pooling of blood in the venous system with relative hypovolaemia in the arterial system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Anaphylactic shock

A

IgE-mediated hypersensitivity response (type 1) is associated with systemic vasodilation and increased vascular permeability. Pooling of blood and relative hypovolaemia results.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly