Week 2

Question 1

Define shock.

Answer 1

Shock is a state of inadequate tissue perfusion resulting in impaired cellular metabolism and function.

Question 2

If shock is inadequately treated what can it result in?

Answer 2

Organ damage, and if left untreated it will become irreversible, leading to death.

Question 3

Name the FIVE subcategories of shock.

Answer 3

• hypovolaemic
• cardiogenic
• septic
• neurogenic
• anaphylactic

Question 4

Explain the pathophysiology of shock.

Answer 4

1. initiating insult (sepsis, injury or disease)
2. neuroendocrine system activated with the release of stress hormones into the blood stream.
3. sympathetic nervous system is stimulated to compensate for complications
4. vascular endothelium damage occurs as a direct result from injury or damage by bacterial toxins
5. inflammatory mediators released into the ciculation
6. vascular endothelium is damaged, platelets and tissue thromboplastin are activated
7. systemic microvascular coagulation
8. systemic immune/inflammatory response

The numerous inflammatory and clotting processes operation in multiple organ dysfunction syndrome (MODS) cause maldistribution of blood flow and hypermetabolism.

Question 5

Explain hypovolaemic shock.

Answer 5

Hypovolaemia is the loff of intravascular volume (>15% of circulating volume). Smaller loses in paediatrics and the elderly can lead to a shock state sooner.

Question 6

Explain septic shock.

Answer 6

Infection directly enters blood stream or produces toxic substances which are released into the blood stream. The inflammatory process is disordered and out of control. Excess mediators overwhelm the system resulting in tissue damage and organ failure.

Question 7

Explain neurogenic shock.

Answer 7

Neurogenic shick is the imbalance between sympathetic and parasympathetic stimulation of vascular smooth muscle. It also results in massive systemic vasodilation.

Question 8

Explain cardiogenic shock.

Answer 8

Cardiogenic shock is the inability of the heart to pump blood, resulting in decreased CO and BP, leading to tissue hypoperfusion.

Question 9

Explain anaphylactic shock.

Answer 9

It is a systemic hypersensitivty reaction. It is sudden, severe and systemic. It can progress to death within minutes unless emergency treatment is initiated.

Question 10

Name the THREE primary aims in the management of shock.

Answer 10

• treat underlying cause
• increase arterial oxygenation
• improve tissue perfusion