Shock

Question 1

What is it?

Answer 1

State of generalised cellular hypoperfusion leading to inadequate cellular oxygenation to meet metabolic

Question 2

Warm Ischaemia Time

Answer 2

What is it - the amount of time that an organ remains at body temperature after its blood supply has been stopped/reduced

Heart, Brain, Lungs - 4-6 minutes
Kidneys, liver, Gi tract - 45-90 minutes
Muscle, bone, skin - 4-6 hours

Question 3

How does Hypovolaemia relate to Impaired Metabolism?

Answer 3

The pt is losing blood volume, loss of volume means fewer RBCs circulating through the capillary beds to deliver oxygen to the cells. the lack of oxygen impairs metabolism.

Question 4

Consequences of Decreased ATP

Answer 4

K+ and Lactic acid - low pH results of cellular enzymes that auto digest cells. Cellular death, organ failure result
Na+ and H2O enter the cell - cellular oedema, further loss of blood volume

What the Pt looks like:
- ATP produces heat therefore pt without ATP can’t produce/regulate heat
- Happens even in mild temps

Question 5

Hypovolaemic Shock

Answer 5

Shock caused by haemorrhage is the most common cause of shock in trauma pt.

Assume haemorrhagic shock until proven otherwise

Question 6

Measure of an Effective Pump (CO)

Answer 6

• CO = SV x HR
• Decrease in SV which less blood volume

Question 7

Adequate Perfusion

Answer 7

• CO is a factor for maintaining BP
• Adequate BP is required perfusion
• BP = CO x SVR

Question 8

The 5 Types of Shock

Answer 8

• Distributive - Broken gas hose
• Neurogenic - Gas pump electricity gone bad
• Obstructive - Gas blockage
• Cardiogenic - Gas pump not working
• Hypovolaemic - Not enough gas

Question 9

Causes of Distributive Shock

Answer 9

Causes; global vasodilation - anaphylaxis, sepsis, adrenal crisis, neurogenic

Question 10

The Different Presentations of Distributive:

Answer 10

Septic - increased CO, HR and decreased BP, sats
Neurogenic - decreased CO, HR, BP, sats
Anaphylactic - increased HR and decreased CO, BP, sats
- Will give a similar presentation to hypovolaemic shock, the ‘pipes’ that flow are very wide, decreasing the pressure

Question 11

Causes of Neurogenic Shock

Answer 11

dmg to spinal cord above T5

Question 12

How does Neurogenic Shock work?

Answer 12

• This dmg causes the distraction of the sympathetic NS meaning the continual stimulation of vasodilation
• The body then can’t adequately fill the ‘container’ by the normal amount of blood in the vascular system

Question 13

Signs and Symptoms of Neurogenic Shock

Answer 13

• Warm, dry skin
• Normal skin colour, especially below the spinal injury
• Bradycardia
• Hypotension

Question 14

Causes of Obstructive Shock

Answer 14

reduced return to heart due to blockage - tension pneumothorax, pulmonary embolism (PE) and cardiac tamponade

Question 15

How does Obstructive Shock work?

Answer 15

• Reduced venous return means less blood to organs and tissue, reducing perfusion
• The compensation for this is increased HR, resps and reducing BP

Question 16

Causes of Cardiogenic Shock

Answer 16

insult to the heart - MI, ACS, cardiomyopathy, myocarditis, drug toxicity, contusion
→ Blood will be directed to central, vital organs. Therefore the heart and O2 demand increasing HR and resps

Question 17

Intrinsic Causes of Cardiogenic Shock

Answer 17

• Blunt cardiac trauma leading to muscle dmg and/or dysrhythmias
• Valve disruption

Question 18

Extrinsic Causes of Cardiogenic Shock

Answer 18

• Pericardial tamponade
• Tension pneumothorax

Question 19

Causes of Hypovolaemic Shock

Answer 19

dehydration, D&V, GI bleed, trauma

Question 20

How does Hypovolaemic Shock work?

Answer 20

• Loss of circulating volume RBCs therefore reduces capacity of O2 carrying cells
• Reduces CO
• Reduces BP and reduces oxygenation
• The body tries to compensate for this by increasing the HR and resp rate

Question 21

Signs of Shock (B)

Answer 21

• Hypoxia and acidosis stimulate the respiratory centre
• 20-30 breaths per minute is moderate
• > 30 more severe
• ‘Air hunger’ - pt may not tolerate mask on face as it will distress them ‘getting air’ - turn on O2 before putting it on

Question 22

Things to Look for in C

Answer 22

• Levels of consciousness
• Haemorrhage
• HR
• Skin colour and temp
• CRT
• BP

Question 23

Signs of Shock in D

Answer 23

– Decreased cerebral perfusion will mean altered LOC
- Assume altered LOC is due to shock and treat as such
- DONT FORGET to rule out TBI before giving fluids

Question 24

MSK Considerations

Answer 24

• Major or multiple fractures can lead to significant blood loss therefore hypovolaemic shock
• Of most concern are pelvic and femur fractures
• Tibia/Fibia - 10-20% of blood volume
• Femur - 20-40% of blood volume
• Pelvis - 100% blood volume

Question 25

4 Qs of Shock Managment

Answer 25

• What is causing the shock?
• What type of shock is it and what is its care?
• Where can this pt get this care?
• What can be done now before reaching defninitive care?

Question 26

The Lethal Triad

Answer 26

→Metabolic Acidosis → Hypothermia → Coagulopathy→

• Severe bleeds reduced oxygen deliver, leading to hypothermia
• Meaning, coagulopathy is reduced as its harder to clot at lower temps, increasing bleeding times
• In the absence of blood with O2 and nutrients, metabolic acidosis starts, damaging organs which reduces myocardial performance, decrease CO/oxygen delivery even more

A decrease in pH by 0.4 can reduce enzyme activity that activated clotting by more than 70%