Shock (Physiological Shock)

Shock - What is it ?
Your body experiences shock when you do not have enough blood  (and/or the oxygen contained within the blood) travelling through your circulatory system to meet the demands of your body's organs and tissues.  Shock can lead to multiple organ failure and death, and so medial assistance is required in all cases.

You may remember that this is very similar to 
he  definition we gave for Hypoxia.

Hypoxia ... insufficient blood oxygen ... causes shock.

There are 4 main categories of shock :

Obstructive shock.  As it's name suggests, this is caused by an obstruction, like a blood clot which stops the blood getting to where it needs to be, or something obstructing the supply of oxygen to the blood.
Distributive Shock. Any condition that causes your blood vessels to  'lose their tone' and dilate means that they are incapable of sustaining enough pressure to supply the organs with the blood they need.
Hypovolemic Shock.  This is when the cause of the shock is insufficient blood in your circulatory  system ... usually because of severe blood loss due to injury.
Cardiogenic Shock.  This shock is related to the heart being damaged or experiencing trauma which impairs the function of the heart, and can include heart attack, angina, irregular or slow heart rhythm.

What Causes Shock? 
Now what we know what shock is, we can probably work out what kinds of things might result in a casualty going into shock.


Causes of Obstructive Shock could be ... 
  • Damage to the lungs
  • Hemothorax (blood collecting around the lungs, preventing them from functioning effectively.)
  • Cardiac Tamponade (blood or fluids collecting around the heart that impair the function of the heart.

Causes of Distributive Shock could be ... 

  • Anaphylaxis
  • Sepsis (Blood poisoning, caused by infections.  bacteria and their toxins cause serious damage to tissues or organs in the body).
  • Burns
  • Neurogenic Shock (damage to the central nervous system, for example a spinal injury or a head injury, that causes the blood vessels to dilate, heart rate to slow, and blood pressure to drop).

Causes of Hypovolemic Shock could be ... 

  • Dehydration
  • Diarrhroea
  • External Bleeding
  • Internal Bleeding
  • Vomiting

Causes of Cardiogenic Shock could be ...

  • Heart Attack
  • Heart Disease
  • Cardiac Failure
Signs and Symptoms of Shock
Note that most of these are the same as the signs and symptoms of Hypoxia.
Signs and symptoms of Shock could be ... 

  • Air hunger
  • Clammy skin
  • Pale Skin and cyanosis
  • Rapid, shallow breathing.
  • Lowered mental state
  • Unconsciousness.
  • nausea - feeling sick, and inclined to vomit.
  • Dizziness
  • Thirst
  • Weak 'thready' pulse.
  • Restlessness/aggression
Treatment of Shock
The treatment for shock is very straightforward ....
  • Keep the casualty warm
  • Lay them down on their back, and raise their legs by placing them of a cushion or something similar.
  • Loosen any tight clothing.
  • Nil by mouth - you may not be clear what the cause of the shock is, and they may need surgery, for example.
  • Reassure the casualty.
  • Treat the cause of the shock where possible.
  • Call for an medical assistance (Ambulance)
  • Monitor the casualty.
For more information on Shock, please refer to page 24 of your Learning Pack.
© Copyright Simon Watson