Shock

Shock is acute circulatory failure leading to inadequate tissue perfusion and end organ injury

"Acute circulatory failure with inadequate or inappropriately distributed tissue perfusion resulting in generalized cellular hypoxia."

Shock is caused by a disruption to the cardiovascular system, and inadequate compensation to maintain tissue perfusion.

How do you classify shock?
Shock is hypotension with end organ injury: it classified as being due to malfunction of,
1) the Pump (cardiogenic),
2 ) the Tubing (distributive), or
3) the Fluid (hypovolemic).

Hypotension and Shock are caused by a problem with
Heart Rate, Stroke Volume or Peripheral Resistance.

There are only three types of shock,
problems with the heart, sometimes called cardiogenic shock, problems vascular system, known as distributive shock, and
loss of circulating volume, known as hypovolemic shock.

Although textbooks and examiners often emphasize the classification of shock, in the real world, it is often more effective to use the physiologic approach to shock:

Shock is due to inadequate blood pressure.

Low blood pressure is due to inadequate cardiac output or low peripheral resistance.

Low cardiac output is caused by a problem with heart rate or stroke volume.

Heart rate abnormalities: too fast (tachycardia), too slow (bradycardia).

Stroke Volume abnormalities: failure to receive, failure to eject, inadequate volume

Low peripheral vascular resistance is due to inappropriate vasodilatation.