Shock

Definition:
It is a systemic state of low tissue perfusion, which inadequate for normal cellular respiration, with insufficient delivery of oxygen and glucose, cell switch from aerobic metabolism to anaerobic metabolism.
Pathophysiology:

• Cellular.
• Microvascular.
• Systemic.
• Ischemia-reperfusion syndrome.

Cellular: As perfusion of tissues reduced, the respiration switch from aerobic to anaerobic respiration, the end product of anaerobic respiration is not carbon-dioxide while it is lactic acid that cause metabolic acidosis.

Microvascular: As tissue ischemia progresses, changes in local milieu result in activation of the immune and coagulation system.

Systemic: There are many system involves;

CVS; Tachycardia, Decreased Blood pressure.

Respiratory system; Metabolic acidosis that cause respiratory alkalosis , reduced CO2 lead to Hyperventilation.

Renal System; Decreased perfusion pressure in the kidney leads to reduced filtration at the glomerulus and a decreased urine output.

Endocrine; Activation of sympathetic system.

Ischemia-reperfusion syndrome:

During the period of Ischemia, hypoperfusion, cellular and organ damage progresses because of direct effects of tissue hypoxia and local activation of inflammation.

Classification of Shock:

1. Hypovolaemic Shock.
2. Cardiogenic Shock.
3. Obstructive Shock.
4. Distributive Shock.
5. Endocrine Shock.
6. Anaphylatic Shock
7. Neurogenic Shock.
8. Septic Shock.

Classification of Shock

Severity of Shock:

• Compensated Shock.
• Decompensated Shock.
• Mild Shock.
• Moderate Shock.
• Severe Shock.

Multiple Organ failure Due to Shock:

Multiple organ failure is defined as two or more failed organ systems.

There is no specific treatment for multiple organ failure.

Management is by supporting organ system with ventilation, cardiovascular support and haemofiltration/ Dialysis until there is recovery of organ functions.

Effects of organ failure;

Lungs                           Acute respiratory distress syndrome (ARDS).

Kidney                         Acute Renal Insufficiency.

Liver                             Acute Liver Insufficiency.

Clotting                         Coagulopathy.

Cardiac                           Cardiovascular Failure.

Management of Shock: