What you should know about Shock

 What you should know about Shock

Outline

1. Definition
2. Epidemiology
3. Physiology
4. Classes of Shock
5. Clinical Presentation
6. Management
7. Controversies

Definition:- of shock 

Shock is may be defined as total collapse of an individual due to disparity between circulatory blood volume & volume of the vascular bed resulting in inadequate tissue perfusion & metabolic acidosis.

a.May refer to a psychological or a physiologic type of shock.
b.Psychological shock is caused by a traumatic event and is also known as acute distress disorder. 
c.The multiple causes of physiologic shock.

A physiologic state characterized by shock:-

   Inadequate tissue perfusion

Clinically manifested by shock:-

  Hemodynamic disturbances

  Organ dysfunction

Epidemiology:-

Mortality:-

1. Septic shock – 35-40% (1 month mortality)
2. Cardiogenic shock – 60-90%
3. Hypovolemic shock – variable/mechanism 

Pathophysiology:-

1. Imbalance in oxygen supply and demand
2. Conversion from aerobic to anaerobic metabolism
3. Appropriate and inappropriate metabolic and physiologic responses
4. Cellular physiology:-

                    Cell membrane ion pump dysfunction

                     Leakage of intracellular contents into the extracellular space

                     Intracellular pH dysregulation 

       5. Resultant systemic physiology:-

Cell death and end organ dysfunction

MSOF and death

Physiology:-

Characterized by three stages

Preshock (warm shock, compensated shock)

Shock

End organ dysfunction

Compensated shock

Low preload shock – tachycardia, vasoconstriction, mildly decreased BP

Low afterload (distributive) shock – peripheral vasodilation, hyperdynamic

Classification of shock :-

A. Hypovolaemic shock 

     1. Diarrhoea. 

     2. Vometing.

     3.Excessive sweating.

     4. Haemorrhage.

     5.Fluid sequestration -  a.Acute pancreatitis. 

                                           b.Paralytic ileus.

    6.Diabetic ketoacidosis.

B. Carcinogenic shock

    1. Myocadical infarction. 

    2. Acute mitral regurgitation. 

C. Obstructive shock .

     1. Acute massive.pulmonary embolism.

     2. Cardiac tomponade.

     3. Pneumothorax.

D. Anaphylaetic shock .

     1. Severe allergy. 

E. Septic shock 

  1. Severe infection.

F. Neurogenic shock.

   1. Spinal cord injuries .