Shock

for MBBS student

1. Dr. Md. Majedul Islam FCPS(Surgery) Asst Professor JIMCH Shock

2. SHOCK Def: Shock is a systemic state of low tissue perfusion which is inadequate for normal cellular respiration.

3. Classification of shock Hypovolaemic shock Cardiogenic shock Obstructive shock Distributive shock Endocrine shock

4. Hypovolaemic shock Hypovolaemic shock is due to a reduced circulating volume.

5. Sign of Hypovolaemic Shock Intense Thirst Cold clammy skin Tachycardia, Tachypnoea Hypotension Reduced Urine output Collapse peripheral vein Altered consciousness level

6. classification of haemorrhagic shock.

7. Cardiogenic shock: due to primary failure of the heart to pump blood to the tissues. Causes of cardiogenic shock include myocardial infarction, cardiac dysrhythmias , valvular heart disease , blunt myocardial injury and cardiomyopathy . Cardiac insufficiency may also be due to myocardial depression due to : endogenous factors (e.g. bacterial and humoral agents released in sepsis) or exogenous factors, such as pharmaceutical agents or drug abuse.

8. Obstructive shock: In obstructive shock there is a reduction in preload due to mechanical obstruction of cardiac filling. Common causes of obstructive shock include cardiac tamponade , tension pneumothorax , massive pulmonary embolus or air embolus . In each case , there is reduced filling of the left and/or right sides of the heart leading to reduced preload and a fall in cardiac output.

9. Distributive shock  is a medical condition in which abnormal distribution of blood flow in the smallest blood vessels results in inadequate supply of blood to the body's tissues and organs. describes the pattern of cardiovascular responses characterising a variety of conditions, Example of Distributive shock Septic shock , Anaphylaxis(Anaphylactic shock) and spinal cord injury ( neurogenic shock)

10. Pathophysiology of Distributive shock : In anaphylaxis, vasodilatation is due to histamine release In spinal cord injury there is failure of sympathetic outflow and adequate vascular tone In sepsis is less clear but is related to the release of bacterial products ( endotoxin ) and the activation of cellular and humoral components of the immune system Inadequate organ perfusion is accompanied by vascular dilatation with hypotension low systemic vascular resistance, inadequate afterload and a resulting abnormally high cardiac output.

11. Inadequate organ perfusion is accompanied by vascular dilatation with hypotension low systemic vascular resistance, inadequate afterload and a resulting abnormally high cardiac output.

12. Endocrine Shock Endocrine shock may present as a combination of hypovolaemic , cardiogenic or distributive shock . Causes of endocrine shock include H ypo- and hyperthyroidism and A drenal insufficiency.

13. Classification of Shock According to the severity In general, loss of around 15 per cent of the circulating blood volume is within normal compensatory mechanisms . Blood pressure is usually well maintained and only falls after 30–40 per cent of circulating volume has been lost . Mild Shock Moderate Shock Severe Shock