2. Shock Dr. Afsar Saeed Shaikh M.B.B.S, M.Phil.
Assistant Professor of Chemical Pathology
Pathology Department, KEMU, Lahore.
What is haemodynamics?

3. INTRODUCTION Cardiovascular Collapse Final common pathway Definition:
‘A clinical entity characterized by systemic hypoperfusion caused by reduction either in cardiac output OR in the effective circulatory blood volume’

4. INTRODUCTION Clinical Effects of Shock: Hypotension
Impaired tissue perfusion
Cellular hypoxia

5. Shock ETIOLOGICAL CLASSIFICATION: Cardiogenic Shock Hypovolemic Shock
Septic Shock (Endotoxin Shock)
Neurogenic Shock
Anaphylactic Shock

6. Stages of Shock FIRST stage; Non-progressive Stage: are activated
Reflex compensatory mechanisms
are activated
Profusion of vital organ is maintained

7. Stages of Shock 2nd Stage; Progressive Stage: Tissue hypoperfusion
Circulatory & metabolic imbalances leading to Acidosis

8. Stages of Shock 3rd Stage; Irreversible Stage:
Cellular & tissue injury
Even with correction of hemodynamic defects, survival is not possible

9. Mechanism of different Stages of Shock
1. Non-progressive Stage :
Neurohumoral Mechanisms maintain cardiac output and blood pressure:
Baroreceptors reflexes
Release of catecholamine
Activation of renin-angoitensin axis
ADH release
Generalized sympathetic stimulation

10. Mechanism of different Stages of shock
1. Non-progressive Stage :
Different Clinical Outcome of these compensatory mechanisms:
Tachycardia
Peripheral vasoconstriction (cool & pale skin)
Renal conservation of fluid

11. Mechanism of different Stages of shock
2. Progressive Stage :
Widespread hypoxia:
Anaerobic glycolysis
Production of lactic acidosis
pH lead to blunting of vasomotor response leading to vasodilatation
Peripheral pooling of blood
cardiac output

12. Mechanism of different Stages of shock
2. Progressive Stage :
Different Clinical Outcome of these failing mechanisms:
Feeble, failing pulse
Mental confusion
urine output

13. Mechanism of different Stages of shock
3. Irreversible Stage :
Widespread Cellular injury:
Damage to the organelle of cells
Leakage of lysosomal enzymes
Production of nitric oxide by cells
Worsened myocardial contractility

14. Mechanism of different Stages of shock
3. Irreversible Stage :
Different Clinical Outcome of cellular injury:
Septic shock (entry of intestinal flora into circulation)
Complete renal shutdown (acute tubular necrosis)
Downward clinical spiral

15. THANK YOU!