Shock & Hemorrhage
- By Dr. Nisit Patel
, Shock
Shock is the most common and therefore the most
important cause of death of surgical patients.
,Shock – Definition
• Shock is a systemic state of low tissue perfusion that is
inadequate for normal cellular respiration.
• With insufficient delivery of oxygen and glucose, cells
switch from aerobic to anaerobic metabolism.
• If perfusion is not restored in a timely fashion, cell death
ensues.
, Shock – Pathophysiology
1. Cellular 2. Microvascular
• Perfusion to tissue decreased • As tissue ischaemia progresses…
• Cells deprived of O2 • Activation of the immune and coagul
• Switch from aerobic to systems
anaerobic metabolism • Hypoxia and acidosis activate
• By product – Lactic Acid complement
• Cause Metabolic Acidosis • Generation of oxygen free radicals a
cytokine release
• Glucose also exhausted
• Injury of the capillary endothelial cel
• So no energy / ATP
• Damaged endothelium loses its integ
• Failure of Na /K pump
+ +
and becomes ‘leaky’
• Intracellular lysosomes release
• Fluid leaks out and tissue oedema oc
• Cell lysis/death exacerbating cellular hypoxia
- By Dr. Nisit Patel
, Shock
Shock is the most common and therefore the most
important cause of death of surgical patients.
,Shock – Definition
• Shock is a systemic state of low tissue perfusion that is
inadequate for normal cellular respiration.
• With insufficient delivery of oxygen and glucose, cells
switch from aerobic to anaerobic metabolism.
• If perfusion is not restored in a timely fashion, cell death
ensues.
, Shock – Pathophysiology
1. Cellular 2. Microvascular
• Perfusion to tissue decreased • As tissue ischaemia progresses…
• Cells deprived of O2 • Activation of the immune and coagul
• Switch from aerobic to systems
anaerobic metabolism • Hypoxia and acidosis activate
• By product – Lactic Acid complement
• Cause Metabolic Acidosis • Generation of oxygen free radicals a
cytokine release
• Glucose also exhausted
• Injury of the capillary endothelial cel
• So no energy / ATP
• Damaged endothelium loses its integ
• Failure of Na /K pump
+ +
and becomes ‘leaky’
• Intracellular lysosomes release
• Fluid leaks out and tissue oedema oc
• Cell lysis/death exacerbating cellular hypoxia
