Shock Flashcards
What is the term shock used to describe?
Acute circulatory failure, with either inadequate or inappropriately distributed tissue perfusion, resulting in generalised lack of oxygen supply to cells
What are the different types of shock?
Cardiogenic
Mechanical
Hypovolaemic
Normovolaemic (distributive)
What is cardiogenic shock?
The inability of the heart to eject enough blood
What can cause cardiogenic shock?
Ischaemic heart damage
Arrythmias
What can mechanical shock be due to?
A restriction on the filling of the heart
Obstruction to blood flow through the lungs
What can cause a reduced filling of the heart?
Cardiac tamponade
What happens in cardiac tamponade?
Pressure outside the heart impairs filling
What can cause obstruction of blood flow through the lungs?
Pulmonary embolism
How does a pulmonary embolism cause mechanical shock?
RV cannot empty, reduced return to LA
What is hypovolaemic shock?
Loss of circulating fluid volume
What can cause a loss of circulating fluid volume?
Haemorrhage
What happens in hypovolaemic shock?
Venous pressure falls and so cardiac output falls (Starling’s Law)
How is hypovolaemic shock treated?
Infusing fluid, colloid/blood
What is normovolaemic (distributive) shock due to?
Uncontrolled falls in peripheral resistance
What can cause an uncontrolled drop of peripheral resistance?
Dramatic drops in arerial pressure
Sepsis
Anaphylaxis
