Flashcards in Shock Deck (19)
1
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
2
What are the different types of shock?
Cardiogenic
Mechanical
Hypovolaemic
Normovolaemic (distributive)
3
What is cardiogenic shock?
The inability of the heart to eject enough blood
4
What can cause cardiogenic shock?
Ischaemic heart damage
Arrythmias
5
What can mechanical shock be due to?
A restriction on the filling of the heart
Obstruction to blood flow through the lungs
6
What can cause a reduced filling of the heart?
Cardiac tamponade
7
What happens in cardiac tamponade?
Pressure outside the heart impairs filling
8
What can cause obstruction of blood flow through the lungs?
Pulmonary embolism
9
How does a pulmonary embolism cause mechanical shock?
RV cannot empty, reduced return to LA
10
What is hypovolaemic shock?
Loss of circulating fluid volume
11
What can cause a loss of circulating fluid volume?
Haemorrhage
12
What happens in hypovolaemic shock?
Venous pressure falls and so cardiac output falls (Starling's Law)
13
How is hypovolaemic shock treated?
Infusing fluid, colloid/blood
14
What is normovolaemic (distributive) shock due to?
Uncontrolled falls in peripheral resistance
15
What can cause an uncontrolled drop of peripheral resistance?
Dramatic drops in arerial pressure
Sepsis
Anaphylaxis
16
How does sepsis cause a fall in peripheral resistance?
Endotoxins released by circulating bacteria cause profound peripheral vasodilation
17
How is normovolaemic shock caused by sepsis treated?
Adrenaline (causes vasoconstriction) and antibiotics
18
How does anaphylaxis cause normovolaemic shock?
Release of histamine from mast cells causing profound vasodilation
19