Cardiovascular responses to shock Flashcards
What is shock?
An abnormality of the circulatory system resulting in inadequate tissue perfusion and oxygenation
What is the formula for mean arterial pressure (MAP)?
MAP = cardiac output (CO) x total peripheral resitance (TPR)
What three things affect stroke volume?
Preload
Myocardial contractility
Afterload
What is hypovolaemic shock?
Severe fluid/blood loss results in decreased blood volume, decreased venous return, decreased end diastolic volume, decreased SV, decreased CO, decreased BP = inadequate tissue perfusion
What does the Frank-Starling curve show?
The relationship between end diastolic volume and SV
What is cardiogenic shock?
Sustained hypotension caused by decreased cardiac contractility
What is obstructive shock?.
Shock caused by physical obstruction of the great vessels or the heart itself
Give an examples of obstructive shock
Tension pneumothorax
How does a tension pneumothorax result in shock?
There is increased intrathoracic pressure that effects the pressure gradient. This results in decreased venous return.
What is neurogenic shock?
Loss of sympathetic tone which results in massive venous and arterial vasodilation. Decreased venous return and total peripheral resistance
What is vasoactive shock?
Release of vasoactive mediators that result in massive venous and arterial vasodilation and increased capillary permeability
What as the treatment for all types of shock?
ABCDE approach
High flow oxygen
Volume replacement
What is the treatment for cardiogenic shock?
Inotropes
What is the treatment for tension pneumothorax obstructive shock?
Immediate chest drain
What is the treatment for anaphylactic shock
Adrenaline
