Shock Flashcards
what is the definition of shock ?
An abnormality of the circulatory system resulting in inadequate tissue perfusion and oxygenation - can lead to anaerobic metabolism, which will cause metabolic waste products to accumulate, resulting in cellular failure
Adequate tissue prefusion depend on ?
mean arterial blood pressure and stroke volume (thus Cardiac Output )
a patient can only be present with one type of shock True/False
False
Type of shocks
- Hypovolaemic Shock
- Cardiogenic Shock
- Obstructive Shock
- Distributive Shock
Hypovolaemic Shock is and what is causes it
is decrease in the blood of the body
Haemorrhage - direct blood loss (e.g. trauma, surgery)
Non-haemorrhage - decrease in ECFV e.g. due to vomiting,
what is the pathophysiology of Hypovolaemic Shock?
g
Hypovolaemic shock compensatory cardiac mechanism
the body compensates by activating various mechanisms to maintain blood pressure and perfusion to vital organs. These mechanisms include:
- The baroreceptor reflex, which causes an increase in heart rate to maintain cardiac output and blood pressure.
- Vasoconstriction, which increases resistance in blood vessels to redirect blood flow to vital organs.(cool periphery)
- The myogenic response, which is the ability of blood vessels to regulate their own diameter in response to changes in blood pressure.
However, these compensatory mechanisms may not be enough to maintain blood pressure and perfusion to vital organs in severe cases of hypovolemic shock, and medical intervention is necessary to restore blood volume and prevent organ damage.
Cardiogenic Shock pathophysiology
Decreased cardiac contractility (e.g. due to acute MI) → decreased stroke volume → decreased CO and BP → inadequate tissue perfusion
tension pneumothorax pathophysiology
Increased intrathoracic pressure → decreased venous return → decreased EDV → decreased SV (Frank-Starling) → decreased CO and BP → inadequate tissue perfusion
Neurogenic e.g. spinal cord injury pathophysiology
- Loss of sympathetic tone to blood vessels and heart → massive venous and arterial dilation and heart rate slows → decreased venous return and SVR → decreased CO and BP → inadequate tissue perfusion
Vasoactive shock e.g. septic shock, anaphylactic shock pathophysiology ?
- Release of massive vasoactive mediators → massive venous and arterial vasodilation, increased capillary permeability → decreased venous return and SVR → decreased CO and BP → inadequate tissue perfusion
What’s the managements for Shock ? (8)
- ABCDE approach
- High flow oxygen
- Volume replacement for hypovolaemic shock
- Inotropes for cardiogenic shock
- Immediate chest drain for tension pneumothorax
- Adrenaline for anaphylactic shock
- Vasopressors for septic shock
- Call for help early