Shock Flashcards
What is shock?
The clinical syndrome of tissue hypoperfusion due to circulatory failure
What occurs in the pathophysiology of shock?
Low mean arterial pressure means slow flow to organs causing inadequate perfusion for cellular metabolic requirements
Give some effects of inadequate perfusion of tissues
Systemic acidosis
Microcapillary thrombus
Large vessel thrombosis
Cellular necrosis
What are the three main signs of tissue hypoperfusion?
Skin mottling
GCS <15
Oliguria (<0.5ml/kg/hr)
What lactate level is thought to be diagnostic of tissue hypoperfusion?
> 2mmol/l
What occurs in cardiogenic shock?
Reduced force of cardiac contraction and stroke volume reducing cardiac output and mean arterial pressure
Cardiogenic shock will present with cool/warm peripheries
Cool
What occurs in obstructive shock?
Obstruction to cardiac outflow reduces stroke volume reducing cardiac output and mean arterial pressure
What is the main clinical feature of obstructive shock?
Distended neck veins (raised JVP)
What are the main causes of obstructive shock?
Cardiac tamponade
Tension pneumothroax
Pulmonary embolism
What occurs in hypovolaemic shock?
A reduced blood volume decreases venous return reducing force of cardiac contraction and cardiac output (Frank-Starling curve)
Give some clinical features of hypovolaemic shock
Cool peripheries
Tachycardia
What occurs in distributive shock?
Vasodilation reduces systemic vascular resistance reducing mean arterial pressure and increasing cardiac output
Give some clinical features of distributive shock
Warm peripheries
Bounding pulse
