Shock Flashcards
What so shock?
Clinical syndrome of tissue hypoperfusion due to circulatory failure
Is MAP high or low in shock?
Low - below necessary (50-60mmHg)
What does inadequate perfusion lead to?
Systemic acidosis (pH <7.35) -> worsens enzyme function and cellular performance.
Micro capillary thrombus with patchy tissue injury / large vessel thrombus with organ infarction.
Tissue necrosis -> mortality / chronic morbidity
Recognition of shock from end of bed?
Mottled skin
Confusion, agitation , decreased Glasgow coma score <15
Oliguria
Lactate levels diagnostic of shock?
Above 2mmol/L
What do lactate levels >4mmol/L indicate ?
Significant mortality
4 mechanisms of shock?
Cardiogenic
Obstructive
Hypovolaemia
Distributive
In cardiogenic shock, what leads to decreased MAP?
Decreased HR
Decreased SV
Decreased CO
Increased systemic vascular resistance to compensate
What effect does increased systemic vascular resistance have?
Cool clammy peripheries
How does obstructive shock occur?
Obstruction to cardiac outflow
Features of obstructive shock?
Raised JVP
Distended neck veins
What is hypovolaemic shock?
Decreased blood volume -> lower venous return to the heart
Clinical features of hypovolaemic shock?
Tachycardia
Cool, clammy peripheries
What causes low MAP in hypovolaemic shock ?
Decreased SV due to low preload
Decreased CO
Increased HR to compensate
Increased systemic vascular resistance to compensate
Clinical features in distributive shock?
Warm red peripheries
Bounding, hypovolaemic circulation
