circulatory shock Flashcards
effect of hypoperfusion
shock is when…
Shock if MAP < 60 mmHg and/or SBP< 90
what causes vasodilation
Activation of nitric oxide and prostacyclin via cGMP and cAMP respectively. Secondary messengers cause a decrease in calcium and smooth muscle relaxation
what causes vasoconstriction
Predominantly controlled through the sympathetic nervous system
Noradrenaline acts on α1 and 2 receptors to cause vasoconstriction of vessels and SMC contraction
Angiotensin and vasopressin have vasoconstrictive effects
four types of shock
obstructive
hypovolemic
cardiogenic
distributive
causes of obstructive shock (3)
PE, tension pneumothorax, cardiac tamponade
How does pleuritic chest pain present
chest pain which in creases with breathing
signs and symptoms of tension pneumothx (5)
Tachycardia and tachypnoea
-Hypoxia
-Chest pain
-Reduced breath sounds on the affected side
-Deviated trachea, away from the affected side
what is tension pneumothx
influx of air into pleural space
cardiac tamponade Beck’s triad
hypotension, jugular venous distension, and muffled heart sounds
cardiac tamponade problems
heart can’t distend so hypotension
disruptive shock 3 subtypes
septic
anaphylactic
neurogenic
septic shock diagnostic bp and map
persistent hypotension MAP <65mmhg
mechanism of septic shock
too much vasodilation
typical signs of septic shock
tachycardia and low BP
can be fever but not always
what is LOC
level of consciousness
neurogenic shock cause and pathophysiology
spinal injury above T6
unopposed parasympathetic
bradycardia
hypotension
dysregulated thermoreg
what is cardiogenic shock caused by
basically failure of heart to pump blood
cause of cardiogenic shock
acute MI most common cause
what is melena
dark tarry stool
causes of hypovolemic shock
burns
cholera
haemorrhage
femur fracture danger
can have massive haematoma -> hypovolemic shock
slow capillary refill indicates
hypovolemia
