Cardiogenic shock Flashcards
Definition of cardiogenic shock
critical condition in which the heart is unable to pump adequate amounts of blood around the body for sufficient end-tissue perfusion, despite adequate circulating volume.
Causes for cardiogenic shock
ACS
acute decompensatory heart failure
arrythmias
mechanical failure (valves, septum, cardiac wall.)
Cycle in cardiogenic shock
Myocardial O2 depletion
Pump failure due to infarction
Decreased cardiac output
decreased coronary perfusion
worsened infarction and increases oxygen demand
heart rate increases to increase O2 supply, faster rate further increases O2 demand
Decreased tissue perfusion causes lactic stenosis which triggers increase in heart rate.
Compensatory mechanisms for cardiogenic shock
RAAS system
Baroreceptors - stimulates SA node to increase HR
Chemoreceptors - adrenaline and noradrenaline release to increase BP through vasoconstriction
Signs of CGS
tachycardia
hypotension
delayed capillary refill
tachypnoea
reduced O2 saturations
reduced GCS
oliguria
pallor
clammy
most sensitive organs to CGS
brain and kidneys
Prehospital identification of CGS
BP, GCS, urine output, stability of patient
Treatment - revascularisation
anticoagulants and platelet agglutination inhibitor
Treatment - afterload
to increase afterload - norepinephrine and vasopressin
to decrease afterload - vasodilators and nitrates
Treatment - preload
to increase preload - crystalloid fluids
to decrease preload - diuretics and dialysis
treatment - contractility
to increase contractility - dobutamine, epinephrine (PCEIII-inhibitor)
Treatment - heart rate
to increase heart rate - atropine
to decrease heart rate - amiodarone, B-blockers, cardioversion
