Shock Flashcards
Shock
Hypoperfusion to the tissues due to fluid shifts between the intracellular and extracellular spaces
Stages of shock
Initial, compensatory, progressive, refractory
Hypovolaemic shock
Decrease in blood circulating volume
Cardiogenic shock
Left ventricle failure of the pump. Not enough blood circulating and profusing the tissues (AMI, HF)
Obstructive shock
Blockage stops blood supply to tissues
Distributive shock (sepsis, neurogenic, anaphylactic)
Dilation of capillaries leading to fluid leaking out into the extracellular space. Oxygen cant move through the space well
Initial phase of shock
Body responds to imbalance of O2 supply and demand. Metabolic changes (increased energy requirements and anaerobic metabolism), anaerobic metabolism causes increase in lactic acid causing metabolic acidosis
Initial phase (symptoms)
Increase in RR
Increase HR
Compensatory phase
HR increases as the baroreceptors and chemoreceptors detect low CO causing vasoconstriction
blood flow to major organs maintained will non-vital organs flow diverted
Compensatory symptoms
GI motility slow (hypoactive bowel sounds, diarrhoea,N&V)
Skin cold and clammy
Decrease in UO (kidneys)
Increased HR
Progressive shock
Compensatory mechanisms fail Organ failure (MODS) BP falls Hypoxia, ischemia Disseminated intravasular coagulation (micro clots occur and bleeding)
Refractory phase
Ischemic changes in the heart
Heart dysfunction
Decreased flow to the brain
Cerebral flow cannot be maintained
Anaphylactic shock
Severe allergic reaction that results in the release of chemicals that dilate blood vessels and increase capillary permeability
Sepsis
A systemic inflammatory response with known or suspected infection. Macrophages damage capillary membranes
Neurogenic shock
Disruption in the nervous system affects the vasomotor centre in the medulla causing vasodilation. HR/BP drops
