module 10 shock Flashcards
shock
imbalance between O2 supply and demand at the cellular level : inadequate O2
- group of life threatening condition s
common factor: hypo-perfusion and impaired cellular oxygen utilization
could result from:
- dec. CO
- maldistribution of blood flow
- dec blood O2 content
cardiogenic shock
inadequate CO despite sufficient vascular volume
blood pump problem
obstructive shock
circulatory blockage - large pulmonary embolus - cardiac tamonade disrupts CP blood flow problem
hypovolemic shock
loss of blood volume as a result of hemorrhage or excessive loss of extracellular fluids
blood volume problem
distributive shock
greatly expanded vascular space because of inappropriate vasodilation
- blood vessel problem
common factor of shock
impaired O2 utilization by cells
- > dec. function, cell death, organ dysfunction, inflammatory reactions.
- > glycolysis to produce ATP -> lactic acidosis
dec. ATP -> plasma membrane dysfunction - > inc. intracellular Na and Ca -> swelling
- > free radical formation
- > inflammatory cytokines
- > cell death
Hallmark of shock
failure of microcirculation to auto-regulate blood flow
-> abnml distribution of blood flow
Shocks with hypotension
cardiogenic
obstructive
hypovolemic
distributive
systemic vascular resistance and shocks
cardiogenic: high
obstructive: high
hypovolemic: high
distributive: low
cardiac output and shocks
cardiogenic: low
obstructive: low
hypovolemic: low
distributive: high
cardiac preload and shocks
cardiogenic: high
obstructive: low
hypovolemic: low
distributive: normal to low
venous oxygen saturation and shocks
cardiogenic: low
obstructive: low
hypovolemic: low
distributive: high
urine output and shocks
cardiogenic: low
obstructive: low
hypovolemic: low
distributive: low
skin temperature and shocks
cardiogenic: cool
obstructive: cool
hypovolemic: cool
distributive: warm
compensation
works in early stages
- especially hypovolemic shock
- cardiogenic: may worsen already high pre-load -> inc. workload
- distributive: vasculature non-responsive to SNS signals to constrict -> blood pooling in tissues
s/s of early compensated shock
narrow pulse pressure, w/ or w/out hypotension HR > 100 fast and deep resp dec. urinary output inc. urine specific gravity cool clammy skin altered mentation dilated pupils
s/s of progressive stage
low BP, < 90 narrow pulse pressure tachycardia acute renal failure - oliguria, inc. blood urea nitrogen and creatinine dec. LOC inc. resp. rate metabolic and respiratory acidosis with hypoxemia
cardiogenic shock primarily results from
dysfunction of one or both ventricles -> inadequate pumping
- MI
- end stage cardiomyopathy
- papillary muscle dysfunction
- free wall rupture
- congenital defects
inc. LV diastolic filling (preload)
- - differentiates cardiogenic from hypovolemic
-> pulmonary: fluid in tissue -> pulmonary edema
possible S3 heart sound
causes of obstructive shock and s/s
mechanical obstruction that prevents effective cardiac filling and SV
common causes:
- pumonlary embolism
- cardiac tamponade
- tension pneumothorax
Manifests as RSHF
RV enlargement -> LV compression -> dec. CO
obstructive shock and cardiac tamponade
pericardial sac has inc. fluid volume
- sac can only stretch so much, then pressure pushes on heart
- > compression of vena cava, atria, and pulmonary veins
- > RV collapse
- > dec. RV filling in diastole
- > dec. SV and CO
- > cardiac arrest
causes of hypovolemic shock
hemorrhage burns dehydration - dec. intravascular vol. -> dec. preload -> dec. CO -> hypotension -> dec. tissue perfusion -> hypoxic cell injury -> progressive shock
causes of distributive shock
abnormally expanded vascular space caused by excessive vasodilation -> polling of blood in venous capacitance vessels -> relative hypovolemia
- Types
- Anaphylactic: IgE mediated
- Neurogenic:
- – brain trauma
- – spinal cord injury
- – high spinal anesthesia
- – drug overdose
- Septic: gram-negative bacteria: endotoxin -> vasodilation
neurogenic shock
type of distributive
imbalance between SNS and PSNS stimulation
- depression of vasomotor center in medulla
- interruption of sympathetic nerve fibers
- baroreceptor reflex not working
Massive vasodilation
-> dec. vascular tone
-> dec. SVR
-> dec. CO
-> dec. tissue perfusion
-> impaired cellular metabolism
anaphylactic shock
type of distributive antigen (allergen) reaction with IgE -> complement, histamine, kinins, and prostaglandin activation -> peripheral vasodilation, inc. capillary permeability -> dec. SV, edema -> relative hypovolemia -> dec. CO -> dec. tissue perfusion -> impaired cellular metabolism
septic shock
type of distributive bacteremia -gram-negative: endotoxin release -> proinflammatory cytokines -> activation of complement system, coag system, kinin system, and WBC's -> release of anti-inflammatory cytokines -> endothelial cell dysfunction -> cell damage and death -> multiple organ dysfunction -> death
high risk for septic shock
young and elderly debilitated malnourished immunocompromised chronic health problems invasive lines catheters surgery
