N434 Final Exam - Perfusion (Shock)
Shock defintion - correct answer Syndrome of decreased tissue perfusion and impaired cellular
metabolism > imbalance in supply/demand for oxygen and nutrients > hypoperfusion
When the cells experience hypoperfusion, the demand for oxygen and nutrients exceeds the
supply
Cardiogenic shock pathophysiology - correct answer there is either systolic or diastolic
dysfunction of the heart's pumping action which results in reduced CO
systolic dysfunction - inability to pump blood forward
diastolic dysfunction - poor filling of the heart
Hypovolemic shock pathophysiology - correct answer occurs after loss of intravascular fluid
volume
Absolute hypovolemia - correct answer fluid lost through hemorrhage, vomiting, diarrhea,
fistula drainage, diabetes insipidus, or diuresis
Relative hypovolemia - correct answer Fluids moves out of vascular space into extravascular
space (third spacing)
results from bowel obstruction, burns, ascites, fracture of long bone, ruptured spleen,
hemothorax, severe pancreatitis, sepsis
Types of distributive shock - correct answer Anaphylactic
Neurogenic
Septic
Neurogenic shock pathophysiology - correct answer SCI results in massive vasodilation without
compensation because of the loss of SNS vasoconstrictor tone > pooling of blood, tissue
hypoperfusion, impaired cellular metabolism
Anaphylactic shock pathophysiology - correct answer Life-threatening hypersensitivity reaction
> vasodilation, release of vasoactive mediators, and an increase in capillary permeability > fluid
leaks into interstitial space
Obstructive shock pathophysiology - correct answer Physical obstruction to blood flow with
decreased CO
,Stages of shock - correct answer Initial stage
Compensatory stage
Progressive stage
Refractory (irreversible) stage
Initial stage - correct answer Usually not clinically apparent
Occurs at cellular level
Metabolism changes from aerobic to anaerobic caused lactic acid build up
Removal of lactic acid - correct answer Lactic acid is a waste product removed by the liver
The process requires oxygen
Compensatory stage - correct answer SNS activated - attempt to overcome anaerobic
metabolism and maintain hemostasis
Blood shunted to the brain and heart
Blood shunted away from lungs, kidneys, GI, and skin
Manifestations during compensatory stage - correct answer Cardiac - increase in oxygen
demands, tachycardia, hypotension, chest pain
Neuro - confusion
Lungs - increased VQ mismatch, increased RR and depth
GI - risk for paralytic ileus
Kidneys - decreased UOP
Skin - cool, clammy (unless septic shock - they may feel warm)
Progressive stage - correct answer Compensatory mechanisms fail
Changes in mental status are important findings during this stage
, Aggressive interventions are needed to prevent MODS - move patient to ICU
Cardiac presentation during progressive stage - correct answer Continued decreased CO >
decrease BP and coronary artery, cerebral, and peripheral perfusion > altered capillary
permeability > leakage of fluid and protein into interstitial space > diffuse profound edema
(anasarca)
Respiratory presentation during progressive stage - correct answer Increased pulmonary
vascular constriction > blood low to pulmonary capillaries decreases and ventilation-perfusion
mismatch occurs
Tachypnea, crackles, increased WOB
Renal presentation during progressive stage - correct answer Renal tubular ischemia > acute
tubular necrosis > AKI
Decreased UOP, elevated BUN and creatinine, metabolic acidosis
Nephrotic drugs - correct answer Antibiotics (gentamicin, aminoglycosides), anesthetic,
diuretics
GI presentation with progressive stage - correct answer Impaired motility continues with
ischemic mucosal barrier > ulcers, bleeding, decreased absorption of nutrients
Liver presentation during progressive stage - correct answer Functions fail > failure to
metabolize drugs and waste products, jaundice, decreased immunity, elevated enzymes,
increased risk for bacteremia
Hematologic presentation during progressive stage - correct answer DIC begins (consumption
of platelets and clotting factors) > bleeding from many orifices
Refractory stage - correct answer Sustained hypoperfusion
Profound anaerobic metabolism
Accumulation of lactic acid
Increased permeability and dilation > blood pools in cap beds
Worsened hypotension and tachycardia, decreased CO, cerebral ischemia
Organs fail from accumulation of waste products (lactate, urea, ammonia, CO2)
Diagnostics - correct answer No single diagnostic to determine shock
Shock defintion - correct answer Syndrome of decreased tissue perfusion and impaired cellular
metabolism > imbalance in supply/demand for oxygen and nutrients > hypoperfusion
When the cells experience hypoperfusion, the demand for oxygen and nutrients exceeds the
supply
Cardiogenic shock pathophysiology - correct answer there is either systolic or diastolic
dysfunction of the heart's pumping action which results in reduced CO
systolic dysfunction - inability to pump blood forward
diastolic dysfunction - poor filling of the heart
Hypovolemic shock pathophysiology - correct answer occurs after loss of intravascular fluid
volume
Absolute hypovolemia - correct answer fluid lost through hemorrhage, vomiting, diarrhea,
fistula drainage, diabetes insipidus, or diuresis
Relative hypovolemia - correct answer Fluids moves out of vascular space into extravascular
space (third spacing)
results from bowel obstruction, burns, ascites, fracture of long bone, ruptured spleen,
hemothorax, severe pancreatitis, sepsis
Types of distributive shock - correct answer Anaphylactic
Neurogenic
Septic
Neurogenic shock pathophysiology - correct answer SCI results in massive vasodilation without
compensation because of the loss of SNS vasoconstrictor tone > pooling of blood, tissue
hypoperfusion, impaired cellular metabolism
Anaphylactic shock pathophysiology - correct answer Life-threatening hypersensitivity reaction
> vasodilation, release of vasoactive mediators, and an increase in capillary permeability > fluid
leaks into interstitial space
Obstructive shock pathophysiology - correct answer Physical obstruction to blood flow with
decreased CO
,Stages of shock - correct answer Initial stage
Compensatory stage
Progressive stage
Refractory (irreversible) stage
Initial stage - correct answer Usually not clinically apparent
Occurs at cellular level
Metabolism changes from aerobic to anaerobic caused lactic acid build up
Removal of lactic acid - correct answer Lactic acid is a waste product removed by the liver
The process requires oxygen
Compensatory stage - correct answer SNS activated - attempt to overcome anaerobic
metabolism and maintain hemostasis
Blood shunted to the brain and heart
Blood shunted away from lungs, kidneys, GI, and skin
Manifestations during compensatory stage - correct answer Cardiac - increase in oxygen
demands, tachycardia, hypotension, chest pain
Neuro - confusion
Lungs - increased VQ mismatch, increased RR and depth
GI - risk for paralytic ileus
Kidneys - decreased UOP
Skin - cool, clammy (unless septic shock - they may feel warm)
Progressive stage - correct answer Compensatory mechanisms fail
Changes in mental status are important findings during this stage
, Aggressive interventions are needed to prevent MODS - move patient to ICU
Cardiac presentation during progressive stage - correct answer Continued decreased CO >
decrease BP and coronary artery, cerebral, and peripheral perfusion > altered capillary
permeability > leakage of fluid and protein into interstitial space > diffuse profound edema
(anasarca)
Respiratory presentation during progressive stage - correct answer Increased pulmonary
vascular constriction > blood low to pulmonary capillaries decreases and ventilation-perfusion
mismatch occurs
Tachypnea, crackles, increased WOB
Renal presentation during progressive stage - correct answer Renal tubular ischemia > acute
tubular necrosis > AKI
Decreased UOP, elevated BUN and creatinine, metabolic acidosis
Nephrotic drugs - correct answer Antibiotics (gentamicin, aminoglycosides), anesthetic,
diuretics
GI presentation with progressive stage - correct answer Impaired motility continues with
ischemic mucosal barrier > ulcers, bleeding, decreased absorption of nutrients
Liver presentation during progressive stage - correct answer Functions fail > failure to
metabolize drugs and waste products, jaundice, decreased immunity, elevated enzymes,
increased risk for bacteremia
Hematologic presentation during progressive stage - correct answer DIC begins (consumption
of platelets and clotting factors) > bleeding from many orifices
Refractory stage - correct answer Sustained hypoperfusion
Profound anaerobic metabolism
Accumulation of lactic acid
Increased permeability and dilation > blood pools in cap beds
Worsened hypotension and tachycardia, decreased CO, cerebral ischemia
Organs fail from accumulation of waste products (lactate, urea, ammonia, CO2)
Diagnostics - correct answer No single diagnostic to determine shock
