NURS 3812 Exam 2: Perfusion (week 9)
Questions and Correct Answers
What two factors is cardiac output determined by?
heart rate and stroke volume
What is the equation for cardiac output?
CO = HR x SV
What does cardiac output determine?
how much blood heart pumps each minute
What is stroke volume?
amount of blood ejected from the ventricles per contraction
What is stroke volume influenced by?
preload, contractility, afterload
What is preload?
stretch of ventricles
What is contractility?
strength of myocardial contraction
What is afterload?
force ventricles exert to open aortic and pulmonic valves
How does ischemia occur?
, when tissue oxygen demand exceeds oxygen supply due to reduction or cessation of blood flow
Initially, what does ischemia cause?
reversible cellular injury
What is the consequence of prolonged ischemia?
irreversible cellular injury and tissue death --> stroke, myocardial infarction, and pressure
injuries
What lifestyle factors can increase the risk of impaired perfusion?
smoking, physical inactivity, unhealthy diet
How does smoking impact perfusion?
damages blood vessels, promotes vasoconstriction and atherosclerosis (plaque build up)
What PT teachings about diet and perfusion should a nurse provide?
limit sodium and saturated fats; encourage lean protein sources, fruits and vegetables, and whole
grains
Generally, how much exercise is recommended to support good perfusion?
150mins/week
What assessment is a direct indicator of peripheral tissue perfusion?
capillary refill time
What capillary refill time would suggest impaired perfusion?
>3 seconds
Questions and Correct Answers
What two factors is cardiac output determined by?
heart rate and stroke volume
What is the equation for cardiac output?
CO = HR x SV
What does cardiac output determine?
how much blood heart pumps each minute
What is stroke volume?
amount of blood ejected from the ventricles per contraction
What is stroke volume influenced by?
preload, contractility, afterload
What is preload?
stretch of ventricles
What is contractility?
strength of myocardial contraction
What is afterload?
force ventricles exert to open aortic and pulmonic valves
How does ischemia occur?
, when tissue oxygen demand exceeds oxygen supply due to reduction or cessation of blood flow
Initially, what does ischemia cause?
reversible cellular injury
What is the consequence of prolonged ischemia?
irreversible cellular injury and tissue death --> stroke, myocardial infarction, and pressure
injuries
What lifestyle factors can increase the risk of impaired perfusion?
smoking, physical inactivity, unhealthy diet
How does smoking impact perfusion?
damages blood vessels, promotes vasoconstriction and atherosclerosis (plaque build up)
What PT teachings about diet and perfusion should a nurse provide?
limit sodium and saturated fats; encourage lean protein sources, fruits and vegetables, and whole
grains
Generally, how much exercise is recommended to support good perfusion?
150mins/week
What assessment is a direct indicator of peripheral tissue perfusion?
capillary refill time
What capillary refill time would suggest impaired perfusion?
>3 seconds
