Card Set Information
heart perfusion nursing blood pressure CO hypotension cardiovascular hypertension MI
What is the normal MAP?
How is perfusion measured?
Perfusion is the passage of fluid through a specific organ or an area of the body.
MAP= [SBP + (2DBP)] ÷ 3
MAP is kept at what to maintain perfusion?
Greater than 60. (60-70 is the titration goal of vasoactive drugs)
What is normal stroke volume? (What is the normal amount of blood ejected from the left ventricle in one contraction?)
What is the normal CO?
: SV x HR/min
Normally, what volume does your left ventricle hold at the end of diastole?
100ml. Your ejection fraction is usually the same amount of ml being pumped out. EF of 70% is equal to 70 ml in a stroke volume.
What is the normal stroke volume?
At what EF do we say that the patient is at risk for impaired perfusion?
Less than 40%.
What effects CO?
HR, SV, EF,
Greater than ____ heart rate decreases diastolic filling time in the ventricles? How does that effect the SV? The CO?
A HR >150 decreases diastolic filling time, which decreases SV and CO.
A HR of less than _____ indicates ____volume returning to the heart and a ____ in CO.
A HR of less than
volume returning to the heart and a
A heart rate greater than ____ and less than ___ decrease cardiac output.
A heart rate greater than
and less than
decrease cardiac output.
The sympathetic nervous system _____ HR and CO, the stimulation of the parasympathetic nervous system ____ HR and CO.
The sympathetic nervous system
HR and CO, the stimulation of the parasympathetic nervous system
HR and CO.
Cardiac Index allows for what in measuring CO?
The Cardiac Index adjusts the normal cardiac output related to a patient's size. CI = CO/BSA Normal = 2.8-4.2 L/min/m
What is the normal Cardiac Index?
Normal is 2.8-4.2L/min/m
What is the normal EF?
What happens if the EF is <40%?
CO is decreased. Perfusion to the body is decreased. Blood can accumulate in the pulmonary vessels.
And increased thyroid hormone increases or decreases CO?
A decreased thyroid hormone decreases CO.
How can you measure EF%?
ECHO cardiogram, cardiac cath, or chemical stress test.
What is cardiac reserve?
The ability of the cardiovascular system to respond to demands (stress, exercise, hypovolemia) by altering CO threefold or fourfold.
Increased age impact sympathetic control and cardiac reserve how?
Slower sympathetic and decreased cardiac reserve = Slower recovery from activity, slower and decreased response to any emotional or physical stress.
What is preload?
The volume of blood in the ventricle at the end of diastole, before the next contraction.
What affects preload?
Anything that changes the return of blood to the heart.
Decreased Preload: Dehydration, hemorrhage...
Increased preload: Overhydrated, HTN: decrease preload by administering diuretics.
What is afterload?
The peripheral resistance against which the left ventricle must pump.
How can you indirectly measure afterload?
Arterial blood pressure.
What medications decrease afterload?
What kind of medications affect contractility?
Positive (increases) and negative (decreases) inotropes.
What is contractility?
The force of the contraction of the heart independent of preload (the volume of blood entering the ventricle).