-
What is the normal MAP?
80-100.
-
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?)
70ml.
-
What is the normal CO?
- 4L-8L/min
- Calculation: 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?
70 ml.
-
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 50bpm indicates decreased volume returning to the heart and a decrease in CO.
-
A heart rate greater than ____ and less than ___ decrease cardiac output.
A heart rate greater than 150 and less than 50 decrease cardiac output.
-
The sympathetic nervous system _____ HR and CO, the stimulation of the parasympathetic nervous system ____ HR and CO.
The sympathetic nervous system increases HR and CO, the stimulation of the parasympathetic nervous system decreases 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/m2
-
What is the normal Cardiac Index?
Normal is 2.8-4.2L/min/m2
-
What is the normal EF?
50%-70%
-
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?
- Increases 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?
Antihypertensives, vasodilators.
-
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).
|
|