Quiz 4 Anesthesia for Off Pump Coronary Flashcards
What are the four cardiac function and metabolism concerns?
- Coronary Anatomy
- Utilization of O2
- Supply of O2 and nutrients
- Demand of O2 and nutrients
How much oxygen does the heart extract?
65 - 75 %
T/F: The brain extracts more oxygen than any other organ of the body?
FALSE (Heart extracts the most O2)
What does VO2 mean?
Oxygen consumption
What does MVO2 mean?
Myocardial oxygen consumption
What does SVO2 mean?
Venous Oxygen saturation (mixed venous oxygen)
Using a Frank Starling Curve what would you expect to see in a normal during exercise?
The curve shifting up and to the left.
Using a Frank Starling Curve what would you expect to see in a normal heart that is in a state of heart failure?
The curve shifting down and to the right.
What is the most sensitive cardiac function test?
TEE
What is the benefit of doing a MIDCAB?
-Thoracotomy approach (NO incision through the sternum)
What vessels are involved in a MIDCAB?
-LIMA to LAD
What contributes the most to cardiac O2 demand?
-Heart Rate (MOST)
What are three things to look at for anesthetic concerns for cardiac surgery?
- Culprit lesion
- Collateral Circulation
- Ventricular function
Which has more O2 extraction the SVC or the IVC?
-SVC
What are a few things that affect mixed venous oxygen?
- Anemia
- FiO2
- PEEP
- Temperature
- CO
What are the two main coronary arteries?
- Left Main Coronary Arteries
- Right Coronary Artery
What arteries branches off the Left Main Coronary Artery?
- Left Anterior Descending (LAD)
- Circumflex
The Circumflex perfuses the SA node in ___% of people
40
The circumflex branches into the ______ marginal and supplies the _________ free wall.
Obtuse, lateral
The ______ marginals supplies the anterior wall of the _______ ventricle.
Acute, right
The right coronary artery perfuses the S.A. node in __% and the AV node in __%
60 %, 80 - 90%
What is the percent of people that have a Posterior descending artery perfused by the RCA or referred to as the “________________”.
85 % , right dominate system
What is the equation to determine the O2 content of the blood?
CaO2 = 1.31 x Hgb x SaO2 + (0.003 x PaO2)
What are the goals to get the maximal O2 content?
- High hemoglobin
- Highly saturated blood
- High PO2
What shift would you see on the oxyhemoglobin curve if the patient had warm temperature, normal pH, and high levels of 2,3 -DPG which favors release of oxygen.
RIGHT shift
Coronary Blood Flow varies __________ with coronary perfusion pressure.
directly
Coronary blood flow varies ________with coronary resistance
indirectly
Coronary vascular resistance will _______, if there is an increase in O2 and a decrease in CO2 and H+.
Increase
Coronary vascular resistance will _______, if there is and increase in CO2 and H+ and a decrease in O2.
Decrease
T/F: Adenosine (from ATP breakdown) is probably the MOST important metabolic blood flow regulator.
TRUE
What will adenosine cause to the coronary vascular resistance?
- Dilate
- Increase blood flow
What will an increase in Alpha adrenergic (Norepi) tone and cholinergic (ACH) do to the coronary vascular resistance?
Increase
What will a increase in the beta-adrenergic tone do to the coronary vascular resistance?
Decrease
What will and increase in vasopressin, angiotensin, and throomboxane do the the coronary vascular resistance?
INCREASE
What will an increase in prostacyclin do to the coronary vascular resistance?
Decrease
What will happen to the coronary vascular resistance when the blood viscosity increases and hyporthermia decrease.
INCREASE
What is the most at risk layer of tissue in the heart for ischemia?
Subendocardium
What will stenosis of the coronaries do to blood flow?
Increase in CVR
Decrease in CBF
T/F: Dynamic stenoses is a atherosclerotic plaque.
FALSE (Fixed stenoses is and atherosclerotic plaque.)
What is Dynamic stenoses?
When the coronary artery goes into vasospasm or Prinzmetal’s variant angina
What determines myocardial O2 demand?
- Heart Rate
- Contractility
- Wall Stress
What three things determine wall stress?
- Afterload
- Preload
- Wall Thickness
ST segment depression denotes ___________ ischemia.
endocardial
ST segment elevation denotes ________ ischemia.
transmural
T/F: Milrinone is the most potent smooth muscle vasodilator and is an inotrope.
TRUE
How is significant changes determined on an EKG?
0.1 mV or 1 mm of ST segment elevation or depression at normal gain
What is your ACT goal for off-pump vs on-pump?
Off-pump > 300
On-pump > 450-600
When giving Protamine at the end of a cardiac case, should you give a “test dose”?
Yes - Give 10mg test dose. Pt’s can have allergic reaction
How fast should you give Protamine?
SLOW. Protamine can cause hypotension and cardiopulmonary collapse.
Should you give Protamine while the pt is still on the CPB?
No, can cause the machine to clot
What is the formula for Cardiac Perfusion Pressure?
CPP = AoDBP - LVEDP
Aortic pressure during diastole minus the back pressure in the LV
