Cardiac Surgery Flashcards
During cardiopulmonary bypass, what are some
techniques that offer cerebral protection?
Although many techniques have been introduced into practice
to combat post cardiopulmonary bypass neurologic
dysfunction, only hypothermia has been proven to be
efficacious.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 521.
At what point will a patient with atherosclerotic
coronary disease exhibit symptoms?
Coronary vessels that become 70% occluded will produce
symptoms due to a reduction in blood flow to the coronaries
(stable angina).
Hines RL, Marschall KE. Anesthesia & Co-Existing Diseases.
6th ed. Philadelphia, PA: Elsevier-Saunders; 2012: 1-2.
What are the two major determinants of coronary
artery perfusion pressure?
Left ventricular end-diastolic pressure and aortic diastolic
pressure.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 510
What is the purpose of using miniaturized circuits
during cardiopulmonary bypass?
Standard CPB circuits are associated with dilutional anemia,
inflammatory reactions, hemodilution, and coagulopathy. In
order to reduce these effects, miniaturized CPB circuits have
been developed.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 1091.
What common hemodynamic alteration has the
highest likelihood to cause myocardial ischemia?
Tachycardia decreases the myocardial oxygen supply while
increasing the demand and has the highest likelihood of
resulting in myocardial ischemia.
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 641.
When the balloon of a PA catheter is not inflated,
what pressures are reflected during systole and
diastole?
Right ventricular systolic pressure is transduced during systole
and PA diastolic pressure is transduced during diastole. The
PA diastolic pressure is also a representation of left atrial (LA)
pressure.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 300.
When the balloon of a PA catheter is inflated, what
pressures can be obtained?
During ventricular systole, the left atrial filling pressure is
reflected, upon ventricular diastole, the left ventricular filling
pressure is measured. When the balloon is inflated, it is termed
“wedged”.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 300.
What patient populations should receive pulmonary
artery (PA) catheters during CABG?
Patients who are undergoing complex procedures, when large
volume shifts are anticipated, or the patient exhibits pulmonary
hypertension, diastolic dysfunction, left ventricular failure, or
right ventricular failure.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 525.
What cross allergy is of concern with a DM patient
on NPH insulin presenting for cardiac surgery?
Protamine
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 412.
Why are patients with diabetes mellitus at an
increased risk for adverse outcomes during and after
cardiac surgery?
The possibility of silent ischemia and MI places patients with
diabetes mellitus at an increased risk
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 904
How is cardioplegia accomplished during cardiac
surgery?
By the administration of a potassium solution into the coronary
circulation
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 409
List complications that can arise from the placement
of PA catheters.
Dysrhythmias, knotting of the catheter, injury to cardiac valves,
and rupture of the pulmonary artery.
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 324.
An EF less than 30% is indicative of what?
Poor cardiac function.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 514.
How does nitroglycerin treat myocardial ischemia?
Nitroglycerin relieves myocardial ischemia primarily through
coronary vasodilation and reduction of preload reduction from
venodilation.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 903.
How is the Ejection Fraction (EF) calculated?
EF=(EDV-ESV)/EDV (EDV=End-diastolic volume, ESV=Endsystolic
volume)
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 514.
What factors are associate with increased need for
blood transfusion during cardiac surgery?
- Advanced age (greater than 70 years), 2. low red cell volume
due to anemia or small body size, and 3. urgent or prolonged
surgery with long cardiopulmonary bypass times.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 520.
Define unstable angina.
Unstable angina is longer than 30 minutes in duration, exhibits
ST or T-segment changes, and is new onset. This type of
angina frequently is refractory to medication or rest.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 355
Define stable angina.
Angina is classified as stable if the duration, frequency, or
precipitating event has not changed for the last 2 months.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 355.
Describe the anesthetic goals of CABG.
Ensure cerebral and myocardial protection, abolish autonomic
reflexes, ensure physiologic homeostasis, and provide muscle
relaxation, analgesia, and amnesia.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 903,
912.
For every 1 degree C decline in core temperature,
how much is the metabolic requirement for O2
reduced?
It is reduced by 8%
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 408.
What are the benefits of hypothermia during CPB?
Reduced oxygen consumption, BMR is reduced, the
preservation of tissues and organs, and increased myocardial
protection
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 519.
What is the normal EF?
55%-70%
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 514.
Where would the most accurate measure of core
temperature be obtained?
At the themistor of a PA catheter
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 330
What test is used to monitor the use of heparin
during CPB?
the ACT (Activated Clotting Time)
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 1088.
What is the initial dose of heparin given prior to the
initiation of CPB?
300-400 units/kg. Maintenance doses are given based on the
ACT values assessed during surgery.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 907.
What is the desired ACT value during CPB?
greater than 400 seconds
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 907.
What is the purpose of the cardiopulmonary bypass
(CPB) pump?
The CPB pump acts as the patient’s heart and lungs in order to
provide a surgeon a bloodless field and a non-beating heart.
Blood is removed from the venous circulation via cannulas
usually in the right atrium, or superior and/or inferior vena cava,
oxygenated and CO2 elimintated, then returned to the body
through an arterial cannula located in the ascending aorta.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 899
What factors are important for the anesthetist to
consider upon weaning a patient from bypass.
The aortic cross-clamp time and the pre-bypass function of the
ventricle are important factors to consider. Patients with good
ventricular function and short cross-clamp times usually do not
require inotropic support after successful revascularization of
the coronaries. Also, the patient’s perfusion status, as well as
body termperature and heart rhythm should be assessed.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 908.
What are the two different types of oxygenators used
on a CPB pump?
Membrane oxygenators and bubble oxygenators
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 899
How can venous drainage to the venous reservoir of
the CPB pump be improved?
By raising the height of the operating table or placing a small
amount of negative pressure on the cardiotomy reservoir.
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 407.
In reference to the configuration of the CPB circuit,
where are membrane oxygenators positioned?
Where are bubble oxygenators positioned?
Membrane oxygenators are placed after the pump because they
have a higher resistance to flow. Bubble oxygenators are
located before the pump because they possess reservoirs of
oxygenated blood and blood does not have to be pumped
through them.
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 406.
What benefits are associated with the use of beta
blockers during open heart surgery?
They reduce the use of oxygen through a reduction in
contractility, blood pressure, and heart rate. By slowing the
heart rate, the left ventricle has more time to be oxygenated due
to the increased diastolic time. Beta blockers can also reduce
the incidence of ventricular arrhythmias induced by
catecholamines.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 903.
What modalities may need to be considered if the
heart fails to spontaneously defibrillate?
Electrical cardioversion and/or antiarrhythmic medication may
be required
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 53
What are the risk factors that pose the most
significant risk for increased mortality following
CABG?
renal failure, emergency surgery, history of cardiac surgery,
>80 years of age
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 909
What device may be considered for patients that fail
to wean from CPB despite optimal drug therapies
and the placement of an IABP?
A Ventricular Assist Device (VAD)
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 1099.
Why is the blood pressure lowered prior to
cannulation of the aorta?
In order to reduce aortic wall tension and reduce the risk of
aortic dissection
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 908.
What is the importance of monitoring glucose during
cardiac surgery?
Hyperglycemia increases the risk for infection and the risk for
serious neurologic injury.
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 410
Immediately prior to sternotomy what is the single
most prudent action taken by the anesthesia
provider?
Ventilation is interrupted (typically 15-20 seconds) to allow the
lungs to deflate. This decreases the likelihood that the lung
parenchyma will be cut by the sternal saw.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 907.
What is the drug most commonly used to reverse
heparin-induced anticoagulation?
Protamine
Miller RD, Pardo MC. Basics of Anesthesia. 6th ed.
Philadelphia: Elsevier Saunders; 2011: 427.
What is the purpose of an intra-aortic balloon pump
(IABP)?
It increases the supply of oxygen to the myocardium (diastolic
augmentation) and decreases the myocardial oxygen demand
(decreases the afterload)
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 548-549.
When does inflation of the balloon of an IABP occur?
During diastole. This allows blood to be pushed into the
coronary arteries.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 548-549
What surgical technique would be most appropriate
for a patient with an aortic arch lesion?
Hypothermic circulatory arrest.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 916.
What is the purpose of the MAZE procedure
It is used to eliminate atrial fibrillation (AF). Patients who have
undergone unsuccessful pharmacologic treatment and are at
high risk for stroke are candidates for this procedure. The open
heart procedure’s name is derived from the serial maze-like
incisions made in the atria.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 542-543.
What two valves most commonly necessitate
surgical involvement?
Aortic and mitral valve
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 909.
