Cardiovascular pathophysiology 4

Question 1

A patient with a bare-metal cardiac stent presents for a bunionectomy. What is the minimal amount of time that the patient should wait before she undergoes surgery?

Answer 1

30 days

Question 2

A patient who receives a coronary stent requires

Answer 2

dual antiplatelet therapy to prevent stent thrombosis

Question 3

Dual antiplatelet therapy consists of

Answer 3

aspirin
thienopyridine (usually clopidogrel or ticlopidine)

Question 4

Withholding DAPT therapy after a coronary stent leads to

Answer 4

increased risk of thrombus formation and myocardial infarction

Question 5

Continuing DAPT therapy after a coronary stent when doing another surgical procedure leads to

Answer 5

increased bleeding risk

Question 6

The duration to wait for elective surgery after angioplasty without stent is

Answer 6

2-4 weeks

Question 7

The duration to wait for elective surgery after bare metal stent placement is

Answer 7

1-3 months

Question 8

The duration to wait for elective surgery after drug eluting stent is

Answer 8

6-12 months

Question 9

How many days should clopidogrel be stopped before surgery?

Answer 9

7 days

Question 10

How many days should ticlopidine be stopped before surgery?

Answer 10

14 days

Question 11

For must surgeries, ______ can be continued throughout the perioperative period.

Answer 11

aspirin

Question 12

________________- should NOT be used to “bridge” patients who’ve stopped all antiplatelet therapy.

Answer 12

Unfractionated heparin or LMWH
-heparin paradoxically increases platelet aggregation in the stent leading to an increased risk of thrombosis

Question 13

The best treatment for stent thrombosis is

Answer 13

PCI- best outcome is achieved if blood flow is restored in <90 minutes

Question 14

How long should elective surgery be delayed after a CABG?

Answer 14

6 weeks (3 months preferred)

Question 15

Priming the cardiopulmonary bypass machine with a balanced salt solution reduces all of the following EXCEPT:
a. microvascular flow
b. plasma drug concentration
c. oxygen-carrying capacity
d. blood viscosity

Answer 15

a. microvascular flow

Question 16

__________________ allows the surgeon to operate on an immobile heart.

Answer 16

Cardiopulmonary bypass

Question 17

How does bypass work?

Answer 17

once the blood flows into the bypass circuit, O2 is added and CO2 is removed

Question 18

Blood returning to the patient from the bypass machine resembles

Answer 18

arterial blood

Question 19

Patients on CPB are rendered _____________- to reduce __

Answer 19

hypothermic to reduce metabolic rate

Question 20

A ___________ pump is preferred over a ____________ pump

Answer 20

centrifugal; roller

Question 21

A ____________ oxygenator is preferred over a ______________ oxygenator.

Answer 21

membrane; bubble

Question 21

A ____________ oxygenator is preferred over a ______________ oxygenator.

Answer 21

membrane; bubble

Question 22

If priming the pump with a balanced salt solution, you should expect

Answer 22

hemodilution

Question 22

If priming the pump with a balanced salt solution, you should expect

Answer 22

hemodilution

Question 23

_______________ can occur if air enters the

Answer 23

An airlock; venous line

Question 24

The _______________ is the component of the CBP machine where gas exchange occurs (it replaces the lungs)

Answer 24

oxygenator

Question 25

Why is a bubble oxygenator not preferred?

Answer 25

uses a blood-gas interface (no membrane)- carries a risk of cerebral air emoblism

Question 26

The priming fluid for CBP can be

Answer 26

blood or a balanced salt solution (mannitol, albumin, heparin, HCO3-)

Question 27

Hemodilution has the following effects:

Answer 27

decreased hematocrit decreased oxygen-carrying capacity decreased blood viscosity (good if hypothermia is used) decreased plasma concentration of drugs and plasma proteins increased microvascular flow (due to reduced viscosity

Question 28

When is awareness MOST likely to occur during coronary artery bypass graft surgery with CBP? a. induction of anesthesia b. aortic cannulation c. rewarming d. sternotomy

Answer 28

d. sternotomy

Question 29

What ACT is required to start CPB?

Answer 29

>400

Question 30

Systolic BP should be _______________ before aortic cannulation

Answer 30

<100

Question 31

What should be used pre-bypass to conserve blood loss?

Answer 31

cell saver or antifibrinolytics

Question 32

Cardioplegia is a

Answer 32

potassium-containing solution that arrest the heart in diastole

Question 33

The best way to reduce myocardial oxygen consumption during CPB is

Answer 33

cardioplegia

Question 34

CPB produces ________________________ that can result in critical organ injury and failure

Answer 34

systemic inflammation

Question 35

_________ of protamine reverses 100 units of heparin given

Answer 35

1 mg

Question 36

Radial artery pressure may be _____________________________ immediately after CPB

Answer 36

artificially low

Question 37

What are common in the post-bypass period?

Answer 37

myocardial depression and heart block so vasoactive medications and cardiac pacing may be required

Question 38

Heparin allergy or a history of heparin-induced thrombocytopenia requires

Answer 38

an alternative such as bivalirudin, hirudin, or another factor 10 inhibitor

Question 39

Cardioplegia can be administered

Answer 39

antegrade, retrograde or both

Question 40

Antegrade cardioplegia is introduced into the

Answer 40

aortic root, where the solution enters the coronary arteries

Question 41

Retrograde cardioplegia is administered through a cannula placed in the

Answer 41

coronary sinus

Question 42

________________ complicates our interpretation of blood gas results during CPB

Answer 42

Hypothermia

Question 43

As temp decreases more ____________ dissolves in the blood and affects __________

Answer 43

CO2; pH

Question 44

_____________ does not correct for the patient's temperature and is associated with better outcomes in adults.

Answer 44

Alpha-stat

Question 45

_________ corrects for the patient's temperature and is associated with better outcomes in peds.

Answer 45

pH-stat

Question 46

__________ is when all of the venous return is drained in the venous reservoir, while ______________ describes a situation where the heart receives and pumps a fraction of the venous return

Answer 46

Full bypass; partial bypass

Question 47

How does protamine work?

Answer 47

neutralization reaction- it forms an acid/base complex with heparin

Question 48

Administering protamine over 10-15 minutes reduces the likelihood of

Answer 48

systemic vasodilation as well as pulmonary vasoconstriction it does not impact the probability of anaphylaxis

Question 49

List 2 antifibrinolytics commonly used during cardiac surgery.

Answer 49

TXA aminocaproic acid

Question 50

What is a contraindication to antegrade cardioplegia?

Answer 50

incompetent aortic valve