Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anesthesia Written Board Questions > Cardiac Anesthesia > Flashcards

Cardiac Anesthesia Flashcards

1
Q

On what type of CPB pump can excessive pressure build up proximal to an outflow occlusion, potentially causing the tubing to rupture or the tubing connections to separate?

A

A roller pump

Flow of a roller pump is predictable and depends on the revolutions per minute of the pump. Although retrograde flow is not possible, if there is outflow occlusion to the pump, excessive pressure can build, causing the tubing to rupture or the tubing connections to separate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

On what type of CPB pump can retrograde flow occur and how?

A

The Centrifugal Pump

It operates on a principle of a constrained vortex, where the rotator (impeller) is housed within a rigid container shaped like a cone.

Flow depends on the pressure differential created by spinning cones that create a negative pressure (pressure drop), propelling fluid forward.

Flow varies depending on pump preload and after load.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In a patient with Vfib refractory to repeated attempts at defibrillation and lidocaine administration, what is the most appropriate drug management?

A

The administration of bretylium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At what point in the arterial waveform is an intraarterial balloon pump inflated?

A

At the dicrotic notch, which marks the start of diastole so that there is better coronary perfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

For what procedures and what patients is prophylactic antibiotics recommended against infective endocarditis?

A

It is only recommended for dental/skin/respiratory tract procedures

In high risk patients with a prosthetic valve or unprepared congenital heart disease(CHD) or recently repaired CHD with prosthetic materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe pacemaker syndrome

A

It is characterized by hypotension, vertigo, fatigue, and weakness.

It occurs when pacer leads fail, leading to symptoms which initially indicated the pacemaker placement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the different phases of the cardiac action potential

A

1) Phase 0 (UPSTROKE): at rest with rapid influx of Na+ causes DEPOLARIZATION (Na+ entry; decreased K+ permeability)
2) Phase 1 (EARLY RAPID REPOLARIZATION): partial repolarization (K+ out)
3) Phase 2 (PLATEAU): plateau phase, when Ca2+ is going in and K+ is going out
4) Phase 3 (FINAL REPOLARIZATION): the potential goes back down towards baseline as more and more K+ is driven out
5) Phase 4 (RESTING POTENTIAL and DIASTOLIC REPOLARIZATION): little ion flux occurring during diastole, when pacemaker cells spontaneously depolarize and “generate the cardiac rhythm” Na+ - K+ ATPase pumps K+ in and Na+ out; Diastolic depolarization allows a slow leakage of Ca2+ into cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do volatile anesthetics effect the SA and AV nodes?

A

They depress the SA node (with NO effect on the AV node)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the most resistant arrhythmia to cardioversion?

A

Atrial flutter, often needing 200 joules of biphasic current energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which current is superior in cardioversions; biphasic or monophasic current?

A

Biphasic current is superior to monophasic current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does blood flow differ between the left and right heart?

A

The left ventricle is supplied ONLY during diastole

Right-sided coronary blood flow is CONTINUOUS throughout the cardiac cycle (because the lower pressure in the RV compared to the LV causes substantially less extravascular compression during systole)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the resting coronary blood flow rate? What percentage of the cardiac output goes to the heart?

A

250 mL/min in an adult

5% of CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the best measurement of ventricular function (in the absence of anemia and hypoxia)?

A

Measurement of mixed venous oxygen saturation (MVO2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do the x-axis and the y-axis represent on the Frank-Starling curve?

A

x-axis: LV volume (i.e. LVED volume)

y-axis: LV pressure/work (i.e. cardiac output)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Normal value for SVR

A

900-1500 dynes cm5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Increasing the afterload has what effect on stroke volume (SV)?

A

Increasing afterload DECREASES SV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the most likely valvular pathology in a young pregnant patient presenting with increasing SOB?

A

Mitral stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the most common cause of mitral stenosis?

A

Rheumatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the most likely disease process in a patient with a high PCWP and a low LVEDP?

A

Mitral Stenosis or Pulmonary HTN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

NYHA Classification

A

I. Completely asymptomatic
II. Comfortable at rest, symptomatic with “ordinary physical activity”
III. Comfortable at rest, symptomatic with “less than ordinary physical activity”
IV. May be symptomatic at rest, symptomatic with any physical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What ECG leads correspond to the lateral heart? inferior heart? antero-septal heart?

A

Lateral heart: lead I, V5, V6

Inferior heart: leads II, III, aVF

Ant/Sept heart: leads V1-V4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the most likely ECG abnormality seen intraoperative in a patient with acute ischemia?

A

ST elevation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What component of the vascular tree has NO direct sympathetic innervation?

A

Capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does the sympathetic outflow derive from?

A

The Thoracolumbar Spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the cause for vasovagal syncope?

A

It is a result of reflex activation of both vagal and sympathetic vasodilatory fibers

26
Q

MOA of Digoxin and its elimination

A

Blocks Na+, K+ = ATPase to cause less Na+

which leads to Ca2+ influx and increased contractility (therefore, calcium administration potentiates digoxin toxicity)

*Prolongs AV conductance

Renal elimination

27
Q

MOA of Adenosine

A

Suppresses AV nodal conduction

28
Q

MOA of Amiodarone

A

Depresses SA and AVnode

*anti-adrenergic effect may cause an atropine-resistant bradycardia and hypotension during general anesthesia

29
Q

What does Dopamine stimulate at low doses, intermediate doses, and high doses?

A

At low dose (o.5-3 mcg/kg/min): stimulates dopa 1 receptors

At intermediate dose (3-10 mcg/kg/min): stimulates beta receptor

At high dose (10-20 mcg/kg/min): stimulates beta and alpha1

30
Q

MOA of Dobutamine. Half life?

A

Dobutamine is a synthetic catecholamine that is a DIRECT Beta 1 AGONIST with very limited Beta 2 and alpha 1 effects

It has NO alpha 2, no dopaminergic activity

It primarily acts as a VASODILATOR

Plasma half life is 2 minutes

31
Q

MOA of Norepinephrine

A

It is the primary physiologic post-ganglionic sympathetic neurotransmitter

Acts as a direct alpha 1, alpha 2, and beta 1 AGONIST

32
Q

MOA of Isoproterenol

A

A synthetic catecholamine that is a direct Beta 1 & 2 AGONIST

NO alpha stimulation

33
Q

MOA of Milrinone

A

Phosphodiesterase inhibitor that is an INODILATOR, increasing intracellular concentrations of cAMP by inhibiting its breakdown.

In cardiac myocytes: postive inotropy, lusitropy, chronotropy, dromotropy as well as increased automaticity.

In vascular beds: vasodilatation

34
Q

What is the half life of Nitroglycerin

A

1-3 minutes

35
Q

How does potassium effect a pacemaker’s function?

A

Any acute INCREASE in K+ decreases the potential across the membrane, therefore making the pacemaker MORE likely to capture. (VICE VERSA)

(Hyperventilation may decrease likelihood of capture

36
Q

Can cardiac oxygen extraction be increased via exercise?

A

NO. Cardiac oxygen extraction is near maximal under resting conditions and cannot be substantially increased during exercise.

37
Q

By what percent is myocardial oxygen consumption of the heart decreased at 22 degrees Celsius WITHOUT cardioplegia solution compared to that of a normal heart?
[What is myocardial oxygen consumption of the heart normally; when empty and normothermic; when empty, hypothermic & has cardioplegia?]

A

Normal myocardial oxygen consumption is 10 mL/100g/min.

When the heart is empty and at 37 degrees Celsius, it is reduced to 5.5 mL/100g/min

When the heart is cooled to 22 degrees, its consumption decreases to 2 mL/100g/min, which is an 80% reduction from normal

Had cardioplegia solution been given, it would have been reduced to 0.3 mL/100g/min

38
Q

What are the primary determinants of myocardial oxygen demand?

A

Contractility and wall tension

39
Q

What is the appropriate management of cardiac tamponade?

A

“full, fast, and tight”

Full = maintain preload
Fast = myocardial contractility should be slightly higher
Tight = SVR is high
40
Q

What is pulsus alternans indicative of on a arterial waveform?

A

It is a condition in which there are alternating smaller and larger pulse waves.

Commonly seen in LV Dysfunction

41
Q

What is pulsus paradoxus indicative of?

A

Cardiac tamponade & sometimes RV infarction

A decrease in the blood pressure of > 10 mmHg with inspiration

42
Q

What is pulsus parvus and pulses tardes indicative of on an arterial waveform?

A

Aortic stenosis

Characterized by a diminished pulse wave and delayed upstroke, respectively

43
Q

What is the appropriate initial amount of energy to be set for biphasic cardioversion of atrial flutter?

A

50-100 Joules

Synchronized cardioversion of an adult with Aflutter requires less Joules than other tachydysrhythmias.

44
Q

What does the S on the ECG tracing represent?

A

The S-wave is a small negative wave following the large R-wave. It represents depolarization in the Purkinje fibers

45
Q

Describe coronary steal phenomenon

A

It cause dilation of healthy blood vessels which direct blood AWAY from ischemic areas and thereby worsen ischemia.

46
Q

Describe ischemic preconditioning

A

Inhalational anesthesia may confer protection to the heart after an initial ischemic insult by delaying the onset of necrosis. This occurs within 2 hours of mild ischemic episodes. The effect passes, but is observed 1-3 days after the ischemia

It is believed to be the result of the activation of mitochondrial ATP-sensitive potassium channels, which results in decreased calcium levels in the myocytes.

47
Q

How does supine position effect the audibility of murmurs from pulmonic stenosis?

A

Pulmonic stenosis leads to an outflow track obstruction, which is exaggerated during the supine position because of a larger end-diasoltic volume and greater stroke volume.

Therefore, the murmur is louder

48
Q

What are contraindications for LVAD placement?

A

1) Severe aortic insufficiency
2) Severe mitral stenosis
3) ASD

49
Q

What location of the aortic cross clamp causes the least hemodynamic effects?

A

An infrarenal cross clamp produces the least effect hemodynamically.

50
Q

What are the criteria for diagnosing pulmonary HTN according to the ACC/AHA?

A

All 3 of the following must be present:

1) Resting mPAP > 25 mmHg
2) PCWP/LAP = 15 mmHg
3) PVR > 3 Woods units

(RVH is NOT required)

51
Q

What does “chattering” or “fluttering” of the venous cannula during CPB indicate?

A

This occurs when compliant venous or atrial walls collapse against the annular intake opening as a result of inadequate blood volume or excessive siphon pressure.

This phenomenon is corrected by adding volume to the patient.

52
Q

What is the function of the intra-aortic balloon pump?

A

It provides counter pulsation during diastole in order to do 2 things:

1) Increase coronary perfusion
2) Decrease afterload

Other benefits include:

  • decreasing myocardial oxygen demand
  • decreasing preload
  • increasing cardiac output
53
Q

What cardiac abnormality is associated with acute aortic dissection and aortic aneurysm formation?

A

Bicuspid aortic valve

54
Q

What distinguishes a true ventricular aneurysm from a pseudo aneurysm?

A

A TRUE ventricular aneurysm’s lining consists of:

1) ALL the layers of the of the myocardial wall (MYOCARDIUM, ENDOCARDIUM, EPICARDIUM)
2) Tends to be located at the ventricular apex and appears as a dilated, dyskinetic area with myocardial thinning.
3) Usually occur within 90 days of anterior wall MI
4) Has a smooth transition btw normal myocardium and the aneurysm with a neck to maximal aneurysm diameter ratio of 0.9 - 1
5) Severe mitral regurgitation is common (but NOT a distinguishing trait)

Whereas, a ventricular PSEUDOANEURYSM:

1) Occurs at the side of a chronic ventricular rupture and is lined ONLY by PERICARDIUM.
2) Tend to saccular or globular in shape.
3) Most often the consequence of chronic ventricular rupture after MI and can also result from surgery, trauma, and infection
4) Has a neck to maximal aneurysm diameter ratio usually < 0.5
5) On CDF, noted bidirectional flow of blood btw the LV and the pseudo aneurysm (enters in systole and goes back to LV is diastole); turbulent flow

Both occur after myocardial infarctions.

55
Q

During deep hypothermic circulatory arrest, how is the PaCO2 from an alpha-stat reading, effected?

A

Temperature and PaCO2 are directly proportional.

Therfore, as the temperature decreases, so do PaCO2 levels, because the partial pressure of CO2 decreases.

56
Q

In patients with end-stage heart failure requiring surgery for ventricular assist device placement, what are the goals of anesthesia induction?

A

Heart rate is a very important determinant of cardiac output. Maintain a HR of 80-90 bp is vital.

57
Q

What is the most common congenital cardiovascular anomaly? associations?

A

Bicuspid aortic valve

  • associated with coarctation of the aorta
  • male predominance
58
Q

Which papillary muscle is MOST commonly affected by ischemia of the LV?

A

The posterior papillary muscle, which is fed by the posterior descending artery

59
Q

What are some drug options for medical cardioversion of atrial flutter?

A

Amiodarone
Dofetilide (effective in 70-80%)
Ibutilide (effective in 63%) - risk of QT prolongation and tornadoes de pointes

NOT lidocaine (which is useful for the suppression of ventricular dysrhythmias)

60
Q

What is the recommended heart rate to be maintained in patients with Mitral Regurgitation?

A

80-100 bpm

61
Q

What are the effects of initiating CPB with a non-blood priming solution?

A
  • Reduction of mean arterial pressure
  • Reduction of blood viscosity
  • Reduction in SVR
  • Decrease in after load

Anesthesia Written Board Questions (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions