Exam 3 ppt key points Flashcards

1
Q

What are the Risk Factors for CAD

A
Age
Gender  (Male)
Family Hx
Smoking- 6x greater in women, 3x greater in males
HTN
High Cholesterol- high LDL & low HDL
Diabetes
Obesity
Physical Inactivity
Stress
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2
Q

At the center of the cardiovascular system is ?

A

the heart.

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3
Q

Myocardial blood supply is derived entirely from ?

A

the right and left coronary arteries.

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4
Q

The left coronary normally supplies

A

the LA, interventricular septum, and LV.

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5
Q

The right coronary normally supplies

A

the RA, most of the RV, and variable amounts of LV.

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6
Q

The most frequently performed cardiac operation is?

A

Coronary artery bypass grafting

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7
Q

CABG technique involves bypass of a narrowed or occluded epicardial coronary with a small-diameter conduit distal to the narrowed segment. Selected grafts include?

A

reversed saphenous

internal mammary artery

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8
Q

___________ appears to have superior long-term performance with 90% patency rates at 10 years.

A

The IMA

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9
Q

The choice of conduit in CABG depends on?

A

availability and durability

50% of vein grafts will be significantly diseased or occluded at 10 years.

The IMA appears to have superior long-term performance with 90% patency rates at 10 years.

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10
Q

When using a saphenous vein graft in CABG, the proximal arterial inflow source is?

A

the ascending aorta.

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11
Q

When the LIMA is utilized in CABG, the proximal arterial inflow source is

A

the left subclavian artery.

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12
Q

_________ is used to replace the function of the heart in CPB

A

Arterial pump

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13
Q

Arterial pump generally uses one of two primary technologies

A

A roller pump

A centrifugal pump – thought to be less traumatic

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14
Q

Identify the correct order of steps to CPB

A
  1. Priming
  2. Anticoagulation
  3. Cannulation
  4. Initiation
  5. Maintenance
  6. Weaning and Termination
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15
Q

The solution used to prime the CPB circuit is generally _______

A

a balanced electrolyte solution

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16
Q

Hemodilution in CPB is due to?

A

Prime volume

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17
Q

Standard procedure requires that the patient be ___________ before cannulation for CPB. _______ is still the standard agent used.

A

fully anticoagulated

Heparin

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18
Q

Heparin administered through a central venous catheter at an initial dose of ________ for CPB

A

300 U/kg

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19
Q

Heparin Onset is almost immediate, but generally the drug is allowed to circulate for ______________ before it’s effect is measured.

A

3-5 minutes

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20
Q

The ACT must increase to at least _______ before CPB is initiated.

A

300 seconds

400 for most institutions

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21
Q

The ACT is not used to monitor heparin levels but to monitor __________

A

the anticoagulant effects of heparin and other anticoagulants.

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22
Q

Elevated ACT measurements taken, before, during, or after CPB may be influenced by variables other than heparin which include?

A

Hypothermia
Hemodilution
Aprotinin

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23
Q

Every CPB procedure requires a high-flow cannula in a large vein and another in a large artery for withdrawing blood from and returning blood to the patient. The target for venous cannulation is ?

A

RA- It’s appendage is conveniently accessible through a sternotomy.

The RA may also be approached through the femoral vein.

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24
Q

For CPB venous cannulation, the right atrium can be accessed through?

A

appendage is conveniently accessible through a sternotomy.

The RA may also be approached through the femoral vein.

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25
Q

The CPB circuit returns oxygenated blood to the patient through the arterial cannula.
For CABG procedures, the standard target for the arterial cannula is ?

A

the portion of the ascending aorta below the aortic arch but still 3-4 cm above the aortic valve.

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26
Q

Which patients require direct left ventricular venting in CPB

A

patients with severely compromised ventricular function undergoing CABG

Patients undergoing any intracardiac procedures

Patients with aortic insufficiency

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27
Q

left ventricular venting in CPB may be necessary for patients with aortic insufficiency because?

A

The LV vent is separate from the cardioplegia cannula, it can be used to decompress the heart during antegrade cardioplegia administration.

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28
Q

LV vents are typically introduced through ?

A

the right superior pulmonary vein and advanced through the LA, across the mitral valve, and into the LV

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29
Q

What is the indication that the venous cannula is adequately draining the venous return to the heart?

A

right sided heart pressure (CVP and PAP) should decrease to O mmHg and become nonpulsatile.

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30
Q

During CPB initiation describe arterial BP and arterial tracing

A

Arterial blood pressure should reach a normal mean pressure (60-90 mmHg) while also becoming nonpulsatile.

The arterial tracing usually becomes nonpulsatile as the heart is emptied and the pumping force is changed from the ventricle to the nonpulsatile arterial pump of CPB machine.

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31
Q

During CPB initiation, the heart is arrested in diastole by ?

A

the administration of potassium enriched cardioplegia solution to the heart.

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32
Q

__________ is the single most important step in reducing the heart’s myocardial oxygen consumption by 90%.

A

Interrupting myocardial electromechanical activity

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33
Q

Reduction in myocardial consumption by cardioplegia during CPB is augmented by?

A

Hypothermia at 22 degrees C

This is achieved by administering cold cardioplegia solution.

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34
Q

The combined influence of potassium arrest and myocardial temperatures lower than 22 degress C reduces myocardial oxygen consumption by ________% and enables the tissue to withstand complete interruption of blood flow for periods of ________________

A

97%

20-40 minutes.

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35
Q

For induction of cardioplegic arrest, a “high-K” solution with a potassium concentration of approximately ____________ is used.

A

20-30 mEq

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36
Q

What are the characteristic of the cardioplegia solution during initiation

A

Has a potassium concentration of approximately 20-30 mEq.

Designed to be slightly hypertonic to reduce edema.

Include a buffer to counter the heart’s production of acidic metabolites.

Contains a substrate for energy or catalysts to assist the heart’s production of ATP.

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37
Q

Maintenance phase of CPB entails

A

After isoelectric arrest is induced, the solution is changed to a “low-K” mixture with a potassium concentration of about 10 mEq.

Periodically throughout the procedure, 200-500 mL doses of “low-K” solution are administered to deliver nutrients to the cells and maintain the potassium concentration.

Cardioplegia can be administered antegrade into the coronary arteries via the aortic root, or retrograde into the coronary sinus/veins.

The most complete technique for myocardial protection involves both antegrade and retrograde delivery.

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38
Q

What is the potassium concentration of cardioplegia solution during CPB.

A

10 mEq

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39
Q

Cardioplegia can be administered antegrade into the coronary arteries via ___________, or retrograde into ________.

A

the aortic root

the aortic root

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40
Q

Immediately after termination of CPB, the patient is often hemodynamically supported with?

A

volume (blood, albumin, crystalloids, hespan)

frequently supplemented with vasopressors or inotropic agents.

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41
Q

During the weaning and termination phase of CPB, when the patient is hemodynamically stable, protamine can be administered to reverse the anticoagulant effect of Heparin. Protamine dose is ?

A

1mg / 100 units Heparin given.

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42
Q

What is the primary concern during induction of a patient for CABG

A

Prevention of myocardial ischemia

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43
Q

Two factors associated with myocardial ischemia include

A

Inadequate oxygen supply (coronary lesions)

Excessive oxygen demand (HR, BP, Adrenergic stimulation)

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44
Q

Patients with _____________ are more susceptible to insult during induction.

A

disease of the left main coronary

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45
Q

Many cardiac patients require fluid loading or prophylactic treatment with pressors during induction because?

A

They have low circulating blood volumes because of hypertensive vasoconstriction.

Small doses of phenylephrine or ephedrine may be necessary to avoid excessive hypotension.

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46
Q

The lungs must be deflated to prevent laceration or puncture during sternotomy for how long

A

for approximately 15-20 seconds

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47
Q

Bolus administration of heparin through the central line may decrease arterial pressure by _________?

A

10-20%.

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48
Q

ACT should be approximately __________ before it is safe to institute CPB

A

400 seconds

49
Q

Anticoagulation is measured _______ after heparin bolus by ACT.

A

3-5 minutes

50
Q

Aortic cannulation is associated with hypertensive response, probably because of?

A

Direct stimulation of sympathetic nerves in the aortic arch.

51
Q

___________ assists aortic cannulation and prevents laceration of the aorta.

A

Reduction in MAP

52
Q

Venous cannulation may lead to?

A

Fluctuations in arterial pressure and ventricular tachyarrhythmias secondary to manipulation of the heart.

53
Q

CPB should not commence unless the following have been completed by the anesthesia provider:

A

Heparin administered

ACT checked and at least 350-400

Adequate muscle relaxation

Inotropic infusions turned off

Pupil symmetry assessed for later comparison

Pulmonary artery catheter pulled back 5 cm

Urinary output emptied before bypass

54
Q

During CPB initiation, the clamps placed across the cannulas during insertion are removed in what sequence?

A

venous, then arterial

55
Q

Multiple events occur simultaneously and can cause a significant drop in blood pressure at the initiation of CPB. They are?

A

Preload to the heart decreases causing a loss of stoke volume, while hemodilution decreases blood viscosity and dilutes catecholamines in the plasma contributing to the drop in pressure.

56
Q

During CPB initiation, rapid cooling of the patient occurs to a target temperature of ?

A

28 degrees C

57
Q

ACT is checked every __________ by the perfusionist and is maintained at _________ with the addition of heparin.

A

30-45

> 400 seconds

58
Q

While most think CPB is break time, it is NOT! Why?

A
Swan migration
Paralysis
Amnesia
MAP
pH
Urine output
Glucose
59
Q

What is the checklist for weaning from CPB?

A

Patient is warm, at least 35 C

Heart rhythm has returned

HR 70-100. < 60 reduced CO; > 120 reduced LV filling

Inflate lungs

Labs: K+, iCa++, Hct, pH, ACT

Drugs: Lidocaine, Calcium, Magnesium

60
Q

When the patient is weaned from CPB, considerations should include

A

the ventricular function of the heart before bypass

the length of time the aorta was cross-clamped.

61
Q

3 Basic Groups Coming Off Bypass

A

Patients with good ventricular function

Hypovolemic patients

Patients with pump failure

62
Q

Features of hypovolemic patients (mixed group) coming off CBP

A

Respond quickly to 100 mL aliquots of pump blood, FFP, or PRBC’s. BP and CO rise with each bolus, sustainable. LVEDP below 10-15 mmHg.

Impairment should be suspected when LVEDP rises with volume infusion without appreciable changes in BP or CO. These patients require LVEDP above 10-15 mmHg

63
Q

Features of patients with pump failure coming off CBP

A

Sluggish, poorly contracting heart that progressively distends.

Inotropic therapy is initiated. If SVR is high, afterload reduction can be tried along with inotropic therapy.

Ultimately, CPB may need to be reinstituted.

64
Q

This drug does not increase filling pressure and may be associated with less tachycardia. CO often increases without significant changes in blood pressure.

A

Dobutamine

65
Q

If inotropes and afterload reduction fail during separation from CPB

A

CPB may be used as a bridge to an intra aortic balloon pump.

66
Q

This drug improves renal blood flow (low doses) and is often more effective in raising blood pressure than in raising CO.

A

Dopamine

67
Q

Clinically is the most potent inotrope and is usually effective in increasing both cardiac output and systemic blood pressure when other agents have failed. In low doses, it predominantly has beta-agonist activity.

A

Epinephrine

68
Q

Large doses of this drug compromise renal blood flow.

A

Norepinephrine

69
Q

Amrinone and Milrinone

A

Both are phosphodiesterase inhibitors; inotropes with significant arterial and venodilator properties.

Unlike other inotropes, these two inodilators may not appreciably increase myocardial oxygen consumption because they decrease left ventricular afterload and do not directly increase HR.

70
Q

Two inotropes that may not appreciably increase myocardial oxygen consumption because they decrease left ventricular afterload and do not directly increase HR.

A

Amrinone and Milrinone (phosphodiesterase inhibitors)

71
Q

Chest tube drainage in the first 2 hours of more than ___________ in the absence of a hemostatic defect, is excessive.

A

250-300 mL/hr (10mL/kg/hr)

72
Q

Assess pupils after initiation of CPB as unilateral dilation may indicate

A

arterial inflow into the innominate artery (unilateral carotid perfusion).

73
Q

Protamine should be administrated slowly over a period of ____________ to reduce the risk for hypotension

A

5-10 minutes

74
Q

If the heart fibrillates during rewarming, _________ may be necessary.

A

defibrillation (5-10 J)

75
Q

What is given to decrease the likelihood of fibrillation during rewarming

A

lidocaine 100-200 mg and magnesium sulfate 1-2 g

76
Q

A-line placement when LIMA is being used for CABG

A

If the left mammary artery is to be harvested, A-line placement is best suited in the right radial artery because retractors can dampen the waveform of a left radial A-line.

77
Q

Heparin is always administered before

A

cannulation

78
Q

The PA catheter should be pulled back 3-5 cm to

A

minimize the risk of pulmonary perforation as the pulmonary arteries collapse with the initiation of CPB.

79
Q

What is desirable SBP during termination of CPB

A

After termination of CPB, elevated SBP should be avoided to prevent excessive stress on suture lines in the heart and aorta. Usually 90-120 mmHg is a desirable systolic pressure.

80
Q

___________ is frequently implicated in post-bypass bleeding.

A

Platelet dysfunction

81
Q

Amicar dose

A

10-29 gm load

1-2 gm/hr

82
Q

Stroke is predominant CNS postop complication of CABG. Indicators are

A

Visual impairment
Hemiparesis
Aphasia
Sensory impairment

83
Q

CNS complications after CPB is Usually seen in, pump runs longer than?

A

90 minutes.

84
Q

Cause of coagulopathy after CPB

A

Platelet dysfunction is frequently implicated

Thrombin production and fibrinolysis. Thrombin is produced by the extrinsic and intrinsic pathways and by activated platelets. It is only partially suppressed by heparin therapy.

85
Q

__________ is the single most important intraoperative monitor of renal system during CABG

A

Urinary output

Standard is UO of 1 mL/kg/hr.

86
Q

Renal dysfunction in CPB is related to?

A

length of time on bypass (longer than 3 hours)

cardiac output

Infection

Type of procedure (valve surgery has higher risk)

Excessive blood loss

Diabetes

Increased use of vasopressors

Perioperative myocardial infarction

Use IABP

Massive transfusions

87
Q

Hypothermia during CPB depresses renal tubular function; however what interventions will result in adequate urine output?

A

hemodilution

use of mannitol

maintenance of GFR

88
Q

Hyperglycemia during CPB can also affect ________

A

renal tubules

89
Q

During CPB, as the temp is decreased to 28 C what happens

A

ACT, PT, and PTT are prolonged

platelets become nonfunctional

Cellular potassium uptake is increased and may result in hypokalemia.

90
Q

The beneficial aspects of hypothermia include

A

a reduced basal metabolic rate

improved myocardial protection

tissue and organ preservation

reduced oxygen consumption.

91
Q

The metabolic requirement for O2 is reduced by _________ for each ________ drop in core body temperature.

A

50%

7° C

92
Q

It may not be possible to convert heartbeat to normal sinus rhythm until the rewarming core temperature is _______

A

34°C.

93
Q

Normal stroke volume

A

60-90mL/beath

94
Q

Normal stroke index

A

40-60 mL/beat/m2

95
Q

Normal cardiac output

A

5-6 L/min

96
Q

Normal Cardiac index

A

2.5 - 4 L/min/m2

97
Q

Normal SVR

A

700-1400 dyne/sec/cm5

SVR=(MAP-CVP) /(CO x 80)

98
Q

Normal PVR

A

50-300 dyne/sec/cm5

SVR=(PAP-PCWP) /(CO x 80)

99
Q

Left ventricular stroke work index

A

40-60 g•m/beat/m2

100
Q

Coronary perfusion pressure

A

50 mmHg

101
Q

Normal EF

A

55-70%

102
Q

Rate-pressure product

A

> 15000

103
Q

Tripple index

A

> 180,000

104
Q

Thoracic surgery focuses on the chest organs which are?

A

Heart
Lungs
Esophagus
Trachea

105
Q

a surgical procedure to gain access into the pleural space of the chest

A

Thoracotomy

106
Q

Lung function testing: 80-40-15 rule:

A

FEV1 and DLCO > 80% = no additional testing needed. If < 80 or dyspnea present , diffusing capacity and postoperative function should be predicted.

PPO FEV1 and DLCO < 40% = increased risk; exercise testing should be evaluated

VO2 max < 15 ml/kg per min = increased risk

107
Q

___________ is the leading cause of cancer deaths in the United States

A

Bronchogenic carcinoma

108
Q

The incidence of of lung cancer is ________ among COPD patients than in the general population.

A

four times higher

109
Q

Many patients presenting for lung surgery will have complex underlying pathology. Therefore, ______________________ are crucial to anticipating the patient’s intraoperative and postoperative needs.

A

Evaluating respiratory function and predicting post resection function

110
Q

The Anesthetic risk assessment for patients in need of pulmonary resection surgery specific to pulmonary surgery focuses on

A

how the underlying pathology will challenge the maintenance of adequate gas exchange and general homeostasis under OLV

The potential for post op respiratory failure to make weaning and extubation difficult

111
Q

OLV is commonly provided by three different methods:

A

Double lumen tubes
Bronchial blockers
Single lumen endobronchial tubes

112
Q

The principal advantage of double-lumen tubes are

A

relative ease of placement

the ability to ventilate one or both lungs

the ability to suction either lung

113
Q

All DLTs share the following characteristics:

A

Longer bronchial lumen that enters either the right or left main bronchus and another shorter tracheal lumen that terminates in the lower trachea.

A preformed curve that when properly “aimed” allows preferential entry into a bronchus

A bronchial cuff

A tracheal cuff

114
Q

Principal Disadvantages of Double Lumen Tubes are

A

Size selection

Difficult to place in patients with difficult airways

Not optimal for postoperative ventilation (must be changed out if pt to remain intubated)

115
Q

The most commonly used DLTs are available in several sizes:

A

35 FR to 37 Fr for women over 160 cm

37 FR to 39 Fr for men less than 175 cm

39 Fr to 41 for men over 175 cm

116
Q

Even slight movement of the right DLT can lead to malpositioning because?

A

The distance from the carinal bifurcation to the right upper lobe is 1.5-2 cm, compared to 4-5 cm left mainstem bronchus

117
Q

Many practitioners have resolved to using left DLTs for all right and left thoracotomies unless a left sided tube is contraindicated by?

A

lesions of the airway

compression of the trachea or main bronchi by external mass.

118
Q

The most common complication associated with a DLT is

A

malpositioning

119
Q

The larger size of the DLT is probably also responsible for?

A

the slightly increased incidence of hoarseness and vocal cord lesions observed following DLT vs bronchial blocker.