Brainscape's Knowledge GenomeTM

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


See full index

CV Perf Tech II > Myocardial Protection-Exam 2 > Flashcards

Myocardial Protection-Exam 2 Flashcards

1
Q

What is already in Lactated Ringer’s 1000mL?

A

KCL 20mEq
MgCl 32 mEq
Mannitol 12.5 g
NaHCO2 6.5 mEq

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

What do you need to add prior to use in Lactated Ringer’s 1000mL?

A

Procaine 10% 2.7 mL

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

What is already in Normosol 1000mL?

A

NaHCO2 35 mEq
KCL 35 mEq
Mannitol 25% 12.5 g

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

What do you need to add to Normosol 1000mL prior to use?

A

Lidocaine 75 mg
Ntg 500 mcg
Albumin 25% 12.5g

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

Pure Crystalloid Cardioplegia Advantages

A

Hx of Use
Ease
Cheap
Low viscosity

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

Pure Crystalloid Cardioplegia Pitfalls

A 
Cellular edema
Low O2 capacity
left shift oxy-hgb curve
Activates plts, leukocytes, and complement
Impaired membrane stabilization
Hemodilution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two generic crystalloid solutions?

A

Lactated Ringer’s

Normosol

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

Cold Blood Cardioplegia Advantages

A

O2 carrying capacity
Reduced hemodilution
Buffering/oncotic effects
O2 radical scavengers present

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

Cold Blood Cardioplegia Disadvantages

A

Sludging
Oxy-Hgb curve disruption
Possible red cell damage

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

Primary energy source for adults vs kids

A

Adults: Free fatty acids
Kids: glucose

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

What is the purpose of dextrose?

A

Big macromolecules; brings in water

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

How do you prepare for reperfusion?

A 
Substrate-enhanced warm cardioplegia
• Limit calcium
• Limit PO2
De-air adequately
• Avoid ventricular distension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What pressures do you use in controlled reperfusion?

A

Upon XC MAP → 40 mmHg for 1-2 minutes.

Removal: MAP → 70 mmHg after 2 minutes.

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

When do you do a “Hot shot”

A

Just prior to removal of the aortic cross clamp

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

What is in a hot shot?

A

It is in addition to XC drugs.

Aspartate Glutamate
• Tham
• Dextrose
• CPD

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

Typical Warm Reperfusion SOlution

A 
THAM (0.3 M) solution – 225 mL
• CPD – 225 mL
• Dextrose 50% - 40 mL
• MSA/MSG 0.46 M – 250 mL
• Dextrose 5% - 200 mL
• KCl (2 mEq/L) – 15 mL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What’s another name for custodial cardioplegia?

A

HTK

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

HTK

A

Histidine- Tryptophan- Ketoglutarate

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

What is in Custodial cardioplegia?

A 
Intracellular cardioplegia solution
• Low sodium concentration
• Histidine
• Tryptophan
• Mannitol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What was HTK initially used for?

A

Organ preservation

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

What are the advantages of HTK?

A

Longer safe time of ischemia
• During valve surgery
• Minimally invasive procedures

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

Del Nido Solution (4:1) uses what kind of base?

A

Plasmalyte

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

What’s in a plasmalyte base?

A 
140 mEq/L sodium
• 5m Eq/L potasium
• 3 mEq/L magnesium
• 98 mEq/L chloride
• 27 mEq/L acetate
• 23 mEq/L gluconate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What additives do you add to Del Nido solution? (4:1)

A 
Mannitol 20% 16.3 mL
MgSO4 50% 4 mL
NaHCO2 8.4% 13 mL
KCL 2 mEq/L 13 mL
Lidocaine 1 % 13 mL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What should be the flow for warm retrograde cardioplegia in order to minimize myocardial lactate production?

A

> 100 ml/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What clamp technique is used with calcified and stiff aortas?

A

Single Clamp Technique

27
Q

Single Clamp Technique

A

One clamp episode
• One unclamp episode
• Distals and proximals done during one ischemic time

28
Q

When is the ischemic time of the Side Biting Clamp technique?

A

Ischemic time is only with fully

clamped aorta

29
Q

Side Biting Clamp Technique

A

Two clamp episodes
• Two unclamping episodes
• Distals done during first ischemic time
• Proximals done during second ischemic time
Shorter clamp times

30
Q

What is the clamp time within the intermittent clamp technique?

A

Clamp time is the sum of all

fully ischemic times

31
Q

Intermittent Crossclamp Risk

A

Stroke; not commonly used

32
Q

How is fibrillatory arrest performed?

A

Creates a nearly motionless heart by placing an
alternating current generator in contact with the left
ventricle.

33
Q

Fibrillatory Arrest Advantages

A

Left side of heart can be opened without the fear of ejecting air into the aorta.
Avoid cross clamp
• Quiescent heart with coronary perfusion

34
Q

What should be used in conjuction with the fibrillatory arrest technique?

A

hypothermia

Keep MAP elevated

35
Q

Fibrillatory arrest disadvantages

A

Higher energy requirement than arrested heart

• Spontaneous ejection will result in air emboli

36
Q

Additional Strategies to Enhance Protection

A 
Anesthetic agents (↑ preconditioning)
• Acute normovolemic hemodilution (↓ A fib)
• Neutrophil depletion (↓ V fib)
• Erythropoietin (↓ myocardial injury)
• N-acetylcysteine (↓ oxidative stress)
• Deferoxamine (↓lipid peroxidation)
• Statins (↑NO release)
37
Q

Anesthetic Agents: Pros and Cons

A

Pro: Preconditioning; ameliorate deleterious effects of reactive oxygen species

Cons: unclear which agents are best

38
Q

Acute normovolemic hemodilution: Pros and cons

A

Pro: less myocardial injury; decreased inotrope requirement; reduced A fib and conduction block

Cons: Efficacy not demonstrated in all patient groups; some patients are too anemic for this tehchnique

39
Q

Neutrophil Depletion: Pros and Cons

A

Pros: Decreases post bypass v-fib; lower inotrope use; lower postoperative cardiac enzyme release

Cons: cost; complexity

40
Q

Erythropoietin: Pros and Cons

A

Pro: limits myocardial injury
Con: cost

41
Q

N-acetylcysteine: Pros and Cons

A

Pro: may reduce oxidative stress
Con: may interfere with preconditioning, cost, complexity

42
Q

Deferoxamine: Pros and Cons

A

Pro: decreased lipid peroxidation; increased myocardial protection, LVEF; decreased postoperative wall motion abnormalities

Cons: cost; complexity; not proven in large studies

43
Q

Statins: Pros and Cons

A

Pros: increased nitric oxide release; anti-inflammatory properties; antioxidative properties; decreased monocyte adhesion

44
Q

What 3 parameters do you monitor to determine myocardial protection?T

A

Temperature
pH
electrical activity

45
Q

Possible causes of failure to arrest

A 
Aortic insufficiency
• Cross-clamp or cardioplegia needle malpositioned.
• Inadequate solution (low potassium)
• Low flow?
• Low pressure?
• Temperature?
46
Q

PADCAB

A

Perfusion-assisted direct coronary artery bypass; perfuse completed grafts

47
Q

K+

A

electromechanical arrest

48
Q

Na+

A

↓ edema/intracelluar Ca++ buildup

49
Q

Ca++

A

Membrane stabilization

50
Q

NaHCO3

A

increase pH

51
Q

THAM

A

increase pH

52
Q

Glucose

A

Substrate, ↑ Osmolarity, ↓ edema

53
Q

Mannitol

A

↑ Osmolarity

54
Q

High Potassium Common Solution Concentrations

A 
KCl 100 mmol/L
THAM 12 mmol/L 
MgSO4 9 mmol/L
Dextrose 250 mmol/l 
CPD 20 mL
55
Q

Low Potassium Common Solution Concentrations

A 
KCl 40mml/L
THAM 12 mmol/L 
MgSO4 9 mmol/L
Dextrose 250 mmol/l 
CPD 20 mL
56
Q

Vein Grafts: Pressure and Flow Rate

A

50mmHg

50-100 ml/min

57
Q

Direct Ostial: Pressure and Flow Rate

A

250 mmHg

50-150 ml/min

58
Q

What percent of CO is direct ostial?

A

5-8% of CO

59
Q

Retrograde: Pressure and Flow rate

A

40 mmHg

150-200 ml/min

60
Q

Antegrade: Pressure and Flow Rate

A

50-100 mmHg aortic root P
250-400 ml/min
150 ml/min/m2

61
Q

Antegrade Dose

A

Initial: 10-15 ml/kg

Up to 30 ml/kg

62
Q

Combined doses

A

1-1.5L Antegrade

500 ml Retrograde

63
Q

We should assume the P drop across system is

A

175 mmHg

64
Q

P drop is proportional to

A

Velocity; Shear F, viscosity

CV Perf Tech II (17 decks)

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