Vascular Anesthesia Pt. 3 (Exam II) Flashcards

1
Q

What are some of the multifactorial reasons for why a vascular aneurysm may form?

A
  • Adventitial Elastin Degradation
  • Chronic Inflammation
  • Concomitant Aorto-iliac Occlusive Disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is, definitionally, a vascular dissection?

A

A rupture of the intimal layer of a vessel

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

What are risk factors for an abdominal aortic aneurysm?

A
  • Elderly male
  • Smoking
  • Family hx of AAA
  • Atherosclerotic disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are risk factors for a thoracic aortic aneurysm?

A
  • Congenital syndromes
  • Trauma
  • Aortic cannulation
  • Bicuspid Aortic Valve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What size cm aneurysm is associated with the lowest risk (<0.5%) of rupture?

A

< 4 cm

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

What size cm aortic aneurysm is associated with the highest (30 - 50%) chance of rupture?

A

8cm or greater

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

What are the mortality rates for abdominal aortic aneurysms?

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

What are the risk percentages associated with thoracic aortic aneurysms?

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

What kind of aneurysm is depicted below?

A

Saccular

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

What kind of aneurysm is depicted below?

A

Fusiform

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

What type of aneurysm is characterized by eccentric dilation and a variably sized neck?

A

Saccular

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

What type of aneurysm (saccular or fusiform) is more common?

A

Fusiform

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

What type of symptoms might suggest a thoracic aneurysm?

A
  • Hoarseness
  • Stridor
  • Dysphagia
  • Upper body edema
  • Acute, sharp pain
  • BP changes
  • Absence of peripheral pulses

Very non-specific.

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

What is suggested by the chest x-ray below?

A

Thoracic aneurysm

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

Aortic Aneurysm Classification Chart

Memorize.

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

What is the classic triad of AAA symptoms?

A
  • Hypotension
  • Back pain
  • Pulsatile mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What space do most AAA’s rupture into?

A

Left Retroperitoneum

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

What three factors help avoid renal injury during aortic repairs?

A
  • Preop hydration
  • Avoidance of ↓CO
  • Avoidance of nephrotoxic drugs (i.e. dye)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the cons associated with a trans-peritoneal AAA repair approach?

A
  • More fluid shifts
  • Possible ileus
  • Possible pulmonary complications
  • Longer ICU stay
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the pros associated with a retroperitoneal AAA repair approach?

A
  • Less fluid shifts
  • Less pulmonary & abdominal sequelae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the cons associated with a retroperitoneal AAA repair approach?

A
  • More hernias
  • Chronic wound pain
  • Poorer visualization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where is incision made with a retroperitoneal AAA repair approach?

A
  • Lateral border of left rectus muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What patient conditions might indicate a retroperitoneal AAA repair approach?

A
  • Obesity
  • COPD
  • Previous abd surgeries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the first immediate consequence of aortic clamping?

A

↑SVR

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

What occurs due to the increase in SVR from aortic cross clamping?

A
  • ↓CO
  • Catecholamine release
  • ↑ renal vascular resistance
  • ↑ preload
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How long do renal hemodynamic changes last beyond unclamping?

A
  • 30 min
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Post-operative mortality in AAA repairs will quadruple if what condition secondary to aortic cross clamping occurs?

A

Acute Renal Failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What two hemodynamic “things” are needed once the aorta is cross-clamped?

A
  • ↑ Contractility
  • Coronary flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are some things we do just prior to aortic clamping?

A
  • Small bolus of vasodilator
  • Normalize/replace blood loss
  • Consider epidural catheter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why are vasodilators used to prior to aortic cross clamping?

A

This helps move blood to the periphery and thus increase preload & perfusion post-clamping.

31
Q

What major hemodynamic changes occur with aortic unclamping?

A
  • Substantial ↓SVR
  • Hypotension
32
Q

What is the cause of hypotension post aortic clamping?

A
  • Blood pooling
  • Hypoxia-mediated vasodilation
  • Accumulation of metabolites
33
Q

What drugs can help us prevent severe hypotension on aortic unclamping?

A
  • Ca⁺⁺
  • HCO₃⁻
  • Low-dose pressors
  • ↓ VAA’s
34
Q

Encouraging the surgeon to unclamp _____ can help prevent hemodynamic collapse.

A

gently (or judiciously)

35
Q

Where is the upper aortic clamp typically placed in a AAA repair?

A
  • Distal to subclavian artery
  • Inbetween subclavian & common carotid
36
Q

Where would you place an art line for an Aortic repair requiring clamping?

A

Right arm or right femoral

(Left subclavian and left femoral will be occluded).

37
Q

A MAP of _____mmHg is preferred above the aortic clamp.

A

100 mmHg

38
Q

A MAP of _____mmHg is preferred below the aortic clamp.

A

50 mmHg

39
Q

An ACT of _____ish or greater is required in aortic surgeries.

A

250

40
Q

TEG Review Cards

A
41
Q

Which type of evokes would be useful for tracking any damage to the dorsal column?

A

SSEP’s

Sensory = Dorsal column

42
Q

Which part of the spinal cord is typically more damaged by aortic clamping?

A

Anterior portion of spinal cord

MEPs = impractical due to NMBD usage.

43
Q

What is the study consensus on the usage of mannitol, dopamine, and fenoldopam for the purpose of renal protection in AAA repair cases?

A

All of the above drugs show inconclusive evidence for renal protection.

44
Q

What is used postoperatively for AAA repair pain?

A

Epidural catheter

45
Q

Why are epidural opioids preferred over LA in epidurals for AAA repair patients?

A
  • LA’s are implicated in more hypotension and thus anterior spinal artery syndrome.
46
Q

What is anterior spinal artery syndrome?

A

Condition of paraplegia, back pain, loss of temperature and pain, and autonomic dysfunction below the level of aortic clamping.

47
Q

When can local anesthetics be utilized in an epidural for aortic repair?

A

After unclamping and stabilization of blood pressure

I.e. postoperatively.

48
Q

What major radicular artery comes off around T9 - T11?

A

Artery of Adamkiewicz

49
Q

What technique can be used to help prevent post-operative paraplegia from clamping affecting the artery of adamkiewicz?

A
  • Spinal catheter draining CSF (less CSF = more room for hematoma formation, etc.)

Not a routine method.

50
Q

A clamp placed distal to the left subclavian results in a ___% decrease in renal blood flow.

A

90%

51
Q

A clamp placed infrarenal will result in a ___% drop in renal flow.

A

30%

Though clamped below renal arteries, catecholamine release, metabolites, etc will effect renal flow.

52
Q

Is a full bypass dose of heparin required for left heart bypass for an aortic repair?

A

No

53
Q

What technique is used for repair of a significant ascending aortic aneurysm?

A

DHCA (Deep Hypothermic Circulatory Arrest)

54
Q

What temperature is targeted for DHCA?

A

18 - 20° C

55
Q

How much is CO decreased to during ascending aortic aneurysm repair?

A

400 - 500 cc/min

56
Q

How long is the safe zone for DHCA?

A

30min

>40 min = brain injury.

57
Q

What is mortality for ascending aortic repairs requiring circulatory arrest?

A

10 - 15% (according to book)

58
Q

What is the “R” time in the following TEG?
What is this “R” time dependent on?

A
  • Time from start of test to initial fibrin formation
  • Dependent on clotting factors
59
Q

What is the “K” time in the following TEG?
What is this “K” time dependent on?

A
  • Time from initial fibrin clot to to 20mm of clot strength
  • Dependent on fibrinogen
60
Q

What is the α angle in the following TEG?
What is this α angle dependent on?

A
  • Measures the rate of clot formation
  • Dependent on fibrinogen
61
Q

What does MA stand for in the following TEG?
What is MA dependent on?

A
  • MA = Maximum Amptidude (size & overal strength of fibrin clot)
  • Dependent on platelets primarily (also a little fibrinogen).
62
Q

What does MA stand for in the following TEG?
What is MA dependent on?

A
  • MA = Maximum Amptidude (size & overal strength of fibrin clot)
  • Dependent on platelets primarily (also a little fibrinogen).
63
Q

What is the the LY30 on the following TEG?

A
  • Percentage decrease in amplitude 30 minutes post MA.
  • Showcases fibrinolysis
64
Q

What is a normal TEG “R” value?

A

4 - 8 min

65
Q

What is a normal TEG “K” value?

A

1 - 4 min

66
Q

What is a normal α-angle?

A

47 - 75°

67
Q

What is a normal TEG MA?

A

55 - 73 mm

68
Q

What is a normal LY30%?

A

0 - 8%

69
Q

What are some possible treatment options for the massively increased cardiac afterload from aortic clamping?

A
  • ↑ Anesthetic (propofol or VAA)
  • Nitroglycerin or Nitroprusside
70
Q

What should be limited prior to aortic clamping in order to minimize a hyperdynamic cardiac state?

A

Fluids

(less preload = less contractility = less strain on heart)

71
Q

What systemic change occurs from aortic unclamping?

A

Systemic Acidosis

72
Q

What hemodynamic changes occur during aortic unclamping?

A
  • ↓ sBP
  • ↓ Contractility
  • ↓ SVR
  • ↓ preload
  • ↓ CO
  • ↓ pH

Essentially everything drops.

73
Q

What is the treatment for aortic unclamping?

A
  • ↓ Anesthetics
  • Fluids
  • Vasopressor boluses
74
Q

Does nitroglycerin primarily decrease preload or afterload?

A

Primarily preload (though some arterial vasodilation occurs as well).