Exam III: Vascular Anesthesia

Question 1

Atherosclerosis is the primary process leading to…

Answer 1

CAD, stroke, extremity ischemia, and aneurysms

Question 2

presumed progression of atherosclerosis

Answer 2

fatty streaks to fibrous plaques to complicated lesions

Question 3

atherosclerosis - common formation in:

Answer 3

coronary arteries, carotid bifurcation, infrarenal abdominal aorta, iliac arteries, superficial femoral artery

Question 4

Although atherosclerosis is a slow, gradual process, the reason for the ultimate injury is:
_____ ____ reducing blood flow
_____ of plaque-associated platelet thrombi or debris
Complete _____ of ______ by advanced plaques.

Answer 4

Plaque enlargement
Embolism
occlusion of arteries

Question 5

risk factors for atherosclerosis

Answer 5

hyperlipidemia
smoking (8x)
diabetes
HTN (60%)
family history
male
advanced age
insulin resistance
physical inactivity
elevated c-reactive protein
elevated lipoprotein

Question 6

arteriosclerosis (pathologic)
_____abdominal aorta
_____abdominal aorta
_____ _____ aorta

Answer 6

infrarenal abdominal aorta
thoracoabdominal aorta
descending thoracic aorta

Question 7

____ ____ ____ - degeneration of the aortic media (ascending aorta)

Answer 7

cystic medial necrosis

Question 8

aortic aneurysm mortality rates
- elective repair
- ruptured
- untreated

Answer 8

• elective repair: 1-11%
• ruptured: 75%
• untreated: 5-year 81%, 10-year 100%

Question 9

Due to the relatively low mortality rate with elective AAA repair, surgery is recommended for any one with greater than ____ cm in diameter aneurysm.

Answer 9

5.0 cm

Question 10

Aneurysms greater than __ to __ cm in diameter require surgery.

Answer 10

4 to 5

Question 11

AAA grow approximately ___ ____.

Answer 11

4 mm/year

Question 12

Law of Laplace

Answer 12

As the radius of the vessel increases, the wall tension increases. The bigger the aneurysm, the higher risk of rupture.

Question 13

Law of Laplace
formula

Answer 13

T = P x r

Question 14

25-41% of aneurysms larger than 5 cm rupture spontaneously within __ ____.

Answer 14

5 years

Question 15

DeBakey type I – originates in the ____ ____ aorta and usually involves the ascending aorta, arch and can go to abdominal aorta

Answer 15

proximal ascending

Question 16

DeBakey type II - confined to the ____ ____

Answer 16

ascending aorta

Question 17

DeBakey type III - (a) - confined to the _____ ____ aorta

Answer 17

descending thoracic

Question 18

DeBakey type III - (b) - may extend into the _____ aorta and ____ arteries

Answer 18

abdominal
iliac

Question 19

Stanford classification:
Type A: the ascending aorta is involved, ____ or _____ the _____ or the descending aorta.

Answer 19

with or without the arch

Question 20

Stanford classification:
Type B: the descending thoracic aorta is involved, with or without ____ or _____ extension.

Answer 20

proximal or distal

Question 21

Aneurysms occur most commonly:
Ascending thoracic aorta close to the ____ _____
Descending thoracic aorta just distal to the ____ ______ _____.

Answer 21

aortic valve
left subclavian artery

Question 22

Myocardial infarction, respiratory failure, renal failure, and stroke are the major causes of _____ and _____

Answer 22

morbidity and mortality.

Question 23

Co-existing diseases should be evaluated, optimized, and recorded _______. (See Box 28.4 Nagelhout)

Answer 23

preanesthesia

Question 24

CAD – _____ ______ are responsible for 40-70% of all fatalities occurring after AAA repair.
50% of patients for AAA reconstruction have CAD

Answer 24

Myocardial infarctions

Question 25

The greater number of _______ that exist, the greater the risk of morbidity and mortality during the perioperative period.

Answer 25

comorbidities

Question 26

____ ____ ____ is common during the perioperative period; this is associated with a high risk for cardiovascular-specific mortality comparable to that seen with chronic kidney disease.

Answer 26

Acute kidney injury (AKI)

Question 27

Aortic Cross- Clamping Hemodynamic effects depend on the ____ of the clamp, the patient’s pre-op ____ ____, and the patient’s intravascular _____.

Answer 27

site cardiac reserve volume

Question 28

Aortic Cross- Clamping With X-clamping, hypertension occurs _____ the X-clamp and hypotension occurs _____.

Answer 28

above below

Question 29

Aortic Cross- Clamping systems involved

Answer 29

Hemodynamic Myocardial Pulmonary Renal Spinal cord Hormonal / Metabolic

Question 30

Aortic Cross- Clamping Hemodynamic/cardiac Effects of X-clamp afterload? MAP and SVR? HR? CO? LVEDP?

Answer 30

Afterload increases – myocardial wall tension increases. Mean arterial pressure and SVR increase. Heart rate unchanged Cardiac output may decrease or remain unchanged. LVEDP may increase or show no change.

Question 31

Aortic Cross- Clamping Patients with poor cardiac reserve may have decreased ____ ____ and _____ _____. They will have an increase in LVEDP.

Answer 31

ventricular function and myocardial ischemia

Question 32

LVEDP, CVP and PCWP may ______ due to vasoconstriction of venous vasculature distal to the x-clamp – increasing preload

Answer 32

increase

Question 33

The effects of the X-clamp are altered depending on the _____ of the occlusion.

Answer 33

location

Question 34

The longer the duration of the X-clamping, the greater the increase in ____ and decrease of ____

Answer 34

SVR CO

Question 35

Pulmonary damage related to: ______ pulmonary vascular resistance (more at unclamping) Increased capillary membrane _______ Development of ______ _____

Answer 35

Increased permeability pulmonary edema

Question 36

potential causes of pulm damage:

Answer 36

hypervolemia prostaglandins, oxygen free radicals, activation of RAAS, complement cascade

Question 37

prostaglandins cause ________

Answer 37

bronchoconstriction

Question 38

Renal Effects of X-clamp Renal blood flow is _____ 40% and renal vascular resistance ______ 75% when the X-clamp was placed infrarenally.

Answer 38

decreased increased

Question 39

Renal Effects of X-clamp ______ & ______ cross-clamping can decrease renal blood flow by as much as 80%.

Answer 39

Suprarenal and juxtarenal

Question 40

Renal Effects of X-clamp Renal failure post aortic surgery is usually acute tubular necrosis r/t ____-____ injury.

Answer 40

ischemic-reperfusion

Question 41

_____ occurs in as many as 18% of patients undergoing aortic aneurysm repair.

Answer 41

AKI

Question 42

____ _____ damage is associated with aortic X-clamping.

Answer 42

Spinal cord

Question 43

Specifically, the ____ of _____ is occluded with no collateral flow to the anterior portion which is motor.

Answer 43

artery of Adamkiewicz

Question 44

The more proximal the X-clamp, the greater the risk for ______.

Answer 44

paraplegia

Question 45

Somatosensory Evoked Potential – SSEP – does not provide information about the _____ spinal cord.

Answer 45

anterior

Question 46

Anterior Spinal Syndrome the higher the cross clamping the greater the chance of ____ ____ ____

Answer 46

spinal cord ischemia Elective infrarenal 0.2%, Ruptures of the descending aorta 40%

Question 47

Anterior Spinal Syndrome Main blood supply to anterior cord is from the artery of Adamkiewicz; origin ____ ____-____

Answer 47

unknown (T5-L2)

Question 48

Anterior Spinal Syndrome spinal cord perfusion =

Answer 48

MAP - CSF pressure

Question 49

Anterior Spinal Syndrome drainage of CSF has allowed the ____ ____ of ischemia, limited x-clamp time of 30 mins

Answer 49

best avoidance

Question 50

Anterior Spinal Syndrome artery of adamkiewicz nearly always comes from ____ side

Answer 50

left

Question 51

anterior spinal preventative measures

Answer 51

Shunt from the left atrium to the common femoral artery Maintenance of hypertension during X-clamp (post-op*) Methylprednisolone Moderate hypothermia (30-32 degrees C) Avoiding hyperglycemia Mannitol – lowers CSF pressure by decreasing production Drainage of CSF

Question 52

anterior spine syndrome Nipride decreases pressure proximal to the clamp, BUT also _____ to the _____. This may contribute to the increased risk of spinal cord ischemia.

Answer 52

distal to the clamp

Question 53

anterior spinal syndrome classic s&s: loss of what and preservation of what

Answer 53

Loss of motor function and pinprick sensation Preservation of vibration and proprioception (posterior)

Question 54

*Maintain ____tension (systolic > ______) through the second postoperative day decreased the incidence of paraplegia during thoracic aortic reconstruction anterior spinal syndrome

Answer 54

normo 120 mm Hg

Question 55

Metabolic/Hormonal Effects of X-clamping Tissues distal to the clamp are hypoxic causing metabolites such as _____ to accumulate.

Answer 55

lactate (metabolic acidosis)

Question 56

Metabolic/Hormonal Effects of X-clamping Decreased _____ consumption due to the portion of tissues not being perfused.

Answer 56

oxygen

Question 57

Metabolic/Hormonal Effects of X-clamping Decreased total body oxygen extraction; Increased ____ ____ ____ saturation

Answer 57

mixed venous oxygen

Question 58

Metabolic/Hormonal Effects of X-clamping Increased levels of ______ circulating during X-clamp time (decreased renal blood flow)

Answer 58

catecholamines

Question 59

Metabolic/Hormonal Effects of X-clamping Respiratory _____ (decreased ____ production)

Answer 59

alkalosis CO2

Question 60

Intraoperative Interventions during AoX-clamping reduce afterload:

Answer 60

- nipride - inhalation agents - milrinone - shunt: aorta to femoral bypass

Question 61

Intraoperative Interventions during AoX-clamping reduce preload:

Answer 61

- NTG - atrial to femoral bypass

Question 62

Intraoperative Interventions during AoX-clamping renal protection:

Answer 62

- fluid - renal cold perfusion - pharmacologic

Question 63

Intraoperative Interventions during AoX-clamping _____thermia, decrease ______ ventilation, ______

Answer 63

hypo minute ventilation NaBicarb

Question 64

Release of Aortic X-clamp Metabolites such as lactate are circulated which cause _____, increased _____, hypotension.

Answer 64

vasodilation ETCO2

Question 65

Release of Aortic X-clamp afterload and SVR _____

Answer 65

decrease

Question 66

Release of Aortic X-clamp MAP

Answer 66

decreases

Question 67

Release of Aortic X-clamp preload

Answer 67

decreases

Question 68

Release of Aortic X-clamp CO _____ or no change or _____

Answer 68

increases decreases

Question 69

Release of Aortic X-clamp wedge

Answer 69

decreases

Question 70

Release of Aortic X-clamp EtCO2 _____ and pH ______

Answer 70

increases decreases (metabolic acidosis)

Question 71

Release of Aortic X-clamp temperature

Answer 71

decreases

Question 72

Unclamping Hypotension Blood shifting to _____ – in reperfused tissue

Answer 72

periphery

Question 73

Unclamping Hypotension Hypoxia-related _____ in vessels below the level of the X-clamp

Answer 73

vasodilation

Question 74

Unclamping Hypotension Release of _____ & ______ ______metabolites in the reperfused tissues Increased lactate, prostaglandins, activated complement, metabolic acidosis Increased myocardial depressant factors

Answer 74

vasoactive and myocardial depressant

Question 75

To minimize the effects of the X-clamp release Intravascular _____ must be maintained or restored.

Answer 75

volume

Question 76

To minimize the effects of the X-clamp release Replace ____ loss

Answer 76

blood

Question 77

To minimize the effects of the X-clamp release To prevent hypotension and decreased cardiac output with release of X-clamp, the PCWP should be raised ___ to ___ ____ above pre-clamp values just prior to release.

Answer 77

3 to 4 mm Hg

Question 78

To minimize the effects of the X-clamp release The lower the sight of clamping, the ____ ____ the changes.

Answer 78

less drastic

Question 79

To minimize the effects of the X-clamp release The clamp can be released _____

Answer 79

gradually.