Schmerler - N620 Cardio Week 4 - Vascular Disease

Front 1

___ complications are the leading cause of perioperative morbidity and mortality.

Back 1

cardiac

Front 2

___ surgery pts have higher incidence of CAD and have more significant risk of perioperative MI than any other surgical category of pts.

Back 2

Vascular surgery pts

Front 3

What are the 2 main vascular diseases of the thoracic and abdominal aorta?

Back 3

- aneurysm
- dissection

Front 4

This is the dilation of all 3 layers of an artery, with a 50% incr in diameter from normal.

Back 4

thoracic or abdominal aneurysm

Front 5

This is when blood enters the media layer in the aorta, creating a false lumen and dropping BP when abdomen is open.

Back 5

dissection

abdomen is keeping dissection tamponaded, when opened it can explode and pt can bleed (possibly to death!)

Front 6

Aortic aneurysms can be classified by 3 different morphologies:

Back 6

1. fusiform: vascular out-pouching shaped like spindle
2. saccular: resembles a small sac
3. dissecting: dissects longitudinally

Front 7

What are the 3 debakey type classifications of thoracoabdominal aortic aneurysms?

Back 7

type 1: intimal tear originates in the ascending aorta and dissection involves the aorta, arch and some thoracic aorta
type 2: dissection confined to ascending aorta
type 3: dissection confined to descending aorta but may extend to abdominal region and iliac arteries

Front 8

What are the 2 types of Stanford classifications for aneurysms of the thoracoabdominal aorta?

Back 8

type a: includes all cases that involve ascending aorta with or without involving the arch or descending aorta
type b: includes all others in which ascending aorta is not involved

Front 9

For pts undergoing surgery for a thoracic aneurysm, the principle causes of morbidity and mortality include ____, ____, ____ and ____. Therefore, assessment of these functions is needed preop.

Back 9

MI, resp failure, renal failure, CVA

Front 10

Before correcting the actual aneurysm, some pts with CAD require what other procedure?

Back 10

pre op percutaneous coronary intervention w CABG

Front 11

Thoracic aneurysm pts may require medications to manipulate what two values?

Back 11

preload and afterload

Front 12

In order to assess for resp failure with thoracic aneurysm repair, what inquiries should be made?

Back 12

- PFTs
- smoking hx
- use of bronchodilator treatment

Front 13

Preop renal dysfunction is the most important indicator of _____ in thoracic aneurysm cases.

Back 13

post op renal problems

Front 14

What strategies may be employed intraop to prevent post op renal dysfunction?

Back 14

adequate hydration, normotension, avoidance of nephrotoxic drugs (gentamycin, meperidine)

Front 15

Before thoracic aneurysm surgery, what imaging test is useful to ensure adequate brain perfusion?

Back 15

duplex imaging of carotid arteries (often a bruit present)

Front 16

Most common symptoms of abdominal aortic aneurysm?

Back 16

back pain

Front 17

S/S of rupture of descending thoracic aorta

Back 17

- persisting overriding chest pain
- hypotension
- L hemothorax
- ischemia of legs, abdominal viscera or spinal cord
- renal failure

Front 18

Surgical treatment of distal (Further from myocardium) aortic dissection is associated with ___% mortality.

Back 18

29%

Front 19

All pts with acute dissection of ____ are candidates for surgery, this is more emergent that dissection of ____ Aorta.

Back 19

ascending more emergent than descending

Front 20

What is unique about a repair of type A dissection involving the aortic arch?

Back 20

requires cardio-pulmonary bypass, profound hypothermia and circulatory arrest (30-40 min at body temp of 15-18 deg C)

Front 21

Indication for surgery on a descending thoracic aortic aneurysm involves

Back 21

dissection > 5-6 cm

type b repair if pts have s/s of impending rupture

Front 22

What are the mortality rates of a Type A TA dissection if treated medically vs surgically?

Back 22

med- 56%
surg- 27%

long term survival in surg tx is 90-96%, only 69-89% if med tx.

Front 23

Medical treatment of a TA dissection type A involves...

Back 23

a-line monitoring, drugs to control BP and LV contractility (beta blockers and nitroprusside)

Front 24

This is the ischemic damage to the spinal cord that can result from cross-clamping of thoracic aorta.

Back 24

anterior spinal artery syndrome

Front 25

Cross-clamping of the thoracic aorta is associated with severe ____ and ____ disturbances in all organ systems.

Back 25

hemodynamic and homeostatic

Front 26

What are the pharmacologic interventions to offset the effects of cross-clamping the TA?

Back 26

nitroprusside, NTG

also volume replacement concerns during clamping

related to effects of drugs on arterial/venous capacitance

Front 27

Unclamping the TA is associated with substantial decr in ____. Sometimes ____ is given right before unclamping.

Back 27

SVR, Calcium

Front 28

What causes declamping hypotension after unclamping TA?

Back 28

- central hypovolemia from repooling of blood in tissues below clamp level
- hypoxia-mediated vasodilation causing incr vascular capacitance in tissues below level of clamp
- accumulation of vasoactive and myocardial depressant metabolites in those tissues
- CO2 release and incr O2 consumption (correct metabolic acidosis!)

Front 29

CO2 and thromboxane are powerful _____.

Back 29

vasodilators

Front 30

Why is the R arm best for A-line measurement in thoracic aneurysm anesthesia?

Back 30

thoracic cross-clamping is just distal to L subclavian artery and L carotid -- can occlude measurement in L arm (This is a standard of care)

It is also important to monitor above R radial and below L femoral to assess for cerebral, renal and spinal cord perfusion

Front 31

SSEP (Somatosensory evoked potentials) are not indicated for assessing neuro function in thoracic aneurysm repairs because...

Back 31

requires lighter anesthesia, which is not indicated in this type of case, not reliable and difficult to perform

Front 32

To assess cardiac function during a thoracic aneurysm case, ____ is more useful than _____ because it is less invasive and more reliable.

Back 32

TEE better than PA cath

Front 33

What type of catheter is indicated in thoracic aneurysm cases?

Back 33

cordis - can measure cvp, allows placement for post op swan placement PRN

Front 34

This is considered the "poor man's swan"

Back 34

foley catheter

Front 35

The diuretics given prior to cross-clamping in thoracic aneurysm cases are:

Back 35

mannitol (improves renal cortical blood flow and GFR) and furosemide

Front 36

____ causes the same catecholamine response as doing a sternal split with a saw.

Back 36

laryngoscopy

Front 37

What are the induction and maintenance techniques for anesthesia during thoracic aneurysm repair?

Back 37

- induction and intubation must minimze impact on SVR
- etomidate best to avoid hypotension (as w propofol)
- LTA (squirt down throat) or lidocaine injection to blunt laryngoscopy
- vasodilators and beta blockers to blunt laryngoscopy
- maintain MAP 70-80 mmHg
- double lumen tube to collapse L lung and facilitate surgical exposure
- general anesthesia w opioids (volatile agents, fentanyl, sufentanil -- avoid morphine due to possible hypotension w histamine release)
- NMBs chosen based on renal clearance (avoid gallamine, pancuronium due to high renal excretion and effects on myocardium -- use vec or roc)

Front 38

What are the post op management techniques for thoracic aneurysms?

Back 38

- thoracic epidural cath for post op analgesia- routine if not heparinized
- monitor for sensory and motor deficits in low extrem -- can have delayed paraplegia (12hr-21 days) - q1h neuro exam
- monitor renal fcn
- careful titration of vasoactive substances and neuraxial anesthesia
- local anesthetic use can produce sensory and motor deficits -- can delay recognition of anterior spinal artery syndrome (opioids preferred to LAs)

Front 39

What are the hemodynamic responses to aortic cross clamping?

Back 39

- severe homeostatic disturubances to all organs
- incr in BP and SVR with no significant change in HR, but a drop in CO
- HTN attributed to incr afterload and bc blood volume is redistributed from collapse of venous vasculature distal to cross clamp --> results in incr preload also
- changes in ventricular function and wall motion
- offset these changes w drugs (nitroprusside for afterload, NTG for preload, continuous fluid adjustments)

Front 40

What are the hemodynamic responses to aortic cross clamp removal?

Back 40

- significant hypotension -- treat w crystalloid w balanced salt in solution (LR, NS, 1/2 NS)
- colloids (albumin, PRBC vs whole blood)
- titrate to adequate urine output
- suspect unrecognized bleeding if hypotension persists a few min after cross clamp removed
- echo useful to check if adequate volume replacement has been done/determine cardiac fcn

Front 41

Describe the rollercoaster effect seen in clamping and unclamping of thoracic aorta?

Back 41

initially BP drops due to CO2 accumulation, then rises due to catecholamine release -- may lead to myocardial ischemia or death!

Front 42

CV system mgmt throughout thoracic aneurysm repair (preop, intraop, postop)

Back 42

preop: assess aneurysm extent, cardiac eval per guidelines, beta blockade, statins
intraop: adquate IV access and invasive monitoring, BP control to prevent rupture, manage HD changes of clamp/unclamp, possible bypass
post op: BP controll to ensure SCPP, monitor for s/s of myocardial dysfunction

Front 43

What are the pulmonary anesthesia considerations for thoracic aneurysm repair?

Back 43

preop- smoking cessation 4-6 wk, assess tracheobronch. involvement, discuss possible trach
intraop: DLT placement - possible single ung ventilation, cpap, peep, bronchodilators
postop: airway edema (keep intubated), RLN injury possible, potential for pulm edema, TRALI, ARDS

Front 44

What are the renal anesthesia considerations for thoracic aneurysm repair?

Back 44

preop: assess preexisting renal dysfunction, discuss possible post op renal failure
intraop: renal protection w hypothermia, distal aortic perfusion, cold crystalloid perfusate
postop: monitor for s/s of failure, HD possible

Front 45

What are the CNS anesthesia considerations for thoracic aneurysm repair?

Back 45

preop: assess baseline neuro status and document deficits, discuss potential for paralysis, baseline SSEPs and MEPs
intraop: neuroprotection strategies (permissive hypothermia, LHB, CSF drainage, epidural cooling, reimplantation of intercostal arteries), SSEP/MEP monitoring
postop: assess neuro status, maintain Spinal cord perfusion pressure

Front 46

What are the hematology anesthesia considerations for thoracic aneurysm repair?

Back 46

preop: assess coag status and use of anticoag/antiplatelet drugs, discuss likelihood of blood tx, type and cross
intraop: systemic heparinization (LHB), antifibrinolytic therapy, potential for massive transfusion, promtamine considerations
postop: coag monitoring, ensure normal coags before removing CSF cath

Front 47

What is the antidote to heparin?

Back 47

protamine

used in cardiopulmonary bypass surgery to neutralize the anti-clotting effects of heparin as well as to increase pulmonary artery pressure and decrease peripheral blood pressure, myocardial oxygen consumption, cardiac output, and heart rate

Front 48

When using endovascular approach to repairing thoracic aortic aneurysm, what type of anesthesia is indicated?

Back 48

GETA with TEE, less invasive so lower analgesic requirements

Front 49

What are the primary goals of anesthesia strategy for endovascular approach to thoracic aneurysm repair?

Back 49

- avoid tachycardia and HTN
- preserve cardiac, spinal, splanchnic blood flow
- maintain intravasc. vol, O2, temp
-maintain CSF drains, goal mean pressure 100 mmHg

Front 50

What is the best induction agent for "Sick" hearts?

Back 50

etomidate

Front 51

How are AAAs usually detected?

Back 51

asymptomatic, pulsatile abdominal masses, usually <5 cm

Front 52

In a AAA rupture emergency, the pt goes into severe ______ shock and requires _____. There is no time for an adequate work up, so just ask this one question: ____.

Back 52

hypovolemic shock, volume resuscitation, does the pt have allergies??

Front 53

What is the classic AAA triad of symptoms?

Back 53

- hypotension
- back pain
- pulsatile abd mass

Front 54

If a pt with AAA repair has COPD, they should have a preop ____ test because....

Back 54

PFT -- severe reductions in vital capacity and FEV1 with abnormal renal function may mitigate against AAA resection

Front 55

If a AAA repair pt has ischemic heart disease, it is important to eval. cardiac function with...

Back 55

exercise or pharm. stress test with or without echo or radionucleotide imaging

Front 56

Describe the concerns regarding clamping above the renal vessels during a AAA repair.

Back 56

if above, will not perfuse kidneys during clamping-- time the clamping and try to keep < 60 min to avoid renal impairment. When unclamped, immediately treat acidosis, give volume/colloids/pressors), should start making urine by the end of the case, may take a few hrs if in renal shock -- use heparin to prevent clot formation associated w clamped vessels

Front 57

What kind of monitoring is necessary during anesthesia for AAA repair?

Back 57

foley, PA cath, TEE with CVP cordis, intraop echo useful to eval cardiac response to aortic cross clamp, a-line

Front 58

What are the maintenance techniques for anesthesia during AAA repair?

Back 58

- no single agent ideal
- combo of volatile agents, opioids, w/ or w/o N20
- vasopressors or vasodilators to maintain MAP 70-80 mmHg
- combined general w epidural anesthesia (but may not be indicated depending on anticoag use)

Front 59

What are the post-op considerations for AAA repair?

Back 59

- at risk for developing CV, pulm, and renal dysfunction
- assmt of graft patency and lower extrem blood flow
- overzealous intraop hydration or post op hypothermia may exacerbate HTN post op -- treat immed. by eliminating specific cause (pain) or giving antihypertensive meds
- ensure adeq. pain control

Front 60

Surgery is usually indicated when the diameter of the aorta reaches ___ cm.

Back 60

5 cm

Front 61

What are the 4 parts of the aorta?

Back 61

ascending, arch, thoracic, abdominal (stops at belly button)

Front 62

Pts often refuse open AAA repair, making ____ AAA repair a common alternative when possible.

Back 62

endovascular repair

cant use this on everyone bc some people don't do well -- not as good blood flow as in open AAA repair (still a new technique, hasn't been perfected)

Front 63

What does the preop work up consist of for Endovascular AAA repair?

Back 63

Echo, EKG, carotid ultrasound, PFTs, CBC, Coags, cardio consult

start beta blockers pre op

Front 64

What are the anesthesia options for endovascular AAA repair?

Back 64

- regional: length of procedure dictates choice (if >3 hr, combined spinal epidural technique better choice), contraindicated in LMWH
- GETA: when using LMWH
-MAC
- spinal is best technique for AAA repair w endovasc technique - better morbidity and mortality statistics

Front 65

This is the chronic impairment of blood flow most often due to atherosclerosis whereas arterial embolism is most likely responsible for occlusion -- results in compromised blood flow to the extrem.

Back 65

peripheral vascular disease

Front 66

Risk factors for PVD include:

Back 66

anything that causes peripheral neuropathies!
- ischemic heart disease
- DM
- HTN
- smoking
- hyperlipidemia

Front 67

The principle symptoms of PVD

Back 67

intermittent claudication, rest pain

Front 68

This occurs when the metabolic demands of exercising skeletal muscle exceed the available O2 supply

Back 68

intermittent claudication

Front 69

This occurs when the arterial blood supply does not meet even the minimal nutritional requirements for the affected limb.

Back 69

rest pain

Front 70

The most reliable physical finding of PVD is....other findings include.....

Back 70

absent pulses

other findings include auscultating bruits over abdomen, pelvis or inguinal area coupled w decr pulse in affected limb; subcutaneous atrophy, hair loss, coolness, pallor, cyanosis, dependent rubor

Front 71

Main diagnostic test for PVD

Back 71

-doppler ultrasound
-ankle-brachial index (Ratio of SBP in ankle compared to brachial, ratio of < 0.9 indicative of disease, measures presence and severity)

Front 72

MOST FREQUENT symptom of PVD

Back 72

intermittent claudication

Front 73

What are the medical vs surgical treatment strategies for PVD?

Back 73

- medical: indicated if disease not debilitating, no ischemic rest pain apparent, or if not impending loss of limb apparent; exercise programs, treatment and modification risk factors for atherosclerosis
- surgical: depends on location and severity, aortofemoral bypass (AFB) most typically performed, operative risks similar to those described for AAA (pulm, cardio, renal)

Front 74

AFB requires a huge incision, disrupting a lot of _____. It is often performed under _____ Anesthesia, decreasing the chance of ____ events.

Back 74

valves, regional, thromboembolic

Front 75

What makes a surgical candidate suitable for introp beta blockade?

Back 75

- all pts undergoing vascular surgery with or without evidence of preop ischemia and with or without high or intermittent risk factors (smoking, hx of CVA/cardiac disease)
- pts on long term beta blockers
- pts having vascular surgery

Front 76

What pts may not tolerate regional anesthesia for AFB surgery?

Back 76

copd, orthopnea and dementia pts

Front 77

What are the considerations for use of epidural/spinal anesthesia for AFB surgery?

Back 77

improves blood flow through graft, place epidural at least 1 hr prior to intraop heparinization - useful for pain control (intrathecal opioids)

Front 78

What are the considerations for use of general anesthesia during AFB surgery?

Back 78

better suited for long procedures, TEE useful, volatile agents w or w/o N20, in conjunction w opioids, combo w regional

Front 79

What are the post op strategies for AFB surgery?

Back 79

- epidural/intrathecal opioids (produces analgesia without cardioresp. depression)
- use of LAs
- precedex gtt
- BP monitoring
- monitor for fluid and lyte derangements
- monitor for subclavian steal syndrome (occlusion of subclavian or innominate artery proximal to origin of vertebral artery may result in reversal of blood flow through the ipsilateral vertebral artery, absent/diminished blood flow in ipsilateral arm --> 20 mmHg lower in ipsilateral arm, bruit over subclavian)

Front 80

This is the occlusion of the subclavian or innominate artery proximal to the origin of the vertebral artery - may result in reversal of flow through ipsilateral vertebral artery into distal subclavian artery

Back 80

subclavian steal syndrome

Front 81

This is a rare vascular disorder involving inflammation of the blood vessels usually facilitated through an immune response.

Back 81

Takaysu's Arteritis

Front 82

What are the anesthesia techniques indicated for pts with Takaysu's Arteritis?

Back 82

- consider multi organ involvement and med regimen
- general anesthesia chosen over regional secondary to often pts on anticoag. therapy an dhave significant musculoskeletal changes making lumbar placement impossible

Front 83

What are the CNS effects of Takaysu's arteritis?

Back 83

vertigo, visual disturbance, syncope, seizures, cerebral ischemia or infarction

Front 84

What are the CV effects of Takaysu's arteritis?

Back 84

multiple occlusions of peripheral arteries, ischemic heart disease, cardiac valve dysfunction, cardiac conduction defects

Front 85

What are the respiratory effects of Takaysu's arteritis?

Back 85

pulm HTN, VQ mismatch

Front 86

What are the renal and musculoskeletal effects of Takaysu's arteritis?

Back 86

- renal: renal artery stenosis
- MS: ankylosing spondylosis, Rheumatoid arthritis

Front 87

This is the episodic vasospastic ischemia of the digits, responsive to stress and cold, and more common in women.

Back 87

Raynaud's Phenomenon

Front 88

What are the anesthesia considerations of raynaud's?

Back 88

- incr ambient temp of room (also w sickle cell pts)
- avoid sympathetic response to induction/intubation/surgery
- a-line not usually indicated
- regional anesthesia acceptable --> do not include epi as part of admixture!

Front 89

Why is surgery not typically performed in severe carotid disease that remains asymptomatic, especially in men?

Back 89

greatly incr risk of stroke

Front 90

What is the best induction agent for "Sick" hearts?

Back 90

etomidate

Front 91

How are AAAs usually detected?

Back 91

asymptomatic, pulsatile abdominal masses, usually <5 cm

Front 92

In a AAA rupture emergency, the pt goes into severe ______ shock and requires _____. There is no time for an adequate work up, so just ask this one question: ____.

Back 92

hypovolemic shock, volume resuscitation, does the pt have allergies??

Front 93

What is the classic AAA triad of symptoms?

Back 93

- hypotension
- back pain
- pulsatile abd mass

Front 94

If a pt with AAA repair has COPD, they should have a preop ____ test because....

Back 94

PFT -- severe reductions in vital capacity and FEV1 with abnormal renal function may mitigate against AAA resection

Front 95

What are the preop considerations for carotid endarterectomy?

Back 95

- neuro exam
- assess for response to changes in head position to cerebral fcn (can see compression of the artery, esp w hyperextension, avoid severe rotations and hyperextension of neck)
- presence of comorbidities (CV, ischemia, HTN, renal, pulm, establish normal BP range to ensure perfusion)

Front 96

The two primary goals of anesthesia during carotid endarterectomy are:

Back 96

- maintenance of hemodynamic stability and prompt emergence

maintain VS, normocarbia, pain/stress responses, invasive monitoring

Front 97

What is the technique for regional during carotid endarterectomy?

Back 97

cervical plexus block allows for neuro assmt during surgery, need to have a motivated pt

Front 98

What are the considerations for using general anesthesia during carotid endarterectomy?

Back 98

- use of volatile agents/N20/opioids, need to be able to wake pts for assmt
- monitoring for cerebral ischemia, hypoperfusion and cerebral emboli using EEG or SEP (Can be difficult during case)
- stump of carotid artery pressure monitoring (poor indicator of adequacy of cerebral perfusion, but still used as a guide by many surgeons)

Front 99

What are the post op considerations for carotid endarterectomy?

Back 99

- monitor for airway (patency), cardiac and neuro complications, EKG if suspect
- neuro fcn tests by surgeon and anesthesia provider
- maintain normal BP (HTN common, use nitroprusside and NTG intraop and into post op period indicated)
- carotid denervation may lead to respiratory compromise and predispose pts to aspiration

Front 100

What is the leading cause of post op morbidity/mortality in PVD surgeries?

Back 100

DVT and subsequent PE

Front 101

What factors predispose pts to thromboembolism formation?

Back 101

- venous stasis
- recent surgery
- lack of ambulation
- trauma
- pregnancy
- low CO (CHF, MI)
- CVA
- abnormality of venous wall (varicose veins)
- drug-induced irritation of vessels
- hypercoag. state
- estrogen therapy (birth control)
- cancer
- deficiencies of endogenous anticoagulants (antithrombin 3, protein C, protein S)
- stress response to surgery
- inflammatory bowel disease
- hx of prior thromboemb.
- morbid obesity
- advanced age

Front 102

What are the diagnostic tests to assess for thromboembolism?

Back 102

- contrast venography
- compression ultrasonography of proximal veins
- impedence plethysmography

Front 103

____ anesthesia can substantially decrease risk of DVTs in vascular surgery.

Back 103

regional
ortho hip and TKR surgeries reduced 20-40% w concommitant use of epidural/spinal anesthesia

causes vasodilation and post op analgesia

Front 104

Regional is contraindicated when pts are on what drug?

Back 104

low molecular weight heparin! (LMWH)