Vascular Disease Flashcards
What are the physiological functions of blood vessels? (3)
Regulation of blood to tissues
Synthesis/secretion of vasoactive/antithrombic substances
Delivery of immune cells
What are the measurement of the aorta in cm?
~3cm from the origin
~5-6 cm long
What are the 3 branches off the arch of the aorta from left to right?
Brachiocephalic
Left common carotid
Left subclavian
What are the layers of the aorta?
Intima (innermost)–endothelial cells
Media–smooth muscle cells, elastic/collagen fibers 2:1
Adventitia–collagen (strength), vaso vasorum (vasculature that perfuses the outer layer)
What factors constitute an AAA? (3)
50% increased localized diameter
>4 cm in thoracic aorta
>3 cm in abdominal aorta
Define a true aneurysm.
Involves all 3 vessel layers
2 types: fusiform, saccular
Define a pseudoaneurysm.
Only involves the inner 2 layers: intima and media.
Pseudoaneurysms are more unstable. True or false?
False affects the intima and media and is contained in the adventitia.
Label the types of aneurysms.
________ is the origin of 90% of aneurysm cases.
Atherosclerosis
Note: Usually occurs in males > 50 y/o.
What are cofactors leading to the cause of aneurysms? (4)
Smoking
Hypertension
High cholesterol
Loss of elastin
Men are ___ times more likely to have an aneurysm than women.
8
Abdominal aneurysms are often asymptomatic. True or false?
True
What are the clinical presentations of an aneurysm in the following areas:
Compression of esophagus/trachea
Recurrent laryngeal nerve
Dilation of aortic ring
Compression of esophagus: Wheezing, coughing, dyspnea, difficulty swallowing
RLN stretching: hoarseness
Aortic ring: Pt presents with aortic regurge
What are classic signs of an aortic aneurysm rupture?
Hypotension
Low back pain
Pulsative abdominal mass
Note: Only 1/2 pts present with these signs.
What is the gold standard for treating AAA?
What is the treatment for less severe ones?
surgical repair with prosthetic graft
endovascular graft
When is surgical repair of a AAA considered? (Think of diameter.)
> 4.5 - 5 cm in diameter
What other co-existing conditions with pts with AAA have? (5)
Ischemic heart disease
HTN
COPD
Diabetes
Renal dysfunction
What kind of access do we need prior to surgery?
Large IV
Art line
Central line
What important factors do we need to consider intra-op?
Smooth induction to prevent cardiovascular swings.
Major blood loss may occur.
Hemodynamic changes that can occur during clamping/unclamping.
What hemodynamic changes occur during cross clamping?
Increased afterload–> increased BP
Decreased preload
Decreased perfusion distal to the clamp
Note: Depending on where the clamp is placed, renal perfusion can be compromised.
What hemodynamic changes occur during unclamping? (3)
Sudden decreased afterload –> decreased BP
**need vasoconstrictor to anticipate the change
Lactate washout
What is an aortic dissection?
The splitting of the intima from the adventitia along the length of the vessel.
What are the 2 types of aortic dissection?
Type A
Type B
What is a “Type A” aortic dissection? (3)
Involves the proximal, ascending aorta
Represents 2/3 of dissections
High risk of extruding into coronary and arch vessels
What is a “Type B” aortic dissection?
Distal dissection limited to the thoracic and abdominal aorta
What is the pathogenesis of aortic dissection? (4)
Chronic HTN
Aging
Connective tissue disorder like Marfan’s
Trauma
What type of aortic dissection presents as:
sudden, severe pain with ripping/tearing in anterior chest
Type A
What type of aortic dissection presents as:
sudden severe pain between scapulae
Type B
What other catastrophic events can occur from a dissecting aorta? (4)
MI
Stroke
Renal failure
Loss of pulse in extremities
Note: All occur as a result of occlusion of the propagating hematoma.
What are complications of aortic dissection?
Rupture
Occlusion of aortic branch vessels
Distortion of the aortic annulus
What does the rupture of aortic dissection result in?
cardiac tamponade
hemomediastinum
hemothorax
What does occlusion of the aortic vessels result in?
carotid stroke
coronary MI
How do we treat an aortic dissection intra-operatively?
Stop progression of the dissection by:
decreasing BP –> Beta Blockers
decreasing LV contraction –> Sodium Nitroprusside
Symptomatic pts with >____% blockage yield the greatest benefit from an endarterectomy.
50%
Pts who have already suffered a stroke will yield the most benefit to a carotid endarterectomy. True or false?
False, yields minimum benefit.
What do you consider during a carotid endarterectomy pre-op evaluation?
Neurological status
CAD
Renal disease
Chronic HTN
Effect of changes in head position
What is the anesthetic technique for carotid endarterectomies?
Regional: Cervical Plexus Block allows trial occlusion of carotid to evaluate neuro changes. Pt is awake.
GA: Infer neuro changes from EEG
What are the cons to performing a cervical plexus block for a carotid endarterectomy?
no cerebral protection
What are the benefits to GA for a carotid endarterectomy?
decreased CMRO2
ability to regulate PO2, PCO2
What are the drugs of choice for induction for a carotid endarterectomy? (2)
Thiopental
Propofol
Note: Because they lower CMRO2 and redistribute blood flow to potentially ischemic areas.
Etomidate for hemodynamically unstable pts.
Fentanyl/Alfentanyl
What are anesthetic considerations intraoperatively for carotid endarterectomies?
Control BP
Carotid cross-clamping/unclamping
PROMPT emergence to assess neuro function
What are post-operative concerns for carotid endarterectomies? (5)
HTN (carotid sinus activation) / Hyptension (baroreceptor reactivation)
MI/Infarction (MI is leading cause post-op complications)
Neurological complications
Airway obstruction
Nerve injury (hypoglossal, RLN, SLN)
In what time frame does a carotid endarterectomy incident occur?
8-12 hours post op
Peripheral disease may result from: (3)
atherosclerosis
thromoembolism (acute)
vasculitis
70% of pts > 75 y/o are affectedby peripheral atherosclerosis. True or false?
true
What are the clinical presentations of peripheral atherosclerosis? (4
Claudication (cramping)
Ulceration
Skin necrosis
Decreased arterial pulses
How do we pharmacologically treat peripheral atherosclerosis? (4)
Anti-platelet therapy
Lipid-lowering therapy
DM meds
HTN meds
What are causes of acute arterial occlusions? (4)
Thrombi originating from:
heart
stenosed aorta
damaged endothelium
bypass grafts
What condition:
vasospasm of digital arteries with cold/stress
extreme vasoconstriction
tricolor phasic response- white/blue/red
Affects women 20-40 y/o
Raynaud’s Syndrome
What medications alleviate symptoms of Raynauds? (2)
Calcium channel blockers
Alpha antagonists
Avoid EPI in local anesthetics when treating pts with Raynaud’s. True or false?
True
Where do DVTs normally occur and what is a considerable risk of a DVT?
Calf veins or more proximally
Pulmonary embolism
What are the clinical symptoms of a 2º DVT, or, pulmonary embolism? (4)
Acute dyspnea
Tachypnea
Chest pain
Non-productive cough
What are DVT risk factors? (5)
Morbid obesity
Stasis of blood flow
vascular damage
Hypercoagulable states
Advanced age
