Anesthetic Management for Vascular Surgery Flashcards
What are 6 significant risk factors for post-op cardiac events?
high risk surgery
ischemic heart disease
creatinine > 2.0
Hx of TIA, CVA
Type I diabetes
Hx of CHF
What are 3 noninvasive cardiac evaluations we can perform?
Stress test
Dipyridamole-Thallium Stress test
Dobutamine Stress Echo
What are severe cardiac risk factors? (4)
Recent MI
Decompensated heart failure
Significant arrhythmias
Severe valvular disease
What are moderate cardiac risk factors? (5)
Ischemic heart disease
Compensated CHF
DM
Renal insufficiency
Cerebrovascular disease
What are high risk surgeries? (4)
Emergent surgery
Aortic/major vascular surgery
Peripheral vascular surgery (leg amputation)
Prolonged surgery with large fluid shifts/blood loss
What are considered intermediate risk surgeries? (5)
Carotid endarterectomy
Head/neck
Thoracic/Abdominal
Orthopedic
Prostate
If functional capacity is < 4 mets and >3 risk factors, do you proceed with intermediate risk surgery?
Yes, with HR control or consider testing if it will change management.
When is CABG indicated? (4)
Stable angina w/ left main stenosis
Stable angina and 3-vessel CAD
Stable angina and 2-vessel CAD with LAD
Unstable angina or acute MI
What type of monitoring is required for AAR (abdominal aortic reconstruction)? (6)
All cases need:
ASA standard monitors
2 Large bore IVs
Art line
Good LV, need central line
Poor LV, need PA line and TEE
Renal effects significant even infrarenally!
What are the renal effects of infrarenal aortic cross clamping?
decreased renal blood flow
increased renal vascular resistance
reduced GFR
Note: Changes persis for at least 1 hour after unclamping.
During thoracic aorta repair, what is at risk of ischemia? why?
spinal cord, so drain prior to surgery
ischemia result of thoracic cross clamping
Asymptomatic bruit/stenosis does not increase the stroke risk for general surgery. True or false?
True
What are the neurological risks for carotid endarterectomies? (6)
irregular/ulcerated ipsilateral plaque
thrombus
poor colllaterals
contralateral occlusion
STATINS
history of stroke
When is the highest risk of embolism during a carotid endarterectomy? (4)
dissection
shunt insertion
clamp release
12 hours post op
What issues can arise after a carotid endarterectomy? (7)
Hyper, hypotension
Carotid body damage
MI **
Stroke
Hyperperfusion **
Neck hematoma
Cranial nerve injury
what is MET?
Metabolic Equivalent = estimates energy requirements
1 = basic low level activities
10 = strenuous exercise
coronary stent placement has what effect on coagulopathy increasing the risk for this adverse event?
hypercoagulable
increased risk for MI
what drug must be given prior to aortic cross-clamping and why?
heparin (100 U/kg), repeated hourly to prevent thrombosis
in order to alter CO2 levels, what must be done when the clamp goes up and then comes back down?
Clamp up = decrease RR
Clamp Down = increase RR
What are some differences between Open and Endovascular approaches to AAA repair?
Endo = lower 30 day mortality, less invasive, higher rate of reintervention
How do anterior and posterior spinal cord ischemia present differently?
Anterior = impaired motor fxn and temp
Posterior = proprioception & fine motor skills altered
aTAA is at an increased risk of rupture when is is what size?
>6 cm
what is the main difference between the carotid sinus and carotid bodies?
carotid sinus = baroreceptor
carotid body = chemoreceptor
List some types of cerebral monitoring that can be used during CEA
Awake - monitor fxn
EEG - monitor ischemia
SSEP -somatosensory evoked potentials
Oximeter
JvO2
Stump Pressure - pressure above shunt/clamp
TCD - transcranial doppler
list 5 physiologic ways to enable cerebral protection
hypertension
hemodilution
hypothermia
normoglycemia
normocarbia
what is hyperperfusion syndrome?
vessels maximally dilate distal to stenosis leading to brain edema and hemorrhage
what are the risks and symptoms of hyperperfusion syndrome?
Risks:
severe ICA stenosis
uncontrolled HTN
contralateral stenosis
Symptoms:
unilateral headache
seizures
focal signs
