Vascular PP2a Flashcards
anatomy of arteries for lower extremity
pathway from the aorta down
aorta - iliacs - femoral - popliteal - tibial and peroneal
when your pt has PAD, what other dzs do they probably have
why are they needed bypass sxg (symptoms).
what are they patients at high risk for
what is often a first sign
CAD, CVD
intermittment claudication, cold leg ischemia, intermittent pain
at high risk for CV events
first sign is often intermittent claudication
what is the difference between direct reconstruction and extra anatomic reconstruction
direct: aorta - fem, fem - pop, fem - tib. these procedures have higher mortality but better long term patency
extra anatomic: fem -fem, ax - fem. these have less mortality but but worse patency long term. sicker patients often get these procedures
what are some risk factors for PAD
smoker, dm, HTN, HLD, diabetes, chronic inflammation, renal insufficiency, hypercoaguable, male, nonwhite
what is the cheapest way to test for PAD
ankle brachial index. <.9 is abnormal
if the patient has CAD, step to see if they are ready for surgery
- urgency 2. ACS 3. MACE 4. METS >4 5. Stress test 6. are these tests s going to change whether we do surgery or not
what are some indicators for acute ischemia pathology (3)
timing on surgery
types of procedures
thombus or emboli
cold leg ischemia, loss of pulses
best to get surgery within 4-6 hours
angiography, stent, bypass
chronic ischemia indication
why is this occuring
when is surgery indicated
gangrene, pain at rest, intermittent claudication, ulcers
patho: progressive narrowing of the vessesl
SBi < .9, severe pain, disabling claudication, critical limb ischemia
how do we run the ankle brachial index
ankle SBP/arm SBP
normal is 1.0 - 1.4. <.9 is abnormal
take 2 readings and average
fem-pop procedure
discuss
tolerated better than Aox, bc dont need to clamp aorta
expose areas that will be receiving the graph, clamp fem. can use saphenous as graft
fever hemodynamic hcanges when not clamping aorta. give heparin
confirm flow
why are aorta femoral bypasses tolerated better than aneuysm disease
bc they have time to build up collaterals which will help devert blood flow during clamping
aneurysm repairs typically wont have collaterals built up yet
extra anatomic bypass: fem-fem or ax-fem
which patients get this surgery
patency of graft after 5 years
do you need to clamp AOX with ax-fem?
when is the most stimulating part, how can we help
where is place the A line: which side and proximal or distal
reserved for the higher risk patients
patecy is less at 5 eyars compared to direct repair
ax-fem dont need to cross clamp aorta
tunneling is most stimualting so paralyze
a line is placed opposite side of ax-fem and proximal to clamp
anesthetic management during lower extrm vascular surgery
premeds ti ake
invasive lines
labs to follow
what is an emergency surgery, what (5) things we need to consider
BB, statin, aspiring(way the risks for bleeding)
A line yes, +- CVP or PA depending on PHTN and RV failure
bmp, cbc, coags, TEG
fasciotomy, myoglobenimua, hyperK, ekg ischmic changes, coag status
Regional of GA with lower extrem vascular surgery
when its contrainidication
aid with CVD
aid with graft healing
type of regional placement
pt refuses or when coagulopathic
no differences show w CV when chossing GA or regional
RA is superior for decerased bleeding and increase in blood flow to surgical area, promoting healing to graft site
lumar epidural
what are reasons (4) that GA is worse for graft healing than regional
- Regional provides greater blood flow to the site
- fibrinolytics are decreased GA
- GA is more hypercoagulable
- epi and noepi are released higher w GA
when managing the graft intraop what are some considerations
T10 block with regional
try not use pressors to perfuse the newly placed graft
maintain blood flow and blood pressure to the anastamotic site.
keep warm
frequent pulse checks with doppler
Bypass: postop considerations (5)
prevent anemia
prevent hypotension and give adequate fluids to perfuse the site
high risk MI, check for ST elevation changes
control HR and afterload reduction
discuss the anatomy of the lower extremity and the spine
T12 suprarenal
L1 infrarenal, SMA
L3: IMA inferior mesenteric artery
L5: Iliac
t8-t12 is artery of adomkowit
are most aneuysms repairs suprarenal or infrrenal
85% are infrarenal
for arterial aneurysms, where do most occur thoracic or abdominal
where are most thoracic aneuysms
how are AAA classififed
abdominal, 9x more than thoracic
thoracic 40% ascending 35% descending
supra, 85%infra, juxta
what is the patho of aneursysm
what is most important predictor of rupture and mortality
what is the law of laplace
the connective tissue of the medial layer weakens. from inflammation and immune responses
a weakened wall
law of laplace = wall stress = (pressure x x2radius)/ wall thickness
size of the aneurysm
size of aneurysms and when they need to be fixed
AAA
descending AA
AAA >5.5cm
DAA > 6.5cm
patho of aortic dissection
acute vs chronic
where do most AAA occur
symptoms (3)
DAA death, why?
tear in the intimal layer creating a false lumen
acute <14 days
chronic > 14 days
most occur in the asending region
cardiac tampondae, aortic regur, MI
death from acute DAA because not feeding organs: spleen, liver, bowels, stomach
changes you will see during clamping, things to worry about OVERVIEW
duration, location of clamping. suprarenal above L1 hypertension, decrease of blood flow to spinal cord, bowels, kidneys, spleen. will see hemodyanmic and metabolic changes
if below L1, spleen and visceral organs can take 800cc blood, better tolerated and wont see hypertension. visceral organs get blood flow
