Abdominal Aneurysm Flashcards
Primary risk factors for a AAA
- First degree relative with known AAA
- Smoking
- Older age (typically 65+)
- CAD/Peripheral artery disease
- HTN, HLD, Atherosclerosis
- Male gender (80% of patients with AAA)
(Obviously there is more but those are the main ones)
Classic triad for AAA rupture presentation
Abdominal pain, pulsatile mass, and Hypotension - however a ruptured AAA can exist without any of these findings.
Note: If bleeding retroperitoneal then may not have hypotension because it tamponades.
Other symptoms may be: back or flank pain, N/V, painless Hematuria (if AV fistula), syncope
What size defines a AAA? What size requires repair?
Normal size infrarenal aorta: 2.0cm
> 3.0cm = AAA
> 5.0-5.5 —> repair
Besides rupture, what are some other complications of AAA?
- Embolization of microemboli —> blue toe syndrome and live do reticular is
- Aortoenteric fistula (esp. if Hx of prior repair)
- Aortovenous fistula (most commonly into the IVC) —> high-output CHF
Survival rate of a ruptured AAA decreases by __________ prior to arrival to the ED
1% per minute
Symptoms of non-ruptured AAA vs. ruptured AAA
Non-ruptured: maybe chronic non-specific or colicky abdominal pain
Ruptured: Usually constant, severe abdominal pain. Difficult to localize
What test to diagnose AAA and ruptured AAA?
- US has great sensitivity for AAA, but specificity for rupture is very low (like 4%). FAST will only show peritoneal bleeding but not retroperitoneal.
- CT noncontrast can diagnose and see the rupture too
- CT angiogram is best for pre-operative planning
Target BP for ressucitation of hypotension in ruptured AAA?
SBP of 70-90 mmHg. (FIRST AID says 80-100 mmHg) You can allow some permissive hypotension in order to avoid exacerbating the hemorrhage.
Do this with BLOOD. Try to avoid crystalloids if you can (there is a risk of dilution all coagulopathy and iatrogenic acidosis).
Avoid this part of the ABCs of ressucitation in ruptured AAA if you can’t
Intubation - because induction can lead to cardiovascular collapse
Who can be discharged home with a AAA and who gets admitted?
Home: Asymptomatic incidental findings <5cm with outpatient vascular surgery f/u.
OR symptoms clearly not related to their AAA
Admit: Acutely symptomatic without rupture. Any of the complications such as AE and AV fistulas and microemboli.
Rupture goes straight to the O.R.
What is considered a “rapidly expanding” AAA?
> 1cm increase in size per year
This increases the risk for rupture and should be considered for repair.
Describe the risk of rupture based on the size of a AAA
<4.0cm —> 0% risk of rupture in a year 4-5cm —> 0.5% - 5.0% risk of rupture in a year 5-6cm —> 3-15% 6-7cm —> 10-20% 7-8cm —> 20-40% >8cm —> 30-50%
Estimated prevalence of AAA in patient’s aged 50-85?
1.4%
Percentage of patients that survive a ruptured AAA of those who arrive alive at the hospital?
50-70%
Overall mortality of AAA rupture is 85-90% (a lot die before getting to the hospital)
What are the two types of AAA rupture? How do they differ clinically?
- Into the retroperitoneal space: a “contained rupture”. Creates tamponade effect at rupture site causing blood pressure to stabilize temorarily
- Intraperitoneal space: a “free rupture” leading to rapid exsanguination, shock, and rapid death
