CHAPTER 60 ANEURYSMAL DISEASE Flashcards
An aneurysm is dilation of the arterial wall to _________ its normal diameter.
1.5 times
Pathophysiology of aneurysm
A progressive decrease in elastin, collagen, and fibrolamellar units results in thinning of the media of the vascular wall and a decrease in its tensile strength.
Laplace law:
wall tension = pressure × radius
MC peripheral aneurysm
Popliteal artery aneurysms
-localized dilation of the popliteal artery of >2 cm or >150% of the normal arterial caliber.
-Sx: discomfort behind the knee, leg swelling with or without deep venous thrombosis, or claudication
-Rupture is rare
Most serious Cx: Sudden acute limb ischemia caused by thrombosis or embolization from the aneurysm
Uncommon aneurysm
Aneurysms of the femoral artery
Most common visceral artery aneurysm
renal
splenic
hepatic
All but splenic artery aneurysms are more common in elderly men.
Diameter in abdominal aortic aneurysm
≥3.0 cm
Repair is considered for aneurysm with diameter of?
≥5.0 cm
Risk factors of AAA
first-degree relative with an aortic aneurysm
>60 years old,
males
Most important environmental risk factor in AAA;
Major risk factor for accelerated aneurysmal growth and rupture.
Smoking
- prevalence of abdominal aortic aneurysm being more than four times that in lifelong nonsmokers.
Most common presenting symptom with aortic aneurysm or rupture
Back or abdominal pain
-severe and abrupt in onset
-ripping or tearing pain
Classic TRIAD of a ruptured abdominal aortic aneurysm
abdominal pain
pulsatile abdominal mass
hypotension
The sensitivity of abdominal palpation increases with aortic aneurysm diameter
29% for a diameter of 3.0 to 3.9 cm
50% for a diameter of 4.0 to 4.9 cm
76% for a diameter of ≥5.0 cm
Sign of aneurysmal expansion or rupture
Tenderness to palpation
External signs of acute rupture: periumbilical ecchymosis
Cullen sign
External signs of acute rupture:
flank ecchymosis
Grey Turner sign
unexplained or highvolume upper or lower GI bleeding, especially in patients without liver disease.
aortoenteric fistulas
Fistulas most frequently involve the duodenum, with hematemesis, melenemesis, melena, or hematochezia
Imaging modality of choice for unstable patients.
Bedside US
-Unstable patients should not be sent out of the ED for imaging
Plain abdominal films (more obvious on a lateral view)
calcified and bulging aortic contour
TRUE OR FALSE:
An aortic diameter <3.0 cm does not excludes acute aneurysmal disease.
FALSE
Best detects the anatomic details of the aneurysm and associated hemorrhage
CT scanning with IV contrast
ED Interventions for Symptomatic Abdominal Aortic Aneurysms
- IV access - two large-bore IVs in place for rapid administration of crystalloids, blood, or medication
- Consultation
- Blood and fluids - permissive hypotension, a systolic blood pressure of 80–90 mm Hg, is recommended
- Pain control - Avoid severe hypotension and respiratory depression
In the event of suspected expanding aneurysm and severe hypertension, __________________ is recommended for its ability to be titrated to a target systolic blood pressure of 120 mm Hg.
Esmolol (half-life, 9 minutes)
-can be quickly stopped if the patient’s blood pressure drops suddenly
TRUE OR FALSE: Symptomatic aneurysms of any size are considered emergent.
TRUE