4.4 Dissecting Aortic Aneurysm

Question 1

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Anatomy

Answer 1

(1) Ascending Aorta is the portion of Aorta that starts at the Aortic valve
and ends at the start of the brachiocephalic trunk.
(2) Aortic arch starts at the brachiocephalic trunk and ends just distal the
left subclavian artery
(3) Descending aorta starts just after the left subclavian artery and ends at
the diaphragm
(4) Abdominal aorta starts at the diaphragm and ends at the branch point of
the iliac arteries
(5) 3 layers in the Aorta: the intima, media, and adventitia

Question 2

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Pathophysiology

Answer 2

(1) Aortic dissection is a spontaneous or traumatic tear in the intimal layer
of the aorta causing dissection of the inner and middle walls of the aorta
(2) Blood entering the tear may propagate the dissection into the abdominal
aorta, carotids, subclavian, or lower extremity arteries
(3) Type A dissection: involves the arch of the aorta proximal to the left
subclavian artery
(4) Type B dissection occurs in the proximal descending aorta
(5) Dissections may occlude major aortic branches leading to ischemia of
the brain, kidney, upper extremity, or lower extremities
(6) Spontaneous dissections are highly associated with hypertension,
connective tissue disorders (Marfan syndrome), bicuspid aortic valve,
pregnancy, and coarctation of the aorta

Question 3

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Symptoms/Physical Findings

Answer 3

(1) Sudden severe chest pain radiating to the back, often described as a
ripping or tearing pain
(2) Hypertension
(3) Syncope
(4) Paralysis of lower extremities
(5) Diminished or unequal peripheral pulses
(6) Possible diastolic murmur of Aortic Regurgitation

Question 4

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Differential Diagnosis

Answer 4

(1) AMI
(2) Pulmonary embolism
(3) Pneumonia
(4) Pericarditis
(5) Myocarditis
(6) PTX
(7) Esophageal rupture

Question 5

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Labs/Studies/EKG

Answer 5

(1) CXR: may reveal abnormal aortic contour or WIDENED
MEDIASTIMUM
(2) CT scan with IV contrast is imaging modality of choice

Question 6

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Treatment

Answer 6

(1) Goal is to lower blood pressure to SBP of 100-120 and lower HR to <80
(2) Type A aortic dissections require emergent surgery
(3) Type B aortic dissections do not require emergent surgery unless there
is loss of blood flow to extremities or other organs
(4) ABCs, IV, O2 if saturation < 94%, Monitor
(5) Beta blockers are mainstay of therapy
(a) Metoprolol 5 mg IV, or 50-100 mg orally
(b) Labetalol 5-10 mg IV q 30 minutes to goal, or 100 mg q 6 hours orally
(6) Pain control with Morphine 4-8 mg IV
(7) Long term management can use regular antihypertensive medications in
addition to beta blockers such as ACEI, ARB, Diuretics
(8) Smoking cessation
(9) Surgery is the definitive therapy for Type A dissections

Question 7

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Initial Care

Answer 7

(1) Blood pressure and HR control
(2) Pain control to assist in decreasing blood pressure
(3) ABCs
(4) MEDEVAC to higher level of care

Question 8

DETERMINE the management of a patient with Dissecting Aortic Aneurysm.

Complications

Answer 8

(1) Organ failure
(2) Aortic valve regurgitation
(3) AMI
(4) Death
(5) Untreated type A dissection has a mortality rate of 1% at 72 hours and
90% at 3 months if unrepaired.