CT & CV emergencies Flashcards
Aneurysm def
abnormal vessel dilation, (U) defined as 1.5 to 2 times normal size/greater than 50% enlargement
Dissection def
a tear in vessel wall in intima & part of media->can create a true & false lumen, compromise branch vessel flow resulting in ischemia & can also rupture through remaining media & adventicia
non-traumatic dissections often occur in underlying aneurysms
Aortic Aneurysmal Disease: definition & causes
-degenerative & remodeling of aortic wall
-genetic predisposition & environmental factors
-commonly atherosclerotic
other causes:
A. infection-TB, syphilis
B. Marfan’s, Ehlers-Danos
Atherosclerotic Aneurysms: where, progression, result
95% affect abdominal aorta rather than thoracic
-progressive expansion & eventual rupture
-only 14% have symptoms prior to rupture-so HIGH MORTALITY
in ppl who survive initial rupture, 50% or more still die following surgery
almost always have co-morbidities: CAD, PVD, COPD, DM, renal failure
Abdominal Aortic Aneurysm-AAA Dx
UTZ (ultrasound) both for dx & to follow size, remember to do UTZ if abdominal complaint or greater than 2-3cm on exam
CT/MRI-use to plan endovascular therapy
Abdominal Aortic Aneurysm (AAA) management
less than 5.5cm, not enlarging rapidly, asymptomatic
-UTZ follow-up every 6-12 months
Abdominal Aortic Aneurysm (AAA) indication for intervention
greater than 5.5cm or symptomatic
-rapid expansion->0.5cm in 6-12 months
Ruptured Abdominal Aortic Aneurysm symptoms
the constellation:
A. Flank/Back Pain
B. HD instability
C. Pulsatile Abdominal Mass
abdominal pain, pulsatile abdominal mass, tenderness & hypotension
EMERGENCY!!!
Management of ruptured AAA
ABC, **2 LARGE BORE IVs, type & cross 10 units PRBCs, pain control, UTZ in ED, BP goal 80-100mmHg, EKG-likely have a cardiac history or risks,
Central Line or Swan at some point
**ER or OR
consider endovascular repair if HD stable, contained rupture or impending rupture if available & anatomy acceptable
Surgical repair of AAA
- surgical repair w/Dacron graft
- percutaneous endovascular stent grafts being used now [endovascular now preferred in many]
-balance operative risk w/risk of rupture
-criteria to repair is:
>or= 5.5cm
>6cm for higher risk patients
Operative mortality:
19% for urgent repairs
50% for ruptures
Debakey classifications of thoracic aortic dissections
type I: complete aorta
type II: just ascending aorta
type III: just the descending aorta
Dissections are due to a tear wear, & then what happens
a/w what feeling?
due to tear in intima
- blood penetrates into the media which splits longitudinally
- can involve thoracic &/or abdominal aorta
- can occur 2* to connective tissue dz or in presence of aneurysm. Thoracic dissctions are also a/w HTN & trauma
a/w acute onset of “tearing” pain in either chest or abdomen
What is the main way you dx dissections
CT scan
Acute aortic dissection (U) starts where?
mortality?
in the thoracic aorta
an ACUTE EMERGENCY
mortality 15-20% initially
1% per hour for first 48 hours
risk factors for aortic dissection (3)
age
HTN
connective tissue dz (eg Marfan’s)
pregnancy
Where does blood go in an intimal tear?
blood penetrates into & splits the medial layer, inner 2/3 & outer 1/3 of media
false channel created-intimomedial flap separates true & false lumens-reentry occurs
Aortic Dissection: Potential signs & symptoms
-chest pain
-back pain, particularly between shoulder blades
neurologic changes-transient or permanent
-distal ischemia-limbs, gut, kidney
-acute cardiac failure: aortic regurgitation, coronary ischemia
-hypotension & shock: rupture
-hypertension
-discrepant blood pressures (check BPs in all 4 extremities)
-widen mediastinum
-pleural capping
-pleural effusion
-hoarse voice
TRIAD OF AORTIC DISSECTION-constellation
- Abrupt onset of thoracic or abdominal PAIN with a sharp, tearing quality
- Mediastinal and/or aortic WIDENING on chest radiograph
- HTN +/- DISCREPANT BP or pulse (absence of a proximal extremity)
Aortic Dissection: subsequent management -TYPE A
75% of cases emergent surgery in all patients mortality>50% within 48 hours complications: 1. aortic rupture 2. cardiac tamponade 3. acute aortic regurgitation 4. acute coronary ischemia
Aortic Dissection: subsequent management- TYPE B un complicated
type B uncomplicated (no rupture or ischemia)=medial therapy
What is Type B complicated & what is the tx
Type B complicated or failed medical management in characterized by
- persistent pain
- progression of dissection
- Marfan’s
tx: surgical or endovascular tx
- endovascular therapy can be effective when tailored to specific indication such as contained rupture & in some cases of branch vessel ischemia
Aortic Dissection imaging
Spiral CT Scan: gold standard
MRI (good for following, but not dz/tx)
TEE: may miss distal tears, good for evaluation of aortic valve proximal root
Initial medical management of aortic dissection
- reduce systolic BP
- decrease LV dP/dT (force of ejection of the heart)
- pain control
Beta blockers first, then add vasodilators like Nipride
Thoracic Aortic Aneurysm-Invasive tx
Ascending and/or arch: sternotomy surgical repair +/-aortic valve
Descending Aorta: left Thoractomy
- surgical repair OR
- endovascular repair/graft
What is the most common cause of aortic dissection in a woman under 40?
PREGNANCY
Transection of thoracic aorta causes, clinical clue
accounts for 1.5-2% of blunt thoracic trauma
RAPID DECELERATION-(MVA/falls)
-accounts for 15% of deaths following MVA
pt responds to fluid, then hypotension, responds to fluid, then hypotension: stop & go to OR, avoid HTN rupture
Thoracic Aortic Injury: Transection dx (7)
- ‘funny-looking mediastium’
- blurred aortic knob
- widened mediastinum
- 2nd rib fracture
- pleural effusion
- apical capping
- CXR then spiral CT scan, angiogram if equivocal
Thoracic Aortic Injury: Transection Management
open repair vs. endovascular repair if available
- clamp & run, vs. partial bypass
- high risk of paraplegia (artery of Adamkiweicz
-if aorta is injured but not the source of active hemorrhage, if should be lower on list of management after hemorrhage control (abdomen/pelvin) & neuro stabilization
