Aortic Emergencies Flashcards
(33 cards)
What is aortic dissection?
Aortic dissection occurs due to an aortic intimal tear, intramural haematoma or separation of the tunica media creating a false lumen
Predisposing factors of Aortic Dissection
Uncontrolled Hypertension
Smoking
Atherosclerosis
3rd trimester pregnant patients
Disorders of collagen, or vasculitis (Marfan’s syndrome, Ehlers-Danlos syndrome or giant cell arteritis)h
Types of classifications used in Aortic Dissections
Stanford and Debakey
Stanford system is divided into 2 groups
- Type A involves the ascending aorta (+/- descending aorta)
- Type B involves only the descending aorta
DeBakey system is divided into 3 groups
- Type I involves the ascending aorta, aortic arch and descending aorta
- Type II involves the ascending aorta, but does not extend beyond the left subclavian artery
- Type III involves only the descending aorta, starting at, or distal to, the left subclavian artery
3 key questions to ask for AD
- Intensity at onset
- Quality of pain
- Radiation of pain
Classical clinical features of AD
Sudden, severe, maximal pain at onset, tearing migratory chest pain that radiates to the back
- chest pain with syncope, neurological deficits
What is another possible clinical feature of AD?
Ischemia of the Lower Extremities due to Aortic dissection:
- Migratory pain from the chest to the abdomen to the lower limbs
If AMI (non-migratory) and AD occur together, which would begin first?
Dissection typically begins first and leads to the MI
What type of MI would be seen in AD? Due to involvement of which coronary artery?
Inferior MI, due to involvement of right coronary artery
PE findings for AD
- Hypertensive
- Radial-radial delay: Difference in systolic blood pressure in both arms (>20mmHg)
- Decreased pulse left arm
- Radial-femoral delay: Blood pressure in the upper limbs is greater than in the lower limbs
- New onset aortic regurgitation murmur (EDM)
- Tracheal deviation to the right (due to development of hemothorax and dissection extending to pleural cavity -> can lead to hemoptysis)
New onset of what type of murmur can be observed in AD patients
Aortic regurgitation murmur (early diastolic murmur: URSE or Erb’s point)
What can be seen in CXR in AD patients?
- Widened mediastinum of >8cm on PA CXR***
- Loss of contour of aortic knuckle
- Aortic enlargement
- Double density of the aorta (false lumen less radiopaque)
- New pleural effusion (free haemothorax)
- Deviation of trachea to the right (away from the developing haematoma)
Overarching principles in medical therapy for AD
Lower rate of rise of blood pressure by lowering mean blood pressure and heart rate and velocity of left ventricular contraction
-> leads to a decrease in aortic shear stress and minimise the tendency for propagation of the dissection
What investigations should be sent off?
POCT:
POCUS
VBG - to look at electrolytes
ECG - look for concomitant AMI
+ CXR
+ Bedside 2D echocardiography
Bloods:
FBC
RP to assess kidney function (esp since there might be reduced perfusion)
Coagulation panel
GXM
Cardiac enzymes
Radiology:
CT aortogram*** once AD highly suspected
Management of AD
- ABCs and set 2 large-bore IV cannulas
- Bedside: ECG TRO concomitant AMI, 2D echocardiography (>3.5cm root of aorta)
- Run investigations: FBC, RP, coagulation panel, GXM, cardiac enzymes
- Imaging: CXR, then CT aortogram once highly suspected - Monitor vitals and continuous cardiac monitoring in critical care area. Contact CVS the moment AD is suspected.
- PAIN CONTROL - IV morphine/fentanyl
- BP CONTROL - Reduce BP to SBP 100-120mmHg, HR <60bpm:
A. IV beta-blocker
- IV labetalol** (slow bolus 20mg IVx2mins initially followed by 1-2mg/min continuous IV infusion until total dose of 300mg )
- IV esmolol
- IV propanolol (used with nitroprusside)
B. IV GTN, nicardipine or nitroprusside - Insert IDC to monitor I/O especially for anuria/oliguria in renal artery involvement
- Put patient on circulation and neurological observation chart
- Surgical vs Medical repair
Typically
- Stanford A: Surgical
- Stanford B: Medical
Send for surgical repair
- Bentall procedure with Dacron polyester graft - Ascending aorta +/- arch replacement
Indications for surgical repair of AD include
- All Stanford type A dissections
- Type B dissections with complications such as:
a. Persistent pain
b. Aneurysmal dilation > 5cm
c. End organ or limb ischemia
d. Progression of dissection -> cardiac tamponade, EDM, hemothorax
Abdominal aortic aneurysm
Localised dilatation of an artery of >50% of the normal diameter & >30mm absolute diameter
*dilatation of <50% of the normal arterial diameter is termed ectasia
How will patients with AAA present?
- Asymptomatic (75%)
- RUPTURE triad:
- Abdominal, flank or back pain (can mimic ureteric colic)
- Pulsatile abdominal mass
- Syncope with postural hypotension
*back pain could be due to expansion of AAA with erosion of the spinal vertebrae or ruptured AAA
Other possible clinical features:
3. Distal embolisation of thrombus -> ALI
4. Acute thrombotic occlusion of small aortic aneurysms -> loss of blood flow to LL -> acute bilateral lower limb ischemia/paralysis
5. Pressure symptoms on adjacent structures
- dysphagia
- ureteric obstruction
- vena caval obstruction
6. Rupture into adjacent structures causing aortic fistula
- Aortoenteric fistula
- Aortocaval fistula
Any elderly patient presenting with hypotension, shock and back pain must TRO ruptured AAA
Most who present have sealed retroperitoneal hematoma with temporary haemodynamic stability
Look for expansile pulsation by placing fingers alongside pulsation; deviation of the fingers laterally is due to aneurysm
-
All patients with a pulsatile mass >__cm should have an ultrasound evaluation
3cm
Aortic aneurysms are associated with…
atherosclerosis
Risk factors of AAA
- Hypertension**
- Smoking
- HLD
- Prior CVD/PAD
- Male
- Elderly
Also screen for
- Fam hx of AAA (1st degree relatives)
- CTD
*CVS risk factors minus DM, obesity and diet/lifestyle
