VASCULAR Flashcards
What is aortic dissection?
Tearing of the layers of the aorta - blood fills between the intima and the media.
Name the layers of the aorta.
Intima
Media
Adventitia
What is a false lumen?
Tear in the vessel wall forming a blood filled sac.
Which part of the aorta is most commonly affected?
Ascending aorta - right lateral area (vessel is under most stress from blood leaving the heart)
Aortic arch
What are the risk factors?
Smoking Age Male High cholesterol Obesity
Which conditions increase the risk of dissection?
Conditions affecting the heart/aorta: • Coarctation of the aorta • Aortic valve replacement • CABG Connective tissue diseases: • Marfan's Ehlers Danlos
Name two classification systems for aortic dissection
- Stanford
2. DeBakey’s
What is the Stanford system?
- Type A - ascending aorta, before brachiocephalic artery
2. Type B - descending aorta, after left subclavian artery
What is the typical presentation of aortic dissection?
Tearing/ripping chest pain - pain may migrate
HTN
Syncope
Sometimes no chest pain
What is indicated by anterior or posterior chest pain in suspected aortic dissection?
Anterior = ascending aorta Posterior = descending aorta
What are the signs of aortic dissection?
HTN --> hypotension Difference in BP in each arm Diastolic murmur Radial pulse deficit Focal neurological deficit
What type of murmur is associated with dissection?
Diastolic murmur
What is a radial pulse deficit?
Radial pulse in one arm is absent/weaker and does not match the apex beat.
Why is it important to measure the blood pressure in both arms in suspected aortic dissection?
> 20mmHg
What investigations should be ordered in suspected aortic dissection?
ECG and CXR - to exclude other causes
CT angiogram - diagnostic
MRI angiogram - for management
What is seen on ECG in aortic dissection?
Normal - or MI can occur in combination
What is the initial investigation to confirm the diagnosis of aortic dissection? What investigation imaging will be needed for definitive management?
CT angiogram
MRI angiogram
What is the immediate management of aortic dissection?
- Analgesia - morphine
- Control BP and heart rate - beta-blockers
- refer for Surgery - depends on classification
What beta-blocker is used to control HR and BP in aortic dissection?
IV labetalol
How is type A dissection treated?
Open surgery = sternotomy (aortic valve may need replacing during)
How is type B dissection treated?
Conservative management
OR
TEVAR = thoracic endovascular aortic repair (catheter inserted via the femoral artery)
Why should thrombolysis be avoided in aortic dissection?
Bleeding
Name 6 complications of aortic dissection.
MI Stroke Paraplegia Cardiac tamponade Aortic valve regurgitation Death
What is compartment syndrome?
raised pressure within a closed anatomical space. The raised pressure within the compartment will eventually compromise tissue perfusion resulting in necrosis
Which two fractures are most likely to cause compartment syndrome?
supracondylar fractures and tibial shaft injuries.
What are the signs of compartment syndrome?
Acute compartment syndrome presents with the 5 P’s:
• P – Pain “disproportionate” to the underlying injury, worsened by passive stretching of the muscles
• P – Paraesthesia
• P – Pale
• P – Pressure (high)
P – Paralysis (a late and worrying feature)
What are the two types of compartment syndrome?
Acute or chronic
Name a key differential for compartment syndrome.
Critical limb ischaemia
What is the clinical difference between compartment syndrome and critical limb ischaemia?
Pulses remain intact
How is compartment syndrome diagnosed?
Clinical
What is the investigation used?
Needle manometry can be used to measure the compartment pressure. A device (manometer) measures the resistance to injecting saline through a needle into the compartment.
What would happen if the patient was not treated?
tissue necrosis (death) and permanent damage can occur.
What is the management of compartment syndrome?
- Escalating to the orthopaedic registrar or consultant
- Removing any external dressings or bandages
- Elevating the leg to heart level
- Maintaining good blood pressure (avoiding hypotension)
What is the definitive treatment of compartment syndrome?
Emergency fasciotomy (within 6 hours)
Patients require repeated trips to theatre (every few days) to explore the compartment for necrotic tissue, which needs to be debrided.
As the swelling improves, the wound can be gradually closed, which can take several weeks.
What is chronic compartment syndrome?
Chronic compartment syndrome (also called chronic exertional compartment syndrome) is usually associated with exertion.
During rest, the pressure falls, and symptoms begin to resolve.
How does chronic compartment syndrome differ to acute compartment syndrome?
- Symptoms are usually isolated to a specific location at the affected compartment.
- Not an emergency.
- Associated with exertion.
How is needle manometry used to guide the treatment of chronic compartment syndrome?
Needle manometry can be used to measure the pressure in the compartment before, during and after exertion to confirm the diagnosis. It may be treated with a fasciotomy.
What treatment is recommended for superficial thrombophlebitis?
NSAIDs
Compression stockings
