18 - AAA Flashcards
What is an aneurysm?
Increase of 50% the diameter of a normal lumen with thinning of the vessel wall
What is a true aneurysm?
lined by the vessel wall
What is a false (pseudo) aneurysm?
aneurysm enclosed by tissue rather than vessel wall
What is the normal size of the abdominal aorta?
3-3.5 cm
At what point is a AAA eligible for surgery?
5.5cm - risk of rupture is greater than surgery.
What is the screening for AAA
65 year old males with an abdominal ultrasound
What are the risk factors for AAA?
Smoking male age smoking diabetes hyperlipidaemia positive family history connective tissue disorder - marfans etc.
When to suspect AAA?
60 year old with first presentation renal colic
Why might open AAA repair be used over EVAR?
AAA to large, anatomy not suitable for EVAR.
What are the 6 Ps for acute limb ischaemia?
Pulsless Pain Palor Perishingly in cold Parathesia Paralysis
What is the fontian classification of PVD?
- normal
- intermittent claudication - claudication distance with pain in calf and gluts
- critical limb ischaemia - pain at rest and night, leaves leg out of bed.
- gangrene and necrosis
What antiplatlet is used for PVD?
aspirin 75mg
What is the criteria for endarterectomy?
stenosis of 70-99% or symptomatic. (vascular surgeon will do 50%)
What are the classification of aortic dissection?
Type A - before the left subclavian, MEDICAL EMERGNECY and managed with surgery
Type B - After left subclavian, managed conservatively
What are the symptoms and signs of aortic dissection?
- Severe chest pain radiating between the scapulars.
- Sudden onset
- difference in BP in arms
- radio-radio/femoral delay
What is shock?
A acute clinical syndrome initiated by the ineffective percussion and cellular hypoxia resulting in severe dysfunction of organs vital to survival.
What types of shocks re there?
Hypovolaemic
Cardiogenic
Obstructive
Distributive
What example are there of obstructive shock?
cardiac tamponade
pneumothorax
What examples are there of distributive shock?
sepsis
inflammation
pancreatitis
anaphylaxis
What is the definition of a massive haemorrhage?
> 10 until in 24 hours
> 4 units in 1 hour
What clotting factors are controlled by warfarin?
2, 7, 9 and 10
What are the key points of the cell based model of homeostasis?
Initiated by cell outside the vessel with tissue factor. Amplification and propagation takes place on the surface of platelets
How does the antiplatelet effect of aspire work?
Inhibtion of COX stops thromboxane A2 production.
How does clopidogrel and ticagrelor work?
ADP inhibitors
What is tirofiban?
glycoprotein 2b/a inhibitor for anti-platelets
How doe glycoprotein 2b/a inhibitor work?
stop platelets aggregation
How does fibrinolysis work?
Tissue plasminogen activator (t-PA) produces plasmin form plasminogen and competes with fibrin. Usually released from damaged endothelial cells.
What is DIC?
Disseminated intravascular coagulation. Unrelgulated clotting arounds the body.
What can cause DIC?
dilution - crystalloid etc.
Consumption - inflammation, malignancy and bleeding
What is the lethal triad?
- Hypothermia
- Coagulopathy
- Metabolic acidosis
What is Becks triad?
- raised JVP
- muffled heart sounds
- hypotension with narrow pulse pressure
This indicates cardiac tamponade
What is permissive hypotension?
Low than normal BP. Enough o perfuse major organs however low as possible in order to deceased bleeding.
What investigations for a ruptured AAA?
abdominal ultrasound.
A CT angio is not in the guidelines however in practise it is used.
