Case 18 - AAA

Question 1

What are the 6Ps of Acute Limb Ischaemia

Answer 1

Pale 
Perishingly cold
Pulseless
Painful 
Paresthesia 
Paralysed

Question 2

What are the modifiable risk factors of peripheral vascular disease?

Answer 2

Smoking
Hypertension
Cholesterol
Diabetes

Question 3

What are the differentials for severe abdominal pain of sudden onset?

Answer 3

Perforated viscous e.g perforated ulcer 
Acute pancreatitis 
Bilary colic 
Renal colic 
Acute cholangitis 
Acute mesenteric occlusion (due to embolus)
Ruptured AAA
Inferior MI?

Question 4

What are the signs and symptoms of a ruptured AAA?

Answer 4

Intermittent or continuous abdominal pain - radiating to back, iliac fossa or groin
Collapse 
Expansile abdominal mass felt 
Shock 
Bilateral leg ischaemia

Question 5

What would you want to rule out in a patient over the age of 60 with presentation of renal colic symptoms?

Answer 5

Ruptured AAA

Question 6

What is EVAR?

Answer 6

Endovascular aneurysm repair
Involves inserting a stent graft within the aneurysm through small groin incisions using X-rays to guide the graft into place. Stent is opened and attached to aorta. Aneurysm will eventually shrink around it

Only requires spinal anaesthetic

Question 7

What is the difference between critical limb ischeamia and acute limb ischemia?

Answer 7

Critical limb ischemia - ischemic pain at rest for greater than 2 weeks, with the presence of ulcers and gangrene in one or both legs
Acute limb ischemia - acute embolic event in a patient with previous peripheral arterial disease. Characterised by symptoms for less than 2 weeks (the 6 P’s)

Question 8

How is chronic limb ischemia classified?

Answer 8

By the Fontaine classification
Stage I - asymptomatic 
Stage II - intermittent claudication 
Stage III - ischaemic rest pain 
Stage IV - ulceration or gangrene, or both

Question 9

How is peripheral arterial disease medically managed?

Answer 9

Lifestyle (quit smoking, regular exercise, weight reduction)
Statin therapy - atorvastatin 80mg
Anti platelet therapy - clopidogrel 75mg
Diabetes control

Question 10

What is an aortic aneurysm?

Why do they occur?

Answer 10

A swelling of the aortic greater than 1.5x its normal size (>3cm)

Occur due to underlying weakness in the wall associated with extensive atherosclerosis in adjoining regions of the aorta

Question 11

At what size do you consider an elective surgery for an AAA?

Answer 11

> 5.5cm

Question 12

What are the risk factors for an AAA?

Answer 12

Male sex
>60 yrs
Hypertensive
Smokers
Family history

Question 13

What are the 2 surgical options for AAA repair?

Answer 13

EVAR (endovascular surgery) - stenting the AAA by entering a graft through the groin, done under spinal anaesthetic

Open repair surgery - done under general anaesthetic

Question 14

What is the biggest risk in open surgical repair of AAA and why?

Answer 14

Cross aortic clamp used

This can cause ischemia to major organs - myocardial ischemia is the major risk
Risk of reperfusion injury

Question 15

Why are some patients not suitable for EVAR

Answer 15

Only 70% of patients are sutible

The other 30% are not due to anatomical basis

Question 16

What other type of aneurysm might be present in a patient with an AAA?

Answer 16

Popliteal aneurysms
Often bilateral
Present in 1/8 patients with AAA

Question 17

What is an aortic dissection?

Answer 17

Where high pressure of blood causes a tear between the intima layer and media layer of the aortic wall

Blood enters between the two layers and therefore isn’t able to get to the rest of the body as efficiently. This leads to hypotension and shock

Question 18

What are the causes/risk factors for an aortic dissection?

Answer 18

Chronic hypertension 
Connective tissue disease e.g, marfans 
Anneurysm 
Trauma 
Male sex 
Age >60

Question 19

What are the two classes of aortic dissection and how are they treated differently?

Answer 19

Type A (70%) - involves the ascending aorta before left subclavian origin. Treated with surgery

Type B (30%) - involves the aorta after the left subclavian origin. Can be managed medically

Question 20

What are the signs and symptoms of an aortic dissection?

Answer 20

Sudden tearing chest pain - radiation to back 
Sweating, nausea, SOB
Syncope 
Uneven arm pulses, uneven arm BP
Acute limb ischaemia

Question 21

What is the emergency management of a ruptured AAA?

Answer 21

Summon vascular surgeon and anaesthetist, warn theatre
ECG, take blood for amylase, hb, cross match blood, catheterise bladder
Gain IV access with 2 large bore cannula
Treat shock with O- blood, keep BP >100 systolic
Give prophylactic antibiotics
Go to surgery

Question 22

How do cardiac output and BP change in a patient who is losing blood?

Answer 22

Cardiac output falls
BP is maintained by compensatory mechanisms e.g, kidney
Only when the compensatory mechanisms are unable to cope that BP beings to fall

Question 23

What is shock?

Answer 23

A life threatening condition that occurs when the body is not getting enough blood flow, so that the cells and organs are poorly perfused

Question 24

What are the signs of shock?

Answer 24

Cool, clammy skin 
Pale skin, reduced cap refill 
Rapid pulse
Rapid breathing 
Nausea/vomitting 
Signs of reduced organ perfusion e.g low urine output, raised lactate

Question 25

What are the main outcomes of the Transfusion Management of Massive Haemorrhage protocol?

Answer 25

Control bleeding - direct pressure, reverse anticoagulant effects e.g, vit K
Insert two large bore cannula (14-16G)
Take bloods - FBC, PT, APTT, U&E, Ca, ABG, cross match
Give Blood - major haemorrhage packs (RBS, FFP, platelets)
Keep reassessing bloods after packs given to check levels

Question 26

What are the complications of a massive blood transfusion?

Answer 26

Transfusion related acute lung injury (TRALI)
Hypothermia - RBCs must be heated before transfused
Hypocalcaemia - as a result of citrate (solution used to preserve blood products)
Hyperkalaemia
Dilutional coagulopathy - Packed RBCs do not contain coagulation factors
Haemolytic reactions - mis matched blood given

Question 27

What is disseminated intravascular coagulation (DIC) and why can it occur in Massive Haemorrhage?

Answer 27

Lots of clotting occurring, followed by lots of fibrinolysis
If all the platelets are being used up clotting in one area of the body, then bleeding can occur in other areas

Question 28

What are the different classifications of shock?

Answer 28

Hypovolemic e.g, haemorrhage, GI loss, dehydration
Cardiogenic - e.g, myocardial damage
Distributive - e.g sepsis and anaphylactic
Obstructive - e.g, tension pneumothorax, PE

Question 29

How often is an AAA checked?

Answer 29

Yearly until 4.5cm

Then every 3 months until 5.5cm

Question 30

What is the treatment of shock?

Answer 30

Oxygen
IV Fluids
ABG - check for hypoxia and lactate
Treat the cause

Question 31

How is an aortic dissection diagnosed?

Answer 31

ECHO (only sees top of aorta)

CT scan - can see all of aorta (Gold standard)

Question 32

Why can abnormalities in clotting occur during a massive blood transfusion?

Answer 32

Due to dilation of platelets and clotting factors

Question 33

What complications might a patient have after a prolonged stay in ICU?

Answer 33

Muscle weakness and wasting 
Nutritional deficiencies 
Sleep disorders
Inability to swallow effectively 
Recurrent chest infections

Question 34

What are the normal and abnormal ABPI results?

Answer 34

>1.2 - associated with diabetes
1 - normal 
0.6-0.9 - claudication symptoms 
0.3-0.6 - pain at rest
<0.3 - associated with gangrene

Question 35

When would an AAA be considered high ruptured risk and need surgery?

Answer 35

If >5.5cm
If symptomatic
If rapidly enlarging (>1cm a year)