Case 18 - AAA Flashcards
What are the 6Ps of Acute Limb Ischaemia
Pale Perishingly cold Pulseless Painful Paresthesia Paralysed
What are the modifiable risk factors of peripheral vascular disease?
Smoking
Hypertension
Cholesterol
Diabetes
What are the differentials for severe abdominal pain of sudden onset?
Perforated viscous e.g perforated ulcer Acute pancreatitis Bilary colic Renal colic Acute cholangitis Acute mesenteric occlusion (due to embolus) Ruptured AAA Inferior MI?
What are the signs and symptoms of a ruptured AAA?
Intermittent or continuous abdominal pain - radiating to back, iliac fossa or groin Collapse Expansile abdominal mass felt Shock Bilateral leg ischaemia
What would you want to rule out in a patient over the age of 60 with presentation of renal colic symptoms?
Ruptured AAA
What is EVAR?
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
What is the difference between critical limb ischeamia and acute limb ischemia?
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)
How is chronic limb ischemia classified?
By the Fontaine classification Stage I - asymptomatic Stage II - intermittent claudication Stage III - ischaemic rest pain Stage IV - ulceration or gangrene, or both
How is peripheral arterial disease medically managed?
Lifestyle (quit smoking, regular exercise, weight reduction)
Statin therapy - atorvastatin 80mg
Anti platelet therapy - clopidogrel 75mg
Diabetes control
What is an aortic aneurysm?
Why do they occur?
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
At what size do you consider an elective surgery for an AAA?
> 5.5cm
What are the risk factors for an AAA?
Male sex >60 yrs Hypertensive Smokers Family history
What are the 2 surgical options for AAA repair?
EVAR (endovascular surgery) - stenting the AAA by entering a graft through the groin, done under spinal anaesthetic
Open repair surgery - done under general anaesthetic
What is the biggest risk in open surgical repair of AAA and why?
Cross aortic clamp used
This can cause ischemia to major organs - myocardial ischemia is the major risk
Risk of reperfusion injury
Why are some patients not suitable for EVAR
Only 70% of patients are sutible
The other 30% are not due to anatomical basis
What other type of aneurysm might be present in a patient with an AAA?
Popliteal aneurysms
Often bilateral
Present in 1/8 patients with AAA
What is an aortic dissection?
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
What are the causes/risk factors for an aortic dissection?
Chronic hypertension Connective tissue disease e.g, marfans Anneurysm Trauma Male sex Age >60
What are the two classes of aortic dissection and how are they treated differently?
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
What are the signs and symptoms of an aortic dissection?
Sudden tearing chest pain - radiation to back Sweating, nausea, SOB Syncope Uneven arm pulses, uneven arm BP Acute limb ischaemia
What is the emergency management of a ruptured AAA?
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
How do cardiac output and BP change in a patient who is losing blood?
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
What is shock?
A life threatening condition that occurs when the body is not getting enough blood flow, so that the cells and organs are poorly perfused
What are the signs of shock?
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
