Abdominal Aortic Aneurysm Flashcards
How does AAA commonly present?
- Severe abdominal and back pain
- Tachycardia
- Hypotension
- Cold, clammy hands and feet
- Slow capillary refil
What are some common differentials for AAA?
- Perforated viscus: e.g perforated gastric/duodenal ulcer
- Acute pancreatitis
- Biliary colic or acute cholangitis
- Acute mesenteric occlusion (possibly due to an embolus)
- Ruptured or leaking abdominal aortic aneurysm.
The above are some of the conditions that need to be considered.
Rarely, diseases that originate above the diaphragm: basal pneumonia or an inferior MI also may also present with abdominal pain……so have a very high index of suspicion
How do we investigate a suspected AAA?
- History
- Examination - tender pulsatile mass in abdomen
- obs: tachycardic and hypotensive
- Examine pulse in all limbs - often popliteal is also aneurysmal
- URGENT USS
What are some important facts surrounding AAAs?
- Ruptured AAA causes generalised shock state and bilateral leg ischaemia. If patient presents with shock and one leg ischaemia, think of dissection or significant peripheral vascular disease (PVD)
- Always suspect ruptured AAA in men older than 60 years with first presentation of renal colic
- In patients with GI bleeding and past history of aortic surgery, suspect aorto-enteric fistula until proven otherwise
How do we tell if something is pulsatile vs transmitted?
- If pulsatile, hands will move upwards and outwards
- If transmitted hands will only move upwards
Which artery is frequently ligated during AAA repair?
Inferior mesenteric artery
- Can be a source of ‘endoleak’ after EVAR
What are the branches of the coeliac trunk?
- Left gastric artery
- Splenic artery
- Common hepatic artery
What are the three different clamping levels used on an AAA?
Supra-coeliac clamping:
- Highest stress on heart
- Ischaemia to all organs below coeliac artery with subsequent reperfusion injury
Supra-renal clamp:
- High stress on heart
- Ischaemic to all organs below the superior mesenteric artery with subsequent reperfusion injury
Infra-renal clamp:
- Relatively less stress on heart
- Ischaemia to all organs below kidneys with subsequent reperfusion injury
How do we manage massive haemorrhage in adults?
- Recognise blood loss
- ABCDE
- Resuscitate, call for help
- Stop the bleeding - TXA, PCC
- Team approach
- Emergency runner
- Communicate with lab early and cleary
- Know where the emergency O- id in your trust
- Massive haemorrhage packs 1 & 2
- Monitor coagulation tests and move to goal directed therapy
How do we recognise blood loss?
- Life threatening haemorrhange
- Patient bleeding/collapses, ongoing bleeding 150mls/min and clinical shock
- Bleeding rate difficult to assess
- Blood loss may be hidden
- Risk of over activation
What measures can be taken to stop bleeding?
- Local measures: pressure, tourniquets
- Early intervention - damage limitation
- Reverse anticoagulants eg PCC
- Tranexamic acid
- Bloods: FBC, U&Es, LFTs, Ca2+, PT, APTT, fibrinogen, crossmatch, group and save
- Emergency runner to take sample to lab and collect blood
What should be communicated when a patient has a major bleed?
- State major haemorrhage adult/child/location
- Request components needed:
- Red cells
- FFP
- Platelets
- Decide on use of emergency O- uncrossmatched blood, or group specific blood
What are the different options of blood for transfusion?
Extreme emergency: Group O RhD neg
~15 mins from sample arriving in lab: group specific, ABO and RhD compatible
- Important antibodies may cause reaction
Safest product if time allows: crossmatched, fully screened for antibodies
~45-60 minutes from sample arriving in lab
What is found in major haemorrhage packs?
Pack 1:
- 4 units red cells
- 4 units fresh frozen plasma (FFP)
Pack 2:
- 4 units red cells
- 4 units FFP
- 1 dose platelets
- 2 packs cryoprecipitate
What clotting and blood results should be aimed for in the MH pathway?
Fibrinogen >1.5g/L
PT ratio <1.5
APTT ratio <1.5
Hb 80-100g/L
Plts >75 x10^9/L
What should you consider when you stand down during a MH pathway?
- Let the lab know when the haemorrhage is under control
- Consider patient’s risk of thrombosis and requirement of thromboprophylaxis
- Record which blood components are given for traceability
What should be examined during a vascular examination?
- Signs of wellness
- Build
- Pulse and regularity
- BP both sides
- JVP
- Heart sounds
- Presence of AAA
- Warmth and perfusion peripherally
- Oedema
- Skin changes
- Tissue loss
- Varicose veins
What is peripheral vascular disease?
- Inevitable, degenerative, generalised
- Consequence of atherosclerosis
Symptoms depend on:
- Vascular bed affected
- Rate of development
- Extent
Risk factors:
- Increasing age, male sex, family history
- Smoking, hypertension, cholesterol, diabetes
How does acute ischaemia of tissues present?
PPPPPP Pale Perishingly cold Pulseless Painful (at this point reversible) Paraesthetic - Muscle tenderness (threatened) Paralysed - Numb - Mottled (non-viable)
Causes:
- Atherosclerosis + thrombosis
- Embolus (cardiac, aneurysm)
- Thrombosis (thrombophilia, graft occlusion, aneurysm)
- Dissection
- Trauma
NOT SWOLLEN HOT OR TENDER
How do we determine the prognosis when faced with tissue ischaemia?
- Rate of development of ischaemia
- Collateralisation
- Acclimatisation of tissues
- Presentation window
- Level of occlusion
- Cause
- Delay in presentation
How do we grade chronic ischaemia?
Fontaine I - asymptomatic
Fontaine II - claudication
Fontaine III - rest pain
Fontaine IV - tissue loss
What symptoms are seen in peripheral vascular disease?
Claudication
- Aching muscles on effort
- Predictable
- Worse on hills, with loads, at speed
- Settles swiftly at rest
Rest pain
- Icy, burning, constant aching pain in foot
- Worse on elevation or at night
- Needs opiates
Tissue Loss
- Ulcers, necrosis, gangrene
How do we manage peripheral vascular disease?
- Stop smoking
- Antiplatelet therapy (aspirin 75mg od)
- Blood pressure control (sBP <140)
- Cholesterol reduction <5 or 25%
- Regular exercise
- Weight loss
- Diabetes HbA1c <7
What is the prognosis of peripheral vascular disease?
Prognosis
- Generally improves over 6-12months
- Collaterals, lifestyle adaption, muscle metabolism
Lifetime amputation risk ~1%
MI in next 5 years ~30%
How do we investigate cerebrovascular disease?
Duplex:
- Cheap, easy, available, no XR
- Morphology
Angiography
- Low flow states, calcification
- Intracranial/proximal disease
MR, CT yet to be proven
- Brain substance imaging
What are the indications for surgical treatment of cerebrovascular disease?
- Symptomatic patients (in last 6 months)
- > 70% stenosis ICA
- 2 year life expectancy
- Fit for surgery
NNT = 12
How do we treat asymptomatic cerebrovascular disease?
- Medical therapy
- Operation in selected circumstance
- No real evidence for benefit overall
- NNT = 50, stroke risk 2%pa to 1%pa
- Younger patients
- CABG aortic surgery
- Cerebral perfusion concerns
What is an aneurysm?
- Abnormal dilation of an artery
- Greater than 50% of its transverse diameter
- Ectasia = dilation of up to 50%
- Ateriormegaly = generalised dilation
Aneurysm = atherosclerotic infrarenal abdominal aortic aneurysm (AAA)