AAA Flashcards
What differentials might you consider in a patient with;
Sudden severe abdo pain + back pain, pale hands + feet, clammy hands, vomiting, HR 124, BP 90/60, cap refill 5 seconds
- Perforated viscera e.g. perforated gastric/duodenal ulcer
- Acute pancreatitis
- Biliary colic or acute cholangitis
- Acute mesenteric ischaemia (possibly due to an embolus)
- Ruptured or leaking AAA
- Rarely: above diaphragm pathology can present with severe abdo pain e.g. basal pneumonia or inferior MI
What possible complications can occur as part of blood transfusions? x7
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Dilutional coagulopathy:
- If pt is given packed RBCs only (which don’t contain coagulation factors or platelets) –> thus blood volume ↑ and the concentration of clotting factors ↓
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Hypocalcaemia:
- Citrate (used in blood product storage solutions) binds Ca2+ ions in blood –> hypocalcaemia
- FFP and platelets contain more citrate than packed RBCs
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Hypothermia:
- RBCs are stored at ~4 degrees
- Hypothermia –> ↓ metabolism of citrate and lactate –> ↑ likelihood of hypocalaemia, metabolic acidosis and arrhythmias
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Haemolytic reactions:
- Most common complication of massive blood transfusion
- Incompatibility between donors RBC antigens and host antibodies –> complement activation + intravascular haemolysis
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Immediate reactions:
- More severe + due to ABO incompatibility
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Delayed reactions:
- Reaction due to minor RBC antigens e.g. Rhesus
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Allergy
- Anaphylaxis
- Minor allergy (uticaria)
- Febrile reaction
- Transfusion-associated circulatory overload (TACO) (HF made worse)
- Transfusion-related acute lung injury (TRALI)
Describe TRALI (transfusion-related acute lung injury)
- Complication of blood transfusion within 6 hrs
- Characterised by;
- Acute
- non-cardiogenic pulmonary oedema
- SoB
- Hypoxemia
- Hypotension/hypertension
- TRALI = often hypotension + minimal response to diuretics
Describe TACO (transfusion associated circulatory overload)
- Is a transfusion reaction that can occur during rapid transfusion of large vol. of blood – can also occur in a single RBC transfusion
- Characterised by;
- SoB
- Orthopnoea
- Peripheral oedema
- Rapid ↑ in BP
- Suspect TACO if pt has signs of respiratory ditress < 12 hrs post transfusion
- TACO = often hypertension + strong response to diuretics
Which drugs are ‘P2Y12 inhibitor’ and what do they do?
Clopidogrel and Ticagrelor and Ticlodipine
- Irreversibly inhibits the P2Y12 subtype of ADP-receptor on platelets –> this inhibits platelet activation and aggregation
Which drug is used as an antiplatelet via its inhibition of COX enzymes?
Aspirin
- inhibits COX enzymes required for prostaglandin and thromboxane synthesis
- Low-dose aspirin irreversibly inhibits COX1 –> thus inhibiting prostaglandin H2 formation – required for formation of thromboxane A2 in platelets –> which is needed for platelet aggregation and activation
Eptifibatide and tirofiban are anti-platelet drugs frequently used during PCI, what class of antiplatelet drug are they?
Glycoprotein IIb/IIIa inhibitors
- Anything with -fib- in the name = glycoprotein inhibitor
- Inhibit platelet aggregation via inhibiting Gp IIa/IIIb receptor on platelets
- Used during PCI
Peripheral arterial disease can be divided in acute vs chronic forms - what are the main causes of each?
Chronic:
- Progressive degeneration of arterial walls –> atherosclerotic occulsion
Acute:
- Atherosclerosis + thrombus
- Embolus
- Aneurysm
- Dissection
- Trauma
What are the 6 P’s of acute limb-threatening ischaemia?
- Present at 4 hours + reversible by vascular surgeon:
- Pale
- Perishingly cold
- Pulseless
- Pain
- 4-6 hours (limb threatened) –> paraesthesia
- 6-8 hours (limb non-viable) –> paralysis (numb + mottled)
NOT SWOLLEN, HOT OR TENDER!! - These indicate acute venous disease e.g. DVT
What are some risk factors for peripheral arterial disease (PAD)?
- ↑ Age
- Men > women
- FHx of PAD
- Smoking
- HTN
- Hypercholesterolemia
- Diabetes
Which classifcation system is used for severity of chronic peripheral arterial disease/ischaemia?
Fontaine Classification
- Fontaine I – asymptomatic
- Fontaine II – claudication (IIa = mild, IIb = moderate)
- Claudication = aching muscles on exertion
- Is predictable – will occur on each instance of activity
- Worse on hills, with loads or at speed
- Settles quickly with rest
- Fontaine III – rest pain
- Icy, burning, constant aching pain in foot
- Worse on elevation or at night
- Often requires opiates
- Fontaine IV – tissue loss
- E.g. ulcers, necrosis, gangrene
How is chronic PAD managed?
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Lifestyle:
- Smoking cessation
- Weight loss (if obese)
- Regular exercise
- ↓ Cholesterol in diet
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Pharmacology:
- Antiplatelet therapy e.g. Aspirin 75mg OD or Clopidogrel 75mg (NICE 1st line)
- Blood pressure control (aim = sBP <140 mmHg)
- Cholesterol reduction e.g. Atorvastatin 80mg (aim = < 5 mmol/L)
- Diabetes control (aim = HbA1c < 7% i.e. 53 mmol/mol or <6.5% i.e. 48 mmol/mol)
- Cilostazol - phosphodiesterase III inhibitor - vasodilator + antiplatelet - licensed for use in intermittent claudication to improve walking distance in patients without peripheral tissue necrosis who do not have pain at rest
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Surgery:
- Angioplasty
- Stenting
- Bypass surgery
What is the prognosis of chronic type PAD?
- Generally improves over 6-12 months with smoking cessation and lifestyle changes
- Lifetime amputation risk = ~1% (if following medical advice)
- Risk of MI in 5-years = ~30%
What symptoms are present in a patient with leg claudication?
- Aching or burning in leg muscles following walking
- Pts typically walk for a predictable distance before symtpoms start
- Relieved within minutes of stopping
- Pain not present at rest
How would you interpet ABPI results?
- > 1.2 = abnormally hard vessels e.g. calcification in diabetes - can’t assess using ABPI as pt may have peripheral arterial disease being obscured by calcification
- 1.0 -1.2 = normal
- 0.5-0.9 = intermittent claudication
- 0.3 -0.5 = rest pain
- < 0.3 = gangrene, ulceration, critical ischaemia