Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gen Surgery > Upper limb ischaemia > Flashcards

Upper limb ischaemia Flashcards

1
Q

What percentage of limb ischaemia occurs in the upper limb

A

5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Embolic occlusion is responsible for 90% of acute upper limb ischaemia, what is usually the source of the emboli?

A
  • The heart (70% of upper limb emboli): atrial fibrillation, mural thrombus, valvular lesions or ventricular aneurysm
  • Other sources: Atherosclerotic plaque from aortic arch or proximal large vessels and aneurysms in the proximal vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Embolic occlusion at which level leads to limb threatening ischaemia?

A

Embolic occlusion of the brachial artery proximal to the origin of the arteria profunda brachii leads to limb threatening ischaemia due to insufficient collaterals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the causes of acute in situ thrombosis

A
  • secondary to atherosclerosis in larger proximal vessels, thrombosis of proximal vessel aneurysm or secondary to arterial thoracic outlet compression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Important iatrogenic causes of penetrating injury to the arteries

A
  • Invasive monitoring (intra-arterial lines)
  • Diagnostic procedures (arteriograms)
  • Therapeutic procedures (percutaneous transluminal angioplasty and stenting)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Examples of pathology in the aortic arch causing acute occlusion of the origin of the arch vessels (brachiocephalic and left carotid and subclavian arteries)

A

Takayasu’s arteritis and acute dissection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Examples of hypercoaguable states causing acute thrombosis

A
  • Deficiency of anti-thrombin
  • Deficiency of protein C and S
  • Presence of antiphospholipid syndrome
  • Paraneoplastic hypercoaguability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Clinical features of acute upper limb ischaemia

A
  • Sudden onset pain, pallor, poikilonthermia, paraesthesia and paralysis
  • On examination: Peripheral pulses absent, limb cold and pale
  • As ischaemic time progresses, the skin may appear mottled which initially blanches on digital pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Signs of irreversible ischaemia and unsalvageable limb?

A

Fixed blue staining of the skin and tense, tender muscle compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Conditions causing acute digital ischaemia

A
  • Embolism
  • Vasospasm
  • Vibration trauma
  • Hypotermic injury
  • ergotism
  • Intra-arterial injections
  • Trauma
  • iatrogenic injury
  • Fibromuscular dysplasia
  • Radiation arteritis
  • Congenital arteriopathies: Ehlers-Danlos, marfan
  • Behcet syndromes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Treatment of acute upper limb ischaemia

A
  • Immediate anticoagulation with 70 - 100 units of unfractionated heparin/ kg body weight given intravenously
  • Appropriate analgesia
  • Referred to specialist vascular unit
  • Embolectomy can be performed under local anaesthesia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is an embolectomy performed for emboli lodged at the site of the brachial bifurcation

A
  • S-shaped incision in ante-cubital fossa
  • Brachial artery exposed
  • Transverse arteriotomy made
  • Embolus is retrieved by passing embolectomy catheter distally into the forearm vessels and proximally into the brachial artery
  • Proximal patency confirmed
  • Distal vessels flushed with heparin-saline solution and arteriotomy closed with 7/0 interrupted sutures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How should patients who present with acute on chronic occlusion be treated?

A
  • Catheter-directed intra-thrombus administration of a thrombolytic agent is of value for dissolution of thrombus to identify underlying lesions.
  • Final treatment depends on the nature and location of the pathology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

management of acute ischaemia due to inadvertent intra-arterial injections

A
  • When diagnosis is made with needle in situ, irrigate with a heparin-saline solution for dilution and anti-coagulant effect
  • Injection of a vasodilator (nitroglycerine/papaverine/ lignocaine)
  • Patient fully anticoagulated with unfractionated heparin
  • Low molecular weight dextran given as continuous infusion together with dexamethosone
  • Prostacyclin may be given
  • Appropriate analgesia
  • Brachial plexus block may be of value
  • Arterial bypass and fasciotomy is indicated with large vessel occlusion and where thrombosis occurred at injection site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How may patients with chronic upper limb ischaemia (proximal large vessel disease) present

A
  • Present with activity induced muscle fatigue
  • Digital ischaemia secondary to distal embolisation (raynauds phenomenon)
  • Ulceration or gangrene secondary to distal embolization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is subclavian steal syndrome

A
  • Seen with occclusion of the subclavian artery proximal to the origin of the vertebral artery
  • The vertebral artery becomes a major collateral to the arm with reversal of the blood flow in the vertebral artery thereby stealing the blood from the posterior cerebral circulation
  • Neurological symptoms of vertebrobasilar insufficiency are provoked by exercise of the ipsilateral arm
17
Q

Etiology of chronic upper limb ischaemia (proximal large vessel disease)

A
  • Atherosclerosis
  • Aneurysms
  • Arteritis: giant cell and Takayasu’s
  • Arterial thoracic outlet syndrome
18
Q

Which arteries are more commonly affected by atherosclerosis

A
  • Origin of the brachiocephalic and subclavian arteries
  • Distal parts of the subclavian, axillary and brachial arteries are involved
  • The origin of the Left subclavian is more commonly involved than the right
19
Q

What structures compress the subclavian artery in arterial thoracic outlet syndrome

A

-Artery is compressed between the scalene muscles, cervical rib and 1st rib

20
Q

natural history of arterial thoracic outlet syndrome

A

chronic arterial trauma leads to fibrosis, focal stenosis, post stenotic dilatation and eventually aneurysm formation with thrombosis and/or distal embolization. Continuous embolization may lead to occlusion of the distal circulation and eventually an unsalvageable situation

21
Q

Clinical findings of arterial thoracic outlet syndrome

A
  • Discrepancy in blood pressure between the two arms
  • Palpable cervical rib
  • Palpable subclavian artery in the supraclavicular space
  • Bruit and thrill over the subclavian artery
22
Q

Special investigations for patients with chronic upper limb ischaemia

A
  • Standard xrays of thoracic outlet

- Arterial duplex doppler

23
Q

Intervention options for chronic upper limb ischaemia

A
  • Percutaneous transluminal angioplasty with or without stenting
  • Major bypass procedures
  • Treatment of arterial thoracic outlet syndrome: resection of the cervical rib and/or anomalous 1st rib. Damaged segment of the subclavian artery is resected and replaced with a vein or prosthetic graft
24
Q

Etiology of small vessel/ distal arterial disease

A
  • Vasospasm
  • Connective tissue disease: Scleroderma, SLE, Rheumatoid arthritis, polymyositis, dermatomyositis
  • Buerger’s disease
  • Ischaemia related to occupational injury: professional athletes involved in ball catching, people working with pneumatic tools, constant cold exposure, workers exposed to polyvinylchloride
  • Vasculitis: Polyarteritis nodosa, Churg-Strauss, Behcets and HIV vasculitis
  • Miscellaneous: Cold agglutinins, cryoglobulins, polycythaemia vera and antiphospholipid antibodies, diabetics with renal failure (Calciphylaxis)
25
Q

What is hypothenar hammar syndrome

A

Repetitive trauma to the distal ulnar artery, as it lies anterior to the hamate bone causes aneurysm formation with thrombosis and distal embolization to the fourth and fifth fingers

26
Q

Treatment of digital ulcers

A
  • Conservative debridement of necrotic and infected tissue
  • Retain normal, viable tissue and skin as far as possible
  • Avoid damaging blood supply
  • Appropriate wound cover, moist wound dressings
  • Treatment of vasospastic conditions
  • appropriate systemic antibiotics where required
  • Protection against further injury
27
Q

When should one suspect secondary Raynauds

A
  • Early onset in child younger than 10 or late onset in adults older than 30 years
  • recurrent chill blains, digital ulcers or gangrene as well as perennial symptoms
  • Structural/ irreversible arterial lesions
  • Decreased digitial blood pressure
28
Q

Conditions associated with Raynauds syndrome

A
  • Connective Tissue disease
  • Arterial occlusive disease: Atherosclerosis, Buergers, Thoracic outlet compression syndrome
  • Occupational trauma
  • Drug therapy: Beta blockers, ergot preparations
  • Neurological conditions: Carpal tunnel syndrome, reflex sympathetic dystrophy
  • Blood dyscrasia: Hyperviscosity syndrome, cold agglutinins, myeloproliferative disorders
  • Diverse conditions: Hypothyroidism, malignancy
29
Q

Drug therapy for Raynauds disease

A
  • Nifedipine: initiate therapy with 5 mg tds and increase dosage according to clinical response. Once the adequate dosage has been established, a slow release, long acting substitute may be given
  • Prostacyclin indicated in severe symptoms. It is administered intravenously in the high care setting and with monitoring of blood pressure
30
Q

Signs of digital and palmar ischaemia

A

-Pallor, cyanosis, digital embolic phenomena, ulcers, gangrene, splinter haemorrhages

31
Q

What is a significant discrepancy of blood pressure in the arms

A
  • Difference of more than 20 mmHg
32
Q

Blood tests done to assess the atherosclerotic risk profile

A

Lipogram, glucose, homocystein

Gen Surgery (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions