Session 5 ILO's Thrombosis and Embolism

Question 1

Understand and explain the principles of thrombosis.

Answer 1

Thrombosis is the formation of a solid mass of blood within the circulatory system

Risk of thrombosis depends on the following: (Virchow’s triad)

1) Stasis of blood flow (abnormality in blood flow)
2) Endothelial injury (abnormality in vessel wall)
3) Hypercoaguability (abnormality in blood components)

Question 2

Understand and explain the principles of embolism and the different types of embolism.

Answer 2

An embolism is the blockage of a blood vessel by a solid, liquid or gas at a distant site from the origin.

Embolisms can be caused by:

• Thombo-emboli (thrombi)
• Air
• Amniotic fluid
• Nitrogen (diving)
• Cancers/tumours
• Fat
• Medical equipment

Sudden occlusion of an artery will cause the 6 P’s:

• Pallor
• Pain
• Paralysis
• Perishingly cold to touch
• Pulseless
• Paraesthesia (pins and needles)

Question 3

Understand and explain the outcomes and complications of thrombosis and embolism.

Answer 3

Outcomes/complications of thrombosis:

1) Lysis - breakdown of the thrombi
- Most favourable outcome
- More likely when thrombi are small
- Complete re-establishment of blood flow

2) Propagation
- The thrombus will progressively spread
-

Thrombi can arise in following places and lead to embolisms in the following places (complications):

• Veins = pulmonary embolism
• Heart (left) = ischaemic stroke, bowel ischaemia, renal infarcts etc. (systematic effects)
• Heart (right) = pulmonary embolism (different severities)
• Carotid artery = ischaemic stroke
• Abdominal aorta = acute limb ischaemia

Question 4

Understand and explain the treatments and preventative methods available for dealing with thrombosis and embolism.

Answer 4

Prevention:
- Individuals who are identified as hypercoagulative could be given prophylactic drugs e.g. heparin or DOACs

• Individuals in hospital who are at risk of DVT can be given ‘Flowtron’ boots to assist venous lower limb circulation
• During any penetrative treatments, the patient should lie flat to prevent air flowing into the veins due to negative pressure gradient

Treatments:
- Immediate treatment for acute thrombosis or embolism is clot busters (ateplase or streptokinase) which activates tissue plasminogen activators