Haemostasis

Haemostasis is essential for survival

• Haemostasis is the normal physiological response that prevents significant blood loss after vascular injury1
• Haemostasis depends on an intricate series of events involving platelets, other blood cells, such as TF-bearing cells, and the activation of specific blood proteins, known as coagulation factors1
  • Knowledge of haemostasis is important in understanding major disease states associated with thrombosis, such as:
    • VTE
    • Atherothrombosis (thrombosis triggered by plaque rupture)
    • Cardioembolic stroke

Initiation of haemostasis

• When blood vessel injury occurs, physiological haemostasis is triggered and the sequence of events listed below takes place:
  • The vessel constricts to reduce blood flow
  • Circulating platelets adhere to the vessel wall at the site of trauma
  • Platelets are activated and aggregate
  • An intricate series of enzymatic reactions occur involving coagulation proteins
  • Fibrin is produced to form a stable haemostatic plug

Balancing haemostasis

• Haemostasis is a finely tuned process involving the dual pathways of platelet activation and coagulation cascade initiation
• It serves to maintain the integrity of the circulatory system2
• However, the process can become imbalanced, leading to significant morbidity and mortality3