COVID-19 Vaccine Induced Thrombosis/Thrombocytopenia (VITT)

Inclusion Criteria [Both of]:

  1. Received AstraZeneca (AZ) COVID 19 vaccination within 42 days (typically 5-42 days from immunisation)
  2. New Onset thrombocytopenia (PLTs <150×109/L) – with or without Thrombosis
    • 5% of cases have had a “Normal” Platelet count at presentation
      • High index of suspicion repeat bloods next day
      • ‘High index of suspicion’ in this context is day 5- 28 post AZ vaccine with new onset headache or abdominal pain which is atypical and severe in nature.

Initial Investigations:

  • FBC– specifically to confirm thrombocytopenia <150x 109/L
  • Coagulation screen and D Dimers
  • Blood film to confirm true thrombocytopenia and identify alternative causes

PROBABLE CASE: (ALL 3 criteria)

  1. Received AZ COVID 19 vaccination within 42 days
  2. New Onset thrombocytopenia (PLTs <150×109/L)
  3. D Dimers > 2000 mcg/L

URGENT Scan to confirm the suspected clot.

[If patient doesn’t fit “PROBABLE CASE” proceed to usual treatment]


Condition specific advice:

Central clot:

  • inc. Cerebral Venous Sinus Thrombosis (CVST), Pulmonary Embolis (PE), Splenic, Proximal DVT
  • Discuss with Haematologist
  • Admit Medicine

Suspected DVT (scan unavailable):

  • Treat with Rivaroxaban (Do Not use Tinzaparin/LMWH)
  • Request Ultrasound
  • Return AAU Next Day
  • Safety-net Advice

Confirmed Distal DVT (Not above inguinal ligament)

  • Platelets  <100×109/L – Discus with Haematology
  • Platelets ≥100×109/L – Treat as normal

Thrombocytopenia only

  • Platelets  <100×109/L – Discus with Haematology
  • Platelets ≥100×109/L – Treat as normal

Treatment (will be directed by Haematology & Specialist teams):

Avoid:

  • Heparin Based anticoagulants
  • Antiplatelets
  • Platelet Transfusion

May Require:

  • IV immunoglobulin
  • Steroid
  • Anticoagulation with: DOAC, Fondaparinux, Argatroban

Further reading

 

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