Haematology (clotting) Flashcards
What steps should you take to prevent venous thromboembolism?
- Early ambulation- get them walking
- Stockings
- Low dose low molecular weigh heparin
Or: low dose Unfractionated heparin/DOAC
What is the acute treatment pathway for haemophilia A?
Effectively we replace the factors and make better use of any clots that do form.
- Factor 8 concentrate (octocog) 1-3 times per day- replace missing factors
- Desmopressin SC,IV or Intranasal- only useful for mild/moderate haemophilia - releases factor 8 stores
- Tranexamic acid PO- Antifibrinolytic: inhibits plasminogen, prolonging clots
- Orthopaedic evaluation: joint bleeds
- Rest, ice, compression and elevation: any joint bleeds
What is the acute treatment pathway for haemophilia B?
Effectively we replace the factors and make better use of any clots that do form.
- Factor 9 concentrate (nonocog) 1-3 times per day- replace missing factors
- Tranexamic acid PO- Antifibrinolytic: inhibits plasminogen, prolonging clots
- Orthopaedic evaluation: joint bleeds
- Rest, ice, compression and elevation: any joint bleeds
What is the long term treatment for haemophilia? (Same for A and B)
Prophylactic factor concentrate (octocog/nonocog) given every week.
- very expensive
What is the treatment pathway for pulmonary embolism?
Depends on haemodynamic status of the patient
If haemodynamically stable:
- Fondaparinux or LMWH or Unfractionated heparin (egfr<30)- for five days (Parenteral anticoagulation)
- Warfarin or rivaroxaban - after the anticoagulation,for three months
If pharmacological anticoagulation isn’t possible:
- Inferior vena cava filter
If haemodynamically unstable:
Thrombolytic therapy (reteplase,streptokinase)
Or Embolectomy
What is the treatment pathway for deep vein thrombosis?
If haemodynamically stable:
- Fondaparinux or LMWH or Unfractionated heparin (egfr<30)- for five days (Parenteral anticoagulation)
- Warfarin or rivaroxaban (maintenance treatment after acute treatment) - for 3+ months
If pharmacological anticoagulation isn’t possible:
- Inferior vena cava filter
If haemodynamically unstable:
Thrombectomy
What is the treatment pathway for von willebrands disease type 1?
- Desmopressin - causes release of factor 8 AND Von willebrand factor
- Tranexamic acid
- Possible VW factor concentrate infusion - since type 1 is only a quantitative, not qualitative deficiency, there may be enough
(Same as haemophilia A)
What is the treatment pathway for Von willebrand disease type 2A and 2B?
How do they differ?
- Von willebrand factor concentrate infusion
- For type 2A give desmopressin
Do not give desmopressin for type 2B, can cause severe thrombocytopenia.
What is the treatment pathway for type 3 Von willebrands disease?
Von willebrands factor concentrate.
And prophylactic VW factor concentrate.
What is the process for initiating the major haemorrhage pathway?
- Recognise blood loss
- Resuscitate and call for help (4444)- DRS ABCDE
- Stop the bleeding - Tranexamic acid (prevents plasminogen activation) and prothrombin complex concentrate
- Gather team with emergency runner
- Communicate situation to the lab
- Locate the emergency 2 units O negative blood (ED resus, theatres, obs and gynae)
- Order massive haemorrhage pack 1 or 2
- Monitor coagulation tests
- Warm the blood: if patient gets hypothermic clotting factors don’t work
- Summon anaesthetist and vascular surgeon
- Let lab know when they are stable
- Send them to ICU: may need organ support (TALI - lungs, kidneys)
How is the haemorrhage controlled?
Local measures - pressure and tourniquets
Early intervention - damage limitation
Reverse any anticoagulants - prothrombin complex concentrate for warfarin
Tranexamic acid - only used if within first hour
Blood samples - FBC, UE, LFT, calcium, PT, APTT, fibrinogen and cross match
Request the blood products needed - red cells, FFP or platelets
When is group O RhD negative blood used for transfusion?
In an extreme emergency situation when you can’t wait 15 minutes (time it takes to type ABO and RhD)
It is a precious commodity
It takes 15 minutes to find ABO and RhD types
It takes 45-60 minutes to fully screen for all antibodies: this gives you the safest product choice
Why are there major haemorrhage pack 1 AND pack 2?
Pack 1 is for initial treatment of major haemorrhage (4 units red cells and 4 units FFP)
Pack 2 is for if the major haemorrhage continues, so pack 2 is only given once pack 1 has been given (4 units red cells, 4 units FFP, 1 dose platelets, 2 packs cryoprecipitate)
The packs provide the coagulation factors and platelets necessary that red cells alone don’t provide.
Targets:
- we aim for PT and an APTT of <1.5
- we aim for 80-100 Hb
- platelets >75
