Bleeding disorders Flashcards
What part of the clot formation process is regarded as primary haemostatic response and which is regarded as the secondary haemostatic response?
Primary haemostatic response:
- Platelet plug formation - dependent on platelets, vWF and the blood vessel wall
Secondary haemostatic response:
- Fibrin plug formation on top of original platelet plug
What key things do you want to ask in order to find out more about a patient’s bleeding history?
- Has the patient actually got a bleeding disorder?
- How severe is the disorder - this is determined by how easily the patient bleeds - is the bleeding appropriate/ understandable amount from the injury?
- Severe = bleeds almost spontaneously with no injury
- Mild = bleeding only in certain situations such as trauma or surgery etc
- Is there a pattern of bleeding? If there is, what is it?
- Congenital or acquired?
- Mode of inheritance if congenital
What can the pattern of bleeding tell clinicians?
Abnormalities at different parts of the pathways that work towards clot formation result in different patterns of bleeding. For example:
Platelet type (Thrombocytopenia)
- Mucosal
- Epistaxis
- Purpura
- Menorrhagia
- GI
Coagulation factor (haemophilia A):
- Articular
- Muscle haematoma
- CNS
What things might come up in a patient’s history of bleeding?
- Bruising
- Epitaxis - nose bleed
- Post-surgical bleeding
- Dental surgery, circumcision, tonsillectomy or appendicectomy in particular as if they didn’t have bleeding after these common surgeries it is unlikely they have a severe coagulopathy
- Menorrhagia
- Post-partum haemorrhage - not very informative as bleeding may be structural i.e a tear and not a coagulopathy
- Post-trauma
Why is it important to ask about menorrhagia?
In most young women who have significant vWD it is very uncommon for them not to have menorrhagia.
Remember this menorrhagia is from menarche - first person to die from vWD did so after 3rd menstrual period
- What interventions have been required?
- Have they ever become iron deficient?
- Have they required iron supplementation as a result?
What is the BAT score?
- It assesses bleeding symptoms retrospectively
- A high bleeding score is associated with the presence of an inherited bleeding disorder
- Scoring is dependent on the type of bleeding you had and what level of care was needed to control it
How can you work out if their bleeding disorder is congenital or acquired from the history taking?
- Previous episodes?
- Age at first event - younger babies/children = more likely to be congenital than a 70 y/o
- Previous surgical challenges
- Dental surgery
- Circumcision
- Tonsillectomy
- Appendicectomy
- If you had these in the past without abnormal bleeding then it is unlikely congenital
- Associated history - FH?
What do you want to know about a patient’s family history in terms of any bleeding disorders?
Whether they have any family members with similar history and if so what sex they are
Haemophilia A and B genetics
- Both are X-linked
- Identical phenotypes
- Severity of bleeding depends on the residual coagulation factor activity
- <1% Severe
- 1-5% Moderate
- 5-30% Mild
What are the clinical features of Haemophilia?
- Haemarthrosis - haemorrhage into a joint space
- Muscle haematoma
- CNS bleeding
- Retroperitoneal bleeding
- Post surgical bleeding
What are some clinical complications of Haemophilia?
- Synovitis
- Chronic Haemophilic arthropathy - may need joint replacement
- Neurovascular compression - compartment syndromes in acute situation
- Other sequelae of bleeding (stroke - rarely seen now)
How do you diagnose Haemophilia?
History - to suspect haemophilia diagnosis
Routine tests to look at coagulation levels:
- Activated partial thromboplastin time (APTT)
- Prothrombin time (PT)
Why is APTT prolonged in severe haemophilia?
It is prolonged as a result of a reduction in Factor VIII or IX in the circulation.
You then go on to look specifically at FVIII (haemophilia A) or FIX (haemophilia B) levels in the blood.
How is haemophilia treated?
- Coagulation factor replacement FVIII/IX
- Now almost entirely recombinant coagulation products - independent of donor, coag factors are grown in lab
- DDAVP - Desmopressin - used in mild haemophilia A or some vWD
- Tranexamic acid - general haemostatic agent which reduces rate of fibrinolysis - allows clot to become stable and prevents ongoing bleeding
- Emphasis is on prophylaxis now
How are haemophilic arthropathy, muscular haematoma and synovitis managed?
- Splints
- Physiotherapy
- Analgesia
- Synovectomy
- Joint replacement
