Haematology 3 Flashcards
Classify thrombocytopenia by severity
Severe - (platelets <20 x 109/L) - risk of spontaneous bleeding
Moderate thrombocytopenia (20-50 x 109/L) -at risk of bleeding during operation or trauma
Mild (50-150) - low risk of bleeding, unless major operation or severe trauma
Symptoms of thrombocytopenia
Bruising
Petechiae
Purpura
Mucosal bleeding
Epistaxis
Bleeding from gums when brushing teeth.
Less common:
severe Gi haemorrhage
Haematuria
Intracranial bleeding
What is the significance of purpura?
May signify thrombocytopenia or platelet dysfunction or vascular disorders (eg vasculitis)
Which conditions cause thrombocytopenia via platelet destruction?
Immune: ITP
SLE
Haemolytic uraemic syndrome
Thrombotic thrombocytopenic purpura
DIC
Congenital heart disease
Presentation of immune thrombocytopenia (ITP)
Between 2-10 yrs
Onset often 1-2 weeks after viral infection
Petechiae
Purpura
Superficial bruising
Can cause epistaxis and mucosal bleeding
Profuse bleeding uncommon
Very rarely intracranial bleeding
How is Immune thrombocytopaenic purpura diagnosed?
Diagnosis of exclusion
Pay careful attention to the history, clinical features and blood film (eg. congenital causes in younger children)
eg. ALL, SLE
Bone marrow examination if treatment with steroids (could mask ALL)
If the only abnormality in the blood is low platelet, no need to examine bone marrow (unless steroids)
Which factor is affected in haemophilia
FVIII
IX:C in haemophilia B
Know the severities of Haemophilia
Graded depending on factor VIII:C
Mild - 5-40% - bleed after surgery
Moderate - 1-5% - bleed after minor trauma
Severe - <1% - spontaneous joint/muscle bleeds
Presentation of haemophilia
Severe - recurrent spontaneous bleeding into joints and muscles - can lead to crippling arthritis if not properly treated
Towards end of first year of life: when crawling starts
40% present in neonatal period: intracranial haemorrhage, bleeding post-circumcision or prolonged oozing from feel stick site
Clinical features of DIC
Acute or chronic
Bruising
Purpura
Haemorrhage
Microvascular thrombosis - purpura fulminans may occur
Acute management of bleeding disorders
Most can be managed at home
Treatment only given if evidence of major bleeding, or persistent minor bleeding such as excessive epistaxis or menstrual bleeding (otherwise not, even if platelets <10x10^9/L)
Options (all have significant side effects)
Oral prednisolone
IV anti-D
IV immunoglobulin
Platelet transfusion is reserved for life-threatening haemorrhage - buys a few hours
Advice to children with bleeding disorders
Avoid trauma as far as possible
Avoid contact sports while platelet count very low
Management of chronic immune thrombocytopaenic purpura
20% of children have it chronically (= low platelets after 6 months)
Supportive
Drug treatment only if persistent bleeding that affects daily life:
Rituximab (monoclonal antibody against B lymphocytes)
Splenectomy can be effective - reserved for children who fail drug therapy (increase in risk of infection and needs lifelong antibiotic prophylaxis)
What is von Willebrand’s disease
Deficiency of von Willebrand factor (responsible for platelet adhesion and carries FVIII)
Many subtypes
Type 1 is commonest and is fairly mild:
Diagnosed in puberty/adulthood
Clinical features of von Willebrand disease
Bruising
Prolonged bleeding after surgery
Mucosal bleeding
Treatment of von Willebrand disease
DDAVP causes secretion of FVIII and vWF
If patient <1 year - it can cause hyponatraemia and seizures if fluid intake not adequate
AVOID:
aspirin
IM injections
NSAIDs
What are the main acquired conditions of coagulation
Haemorrhagic disease of the newborn (Vit K deficiency)
Liver disease
ITP
DIC
Inadequate intake, malabsorption of Vit K
Which bleeding disorders present in neonates
20% of haemophilia
Which bleeding disorders present in toddlers
Haemophilias may present when walking
Which bleeding disorders present in adolescents
vWD with menorrhagia and FHx
What does a FHx of all boys with bleeding suggest?
Haemophilia
What does a bleeding disorder with mucous membrane and skin involvement suggest?
platelet disorder
vWD
What does a bleeding into muscles/joints suggest
haemophilia
Characteristics of Henoch-schonlein purpura (non-thrombocytopaenic)
Lesions confined to buttocks, extensor surfaces of legs and arms
Swollen painful knees and ankles
Abdominal pain
Haematuria
Haematuria
The genetics of haemophilia
A (commoner) and B have X-linked recessive inheritance
A - FVIII deficiency
B - FIX deficiency
2/3 have a FHx
1/3 is sporadic
Clinical features of haemophilia
Recurrent spontaneous bleeding into joints and muscles - can lead to crippling arthritis
Presentation around 1 year age (crawling)
Suspect NAI if no FHx
40% present as neonate - intracranial haemorrhage, bleeding post circumcision, oozing from heel stick/venepuncture site
Acute management of haemophilia
Prompt iv infusion of recombinant FVIII/FIX for haemophilia A/B
Raising it to 30% of normal is usually sufficient to treat minor bleeds
For major surgery or life-threatening bleeds, it needs to be 100%. Maintenance at 30-50% is required for up to 2 weeks to prevent secondary haemorrhage - needs regular infusion of factor concentrate (FVIII - 8-12hrs; FIX - 12-24hrs)
Monitor plasma levels
What should be avoided in all patients with haemophilia?
Intramuscular injections
Aspirin
NSAIDs
Home treatment in haemophilia
To avoid delay in treatment! Risk of permanent damage
Parents are taught to give therapy at home when child is 2-3yrs of age
Many children can administer their own treatment from 7-8 yrs
Psychosocial support
Self-help groups
Specialised physiotherapy to preserve muscle strength
Prophylaxis in severe haemophilia
Prophylactic FVIII given in all children with severe haemophilia A to reduce risk of chronic joint damage
Begins at age 2-3yrs (2-3 times per week)
If peripheral venous access poor, central venous device (eg. portacath)
Prophylaxis has been shown to better joint function in adult life
Similarly, in severe haemophilia B, prophylactic FIX is given
What can be used in mild haemophilia instead of blood products?
Desmopressin (DDAVP)
Allows mild haemophilia A to be managed without the use of blood products
Given by infusion - stimulaters endogenous release of FVIII:C and vWF
Adequate levels for minor surgery and dental extraction
DDAVP is INEFFECTIVE in haemophilia B
