Haematology

Question 1

What’s the difference between ecchymosis and haematoma?

Answer 1

Haematoma is a raised ecchymosis (you can feel a haematoma but not ecchymosis)

Question 2

What tests do you do in a patient presenting with bleeding?

Answer 2

Start with FBC and diff
Platelets
Smear
Bleeding time (normal = <7mins)
PT (normal <12 secs /neonate <18secs) = extrinsic pathway
aPTT (normal <40secs/neonate 70secs)

Large platelets = peripheral destruction (immature release)

Question 3

What is the normal platelet count?

Answer 3

150 000 - 450 000

Question 4

What diseases increase your PT?

Answer 4

Haemorrhagic disease of the newborn
Malabsorption
Liver disease
DIC
Oral anticoagulants
Rat poison

Question 5

What conditions cause increased aPTT?

Answer 5

Haemophilia
Von Willebrand disease
Heparin
DIC

Question 6

Classify haemolytic disease

Answer 6

Primary (thrombocytopenia)
Secondary (coagulopathy - problem with factors)

Question 7

What are the causes of thrombocytopaenia?

Answer 7

Primary
>immune thrombocytopenia purpura
>neonatal isoimmune
>TAR syndrome
>Wiscott-Aldrich syndrome

Secondary
>sepsis
>malignancy
>aplastic anaemia
>DIC
>hypersplenism
>HIV
>lupus

Question 8

What are the causes of coagulopathy?

Answer 8

Primary
>von Willebrand
>haemophilia
>platelet function defect

Secondary
>anticoagulant
>vit K deficiency
>Renal/hepatic failure
>rat poison
>maternal anticonvulsants

Question 9

What is TAR syndrome?

Answer 9

Thrombocytopenia with absent radii (less bone marrow to produce blood products)

Question 10

What mechanisms cause thrombocytopenia?

Answer 10

Decreased production (bone marrow eg TAR syndrome)
Increased destruction (autoimmune conditions)
Sequestration (trapping of platelets eg hypersplenism/large haemangiomas)

Question 11

What are the most common severe inherited bleeding disorders?

Answer 11

Factor 8 deficiency
Factor 9 deficiency

Question 12

What is the most common congenital bleeding disorder?

Answer 12

Von Willebrand factor deficiency

Question 13

What blood tests do you do investigating anaemia?

Answer 13

FBC
Reticulocytes
Peripheral smear
RBC indices
MCV

Question 14

What is red cell distribution width (RCDW)?

Answer 14

Measures the range in volume and size of RBC’s
Low = uniform in size (thalassaemia)
High = high variation in size of RBC’s (nutritional)

Question 15

What are indications for blood transfusion?

Answer 15

Trauma/surgery
Oncology patients
Severe symptomatic acute anaemia
Thrombocytopaenia and platelet disorders
Exchange transfusions
DIC
Thalassaemia and sickle cell disease
Hypofibrinogenaemia