Hematology Flashcards
1
Q
Treatment for hemophilia*
A
- Prophylactic: Factor VII/ IX concentrate (costly and required central venous access)
- Other option: on-demand treatment to replace the missing factors
- FFP/ Cryoprecipitate should be avoided due to high risk of viral transmission
2
Q
Investigation for hemophilia
A
- Full blood count
- Coagulation screen: APTT prolonged, platelet count and prothrombin time are normal
- Specific factor assay: Factor VIII low in Hemophilia A, Factor IX low in Hemophilia B
- Bleeding time: increased BT
- Von Willebrand screen: To exclude VWD in patient with factor VIII deficiency
3
Q
Complication of hemophilia*
A
- Joint destruction
- Infection from plasma derived product
- Development of inhibitors
4
Q
Investigation for thalassemia**
A
- FBC: decrease Hb, MCH, MCV; increase reticulocyte count
- PBF: anisopoikilocytosis, hypochromia, microcytosis, target cells
- Iron status: TRO IDA
- HPLC/ Hb electrophoresis: increase HbF and HbA2, low HbA
- DNA analysis: diagnostic for a-thalassemia
5
Q
HPLC vs Hb electrophoresis*
A
> HPLC
- Objective quantification
- Automation
- No operator-to-operator variation
- Time taken 6 min/ sample
> He electrophoresis
- Subjective
- Manual and laborious
- Operator-to-operator variation
- Time taken: hours to entire day
6
Q
Management for thalassemia **
A
- Blood transfusion therapy (4 weekly interval, leucodepleted PRBC of <2 weeks old -> minimize non-hemolytic febrile reaction and alloimmunization)
- Iron chelation therapy (Desferrioxamine: usually after 10-20 transfusion)
- Monitor for complications
- Consider stem cell transplantation
7
Q
When to start transfusion in thalassemia
A
- Thalassemia major: once diagnosis is confirmed or Hb <7 g/dl on 2 occasions /2 weeks apart
- Thalassemia intermedia: Hb < 8g/dl if there is evidence of impaired growth
- Bone changes, enlarging liver and spleen, paraspinal mass
- Alpha thalassemia: transfuse only if Hb persistently <7 g/dl or symptomatic of chronic anemia
8
Q
Indication of splenectomy in thalassemia
A
- Hypersplenism: evidence of cytopenia
- Symptomatic: LUQ discomfort, early satiety, risk of splenic rupture
9
Q
Describe hypersplenism + complicaiton
A
- Hypersplenism refer to splenomegaly with normal function of bone marrow
- Pancytopenia caused by enhanced capacity of splenic pooling, sequestration and destruction of blood cells
- Complication include splenic rupture, splenic volvulus, and hemorrhagic or infectious complication (due to thrombocytopenia or leucopenia)
10
Q
Complication of splenectomy
A
- Overwhelming sepsis
- Hypercoagulability
- Pulmonary hypertension
- Higher risk of iron overload
11
Q
Precaution taken before and after splenectomy
A
- Pneumococcal, HIB, Meningococcal vaccination at least 2 weeks prior to splenectomy
- Penicillin prophylaxis for life after splenectomy: encapsulated organism (eg: S. pneumoniae, H. influenza, N. meningitidis) will thrive in the absence of splenic macrophages
- Low dose aspirin if thrombocytosis after splenectomy
- If the patient receive regular blood transfusion, less likely to get bone marrow expansion/ organomegaly because less burden for RBC production
12
Q
Complication of blood transfusion
A
> Iron deposition
- Cardiac siderosis
- Liver cirrhosis
- Pancreas (DM)
- Pituitary (Infertility)
> Antibody formation
- HLA antibodies -> shock
> Infection
- Hepatitis B & C, HIV, CMV, syphilis, malaria
> Others
- Fluid overload
- Hypothermia
- Hypocalcemia
- Febrile reaction
13
Q
Indication for iron chelation therapy in thalassemia
A
- Age >3 years old
- Serum ferritin reaches 1000ug/l
- Usually after 10-20 transfusion
- Given together with Vitamin C, which augments iron excretion
14
Q
Complication of thalassemia
A
- Bone deformity
- Enlarged spleen
- Slowed growth rate
- Cholelithiasis
15
Q
How female being affected in hemophilia
A
- Compound heterozygosity
- Skewed lyonization
- X chromosome loss
