Hemoglobinopathies

Question 1

What is the definition of an acute chest syndrome in sick cell disease?

Answer 1

Diagnostic Criteria:
(1) Evidence of radiographic pulmonary infiltrates AND

(2) At least one of the following:
- Temperature > 38.5
- Tachypnea
- Chest Pain
- > 2% decrease in O2 saturation
- Cough
- Wheezing
- Rales

Question 2

What is sickle cell disease?

Answer 2

Two abnormal copies of the B-globulin gene (HbS) that results in RBC sickling, with chronic hemolytic anemia and complications from microvascular occlusion.

Question 3

What is the pharmacological treatment used in sickle cell disease?

Answer 3

(1) Hydroxyurea

(2) Folic Acid

Question 4

How is an acute chest syndrome in sickle cell disease managed (6)?

Answer 4

(1) Pain Control
(2) Fluids (1.5x maintenance)
(3) Simple transfusion if HgB < 100 to dilute HbS
(4) Supplemental Oxygen
(5) DVTp
(6) Exchange Transfusion

Question 5

What is the target Hb & HbS in sick cell acute chest syndrome or multi organ dysfunction?

Answer 5

HbS < 30%

Hb ~ 100

Question 6

When would you recommend an exchanged transfusion for a sick cell patient?

Answer 6

In the setting of severe acute chest syndrome if Hct 0.35 or Hb > 100 to avoid hyperviscosity.

Question 7

What is beta thalassemia major?

Answer 7

The most severe form of beta-thalassemia in which there is minimal to no beta-globulin chain produced, and consequently no HbA, due to homozygosity or compound heterozygosity for beta thalassemia mutations.

Question 8

What are the clinical manifestations of beta thalassemia?

Answer 8

(1) Ineffective erythropoiesis
(2) Extramedullary hematopoiesis (hepatosplenomegaly, skeletal changes)
(3) Hemolysis - Anemia, gall stones
(4) Iron overload due to ineffective erythropoiesis and transfusion support.

Question 9

How are people with beta thalassemia monitored?

Answer 9

(1) Ferritin Q3 months
(2) Liver/Cardiac MRI for iron quantitation
(3) Iron Chelation for features of iron overload