14 2c sickle

Question 1

Sickle Cell Disease : sickling episodes

The major pathophysiologic event of this disease

Answer 1

◦ Triggered by low O2 in the blood (hypoxaemia)
◦ Infection is the most common precipitating factor, also altitude and cold temp’s
◦ Initially, sickling is reversible with re-oxygenation.

Question 2

Sickle cell crisis

Answer 2

◦ Severe, painful, acute exacerbation of sickling causes a vaso-occlusive crisis.
◦ Severe capillary hypoxia eventually leads to tissue necrosis.
◦ Life-threatening shock is a result of severe O2 depletion of the tissues and ↓
circulating fluid volume.

Question 3

Multidisciplinary Management

Sickle cell crisis

Answer 3

§ Hospitalised patients in sickle cell crisis
§ Under-treatment is a major problem.
§ Pain management (opioids)
§ Treat infections.
§ Administer folic acid.
§ Hydrea is the only antisickling agent shown to be clinically beneficial.
§ Haematopoietic stem cell transplantation (HSCT)
§ Patient and caregiver teaching and support

Question 4

Thalassaemia

Answer 4

§ Most common inherited blood disorder in the world (genetic acquisition)

Question 5

Thalassaemia

§ A group of diseases involving inadequate production of normal haemoglobin due to

Answer 5

◦ Decreased erythrocyte production
◦ Problem with globulin protein
◦ Abnormal Hb synthesis
◦ Haemolysis also occurs.

Question 6

Thalassaemia types

Answer 6

One thalassaemic gene (Thalassaemia minor)

Ø Two thalassaemic genes (Thalassaemia major

Question 7

Thalassaemia minor signs

Answer 7

◦ Asymptomatic frequently; body adapts to reduction of Hb – thus no treatment is
indicated.
◦ Mild to moderate anaemia

Question 8

Thalassaemia major

signs

Answer 8

◦ Life-threatening
◦ Physical and mental growth often retarded
◦ Pale and jaundiced
◦ Splenomegaly, hepatomegaly, and cardiomyopathy

Question 9

Multidisciplinary care

Thalassaemia

Answer 9

No specific drug or diet is effective in treating Thalassaemia.
Symptom management only.
Thalassaemia major
◦ Blood transfusions or exchange transfusions with chelating agents
that bind to iron to reduce iron overloading
◦ Splenectomy

Question 10

Polycythaemia

Answer 10

§ An overproduction of cells
ü relative
ü absolute

Question 11

§ Relative Polycythaemia

Answer 11

results from haemoconcentration associated with dehydration (minor
consequence and resolves quickly with fluid hydration)

Question 12

Absolute Polycythaemia

Answer 12

consists of two forms ( primary and secondary)

Question 13

Primary Absolute Polycythaemia form

Answer 13

is known as polycythaemia vera – an overproduction of red blood
cells despite low levels of erythropoietin ( rare condition)

Question 14

Secondary Absolute Polycythaemia form

Answer 14

§ Secondary is more common, and results from a physiological response to secretion
of erythropoietin from hypoxia (E.g: living at high altitude > 3000m, smokers with
increased carbon monoxide or COPD sufferers), or caused by inappropriate levels of
erythropoietin (renal, hepatic or brain tumours) 24