Hematologic Flashcards
(26 cards)
Describe the pathophysiology of sickle cell disease (2)
- Sickled RBCs are unable to pass through circulation
- Vaso-occlusion causes hypoxia / ischemia
Describe the occurrence of manifestations of sickle cell disease (2)
- Asymptomatic for first 4 - 6 months
- Symptoms present during period illness (causes exacerbation)
Why are children with sickle cell disease asymptomatic for the first 4 - 6 months of life?
Presence of fetal hemoglobin (HbF) - does not sickle
Describe the pathophysiology of a vaso-occlusive crisis (2)
- Oxygen cannot reach tissues, leading to ischemia
- Causes extreme pain
How long does vaso-occlusive crisis pain typically last?
4 - 6 days
What is the first sign of a vaso-occlusive crisis in young children?
Hand-foot syndrome
Describe the pathophysiology of a sequestration crisis (2)
- Blood pooling in spleen / liver
- Decreased circulation causes shock / cardiac arrest
A sequestration crisis is typically seen in children of what age?
< 3 years old
What is the mortality rate of a sequestration crisis?
50%
When is sickle cell disease usually diagnosed?
Newborn screening
What tests are used for the diagnosis of sickle cell disease? (3)
- CBC
- Sickledex
- Hemoglobin electrophoresis
Describe the prevention of sickle cell disease crisis (3)
- Immunizations
- Prophylactic antibiotics
- Avoid stress on the body (fever, infection, acidosis, dehydration, hypothermia)
Prophylactic antibiotics for sickle cell disease are especially important for …
Children who have had their spleen removed
Describe the management of sickle cell disease (2)
- Hydroxyurea
- Warm compress
What is the function of hydroxyurea for sickle cell disease?
Increases fetal hemoglobin (HbF) which does not sickle
It is important to maintain an oxygen saturation of ______ in children with sickle cell disease
> 93%
Why is a warm compress used for children with sickle cell disease?
Vasodilation to prevent vaso-occlusion
DO NOT ______ to hot / swollen hands in sickle cell disease
Apply ice
Which pain medication is contraindicated for sickle cell disease?
meperidine (Demerol) - risk of seizures
What age has the greatest risk for complications from sickle cell disease?
< 5 years old
Describe the pathophysiology of hemophilia A (2)
- Lack of factor VIII causes impaired clotting
- Causes fatal hemorrhage
What is the function of factor VIII?
Formation of thromboplastin (essential for blood clotting)
Where is the most common site of internal bleeding from hemophilia A?
Bleeding into the joint cavities / muscles (hemarthrosis)
What laboratory findings are associated with the diagnosis of hemophilia A? (2)
- Decreased factor VIII
- Prolonged PT / PTT
