L3_Sickle Cell Anemia 2 Flashcards
What is the primary cause of polymerization in HbS? what are some other factors?
Primary cause is deoxygenation. Other factors include fever, acidosis, and dehydration.
What is a crucial factor that hinders the effective treatment and prevention of sickle cell disease?
OUr inability to accurately identify patients destined to have more severe disease impairs our ability to adjust their therapy.
Why is newborn screening performed?
Because it is important to diagnose ASAP bc you would treat certain symptoms in a NB much differently if you knew they had SSD
What is a common lab technique used for Hb screening?
Gel electrophoresis. HbS mutations decreased neg charge and causes slower migration. HbC increase positive charge and greatly decreases migration.
What is the abbreviation used to ID people with sickle cell trait? do they show symptoms?
AS, no they usually do not know they have the disease.
Describe the problems that Hemoglobin SC causes and the severity of the disease
C does not sickle but increases Hb viscosity. patients with this disease have a milder form of sickle cell.
Describe the genetics of Sickle Beta thalassemia and the range of severity.
Inhert HbS from one parrent and little or no HbA from ineffective beta thalassemia gene (1 parent AS other thalassemia trait) Disease can be very severe if no HbA is produced or it can be mild if some HbA is produced.
What is a major complication you worry about in children with sickle cell disease?
Bacterial sepsis. This is caused by splenic vassoocclusion which inhibits bacterial clearance, particularly encapsulated (pneumococcus). Prophylatic penicillin and immunizations can greatly decrease the risk. Death withing 8 hours of first symptoms of fever!!!!!
How would you treat fever in a child with sickle cell differently than a child without?
Urgent administration of IV antibiotics, you must recognize fever as the first sign of sepsis in these children.
What is the most common complication throughout life for someone with sickle cell?
Sickle cell events- panful vaso-occlusive episodes.
Hand and foot syndrome is first sign in many children
What needs to be done to help a person who is in sickle cell crisis? What is a common mistake made?
Pain control, fluids, ensure oxygenation, control fever (transfusion is not usually helpful). Too often, children are under prescribed narcotics due to assumption of addiction.
What types of strokes are more common in children? adults?
children-thrombotic
Adults- hemohhragic
What is done to treat strokes and prevent future strokes?
RBC transfusions and prophylaxis
in bad cases can indicate for marrow transplant
What can be done to help prevent/catch strokes before they start?
Tanscranial Doppler (MRI)
If you see signs of or indicating a stroke on MRI what should you do?
immediately start transfusions
What is the most common cause of death in people older than 5 yrs?
Acute Chest Syndrome, includes any/all of infection/vaso-occlusion,/fat embolus and can lead to chronic lung disease
How is Acute Chest Syndrome treated?
Antibiotics, oxygenation, incentive spirometry, possible transfusions
What is Acute Splenic Sequestration Crisis? Who does it usually effect and what is done to treat/prevent it?
Sudden enlargement of the spleen due to vasso-occlusion can rapidly lead to hypovolemic shock in the first five years of life. Acute treatment involves fluid resuscitation and transfusion. Teach parents to palpate spleen and listen to them!
How is a prenatal diagnosis made? when would this be considered?
If at risk, prenatal diagnosis made via amniocentesis ONLY if termination is considered
What is the safest possible transplant?
Chord blood from an unaffected sibling.
What is the only effective therapeutic that is currently used?
hydroxyurea
What does bone marrow transplant currently require?
HLA identical sibling
Who usually is considered for a marrow transplant?
strokes, frequent episodes, severe acute chest syndrome
Do you need to make 100% HbA to get better?
NO, 5-10-15% could be enough
