Week 4: Sickle Cell Disease Flashcards
What is sickle cell disease?
An autosomal recessive genetic disorder involving the inheritance of abnormally shaped- Hgb S which stiffens and changes the shape and lifespan of RBCs in the presence of low O2 levels
Which populations are at risk for SCD?
African descent, also middle east, mediterranean and aboriginal tribes from India
What condition would heterozygous Hb S genes denote?
Sickle cell trait
Mild/asymptomatic form of SCD, less than 50% of Hgb is HbS
What condition does homozygous Hb S genes denote?
An opthalmologist should perform an eye exam every 1-2 years in those with SCD
True or False?
True
People with SCD are at risk for retinopathy due to vasooclusion and hypoxia to the retina
Repeated deoxygenation results in permanent sickling of RBCS
True or False?
True
SCD cannot be diagnosed before an infant is 3 to 4 months old
True or False?
Newborns are screened for SCD using a simple blood test that detects the presence of Hgb S
*Hgb electrophoresis
Which statement is true about the inheritance pattern of SCD?
1. If ’s K.J. mother has sickle cell trait and her father has SCD, each child will either have SCD or have sickle cell trait/be a carrier.
2. If K.J.’s mother has sickle cell trait and her father is normal, each child will have sickle cell trait.
3. If both K.J.’s parents have SCD, each child will have with either have SCD or be normal.
4. If K.J. has children, each child will automatically have SCD regardless of her spouses status.
- if her mother has sickle cell trait and her father has SCD, child’s risk is 50% for either having SCD or being a carrier
SCD is an autosomal recessive disease
What role does Hydroxyurea play in managing SCD?
-chemotherapy agent that works as antisickling agent
-Increases production of hemoglobin F (fetal hemoglobin)
-Decreases reactive neutrophil count
-Increases erythrocyte volume and hydration altering the adhesion of erythrocytes to the endothelium, prolongs RBC life
-Reduces number and severity of pain episodes, fewer blood transfusions and hospitalizations
VOC should be treated aggressively within 30-60 minutes of arrival in ED
True or False?
True
VOC should be treated aggressively with a higher dose of pain medication initially. This facilitates pain being effectively managed and usually decreases the length of the VOC
Why is anemia common in pts with SCD?
Because the affected RBCs are hemolysized at faster rate and RBC production cannot keep up
Sickled RBCs are less effective at O2 transport
What is the lifespan of a sickled cell?
10-12 days as opposed to 120 days
What does increased reticulocyte count indicate?
The body is trying to compensate for the increased destruction of RBCs
ou are following your facility protocol for adolescents with VOC. Based on the protocol, which interventions are the priority at this time?
A. Assess O2saturation
B. Administer a loading dose of morphine sulfate
C. Start IV fluids of D 5 ½ NS at maintenance rate
D. Place a peripheral IV (PIV) or access a central venous access device
E. Obtain a urine for UA and bHCG (pregnancy test) if over age 10 years
F. Draw a CBC with differential including a retic count, BMP, and blood cultures if fever greater than or equal to 38.5 °C (101.3 °F)
A, B, C, D
What are possible causes of sickling episodes?
-Low O2 tension in blood
-Viral/bacterial infection
-High altitude
-Emotional/physical stress
-Surgery or blood loss
-Dehydration/Decreased plasma volume
-Acidosis
-Low body temperature
