Flashcards in Hematology Deck (111)
What triggers RBCs to sickle in affected individuals?
Low O2 states
Why are sickle cells bad - how do they cause harm?
Vasoocclusion of organs/tissues
How does acute chest syndrome present?
Pulmonary infiltrates on CXRFever, hypoxia, acidosisNo infection
What is the typical electrophoresis in sickle cell disease and trait?
SS: Mostly Hgb S, some A2 and FTrait: Mostly Hgb A noted, with some S, A2, and F
Who should be offered sickle cell carrier screening?
Those of African and mediterranean ancestry
How should you screen for sickle cell in those with African or other heritage?
African-American: CBC + electrophoresisOther: CBC with diff, and electrophoresis only if microcytic (<80)
What are the risks associated with sickle cell disease in pregnancy?
PTL, PPROM, infection post-partum, IUGR, IUFD
How much folic acid should patients with sickle cell take daily?
How do you counsel patients with sickle cell on crisis avoidance?
Avoid triggers (cold, physical exertion, dehydration, and stress)
Can hydroxyurea be used in pregnancy to avoid a sickle crisis?
No - hydroxyurea is teratogenic
How do we treat sickle crises?
O2, opiodsEvaluation/treatment of cause (infection, dehydration)Management of compliations (acute chest)
When exchange transfusions are utilized in pregnancy for sickle cell, what is the typical indication?
Reduce frequency of pain crises
With an exchange transfusion, what is the treatment goal for % HgbS?
Hgb S <40%
How should we monitor fetuses in pregnancies complicated by SS?
Serial growth ultrasound q 4-6 weeksAntepartum testing beginning at 32 weeks
What electrophoresis pattern is consistent with beta-thalassemia?
Increased Hgb A2 > 3.5%, increased Hgb F, no Hgb S
What causes B-thal?
Bad beta-chain -> loss of type A Hgb (alpha/beta)
What are the two general types of gene mutations associated with B-thal?
B (0) - absent beta chain productionB (+) - decreased amount of beta chain production
What are the two grades of B-thal severity?
B-thal MINOR: mild anemiaB-thal MAJOR: severe anemia, complications
What complications are associated with B-thal major over a lifetime (outside of pregnancy)
Extramedullary hematopoeisisDelayed sexual development (due to hemosiderin deposition in hypothalamus)Poor growthDeath by age 10 if blood transfusions are not initiated
What patients with B-thal major are candidates for pregnancy?
Normal heart functionNo end organ damage from chronic transfusion (or h/o transfusion, coupled with deferoxamine for chelation)
Which ethnicities are most commonly associated with B-thal mutations?
Mediterranean, Asian, middle eastern, Hispanic, W.Indian
What is the outcome of B-thal combined with HgbS?
Severe anemia due to absent functional beta-chain production -> no Hgb A production
While pregnancies with B-thal minor are usually favorable, what outcomes should be monitored for?
Instead of iron, what supplement should be given to women with B-thal?
Folic acid 1mg/day
If you diagnose a patient with B-thal, what supplement should be initiated, and who else should be tested?
Initiated folic acid 1mg/dayTest father with CBC -> electrophoresis if microcyticGenetic counseling if dad also a carrier
When should you refer a patient for alpha-thal testing?
Microcytic anemiaNormal electrophoresis and iron testingSE Asian, African, W Indian, and mediterranean
What causese alpha-thalassemia?
Defunct alpha-chain production -> decreased Hgb A (alpha/beta), A2 (alpha/delta), and F (alpha/gamma)
Alpha thall involves mutations in how many alpha genes? What are the possible mutation combinations called?
TRANS: a_/a_CIS: __/aa
What ethnicities are most likely to be affected by sickle cell?
SE Asian, African, W. Indian, Mediterranean