Chapter 36: Sickle Cell Disease

Question 1

RBCs have a lifespan of about __-__ days

Answer 1

90-120

Question 2

SCD is a group of inherited RBC disorders resulting from a genetic mutation in the genes that encode _____

Answer 2

hemoglobin

Question 3

Patients with homozygous inheritance of the sickle cell gene have RBCs that contain abnormal Hgb, called ___

Answer 3

HgbS or sickle hemoglobin

Question 4

Sickled RBCs burst (hemolyze) after __-__ days, which causes anemia and fatigue

Answer 4

10-20

Question 5

SCD most commonly affects which population

Answer 5

African Americans

Question 6

Symptoms of SCD develop ~__-__ months after birth

Answer 6

2-3

Question 7

What is unique about fetus and young infants hgb?

Answer 7

a fetus and young infants have RBCs with fetal hemoglobin (HgbF), which blocks the sickling of RBCs.

Question 8

____ prevents O2 from reaching the tissues, causing them to become ischemic

Answer 8

Vascular occlusion

Question 9

If the pain from vaso-occlusive crisis is in the chest and there is evidence of a pulmonary infection, it is called ____

Answer 9

acute chest syndrome

Question 10

Most common chronic complications of SCD are chronic pain, avascular necrosis (bone death), ____, and renal impairment

Answer 10

pulmonary HTN

Question 11

healthy spleen aids in immune function and clears bacteria such as _____, ____ & ____

Answer 11

Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis

All encapsulated organisms

Question 12

In SCD, the spleen becomes fibrotic and shrinks, causing ______ & these patients are at increased risk for ____

Answer 12

functional asplenia (decreased or absent spleen function)
serious infections

Question 13

____ provide RBCs with HgbA

Answer 13

Blood-transfusions

Question 14

When administering chronic (monthly) blood transfusions, the goal Hgb level should be no higher than __ g/dL post-infusion

Answer 14

10

Question 15

One of the risks of blood transfusions is

Answer 15

iron overload

can lead to hemosiderosis (excessive iron that impairs organ fxn)

Question 16

What can be done to remove excess iron

Answer 16

Chelation therapy

Question 17

The only cure for SCD is

Answer 17

bone marrow transplantation

Question 18

Primary drug classes used in SCD

Answer 18

• Immunizations & Antibiotics to reduce infection risk
• Analgesics to control pain
• Hydroxyurea to prevent or reduce the frequency of acute and chronic complications
• Chelation therapy to manage iron overload from blood transfusions
• L-glutamine, voxelotor and crizanlizumab

Question 19

Which complications can occur from Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis in SCD

Answer 19

Sepsis and meningitis

Question 20

Prophylactic ___, given PO, reduces the risk of death from invasive pneumococcal infections in young children with SCD

Answer 20

penicillin

Question 21

Infants who screen positive for SCD at birth should be initiated on ___ daily ___ and treated until age __ years

Answer 21

twice
penicillin
5

Question 22

Key vaccines in SCD

Answer 22

Routine Childhood Series
* Haemophilus influenzae type B (Hib)
* PCV13

Additional Vaccines for Functional Asplenia
* Meningococcal conjugate series plus boosters
* Meningitis serogroup B (Bexsero, Trumenba) – age ≥ 10 yrs
* pneumococcal vaccines ≥ 19 years
1. PCV20
2. PCV15

Question 23

Patients with severe pain and vaso-occlusive crisis will require __ administration of ___ or ____

Answer 23

IV administration of opioids or PCA

Question 24

Hydroxyurea MOA

Answer 24

stimulates production of HgbF (blocks sickling of Hgb)

Question 25

Hydroxyurea is indicated in which pts

Answer 25

For adults with ≥ 3 moderate – severe pain crises in one year, or patients w/ severe or recurrent acute chest syndrome, chronic symptomatic anemia or disability.

consider in all children ≥ 9 months

Question 26

T/F: Hydroxyurea doses should be rounded to the nearest capsule size

Answer 26

True

Question 27

Hydroxyurea boxed warning

Answer 27

Myelosuppression (↓ WBCs and plts)

Question 28

what should be avoided with Hydroxyurea

Answer 28

live vaccines

Question 29

Hydroxyurea requires ___ during treatment and after discontinuation due to a risk of ____

Answer 29

contraception
fetal toxicity

Question 30

What must be worn when dispensing hydroxyurea

Answer 30

gloves & wash hands before and after handling (hazardous drug)

Question 31

____ supplementation is recommended to prevent macrocytosis with hydroxyurea

Answer 31

Folic acid

Question 32

Voxelotor MOA

Answer 32

inhibits HgbS polymerization, which is the cause of SCD

Question 33

Iron chelation treatment: ____ was previously used, but it has significant toxicities, is not available PO, and requires slow, prolonged infusions

Answer 33

deferoxamine

Question 34

Which oral chelating drugs are now used for chelation treatment with chronic blood transfusions

Answer 34

deferasirox and deferiprone