Chapter 36: Sickle Cell Disease

Question 1

What is the lifespan of RBCs?

Answer 1

90-120 days

Question 2

SCD is a group of inherited ____ resulting from a genetic mutation in the genes that encode ____.

Answer 2

RBC disorders
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 the purpose of hemoglobin F (HgbF) in fetus?

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

What are the most common chronic complications of SCD?

Answer 10

• chronic pain,
• avascular necrosis (bone death),
• pulmonary HTN,
• renal impairment

Question 11

What is the preferred method of contraception for female patients with SCD?

Answer 11

• Progestin only contraceptives
• Levonorgestrel IUD
• Barriers

Question 12

What bacteria does a healthy spleen help clear?

Answer 12

• Streptococcus pneumoniae,
• Haemophilus influenzae,
• Neisseria meningitidis

Question 13

What happens to the spleen in Sickle Cell Disease (SCD)?

Answer 13

The spleen becomes fibrotic and shrinks.

Question 14

What is the result of a fibrotic and shrunk spleen in SCD patients?

Answer 14

Functional asplenia (decreased or absent spleen function)

Question 15

Patients with functional asplenia are at risk of

Answer 15

serious infections

Question 16

What provides RBCs with HgbA in patients with SCD?

Answer 16

Blood-transfusions

Question 17

What should be the goal Hgb level after chronic blood transfusions?

Answer 17

No higher than 10 g/dL post-infusion

Question 18

What is one of the risks of blood transfusions?

Answer 18

Iron overload

Question 19

What can be done to remove excess iron?

Answer 19

Chelation therapy

Question 20

What is the only cure for SCD?

Answer 20

Bone marrow transplantation

Question 21

What is the primary drug class used to reduce infection risk in SCD?

Answer 21

Immunizations & Antibiotics

Question 22

What is the primary drug class used to control pain in SCD?

Answer 22

Analgesics

Question 23

What is the primary drug class used to prevent or reduce the frequency of acute and chronic complications in SCD?

Answer 23

Hydroxyurea

Question 24

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

Answer 24

Sepsis and meningitis

Question 25

What prophylactic treatment reduces the risk of death from invasive pneumococcal infections in young children with SCD?

Answer 25

Prophylactic Oral Penicillin

Question 26

What should infants who screen positive for SCD at birth be initiated on?

Answer 26

Twice Daily PCN ## Footnote .

Question 27

Until what age should infants with SCD be treated with PO PCN?

Answer 27

Until age 5 years

Question 28

What vaccines are included in the Routine Childhood Series for SCD?

Answer 28

Haemophilus influenzae type B (Hib) and PCV15 or PCV20.

Question 29

What additional vaccines are recommended for individuals with Functional Asplenia?

Answer 29

* Meningococcal conjugate series plus boosters, * Men B (Bexsero, Trumenba) * PCV20 x1 OR PCV15 x1 followed by PPSV23 if never received as part of routine childhood series.

Question 30

What is the age requirement for Men B vaccination in Functional Asplenia?

Answer 30

Men B (Bexsero, Trumenba) is recommended for individuals age ≥ 10 years.

Question 31

What is the schedule for PPSV23 vaccination in Functional Asplenia?

Answer 31

PPSV23 is given at age ≥ 2 years, with a booster 5 years later and again at age ≥ 65 years.

Question 32

What is required for patients with severe pain and vaso-occlusive crisis?

Answer 32

IV administration of opioids or PCA

Question 33

What is the mechanism of action (MOA) of Hydroxyurea?

Answer 33

Stimulated production of HgbF (blocks sickling of Hgb)

Question 34

What are oral chelating drugs commonly used to remove excess iron from the body?

Answer 34

Deferasirox and deferiprone

Question 35

Hydroxyurea brand name

Answer 35

Hydrea, Droxia

Question 36

Who is Hydroxyurea indicated for?

Answer 36

Hydroxyurea is indicated for adults with ≥ 1 moderate – severe pain crisis in one year.

Question 37

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

Answer 37

True

Question 38

What is the boxed warning for Hydroxyurea?

Answer 38

Myelosuppression (↓ WBCs and plts)

Question 39

What should be avoided with Hydroxyurea?

Answer 39

Live vaccines

Question 40

What is required during treatment with Hydroxyurea due to fetal toxicity risk?

Answer 40

Contraception

Question 41

What must be worn when dispensing hydroxyurea?

Answer 41

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

Question 42

What supplementation is recommended to prevent macrocytosis with hydroxyurea?

Answer 42

Folic acid

Question 43

What is a monitoring parameter for Hydroxyurea?

Answer 43

CBC with differential (ANC <2000)

Question 44

What is the mechanism of action (MOA) of Voxelotor?

Answer 44

Voxelotor inhibits HgbS polymerization, which is the cause of SCD.