Chapter 36: Sickle Cell Disease Flashcards

1
Q

RBCs have a lifespan of about __-__ days

A

90-120

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2
Q

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

A

hemoglobin

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3
Q

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

A

HgbS or sickle hemoglobin

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4
Q

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

A

10-20

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5
Q

SCD most commonly affects which population

A

African Americans

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6
Q

Symptoms of SCD develop ~__-__ months after birth

A

2-3

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7
Q

What is the purpose of hemoglobin F (HgbF) in fetus

A

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

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8
Q

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

A

Vascular occlusion

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9
Q

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

A

acute chest syndrome

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10
Q

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

A

pulmonary HTN

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11
Q

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

A

Streptococcus pneumoniae

Haemophilus influenzae

Neisseria meningitidis

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12
Q

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

A
functional asplenia (decreased or absent spleen function)
serious infections
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13
Q

_____ provide RBCs with HgbA

A

Blood-transfusions

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14
Q

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

A

10

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15
Q

One of the risks of blood transfusions is

A

iron overload

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16
Q

What can be done to remove excess iron

A

Chelation therapy

17
Q

The only cure for SCD is

A

bone marrow transplantation

18
Q

Primary drug classes used in SCD

A
  • 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
19
Q

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

A

Sepsis and meningitis

20
Q

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

A

penicillin

21
Q

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

A

twice

5

22
Q

Key vaccines in SCD

A

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

Additional Vaccines for Functional Asplenia
• Meningococcal conjugate series plus boosters
• Men B (Bexsero, Trumenba) – age >/= 10 yrs
• PPSV23 – age >/= 2 years, booster 5 years later and at age >/= 65 years
• PCV13 x 1 in any patient >/= 6 years of age, if never received as a part of routine childhood series

23
Q

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

A

IV administration of opioids or PCA

24
Q

Hydroxyurea MOA

A

stimulated production of HgbF (blocks sickling of Hgb)

25
Q

Hydroxyurea is indicated in which pts

A

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.

26
Q

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

A

True

27
Q

Hydroxyurea boxed warning

A

Myelosuppression (↓ WBCs and plts)

28
Q

what should be avoided with Hydroxyurea

A

live vaccines

29
Q

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

A

contraception

fetal toxicity

30
Q

What must be worn when dispensing hydroxyurea

A

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

31
Q

____ supplementation is recommended to prevent macrocytosis with hydroxyurea

A

Folic acid

32
Q

Voxelotor MOA

A

inhibits HgbS polymerization

which is the cause of SCD

33
Q

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

A

deferoxamine

34
Q

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

A

deferasirox and deferiprone