Sickle Cell Disease

Question 1

Sickle cell disease (SCD) is autosomal recessive. People with disorder have hemoglobin S, which distort RBC = HbSS = not protect against malaria. People with sick cell trait = HbAS = has no symptoms = protect against malaria

Symptom occurs after age 4 months

• How to test for SCD

Answer 1

Test:

• CBC
• Hemoglobin electrophoresis
• Sickle cell test

Question 2

S/S of SCD

Answer 2

• Anemia and High bilirubin: due to quick RBC break down prematurely (10-20 days)
• Painful episodes:
  
  • Lung = Pulmonary HTN
  • Kidneys = CRF
  • Spleen = auto-splenectomy
  • Long bone = pain/necrosis
  • Brain = stroke

Question 3

How to manage:

• Vaso-occlusive crisis
• Aplastic crisis
• Hemolytic crisis
• Splenic sequestration crisis
• Actue chest crisis

Answer 3

Vaso-occlusive crisis
- Hydration, blood transfusion, pain mgmt

Aplastic crisis = worsening baseline of anemia

• Trigger by parvovirus B12
• Transfusion

Hemolytic crisis

• Common in pt w/ G6PD deficiency
• Blood transfusion

Splenic sequestration crisis = infarcting spleen sequesters all the circulatory blood volume => hypovolemic shock. Can lead to asplenia. Vaccine with the follwings
- Pneumococcal vaccine
* Prevnar (PCV 7 or 13 valent) + Adult pneumovax (PPV 23
23 valent at age 2 y.o w/ revaccination after 3-5 yrs for
children less than 10 y.o
- Hib
- Meningococcal vaccine: greater than 2 y.o
- Annual influenza

Actue chest crisis = lung infection

• Hydration, blood transfusion, pain mgmt, O2
• Abx: macrolide or quinolone for atypical

Question 4

SCD measurement

Answer 4

• PNC prophylaxis: for less than 5 y.o. ALL to PEN => azithromycin
• Vaccination
• Hydroxyurea
• Folic acid: 1g QD
• Malaria chemoprophylaxis
• Leg ulcer wound care: zinc oxide
• Bone marrow or stem cell transplants: can cure SC anemia

Question 5

PCN prophylaxis in SCD

Answer 5

To prevent pneumococcus ppx in less than 5 y.o

• Penicillin VK 250mg BID
• PNC Atn: Amoxicillin 20mg/kg/d
• PNC ALL: Erythromycin
• Greater than 5 y.o, less chance of pneumococcal infection in this age group.

Question 6

Hydrea
Droxia

• MOA
• Indication
• Dose
• Monitor
• C/I
• SEs
• Preg Cat

Answer 6

Hydroxyurea

• Antineoplastic MOA: reduction of production of deoxyribonucleotide via inhibition of the enzyme ribonucleotide reductase
• SCD MOA: Reactivating fetal Hgb production, decrease the #s and severity of attacks and increase survival

Indication

• Solid tumor, leukemias
• SCD
• HVI anti-retrovial adjunct
• Dose: 15mg/kg. Titrated up until cytopenias develop
• Monitoring: CBC*, renal, uric acid, electrolytes, LFTs
• CI; BMS

SEs

• BMS, GI, Rash, skin ulcers
• Neurological: HA, dizziness, SZ
• Hepatitis, pancreatitis
• Pulmonary fibrosis

Preg Cat D