Sickle Cell Disease EXAM 4 Flashcards
What are the complications/symptoms of Sickle Cell Disease?
-Anemia
-Pain Crisis (ischemia)
-Stroke (blood vessels blocked, vaso-occlusion)
-Acute chest syndrome (blood vessels blocked)
-Avascular necrosis (tissue dies)
-Splenic infarction
-Pulmonary diseases
-Priapism (prolonged erection bc blood cant escape due to blocked vessels)
What is the genotype associated with Sickle Cell Disease?
HbSS
HbAS -> sickle cell trait, often asymptomatic
normal gebotype: HbAA
How does the Sickle Cell gene affect the shape of RBC?
When does an RBC (HbSS genotype) change its shape?
substituion from Valine to glutamic acid on the ß-chain
-after unloading O2, deoxygenated RBC becomes sickle-shaped
Which type of hemoglobin is not affected by the Sickle cell gene?
Why?
Fetal (fetus) hemoglobin [α2γ2]
bc it doesn’t have the ß-chain -> so no mutation that causes the sickle-shape
What can trigger a pain crisis in patients with the sickle cell trait?
-Heavy exercise
-extreme conditions (cold weather)
-dehydration
How is the level of Hbg different between patients with Sickle cell disease and the sickle cell trait?
normal Hbg in patients with SCT
Anemia in patients with SCD
Which organ is commonly dysfunctional in patients with Sickle cell disease?
SCD patients are therefore at higher risk of what?
Spleen (functional asplenic)
higher risk of encapsulated bacterial infections
-Streptococcus pneumoniae
-Haemophilus influenzae
-Neisseria meningitis
-Salmonella
What should be assumed until proven otherwise for sickle cell disease patients with fever?
sepsis and bloodstream infections
-> treat with 48h IV antibiotics until blood culture is negative
SCD patients of what age need Penicillin Prophylaxis?
Penicillin until the age of 5
-125 mg PO BID until age 3
-250 mg PO BID until age 5
also patients with a history of
-invasive pneumococcal infection
-splenectomy
What is the treatment of choice for acute chest syndrome in sickle cell disease patients?
-Ceftriaxone
-Vancomycin if MRSA is suspected
-Macrolide for atypical coverage if the patient is older than 5
What supportive treatment may help in acute chest syndrome?
-incentive spirometry (inflate alveoli and prevent collapse)
-pain management (opioids)
-IV fluids (helps loosen the sickle cells, but not too much due to pulmonary edema)
How is a Vasoocclusive Pain Crisis managed?
-Hydration -> #1 treatment is hydration!
-Pain meds (opioids or Ketorolac (IV NSAID))
-Blood transfusion if necessary
What is the maximum duration of IV Ketorolac?
NAPLEX
5 days
due to the risk of GI bleeding and renal toxicity
What is the treatment plan for an aplastic crisis in sickle cell patients?
What is the most common cause?
RBC transfusion and supportive care
Parvovirus B19 is the most common cause
What is the treatment plan for a Sequestration crisis in sickle cell patients?
What is the cause?
-RBC transfusion and fluids
-Broad-spectrum antibiotics (gets worse with an infection)
this crisis is due to hypovolemic shock from rapid hemolysis
Which drug is used for Sickle Cell disease treatment?
What is the MOA?
!!!
Hydroxyurea
-inhibits conversion from ribonucleosides to deoxyribonucleotides (chemotherapy agent) -> reduces WBC adhesion (less occlusion)
-increases hemoglobin F production (HbF) !!!
HbF doesn’t produce sickle-shaped RBCs
decreases SCD episodes
-painful crisis
-acute chest syndrome
-hospitalizations
-need for blood transfusion
What is the brand name of Hydroxyurea?
!!!
Hydrea
What should be monitored when using Hydroxyurea?
Which lab test indicates adherence to Hydroxyurea?
monitor: signs of myelosuppression, leukemia, infection, neutropenia (ANC)
if taken appropriately the MCV should be elevated (remember: also MCV is also elevated with Folic acid and Vitamin B12 deficiency)
When do we use Hydroxyurea for Sickle cell disease patients?
-> 3 hospitalizations for pain crisis per year
-severe symptomatic anemia
-history of acute chest syndrome
-other severe vasoocclusive complications (like stroke, heart attack)
What supportive treatment (besides Hydroxyurea) does a patient with Sickle Cell disease need?
-Vaccines (Pneumococcal, H. flu, Meningococcal)
-PNC prophylaxis until age 5
-Folic acid supplements (need lots of folic acid to renew RBC after sickle cell destruction)
Which monoclonal antibody is approved for Sickle Cell disease treatment?
How does it work?
Crizanlizumab
-blocks P-selectin binding on the lining of endothelial cells
-no side effects
Which potentially curative treatment is reserved for severe cases?
Why is it only used for severe cases?
Allogenic Hematopoietic Stem Cell Transplantation
-risky bc we need to kill all the bone marrow with chemo -> transplant the stem cells -> then use immunosuppressants to block the T-cells from attacking the stem cells
-high infection risk, risk for autoimmune disease (against any organ)
JP is an 11 year old AA male with SCD. He was diagnosed with acute chest syndrome and started on IV fluids. What is an appropriate antibiotic regimen for JP? has tried PNC before
A: Cefotaxime and Ciprofloxacin
B: Penicillin and Azithromycin
C: Ceftriaxone and Vancomycin
D: Ceftriaxone and Azithromycin
D: Ceftriaxone and Azithromycin
need to cover Strep pneumo and H. flu, Azithromycin covers atypical (required if older than 5)
B: PNC will not work, probably resistant
-no worries about Staph coverage (Vancomycin) at this point
-if he was 4 years old, we would only use Ceftriaxone
A 24 yo male with SCD presents with acute chest pain in the ER. Last winter he required hydromorphone at a basal rate of 1.5 mg/hr.
What is the equivalent dose of morphine for this patient?
A: Morphine 0.5 mg/hr
B: Morphine 3 mg/hr
C: Morphine 5 mg/hr
D: Morphine 10 mg/hr
D: Morphine 10 mg/hr
A patient with a history of acute chest pain presents in the ER with another episode, this is his 4th episode this winter. Which medication should be prescribed after he is stabilized and ready for discharge?
A: Crinalizumab
B: Hydrea
C: Methotrexate
D: Voxelotor
B: Hydrea
Which vaccines should be updated for SCD patients per CDC guidelines?
S. pneumoniae
H. flu
Neisseria meningitis
-same for patients who get their spleen removed (2 weeks before splenectomy)
Design an Opioid pain plan
Short Answer Question on the EXAM
- long-acting opioids to cover 24h without breakthrough pain
- short-acting opioid for breakthrough pain
-10-20% of the long-acting dose !!!
-if a patient needs more than 2 breakthrough doses -> increase the long-acting dose - Bowel regimen
-stimulant laxative (senna, bisacodyl) or osmotic laxative (mirlax)
+/- docusate (stool softener)
Which drug should be given as a short-acting opioid for a patient who is using 100 mg of long-acting oxycodone?
10 to 20 mg of IR oxycodone per dose
