Sickle Cell Disease

Question 1

Acute sickle cell chest syndrome presentation

Answer 1

chest pain, cough, pulmonary infiltrates, hypoxemia, fever, lung crackles
in a sickle cell pt

Question 2

Treatment of acute sickle cell chest syndrome

Answer 2

supplemental oxygen, broad spectrum abx, IVF and pain control

Question 3

If acute chest syndrome is mild (SaO2>90% and single lobar infiltrate) what do you do?

Answer 3

0-2 units of RBC TRANSFUSION

Question 4

If acute chest syndrome is moderate (with SaO2>85% and <2 lobes on CXR w/ pulmonary infiltrate), what do you do?

Answer 4

2-3 units of pRBC TRANSFUSION

Question 5

If acute chest syndrome is (SaO2<85% or >2 lobes w/ pulm infiltrate) is severe, what do you do?

Answer 5

exchange transfusion. to prevent hemoconcentration or hyperviscosity.

Question 6

Do we use steroids in acute chest syndrome?

Answer 6

No because it can cause rebound vaso occlusive events and increased risk for avascular necrosis and there’s an association with hemoragic stroke

Question 7

When do we use hydoxyurea for acute chest syndrome?

Answer 7

Never used in acute setting. only used as a way to decrease frequency of pain crises and acute chest syndrome in the chronic setting.

Question 8

What must you do if you see pulmonary infiltrates in someone with sickle cell and acute pain?

Answer 8

they have acute chest syndrome, need to measure oxygen and start empiric abx. May need transfusions or exchange transfusion.

Question 9

what is priapism

Answer 9

> 2-4 hr penile or clitoral erection that is not associated with sexual stimulation or desire

can be seen as a serious side effect of people with sickle cell disease and seen up to 45% of pts.

Question 10

why does priapism occur in sickle cell dx pts?

Answer 10

due to decreased oxygen levels in corpora cavernosa which leads to sickling and blockage of penile venous outflow

can have ischemic changes that can occur in the penile tissue if priapism is not corrected after 4 hrs resulting in fibrosis and ED.

Question 11

how to treat sickle cell disease patients with priapism with milder symptoms <2 hrs

Answer 11

increased fluid intake oral analgesics and attempted urination once erection subsides

Question 12

priapism lasting more than 2 hrs with more significant symptoms need

Answer 12

IV pain meds and IVFs, blood aspiration of the corpus canvernosum with saline irrigation and intracavernosal injection of sympathomimetics (phenylephrine and epinephrine) to restore penile venous outflow. (done by a urologist)

Question 13

priaprism that lasts for >12 hrs may need (what for treatment)

Answer 13

surgical shunting and glans-spongiosum shunt to bypass blood from corpus cavernosum to corpus spongiosum and relieve occlusion.

Question 14

what Hgb target is aimed for with pts who have sickle cell disease and acute pain crisis?

Answer 14

exchange transufsions should help increase hgb level rapidly and the goal Hgb target is <10g/dl. we do not aim for higher because this can cause neurological complications like headaches, seizures, obtundation requiring ventilatory support.

Question 15

Sickle cell trait patients can present with;

Answer 15

recurrent gross hematuria - make sure that urinalysis lacks active urinary sediment which would make glomerular causes more likely.
Normal U?s means no structural kidney lesion , kidney stone or UTI less likely.

Question 16

two renal pathology that you will see with a sickle cell trait patient

Answer 16

hematuria and impaired ability to make maximally concentrated urine

Question 17

why does a sickle cell trait patient have abnormal renal function?

Answer 17

because the renal papilla is in a naturally hypoxic and hypertonic environment and so papillary blood flow velocity is is relatively slow and this all favors sickling of cells and this leads to renal papillary infarction and possibly papillary necrosis

Question 18

what is seen on labs of sickle cell crisis or vasoocclusive phenomena ?

Answer 18

acidosis, hypovolumia, and hypoxia

Tx with aggressive IV hydration and opioid pain control.

Question 19

Parvo B19 infection with sickle cell dx?

Answer 19

pts can develop severe anemia from red cell aplasia due to underlying viral infection like parvovirus B19.

Can see fatigue, rhinorrhea, macular exanthems (slapped cheeks) and myalgias.

Question 20

what does parvovirus B19 do to bone marrow in sickle cell pts?

Answer 20

causes can cause a aplastic anemia in sickle pts.

See cessation of RBC production temporarily and can caused reticulopenia (starts about 5 days after exposure and can continue for 7-10 days) and can see a drop in Hgb that may need transfusions.

Question 21

When should a sickle cell pt get a RBC exchange transfusion?

Answer 21

acute chest syndrome, CVA, TIA, or priapism.

Question 22

what are the causes of acute severe anemia in a sickle cell dx pt?

Answer 22

splenic sequestration crisis
aplastic crisis
hyperhemolytic crisis

Question 23

What is a splenic sequestration crisis?

Answer 23

this is vasoocclusion in spleen causing pooling of RBCs.

see markedly low hgb, high reticulocytosis, and rapidly enlarging spleen

Question 24

where do we see splenic sequestration crisis?

Answer 24

seen in sickle cell children before autosplenectomy (where this sequestration crisis leads to splenic infarction in different areas)

Question 25

what is done to prevent splenic sequestration crisis?

Answer 25

splenectomy to prevent reoccurrences.

By the time sickle cell pt is an adult, they will have functional asplenia as their spleen will have completely infarcted.

Question 26

Aplastic crisis features

Answer 26

transient arrest of erythropoiesis with markedly low bone marrow RBC precursors, markedly low Hgb, and low reticulocytes.

Usually due to infection (Parvo B19, EBV, Strep pneumoniae, and Salmonella)

Recurrent dx is rare due to immunity

Question 27

What is hyperhemolytic crisis?

Answer 27

sudden worsening of anemia with increased reticulocytosis

unclear etiology but possibly delayed transfusion reaction in tps with multiple transfusions

Question 28

what causes aplastic crisis

Answer 28

transient bone marrow arrest leading to decrase erythropoiesis and decreased hgb (<4) and little to no reticulocytosis.

see profound anemia, pallor, weakness, lethargy, dyspnea.

Question 29

What is treatment for aplastic crisis?

Answer 29

supportive with transfusions, rest, analgesics, hydration, and oxygenation. recurrent aplastic anemia is rare due to immunity to viral illness.

Question 30

difference between hyperhemolytic and splenic sequestration and aplastic anemia crisis?

Answer 30

both hyperhemolytic crisis and splenic sequestration present with reticulocytosis

aplastic crisis presents with little or no reticulocytosis

Question 31

side effects of hydroxyurea:

Answer 31

myelosuppression and leukopenia and neutropenia. can also cause thrombocytopenia.

Question 32

what is also associated with sickle cell dx?

Answer 32

Iron deficiency anemia - seen in 20% of SCD due to increased urinary excretion of iron loss but ferritin is <25.

Question 33

Acute chest syndrome is defined as:

Answer 33

new infiltrate on CXR + any of the following: fever, chest pain or respiratory symptoms like cough, wheezing, decreased oxygen saturation, tachypnea, or accessory muscle usage.

Question 34

causes of acute chest syndrome

Answer 34

infection
asthma
hypoventilation
pulmonary vasoocclusion from fat emboli

Question 35

if sickle cell dx pt is admitted for acute pain crisis and their CXR is negative does that mean they don’t have acute chest syndrome?

Answer 35

No. Negative CXR obtained at initial presentation do not rule out subsequent development of acute chest syndrome

ACS develops within 48-72 hrs after admission for acute pain crisis.

Pts admitted for sickle crisis should be considered to be in prodromal phases of acute chest syndrome

Question 36

What are some measures that could be done to prevent a pt in sickle cell crisis from developing acute chest syndrome?

Answer 36

prophylactic measures are: close pulmonary monitoring, cautious hydration, optimal pain control and incentive spirometry

Question 37

What empiric antibiotics should be started for someone with acute chest syndrome:

Answer 37

they need to cover atypical organisms like Chlamydia and Mycoplasma (azithromycin)

Question 38

What type of fluids should be started for a patient in acute sickle cell crisis?

Answer 38

hypotonic 1/2 normal saline or D5 1/2 normal saline.

Question 39

Complications of sickle cell TRAIT

Answer 39

renal disease
hematuria, increased UTI, renal medullary carcinoma

Thrombosis:
splenic infarct, VTE, and priapism

Question 40

pts with sickle cell trait are

Answer 40

asymptomatic and don’t have complications of sickle cell dx like vasoocclusive crisis and hemolysis,

But they can have hematuria from infarction of renal medullary blood vessels

can see splenic infarct in strenuous exercise or exposure to hypoxic conditions - if infarction occurs in portion of spleen next to diaphgram can see small pleural effusion with radiation of pain to shoulder top.

Question 41

splenic infarct is seen with

what’s it’s presentation?

Answer 41

sickle cell trait pts

can see splenic infarct in strenuous exercise or exposure to hypoxic conditions - if infarction occurs in portion of spleen next to diaphgram can see small pleural effusion with radiation of pain to shoulder top.

Question 42

Treatment of splenic infarct in sickle cell trait pts

Answer 42

Tx is supportive care and analgesia.

Question 43

how to prevent secondary stroke in a patient with sickle cell disease

Answer 43

need to get monthly erythrocyte transfusions.

70% of new stroke and subsequent stroke without intervention.