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19 Cards in this Set
- Front
- Back
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What populations are at increased risk for hemoglobinopathy?
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All except:
Japanese, Korean, Caucasian of Northern European ancestry, First Nations, or Inuit |
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What is classic sickle-cell disease?
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Individual has two copies of HbS allele, which results in abnormal hemoglobin HbS (HbS+normal alpha chains). This results in decreased O2 carrying capacity of the Hb and precipitation resulting in sickling of the erythrocyte membrane.
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a) What hemoglobin chain is mutated in sickle-cell disease?
b) What is sickle-cell trait? |
a) beta-chain
b) HbS/HbA - patient has some normal Hb comprised of normal alpha + beta chains, and some abnormal HbS comprised of alpha + HbS chains. |
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What is the carrier frequency (Sickle-cell trait) among US African-lineage blacks?
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1/12
the affected adult individual rate is lower than 1/12x1/12x1/4 because mortality is increased in children with SCD. |
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What adverse maternal/pregnancy/fetal outcomes are associated with maternal sickle-cell trait?
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Maternal:
VTE/PE (2&4-fold higher respectively) Hematuria Renal papillary necrossi Hyposthenuria Pregnancy/fetal: ASYMPTOMATIC BACTERIURIA [Williams OB strongly states that there is an unquestionable increased risk] Fetal: HbSS inheritance SA/IUFD risk is controversial, probably not increased |
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What other sickle cell diseases are there?
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HbSC
HbS/B+, HbS/B0 HbSE |
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If a women and her partner are both known carriers of a hemoglobinopathy with potential risk to the fetus (e.g. HbSA and HbSA) what are pre-conception options for decreasing the risk of having an affected infant?
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Donor sperm
IVF with PGD amniocentesis, genetic testing, with possible termination |
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In sickle-cell disease (HbSS), what end-organs are affected and must be considered in pre-pregnancy counseling/antenatal care?
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Eyes (retinopathy)
Heart (cardiomyopathy Lungs (pulmonary HTN, PE, vaso-oclusive crises) Kidneys (nephropathy, *UTIs*) Vascular (HTN, anemia, isoimmunization) Liver (iron overload) Spleen (aspleenia) Immune (sepsis) |
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What pre-existing medical conditions can women with sickle-cell disease present with?
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Cardiomyopathy
Pulmonary HTN Kidney disease (chronic) HTN history of VTE/PE Hepatitis (less common) Asplenia |
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In a women with a sickle-cell disease (e.g. HbSS), what baseline prenatal tests should be done?
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Partner testing to assess risk to fetus/infant
Blood pressure CBC, ferritin, confirm hemoglobinopathy diagnosis Antibody screen (high-risk isoimmunization from Tx) Creatinine, urine protein (Nephropathy) PFTs Echocardiogram (cardiomyopathy, PHTN) Retinal assessment (retinopathy) Urine culture (incr risk asymp bacteriuria) Ultrasound abdomen (hepatosplenomegaly) |
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List adverse maternal/pregnancy outcomes pregnant women with sickle-cell anemia have are at increased risk for.
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Death
Transfusion Acute pain crises Chest Marrow FGR Perinatal mortality DVT/PE, venous sinus thrombosis Infection Sepsis, Pneumonia, UTI Eclampsia |
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a) What is acute chest syndrome? (Williams OB)
b) What can precipitate this? |
a)
New infiltrates on CXR Respiratory symptoms (e.g. dyspnea) Fever b) Infection Thromboemboli Marrow emboli Atelectasis |
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Describe aspects of antenatal care of a patient with sickle-cell disease.
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Folate high-dose (support erythropoesis)
Screen for Iron overload Screen for RBC antibodies Screen for asymptomatic bacteriuria Ensure vaccination is up to date HiB, pneumococcus, meningococcus U/S for fetal growth Reassess Medications (e.g. hydroxyurea, ACEi) pRBC Transfusion for acute pain crises |
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What are recommended contraception options for patients with sickle-cell disease?
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WHO - all forms including COCP
Williams OB cautious use COCP progesterone appears to reduce pain crises DMPA, micronor, implants concern for infection with IUD barrier methods recommended |
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a) What is hydroxyurea and how does it work in sickle-cell disease?
b) is it safe in pregnancy? |
a)
antimetabolite Increases expression of gamma-chain, resulting in more HbF (gamma+alpha chain Hb) and less sickling--> less occlusive crises decreases pain crises and may prolong survival b) limited safety data, teratogenic in animal studies, generally discontinue. |
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Are prophylactic blood transfusions recommended?
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Controversial. Used as treatment for acute pain crisis.
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List aspects of labour and delivery management for a women with sickle-cell disease.
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Manage like cardiac patient (Williams)
Adequate but not profuse hydration Keep Warm Pain control (epidural) Ensure antibody-compatible blood available |
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How should acute pain crises be managed?
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Oxygen
Hydration Treat inciting factor (e.g. infection) pRBC transfusion Monitor fetus (EFM, U/S) |
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Is sickle-cell disease an immediate neonatal concern?
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No - HbF is main Hb until >3 months.
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