Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
What populations are at increased risk for hemoglobinopathy?
|
All except:
Japanese, Korean, Caucasian of Northern European ancestry, First Nations, or Inuit |
|
What is classic sickle-cell disease?
|
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.
|
|
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. |
|
What is the carrier frequency (Sickle-cell trait) among US African-lineage blacks?
|
1/12
the affected adult individual rate is lower than 1/12x1/12x1/4 because mortality is increased in children with SCD. |
|
What adverse maternal/pregnancy/fetal outcomes are associated with maternal sickle-cell trait?
|
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 |
|
What other sickle cell diseases are there?
|
HbSC
HbS/B+, HbS/B0 HbSE |
|
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?
|
Donor sperm
IVF with PGD amniocentesis, genetic testing, with possible termination |
|
In sickle-cell disease (HbSS), what end-organs are affected and must be considered in pre-pregnancy counseling/antenatal care?
|
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) |
|
What pre-existing medical conditions can women with sickle-cell disease present with?
|
Cardiomyopathy
Pulmonary HTN Kidney disease (chronic) HTN history of VTE/PE Hepatitis (less common) Asplenia |
|
In a women with a sickle-cell disease (e.g. HbSS), what baseline prenatal tests should be done?
|
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) |
|
List adverse maternal/pregnancy outcomes pregnant women with sickle-cell anemia have are at increased risk for.
|
Death
Transfusion Acute pain crises Chest Marrow FGR Perinatal mortality DVT/PE, venous sinus thrombosis Infection Sepsis, Pneumonia, UTI Eclampsia |
|
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 |
|
Describe aspects of antenatal care of a patient with sickle-cell disease.
|
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 |
|
What are recommended contraception options for patients with sickle-cell disease?
|
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 |
|
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. |
|
Are prophylactic blood transfusions recommended?
|
Controversial. Used as treatment for acute pain crisis.
|
|
List aspects of labour and delivery management for a women with sickle-cell disease.
|
Manage like cardiac patient (Williams)
Adequate but not profuse hydration Keep Warm Pain control (epidural) Ensure antibody-compatible blood available |
|
How should acute pain crises be managed?
|
Oxygen
Hydration Treat inciting factor (e.g. infection) pRBC transfusion Monitor fetus (EFM, U/S) |
|
Is sickle-cell disease an immediate neonatal concern?
|
No - HbF is main Hb until >3 months.
|