Chapter 11: Hemoglobinopathies: Sickle Cell Disease

Question 1

Sickle Cell Disease

Answer 1

most common hemoglobinopathy
-it is of recessive inheritance and occurs when the gene for the production of hemoglobin S (HbS) is inherited from both parents (homozygous)

Question 2

Pathophysiology

Answer 2

patients with sickle cell anemia suffer from life-long complications as a result of the shortened life-span of their RBCs
-when HbS is exposed to low oxygen tension, it precipitates into long crystals, or polymers, within the RBC. With the lowered or absent amount of oxygen, the sickle cell hemoglobin molecule becomes rigid and dehydrated and assumes an abnormal crescent; the sickled erythrocytes cannot change their shape and are unable to squeeze through the microcirculation; obstruction results, leading to hypoxia; progressive tissue ad organ damage occur along with painful vaso-occlusive cries and an increased susceptibility to infection

Question 3

S/S

Answer 3

r/t vascular occlusion, hemolysis, and infection
>hemoglobin levels fall to 6 to 8 g/dL
>increase in bilirubin levels caused by hemolysis
>folate, or iron deficiency from bone marrow suppression
-hepatomegaly, cardiomegaly, conjunctival vessel changes, systolic murmurs, and arthritis

Question 4

Effects During Pregnancy

Answer 4

• severe anemia

- vasoocclusive cries

Question 5

Management

Answer 5

-individualized
-folate supplements at least 4 mg/day
-serum iron and ferritin levels monitored; iron supplementation only initiated if levels diminish
>pica may appear
-early detection
-urine cultures routinely to detect asymptomatic bacteriuria
-IV fluids to prevent dehydration
-prompt treatment of sickle cell crisis with oxygen, fluids, and pain management; IV morphine usually drug of choice
-Blood transfusions may be given to increase hemoglobin to 10 g/dL range
-fetal surveillance: fetal kick counts, nonstress test, biophysical profiles, and Doppler velocimetry begin at 26 weeks; assessment of fundal eight and ultrasound for intrauterine growth