Sickle Cell Flashcards
sickle cell is a mutation in?
hemoglobin B chain that leads to hemoglobin S formation which polymerizes when it is deoxygenated
Deoxygenated hemoglobin S causes what
sickling of RBCs that leads to blood vessel occlusion and ischemia
most common form of sickle cell
homogenous HbSS
diagnosis of sickle cell
hemoglobin separation studies and genetic studies
infants with confirmed sickle cell disease should receive what prophylactically
antibiotic prophylaxis against pneumococcal infection
pathophysiology of sickle cell
point mutation in the B globin gene on chromosome 11
glutamic acid is replaced with Valine
sickling of hemobglobin S occurs in deoxygenated states what are some states like this
hypoxia , infections, dehydration, acidosis, and stress
clinical features of sickle cell
painless gross hematuria due to renal papillary necrosis
dactylitis <5 years old
vasooclusive crises: throbbing pain in the limbs, chest and back
infection: osteomyelitis, sepsis
splenic sequestration, aplastic crisis
pigmented stones
osteomyelitis in sickle cell is often caused by?
salmonella spp
sepsis in sickle cell is most often caused by?
streptococcous pneumoniae
CBC findings of sickle cell
cresent shaped sickled RBCs
howell-jolly bodies (basophillic remnants of DNA found in immature RBC that cant be taken out by the spleen)
infants and children with sickle cell should recieve antibiotic prohylaxis against pneumococcal disease until what age?
5 years of age
what drug is used in sickle cell to minimize disease related complications
hydroxyurea
for infants and children with sickle cell what is used to screen for stroke
an annual (yearly) transcranial doppler from 2 months until 16 years old
what immunizations should people with sickle cell definitely get?
pneumococcal and meningococcal
what is the daily prophylactic antibiotic given to kids 2 months until 5 years old with sickle cell
daily penicillin
first line therapy for sickle cell
hydroxyurea
3 or more pain episodes a year
symptomatic anemia
acute chest syndrome
MOA of hydroxyurea
stimulates erythropoiesis and increased fetal hemoglobin
when would you do an allogeneic bone marrow transplant in someone with sickle cell
if they have a hisotry of stroke or abnormal transcranial doppler
recurrent episodes of pain and or ACS
works better if done before age 16
when are exchange transfusions used in sickle cell
to prevent and treat vasoocclusive events
when are simple transfusions used in sickle cell
to manage acute anemia in sickle cell disease
how do you treat vasoocclusive crises aka sickle cell pain crisis
manage their pain
ensure hydration and administer oxygen if needed
what are the vasoocclusive events that may occur in sickle cell disease
stroke or splenic sequestration
how do you treat stroke in sickle cell disease
exchange transfusion
how does splenic sequestration present in sickle cell disease
abrupt left upper quadrant pain, splenomegaly, hypotension, hypovolumeic shock
anemia
what are the supportive findings of splenic sequestration
anemia with a Hb drop of greater than 2 with reticulocytosis
thrombocytopenia
treatment of splenic sequestration
IV fluid resuscitation
RBC exchange transfusion
Aplastic crisis in sickle cell disease is caused by
an infection with parvovirus B19 causing red blood cell aplasia and a drop in hemoglobin and reticulocytopenia
patients with sickle cell disease are at high risk of infection most commonly by
encapsulated bacteria
what is the first line antibiotic to treat infections in sickle cell disease
IV third generation cephalosporins like ceftriaxone
fetal complications in sickle cell disease
increased risk of fetal growth restriction, low birth weight, preterm delivery, stillbirth
what is acute chest syndrome
a complication of sickle cell disease that causes new chest infiltrate and respiratory symptoms
chest pain, dyspnea, hypoxia
- high risk of mortality
skeletal complications of sickle cell disease
avascular osteonecrosis (interrupted blood supply to bone leads to death of bone tissue)
individuals with sickle cell trait are less likely to develop ?
malaria
