Sickle cell Flashcards
Etiology of sickle cell
Valine substituted for glutamic acid at 6th position of beta globin chain, leading to decreased solubility, overwhelming RBC skeleton, leading to sickling
hgb electrophoresis in sickle cell anemia
90% hgb SS
5% hgb A2
3-4% hgb F
hgb electrophoresis in sickle cell trait
60% hgb A
40% hgb S
A2 normal
F normal
Hgb SC electrophoresis
50% hgb S
0% hgb A
50% hgb C
hgb SC specific clinical features
- ocular complications, *sickle cell retinopathy. They have a higher incidence of sickle cell retinopathy than HbSS
- osteonecrosis
sickle b0 phenotype
very similar to hgb ss
sickle b0 hgb electrophoresis
hgb s at 80%
A2 at 3%
*Just remember very little to no hgb A
hgb F at 17%
sickle b+ hgb electrophoresis
hgb s at 80%
A 20%
A2 3%
hgb F at 17%
complications sickle cell trait patients are at risk of
- hematuria
- renal papillary necrosis
- pyelo
- VTE during pregnancy
- hypothesthenuria (inability of the kidney to concentrate the urine normally)
- increased UTI’s in pregnancy
- renal medullary carcinoma
- risk of severe splenic infarction at high altitude
Malignancy sickle cell patients are at higher risk of
Renal medullary carcinoma
Sickle cell additional clinical complications
- developmental delay
- retinal vessel occlusion
- osteomyelitis
- leg ulcers
- biliary stones
- hepatic sequestration crises
Encapsulated organisms sickle cell pts are at risk of
Please SHind ME Skis
Pseudomonas
Strep
H flu
Meningitis
E coli
Salmonella
Klebsiella
Group b strep
Vaccinations sickle cell patients need
- Strep pneumonia
- H flu
- neisseria meningitis
GU complications of sickle cell
- priapism
- renal medullary necrosis
indications for exchange in sickle cell
*acute retinal artery occlusion
- CVA
- severe ACS
How to reduce risk of alloimmunization in sickle cell patients
Extended red cell phenotyping (looking at kell antigens etc)
presentation of splenic sequestration crises
- sudden drop in hgb (RBCs pool in spleen) + left upper quadrant pain + massive splenomegaly
*can be in hypovolemic shock
*Typically occurs in children <2. HOWEVER, adults who have milder forms (HbSC or HbS/b+ can happen because spleen is not auto-infarcted
hyperhemolytic crisis presentation
- hematuria
- severe hemolysis in the setting of transfusion