Sickle Syndromes - study Flashcards
what are sickle syndromes
group of genetic disorders that affect the structure of haemoglobin, resulting in the production of HbS
what type of mutation in what codon in what gene causes sickle?
point mutation in codon 6 of the beta globin gene
if someone has sickle cell trait, when might they sickle
severe hypoxia e.g. high altitude, under anaesthesia
sickle cell trait (HbAS) blood film
normal
what is the diagnosis: HbS >80%, no HbA
sickle cell anaemia (HbSS)
in sickle disease - what is it called when episodes of tissue infarction occur due to vascular occlusion
sickle crisis
what is sickle crisis
episodes of tissue infarction due to vascular occlusion
clinical features of sickle cell anaemia
- vaso-occlusive crises
- acute chest syndrome
- pulmonary hypertension
- anaemia
investigations
bloods: FBC, Hb, red cell indices, blood film
high performance liquid chromatography (HPLC) or electrophoresis
management of a sickle crisis
treatments include:
- high flow oxygen
- IV fluids and opiate analgesia
- red cell exchange transfusion in severe crisis e.g. chest crisis (lung) or brain (stroke)
- antibiotics if evidence of infection
which vaccinations are given to sickle cell anaemia patients
- pneumococcus
- meningococcus
- haemophilus
how does hydroxycarbamide work in sickle cell anaemia
increases foetal haemoglobin concentrations
is hydroxycarbamide teratogenic
yes potentially
newer therapies for long term management of sickle cell anaemia
- Crizaniluzumab (p-selectin inhibitor) for treatment of pain crises
- voxelotor (haemoglobin oxygen-affinity modulator) for haemolytic complications