sickle cell anaemia Flashcards
what connection does sickle cell disease have to malaria
having a copy of the sickle cell trait reduces the severity of malaria and then more likely to pass on their genes
how to test new borns for sickle cell disease
heel prick test at 5 days of age
complications of sickle cell disease
anaemia
increased risk of infection
stroke
AVN in large joints
pulmonary hypertension
painful and persistent penile erection
CKD
sickle cell crises
acute chest syndrome
chest pain + hypoxia + new infiltrates
acute chest syndrome
sickle cell trait
one normal one abnormal gene
asymptomatic carrier state
few clinical features
treatment of sickle crisis
opiate analgesia
hydration
rest
oxygen
antibiotics if infection
red cell exchange transfusion in severe crisis
long term management of sickle cell anaemia
hyposplenism- reduce risk of infection
- prophylactic penicillin
- vaccination (pneumococcus, meningococcus, haemophilus)
folic acid supplemtation
hydroxycarbamide can reduce severity of disease
regular transfusion to prevent stroke in selected cases
presentation of aplastic crises
caused by infection with parovirus
sudden fall in haemoglobin
reduced reticulocyte count
what is sequestration crises
sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
associated with increased reticulocyte count
management of acute chest syndrome
pain relief
oxygen therapy
antibiotics
transfusion
pathophysiology of sickle cell disease
point mutation in codon 6 of the beta globin gene that substitutes glutamine to valine producing betaS (resulting in HbS)
presentation of sickle cell trait
asymptomatic
few clinical features
haemoglobin studies in sickle cell anaemia (HbSS)
HbS > 80%, no HbA
what is sickle crisis
sickle vaso-occulusion
- tissue ischaemia and pain
precipitant of sickle crisis
hypoxia
dehydration
infection
cold exposure
stress/fatigue
