Paeds: haem Flashcards
Sickle Cell Anaemia
inheritance pattern
autosomal recessive
Sickle Cell Anaemia
where is the abnormal gene
abnormal gene for beta-globin on chromosome 11
Sickle Cell Anaemia
what variant of Hb do pts have
haemoglobin S (HbS)
Sickle Cell Anaemia
in normal pts, when does HbA replace HbF
around 6w of age
Sickle Cell Anaemia
what is the relationship between this and malaria
having sickle-cell trait reduces the severity of malaria
Sickle Cell Anaemia
when is sickle cell disease tested
newborn screening heel prick test at 5 days of age
or Pregnant women at risk of being carriers of the sickle cell gene
Sickle Cell Anaemia
complications
- Anaemia
- Increased risk of infection
- Stroke
- Avascular necrosis in large joints such as the hip
- Pulmonary hypertension
- Painful and persistent penile erection (priapism)
- Chronic kidney disease
- Sickle cell crises
- Acute chest syndrome
Sickle Cell Anaemia
general mnx
- Avoid dehydration and other triggers of crises
- Ensure vaccines are up to date
- Abx prophylaxis to protect against infection, (phenoxymethypenicillin)
- Hydroxycarbamide: stimulates production of HbF (does not lead to sickling of RBCs)
- Blood transfusion for severe anaemia
- Bone marrow transplant can be curative
Sickle Cell Anaemia
what is Sickle Cell Crisis
an umbrella term for a spectrum of acute crises related to the condition
can occur spontaneously or be triggered by stresses such as infection, dehydration, cold or significant life events.
Sickle Cell Anaemia
name some Sickle Cell Crisis’
- Vaso-occlusive Crisis (AKA painful crisis)
- Splenic Sequestration Crisis
- Aplastic Crisis
- Acute Chest Syndrome
Sickle Cell Anaemia
mnx for sickle cell crises
supportive:
- low threshold for admission
- treat any infection
- keep warm
- well hydrated
- analgesia
- penile aspiration for priapism
Sickle Cell Anaemia
sickle cell crises: what causes Vaso-occlusive Crisis (AKA painful crisis)
the sickle shaped blood cells clogging capillaries and causing distal ischaemia
Sickle Cell Anaemia
sickle cell crises: signs + symptoms of Vaso-occlusive Crisis (AKA painful crisis)
- dehydration
- raised haematocrit
- pain
- fever
- priapism
Sickle Cell Anaemia
how does vaso-occlusive crisis cause priapism is men
trapping blood in the penis, causing a painful and persistent erection.
Sickle Cell Anaemia
mnx of priapism
urological emergency
treated with aspiration of blood from the penis
Sickle Cell Anaemia
sickle cell crises: what causes splenic sequestration crisis
RBCs blocking blood flow within the spleen
Sickle Cell Anaemia
sickle cell crises: signs and sx of Splenic Sequestration Crisis
- acutely enlarged and painful spleen
- severe anaemia _ hypovolaemic shock due to pooling of blood in spleen
Sickle Cell Anaemia
sickle cell crises: mnx of Sequestration Crisis
emergency!
supportive:
- blood transfusions
- fluid resuscitation
Sickle Cell Anaemia
sickle cell crises: what can prevent sequestration crisis
splenectomy
Sickle Cell Anaemia
sickle cell crises: what can recurrent Splenic Sequestration Crisis lead to
splenic infarction, resulting in susceptibility to infections.
Sickle Cell Anaemia
sickle cell crises: what is Aplastic crisis
temporary loss of the creation of new blood cells
Sickle Cell Anaemia
sickle cell crises: what is Aplastic crisis commonly triggered by
parvovirus B19
Sickle Cell Anaemia
sickle cell crises: what does Aplastic crisis lead to
significant anaemia
Sickle Cell Anaemia
sickle cell crises: mnx of Aplastic crisis
supportive with blood transfusions if necessary
usually resolves spontaneously within a week.
Sickle Cell Anaemia
sickle cell crises: what does a diagnosis of acute chest syndrome require
- fever or resp sx
and
- new infiltrates on CXR
Sickle Cell Anaemia
sickle cell crises: what can acute chest syndrome be due to
infection (e.g. pneumonia or bronchiolitis)
or non-infective causes (e.g. pulmonary vaso-occlusion or fat emboli)
Sickle Cell Anaemia
sickle cell crises: mnx of acute chest syndrome
medical emergency
- trx underlying cause
- abx/antivirals for infection
- blood transfusions for anaemia
0 incentive spirometry: machine that encourages effective + deep breathing - artificial ventilation with NIV or intubation
