4. SCD - Clinical effects + Treatment Flashcards
how come chronic anaemia is less apparent in young
can adapt by increased heart output
why limited life expectancy
as get older, chronic anaemia causes heart and lung problems + repeated crises
Dactylitis
- severe swelling of hand
- cold weather triggers it
how can it cause skeletal deformity
- blocked vessels that supply growth plate
- can cause shortened metacarpal bone
stroke
if blockage occurs in brain, can cause stroke
requires intensive treatment
why scd highly prone to infection
spleen prone to sickling = fibrosis and calcification = spleen protects from infection
how can lung infection cause chest crisis
blood vessels in that area obstructed with neutrophils/bacteria
blood not reoxygenated properly
(pain can prevent full breaths)
mild crisis case treatment
- pain relief
- hydration
- treat causes such as fever or infection
- if serious then send hospital
treatment of crisis if case is more severe
- transfusion
- exchange transfusion
long term treatments
- Preventative:
- education
- vaccination
- antibiotics
- folic acid - Modifying RBC
- raise HbF - Severe cases
- chronic transfusion
- bone marrow transplants
which drug can increase HbF levels
hydroxycarbamide
4 types of experimental therapy
- gene therapy
- anti-sickling molecules
- anti adhesion molecules
- modifying vascular tone
low cost treatments
- screening
- education
- folic acid
- vaccination, antibiotics
- malaria treatment
- hydroxycarbamide (bit more spenny)
what can choice of diagnosis type depend on
- speed
- accuracy
- expertise
- throughput
- cost
blood smear adv + disadv
- cheap and fairly quick
BUT
- need expertise
- some healthy patients have rare sickle cells
- can have multiple other problems affecting cell appearance
haemoglobin solubility test
- detergent added to lyse cells
- add reducing afent
- Hb forms clear suspension of monomers
BUT - sickle Hb is cloudy cuz of polymers
Hb polymerisation adv and disadv
- cheap, quick, little training
BUT - doesnt distinguish homo or het zygous
= used preoperative
flat bed electrophoresis as diagnostic
charged Hb moves faster than uncharged
- normal Hb at bottom
- het has one normal and one slow moving
- homo will move all slow rate
alternative to flat bed gel
high pressure column chromatography
charge based diagnostic adv and disadv
- accurate
- intermediate cost
-good for complex cases - can be scaled up for large number of samples
BUT - not as quick
- needs expertise
genetic testing adv and disadv
- accurate, useful in complex cases
BUT - costly
- takes long
- expertise
