haematology Flashcards
causes of iron deficiency anemia? 2
- low iron intake
- malabsorption
- blood loss: e.g meckels diverticulum
presentation of iron deficiency anemia? symptom and signs
symptoms: fatigue, dizziness, cold, dyspnea, poor feeding, pica
signs: pallor, angular cheilitis, atrophic glossitis
laboratory findings suggestive of iron deficiency anemia?
FBC: low Hb and MCV (microcytic anemia)
iron studies: low free iron, low ferritin, high total iron binding capacity
blood smear: microcytic hypo chromic RBC without schistocytes
management of iron deficient anemia?
dietary advice and iron supplements (Galfer) until iron level is normal for 3 months
define hereditary spherocytosis ? describe genetics
an autosomal dominant condition caused by mutations in spectrum/ankyrin/Band-3, resulting in defective RBC membrane
clinical features
- features of anemia + jaundice (due to hemolysis)
- splenomegaly
- may present with aplastic crisis after infections with parvovirus B19 infection
Diagnosis of hereditary spherocytosis ?
- FBC: low Hb and high reticulocytes
- blood smear shows spherocytes
- confirmatory test: EMA test (Eosin-5 maliemide) - EMA usually binds cell membrane proteins and fluorescence, absence of cell surface proteins reduced fluorescence
define G6PD deficiency? genetics ? what population is it common in
X-linked recessive disorder commonly seen in patients from middle-east and Africa. G6PD enzyme protects the RBC from oxidation and hemolysis. dysfunction leads to increased oxidative stress under certain triggers leafing to hemolysis
precipitants of G6PD deficiency?
- infections (biggest precipitant)
- antibiotics (co-trimaxaole, quinolone, sulphonamide)
- analgesics: aspirin
- chemicals: naphthalene
- food: fava beans
presentation of G6PD?
acute hemolysis from exposure to precipitant which includes
- features of anemia + jaundice + dark urine
- abdomina pain, fever, malaise
how is the diagnosis of G6PD deficiency made? when should it not be done to avoid false negative?
G6PD enzyme assay. not to be performed during an acute hemolytic episode (due to high rates of false-negatives
management of G6PD deficiency?
- avoid precipitants
- treat infections
- manage acute hemolytic episodes: hydration and transfusions
management of hereditary spherocytosis ?
- supportive management: folic acid and transfusions
- if severe disease with aplastic crisis: splenectomy
define Beta-thalassemia?
a disorder of abnormal hemoglobin production
what populations is beta-thalassemia common in ?
india, middle-east, and Mediterranean
what are the 2 types of beta-thalassemia?
major: transfusion-dependent, cannot produce HbA
intermedia: produce a small amount of HbA
minor: often asymptomatic
what age does beta-thalassemia usually present? how may it present?
3-6 months
severe and transfusion dependent anemia and jaundice , faltering growth, if untreated: maxillary overgrowth and skull bossing
management of beta-thalassemia
- regular transfusions (especially for major, less regularly for intermedia) + deferoxamine (iron chelator to prevent transfusion related hemochromatosis, which can lead to cirrhosis and cardiomyopathy)
define sickle cell disease ? genetics and population most commonly seen in?
autosomal recessive disorder cause by the replacement of glutamine by valine on codon 6 of the beta global gene. occurs in 1/2000, commonly in patients of afro-carribean origins
clinical features:
anemia, jaundice, hepatosplenomegaly
presentations of sickle cell disease?
- vaso-oclusive episodes: dactylitisi (typically the first complaint at 6 months), avascular necrosis of the long bones, priapism: painful erection leading to necrosis, acute chest syndrome, splenic sequestration crisis
- long term sequale of chronic anemia: cerebral vascular accident, cardiac disease, renal disease, leg ulcers, delayed puberty
- acute hemolytic or aplastic anemia
management of sickle cell disease?
- long term penicillin prophylaxis and annual immunization with flu and PCV
- avoid precipitants of crises (dehydration, cold)
- management of acute pain crisis: analgesia, fluids and antibiotics (infection-induced), exchange transfusion for acute chest syndrome, priapism or stroke
- chronic disease: hydroxyurea to boost the child HbF production (notable side effect is white cell suppression). if this fails then consider bone marrow transplant
Define hemophilia? what are the 2 types
X-linked recessive disorder characterized by recurrent spontaneous bleeding into joints and muscles, ultimately leading to crippling arthritis. inherited coagulopathy
A= factor 8 deficiency
B= factor 9 deficiency
how may hemophilia present at birth?
scalp hematoma
how may hemophilia present in a neonate?
- bleeding post circumcision
- seizures from intracranial hemorrhage
how may hemophilia present in children?
tripping and bleeding
in haemophilic patients any spontaneous bleeding without minor trauma indicates …. disease with … % of factors present
severe
<1%
how is hemophilia diagnosed?
- coagulation screen: prolonged aPTT, normal PT, normal platelets
- factor activity levels: <5%
management of hemophilia ? prophylactic, active bleeding, mild hemophilia
- prophylactic factor therapy for patient with high risk of bleeding
- active bleeding management: transfusion of recombinant F8 for hemophilia A, or F9 for type B. if unknown, give fresh frozen plasma (prothrombin complex concentrate does not contain factor 8 – only vitamin K dependent)
- mild hemophilia A = desmopressin
what is important to remember to avoid in hemophilia patients ?
always avoid NSAIDs, aspirin and intramuscular injections
recurrent hemarthroses in patients with hemophilia may lead to haemophilic arhtropathic necessitating?
joint replacement
