Haematology Flashcards
(52 cards)
1
Q
What are the common causes of iron deficiency anaemia in children?
A
- Inadequate intake
- Malabsorption
- Blood loss
2
Q
What are sources of iron for an infant?
A
- Breastmilk - low content, but 50% is absorbed
- Infant formula
- Cow’s milk - high content, only 10% absorbed
- Solids introduced at weaning (i.e. cereal)
3
Q
What are the signs and symptoms of iron deficiency anaemia?
A
- Asymptomatic until <60-70g/L
- Feed slowly
- Tire quickly
- “Pica” = eating soil, dirt, etc.
4
Q
What are the appropriate investigations for suspected anaemia?
A
- Microcytic - low MCV
- Hypochromic
- Low ferritin
5
Q
What is the management of iron deficiency anaemia?
A
- Dietary advise → dark-green vegetables, meat, apricots, raisins
-
Oral ferrous sulphate, 200mg, TDS until normal Hb + at least 3/12 after
- Monitoring
- Re-check iron levels 2-4w after therapy start (at 3w, Hb should rise 2g/100mL)
- If normal, check at 2-4m (if not, address compliance issues)
- Advise black stools are a common and normal side effect → reduce by eating with food or reduced dose if appropriate
- Monitoring
6
Q
What are the causes of microcytic anaemia?
A
TAILS
- Thalassaemia
- Anaemia of Chronic Disease
- Iron deficiency
- Lead poisoning
- Sideroblastic / Congenital
7
Q
What are the causes of normocytic anaemia?
A
MR I CALM
- Marrow failure
- Renal failure
- Iron deficiency - early on
- Chronic disease
- Aplastic or Acute blood loss
- Leukaemia
- Myelofibrosis
8
Q
What are the causes of macrocytic anaemia?
A
AMHLF
- Alcoholism
- Myelodysplastic syndrome / Multiple myeloma
- Hypothyroidism or Haemolytic
- Liver failure
- Folate / B12 deficiency
9
Q
What are the signs and symptoms of sickle cell disease?
A
- Hand and foot syndrome → swollen hands & feet; dactylitis
- Acute chest syndrome (ACS)
- Splenic sequestration → anaemia, shock, death
- Painful crises / vaso-occlusive ± priapism
- Infection (pneumococcus and parvovirus)
- Splenomegaly (only in children)
10
Q
What are the appropriate investigations for sickle cell disease?
A
- Family origins questionnaire – Afrocaribean of African descent (some northern Europe)
- Guthrie testing after antenatal screening
- Solubility test - if cloudy → haemoglobin electrophoresis (gold-standard)
- FBC and blood smear
- Sickle cells
- Howell-Jowell bodies (hyposplenism)
- Nucleated RBCs
11
Q
How does sickle cell disease cause anaemia?
A
- Haemolysis
- HbS is a low-affinity Hb → more readily releases O2 → reduced EPO-drive → anaemia
12
Q
What is the management of sickle cell disease?
A
- Education → minimise trigger exposure for crises (cold, dehydration, excessive exercise, hypoxia)
- Vaccination → immunisation against encapsulated organisms (e.g. Pneumococcus / S. pneumoniae and HiB)
-
Prophylaxis
- OD oral penicillin
- OD oral folic acid (due to hyperplastic erythropoiesis, growth spurts, increased turnover)
- Treatment of Chronic Problems:
- Recurrent ACS or vaso-occlusive crisis = Hydroxycarbamide
- Stimulated HbF production
- Monitor for white blood cell suppression
- HSCT (severe cases)
- Recurrent ACS or vaso-occlusive crisis = Hydroxycarbamide
13
Q
What are the common triggers for acute crises?
A
- Cold
- Dehydration
- Excessive exercise
- Hypoxia
14
Q
What is the prognosis of sickle cell disease?
A
- Premature death due to complications
- 50% of patients with the most severe form of sickle cell disease will die <40 years
- Aplastic anaemia from B19 infection
15
Q
What are the signs and symptoms of beta thalassaemia major?
A
-
Extramedullary haematopoiesis
- Bone expansion
- Hepatosplenomegaly
- Frontal bossing
-
Anaemia (3-6m of age)
- Heart failure
- Growth retardation
-
Iron overload - from transfusions
- Heart failure
- Gonadal failure
16
Q
What are the signs and symptoms of beta thalassaemia minor?
A
- Asymptomatic
- Microcytosis with normal/low-normal haemoglobin
17
Q
What are the appropriate investigations for suspected beta thalassaemia?
A
- Family origins questionnaire – Indian, Mediterranean, Middle East
- Guthrie testing after antenatal screening
- Haemoglobin electrophoresis = gold-standard
- Blood smear
- Microcytic red cells
- Tear drop cells
- Microspherocytes
- Target cells
- Schistocytes
- Nucleated RBCs
18
Q
What is the management of thalassaemia?
A
- Beta thalassaemia major
- Blood transfusion ± iron chelation (desferrioxamine, deferiprone)
- HSCT - only for children with an HLA-identical sibling
- Beta thalassaemia minor = No treatment necessary
19
Q
What is the management of an acute crises in sickle cell disease?
A
- Analgesia - avoid morphine <12 years
- O2
- Hydration
- Exchange transfusion - ACS, priapism, stroke
- Antibiotics - if infection
20
Q
What is G6PD?
A
Rate-limiting enzyme in the pentose-phosphate shunt which is vital to prevent oxidative damage to RBCs.
21
Q
What are the risk factors for G6PDD?
A
- Ethnicity = Central Africa, Mediterranean, Middle East, Far East
- X-linked
- Males
- Homozygous females
- ‘Lionised’ females → random X-chromosomes inactivated
22
Q
What are the signs and symptoms of G6PDD?
A
- Neonatal jaundice - most common cause requiring transfusion
- Acute intravascular haemolysis
- Fever
- Malaise
- Abdominal pain
- Dark urine
- Asymptomatic outside of these events
23
Q
What are the causes of acute intravascular haemolysis in G6PDD?
A
- Infection
- Drugs
- Antimalarials (i.e. quinine)
- Analgesics (i.e. high-dose aspirin)
- Antibiotics (i.e. nitrofurantoin)
- Fava/broad beans
- Mothballs/Insect repellent
24
Q
What are the appropriate investigations for suspected G6PDD?
A
- Nothing abnormal between acute episodes
- G6PD
- Raised during an acute episode – higher enzyme concentration in reticulocytes
- Reduced after the acute episode
- Confirm via G6PD in acute setting and 1 month after
- Blood film (acute) → Heinz bodies, bite cells
25
What is the management of G6PDD?
* **Advice to be aware of signs of acute haemolysis** → jaundice, pallor, dark urine
* **Avoidance of specific drugs, chemicals and foods**
* Acute haemolysis → **supportive care + folic acid**
* Blood transfusion rarely required
26
Define Haemolytic Disease of the Newborn.
Maternal antibodies against foetal blood group antigens.
* Maternal antibodies cross placenta / mix at delivery → haemolysis
* Mother must have been sensitised for this to happen → from secondary pregnancy onwards
27
What are the signs and symptoms of haemolytic disease of the newborn?
* Yellow amniotic fluid
* Hydrops fetalis - hepatosplenocardiomegaly
* Pallor
* Jaundice 24-36 hours after birth *(\<2 days)*
28
What are the appropriate investigations for suspected haemolytic disease of the newborn?
* Coombe’s test (DAT) +ve
* Haemolysis = raised uBR and reticulocyte count
* Amniocentesis
* USS = organomegaly
29
What is the management of haemolytic disease of the newborn?
* Prevention
* **Prophylaxis after sensitising events** \<72hrs - Kleiheur test can determine need for more
* 250 IU before 20 weeks
* 500 IU after 20 weeks
* **Routine Antenatal Anti-D Prophylaxis** (identified from antibody screen at 28 weeks
* **2 doses of 500 IU at 28 and 34 weeks** OR
* **1 dose of 1500 IU at 28 weeks and Foetal cord gas post-delivery and prophylaxis** → \<72 hours (500 IU anti-D) if baby +ve Kleiheur
* Treatment
* Jaundice = **Phototherapy** and **IVIG** - *if bilirubin is rising \>8.5 umol/L/hr*
* Severe or in utero = **Transfusion** into umbilical vein → delivery 37-38w
30
Define Idiopathic Thrombocytopaenic Purpura.
Immune destruction of platelets by IgG autoantibodies.
* *Same as Immune TP - new terminology*
31
What is the most common cause of thrombocytopaenia in children?
ITP - usually between 2-6yo
32
What are the signs and symptoms of ITP?
* Short history (days-weeks) of
* **Petechiae / Purpura**
* **Superficial bruising**
* **Epistaxis** and other mucosal bleeding
* Often presents much more acutely than in adults
* Recent history (1-2 weeks) of a viral infection
* Intracranial bleeding - *rare → 0.1-0.5%*
33
What are the appropriate investigations for suspected ITP?
* **Diagnosis of exclusion** → exclude genetic and leukaemia/cancer causes
* FBC
* Blood smear
* Genetic analysis
34
What is the management of ITP?
* Asymptomatic or Minor Bleeding (plts \>20 x109/L) = **Self-limiting → observation**
* Major Bleeding (plts \<20 x109/L) = **IVIG + corticosteroids ± anti-RhD**
* Life-threatening haemorrhage = **Platelet transfusion** - *raises platelets for a few hours*
35
What is the management of chronic ITP?
Platelets remain low 6/12 after diagnosis
* 1st line
* Mycophenolate mofetil
* Rituximab
* Eltrombopag *(thrombopoietin agonist)*
* 2nd line
* Splenectomy
36
What is Haemophilia?
* Deficiency of factors in the intrinsic pathway leading to APTT prolongation
* Factor VIII = A
* Factor IX = B
* X-linked recessive - primarily affecting males
* A: 1 in 10,000
* B = 1 in 50,000
* If a female is affected, it is likely they have Turner’s syndrome (only 1 X chromosome)
37
What are the signs and symptoms of haemophilia?
* Presenting around 1yo
* **Heamarthrosis** → leading to arthritis
* Present when walking begins and therefore so does falling over
* **Suspicions of NAI** (if no FHx)
* Presenting at neonatal age (40%):
* **Intracranial haemorrhage**
* **Bleeding circumcision**
* **Prolonged bleeding** from venepuncture
38
What are the appropriate investigations for suspected haemophilia?
* **Neonate history of bleeding** from Vit-K injection, umbilical cord separation, circumcision
* **FHx**
* Clotting studies
* Extrinsic = normal PT/INR
* Intrinsic = prolonged APTT
* Platelet count
* Factor 8 levels
* *F8 is low in vWD - always consider vWD especially in girls*
39
What is the management of haemophilia?
* Mild haemophilia A = **Desmopressin** - *stimulates F8 and VWF release*
* Severe haemophilia = **Prophylactic factor replacement**
* Can be done at home
* Begins at 2-3yo, 2-3x/week
* Raise baseline to above 2%
* If actively bleeding
* **IV infusion of F8/9 concentrate**
* Minor bleeds = raise to 30% normal to treat minor/simple bleeds
* Major bleeds = raise to 100%; maintain at 30% for 2/52 to prevent secondary haemorrhage
* Avoid
* IM injections
* Aspirin
* NSAIDs
40
What are the complications of haemophilia?
* Chronic arthropathy
* Compartment syndrome
* Haematuria
* HBV → *transfusion-related*
41
What is Gaucher's disease?
The most common lysosomal storage disease → **beta-glucosidase deficiency.**
* *Pompe’s disease = Alpha glucosidase*
* *Fabry disease = Alpha-galactosidase A defect*
* *Niemann-Pick Disease type C = Cholesterol trafficking disorder*
* *Wolman disease = Lysosomal acid lipase defect*
42
What inheritance patterns does Gaucher's disease follow?
* **Autosomal recessive**
* Carrier rate of 1 in 100 → 1 in 40,000 births
* 1 in 100 carrier rates → 2 carriers meeting and having a child = 0.01% chance
* Child homozygous = 25% → 0.0025% chance (100/0.0025 = 1 in 40,000 affected)
* Ashkenazi Jew carrier rate 1 in 10 → 1 in 500 births
43
What diseases are more common in Ashkenazi Jews?
* **Gaucher's disease**
* **Tay-Sachs disease** (hexosaminidase A deficiency)
* *S/S = deaf, blind, progressive neurodegeneration*
* **Inflammatory bowel disease**
44
What are the signs and symptoms of Gaucher's disease?
* Acute infantile form
* **Hepatosplenomegaly**
* **Neurological degeneration with seizures**
* Chronic childhood form (most common):
* **Hepatosplenomegaly**
* **BM suppression** → anaemia, immunodeficiency, clotting issues
45
What are the appropriate investigations for Gaucher's disease?
* FBC
* Blood film
* LFTs and clotting
* USS of liver and spleen
* BM aspirate → Gaucher cells
46
What is management of Gaucher's disease?
* Splenectomy
* Bisphosphonates
* Enzyme replacement - *IV recombinant glucocerebrosidase*
* Anaemia treatment
47
What is Galactosaemia?
* Are 3 forms of galactosaemia → most common is Galactose-1-Phosphate Uridyl Transferase deficiency
48
What are the signs and symptoms of galactosaemia?
* Jaundice
* Hepatomegaly
* Hypoglycaemia
* Sepsis - *gal-1-phos inhibits the immune response*
* Not picked up in infancy → present in early life with bilateral cataracts
49
What are the appropriate investigations for galactosaemia?
* High galactose in urine
* Red cell Gal-1-PUT
50
What is the management of galactosaemia?
Avoid galactose
51
What are Glycogen Storage Diseases?
* Type 1 = von Gierke’s → glucose-6-phosphatase deficiency
* *Glucose can't be liberated from glucose-6-phosphate so builds up inside cells as G6-phosphotase is used to remove the high-energy phosphate group so the glucose can leave the cell*
* Type 2 = Pompe’s → a-glucosidase deficiency
* Type 3 = Cori’s / Forbe’s → amylo-1, 6-glucosidase deficiency
* Type 4 = Anderson’s → 1, 4-a-glucan branching enzyme deficiency
* Type 5 = McArdle’s → myophosphorylase deficiency
* *Muscle cramps / weakness after first few minutes of exercise → ‘second wind’ of energy*
52
What are the signs and symptoms of glycogen storage disease?
* **Hypoglycaemia** → G6P cannot leave cells
* **Lactic acidosis** → G6P builds up as lactate
* **Neutropenia** → G6P supresses the immune system
* Hepatomegaly
* Nephromegaly
