Paediatric Haematology Flashcards
Feotal haemoglobin structure
2 alpha and 2 gamma units - greater affinity to oxygen
Hydroxycarbamide
Used to increase the production of HbF in sickle cell patients
Why do sickle cell patients present after 1 years old
Sickle cell involves a defect in the beta haemoglobin - before 1 years old, infants still have some HbF which has a greater affinity for oxygen
Causes of anaemia in infancy
- Physiological
- anaemia of prematurity
- blood loss
- haemolysis
- twin to twin transfusion
- haemolysis - spherocytosis, G6PD deficiency, haemolytic disease of the newborn
Physiological anaemia
Normal dip in haemoglobin between 6 - 9 weeks due to high oxygen delivery to the tissues causing negative feedback
Less erythropoietinproduction by the kidneys
Causes of anaemia of prematurity
Become anaemic due to:
- neonatal sepsis
- less time in utero recieving iron from mother
- RBC production cannot keep up with rapid growth in first few weeks
- Reduced erythropoietin levels
- Frequent blood tests
Pathophysiology of haemolytic anaemia of the newborn
Caused by incompatibility between the rhesus antibodies of the mother and rhesus antigens of the baby
Occurs in a rhesus negative mother and rhesus positive second child
Test for haemolytic disease of the newborn
Direct Coombs test
Management of haemolytic disease of the newborn
Baby is given phototherapy if jaundiced
May need blood transfusion
Prevention of haemolytic disease of the newborn
Mothers are given RhoGAM during pregnancy which is a rhesus immunoglobulin
Causes of anaemia in older children
Iron deficiency - dietary insufficiency
Blood loss - menstruation in girls
Sickle cell anaemia Thalassaemia Leukaemia Hereditary spherocytosis or eliptocytosis Sideroblastic anaemia
Presentation of anaemia
Fatigue and lethargy SOB on exertion Headaches Dizziness Palpitations
Causes of microcytic anaemia
TAILS:
Thalassaemia Anaemia of chronic disease Iron deficiency Lead poisoning Sideroblastic anaemia
Causes of normocytic anaemia
3 As + 2 Hs
Anaemia of chronic disease
Acute blood loss
Aplastic anaemia
Haemolytic anaemia
Hypothyroidism
Causes of macrocytic anaemia
FAT - L
Folate and B12 deficiency
Alcohol
Thyroid disease - hypothyroidism
Liver disease
Others:
- Azathioprine
- Reticulocytosis
Symptoms specific to iron deficiency
Pica - weird dietary cravings
Hair loss
Signs of anaemia
Pallor
Tachycardia
Pale conjunctiva
Raised RR
Signs of iron deficiency
Koilonychia - spooned nails
Angular chelitis
Atrophic glossitis
Investigations for anaemia
FBC Blood film if required Reticulocyte count Iron - ferritin B12 and folate Bilirubin- if jaundice or haemolysis suspected
Direct Coombs test - autoimmune haemolytic anaemia
Haemoglobin electrophoresis- haemoglobinopathies
Causes of iron deficiency
Inadequate dietary intake
Menstruation
Malabsorption - Crohn’s and Coeliacs, PPI use
Blood tests for iron
Serum ferritin (Fe2+) Serum Iron - not useful on its own as varies throughout the day Total iron binding capacity - space on transferrin molecules for iron to bind Transferrin saturation ( serum iron/ TIBC)
What increases free iron
Supplementation with iron
Acute liver damage - as iron is stored in the liver
Inflammation
Side effects of iron supplements
Constipation
Black stools
Leukaemia
Unregulated production of either myeloid or lymphoid blood cells due to cancer of the bone marrow
Types of leukaemia
Acute lymphoblastic leukaemia - most common in children
Acute myeloid leukaemia
Chronic myeloid leukaemia - rare
In which age groups are acute lymphoblastic leukaemia and acute myeloid leukaemia seen in?
Acute lymphoblastic leukaemia - 2 - 3 years old
Acute myeloid leukaemia - under 2 years old
Risk factors for leukaemia
Radiation exposure during pregnancy Down’s syndrome Kleinfelter syndrome Noonan syndrome Fanconi’s anaemia
Presentation of leukaemia
FLAWS - fever, lethargy, appetite loss, weight loss, sweating at night Failure to thrive Pallor - anaemia Petechiae + abnormal bruising and bleeding - thrombocytopenia Abdominal pain Generalised lymphadenopathy Joint or bone pain Hepatosplenomegaly
Diagnosing leukaemia
Refer any child with unexplained petechiae or hepatomegaly for immediate specialist assessment
Urgent (within 48 hours) FBC - anaemia, thrombocytopenia, leukopenia
Blood film - blast cells
Bone marrow biopsy
Lymph node biopsy
Staging CT scan, chest Xray, LP, genetic analysis using imunnophenotyping
Management of leukaemia
MDT
- paediatric oncologist - chemotherapy
Other therapies:
- radiotherapy
- bone marrow transplant
- surgery
Complications of chemotherapy
Failure to treat leukaemia Stunted growth and development Immunodeficiency- recurrent infections Neurotoxicity Infertility Secondary malignancy Cardiotoxicity
Prognosis for acute lymphoblastic leukaemia
80% cure rate
Pathophysiology of idiopathic thrombocytopenic purpura
Type II sensitivity reaction causing autoimmune destruction of plateletes
Presentation of idiopathic thrombocytopenic purpura
Presents in children under 10 years old often after a viral illness
Symptoms present 1 - 2 days after virus:
- bleeding - epistaxis, gums or menorrhagia
- bruising
- petechial or purpuric rash
Management of idiopathic thrombocytopenic purpura
If actively bleeding or severe thrombocytopenia (<10mmol/l)
- prednisolone
- IV immunoglobulins
- blood transfusion if required
- platelet transfusion if required
Education:
- avoid contact sport
- avoid IM injections and lumbar punctures
- avoid NSAIDs, aspirin and blood thinning medication
- advice on managing nosebleeds
- seek help after an injury that may cause internal bleeding
Investigations for idiopathic thrombocytopenic purpura
Bloods - FBC - thrombocytopenia
Blood culture to rule out sepsis
Complications of idiopathic thrombocytopenic purpura
Chronic idiopathic thrombocytopenic purpura (ITP)
Anaemia
Intracranial and subarachnoid haemorrhage
GI bleeding
Sickle cell anaemia pathophysiology
Abnormal gene for beta haemoglobin on chromosome 11 (glut - valine substitution) causing sickling and haemoglobin S which is prone to haemolysis
Sickle cell trait
Carrier but not symptomatic
Sickle cell inheritance pattern
Autosomal recessive
How to diagnose sickle cell anaemia
Heel prick test at 5 days old
Testing during pregnancy for high risk mothers
Complications of sickle cell anaemia
Increased risk of infection
Stroke
Avascular necrosis especially in the hip
Pulmonary hypertension
Painful and persistent penile erection (priapism)
CKD
Sickle cell crisis
General management for sickle cell
Stay hydrated and avoid triggers for crises
Ensure vaccinations are up to date
Antibiotic prophylaxis
Hydroxycarbamide - stimulates production of HbF
Blood tranfusion - severe anaemia
Bone marrow transplant
Types of crisis
Vaso - occlusive crisis (painful crisis)
Splenic sequestration crisis
Aplastic crisis
Vaso - occlusive crisis
HbS (sickled Hb) blocks capillaries and causes distal ischaemia
- associated with dehydration and raised haematocrit
Symptoms:
- pain
- fever
- priapism
Management of priapism
Urological emergency
Treated with apiration of the blood from the penis
Splenic sequestration crisis
Caused by HbS blocking blood flow within the spleen causing acute and painful splenomegaly
Pooling of blood within the spleen can cause severe anaemia and hypovolaemic shock
Emergency - blood tranfusion and fluod resuscitation to treat anaemia and shock
Recurrent crises - splenectony
Aplastic crisis
Temporary loss of the creation of new red blood cells - often due to parvovirus B19
Causes significant anaemia - often requiring blood transfusions. Can resolve spontaneously within a week
Acute chest syndrome
Fever/resp symptoms + new inflitrates seen on chest Xray
Can be due to infection e.g. pneumonia or bronchiolitis or pulmonary vaso - occlusion
Treatment of acute chest syndrome
Emergency
Antibiotics or antivirals
Blood transfusion - anaemia
Incentive spirometry - encourages deep breathing
Artificial ventilation - NIV/ intubation
