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Paediatrics > Haematology and Oncology > Flashcards

Haematology and Oncology Flashcards

1
Q

What are the differences between fetal and adult haemoglobin?

A

Two alpha subunits and two gamma subunits
Adult is alpha and beta

Greater affinity to oxygen than adult haemoglobin
Oxygen dissociation curve shifts to the left, as adult haemoglobin needs higher partial pressure

HbF production decreases as HbA increases at 32-36 weeks

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2
Q

What is hydroxycarbamide used for?

A

Anit-metabolite chemo drug
Increases production of fetal haemoglobin in sickle cell anaemia - protective against sickle cell crises and acute chest syndrome

Genetic abnormality for beta subunit means sickle shape, fetal haemoglobin cannot be sickle shape as there is no beta subunit

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3
Q

What are the common causes of anaemia in infancy?

A

Physiological anaemia of infancy

Anaemia of prematurity
Blood loss
Haemolysis - haemolytic disease of the newborn, hereditary spherocytosis, G6PD deficiency
Twin-twin transfusion

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4
Q

What is physiologic anaemia of infancy?

A

Normal dip in Hb around 6-9 weeks in term babies
High oxygen delivery at birth due to high Hb causes negative feedback - reduced erythropoeitin from the kidneys - reduces Hb from bone marrow

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5
Q

What are some of the causes for anaemia in a premature neonate?

A

Less time in utero receiving iron from mother
Red blood cell creation cannot keep up with rapid growth
Reduced erythropoeitin levels
Blood tests removing significant amount of circulating volume

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6
Q

What is HDN?

A

Causes haemolysis and jaundice
Incompatibility of rhesus - rhesus negative mum with rhesus D positive baby - sensitisation before future pregnancies
Mother’s anti-D antibodies cross placenta to positive baby, attacks RBCs of fetus and they break down

Haemolysis, anaemia, high bilirubin levels

Direct coombs test to check

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7
Q

What are the key causes of anaemia in older children?

A

Iron deficiency anaemia secondary to dietary insufficiency

Blood loss - menstruation in older girls

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8
Q

What are rarer causes of anaemia in children?

A 
Sickle cell
Thalassaemia
Leukaemia
Hereditary spherocytosis
Hereditary eliptocytosis
Sideroblastic anaemia

Blood loss due to roundworms, hookworms, whipworms in developing countries - treatment with mebedazole

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9
Q

What are the causes of microcytic anaemia?

A 
TAILS
Thalassaemia
Anaemia of chronic disease
Iron defiency
Lead poisoning
Sideroblastic anaemia
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10
Q

What are the causes of normocytic anaemia?

A

Acute blood loss
Anaemia of chronic disease
Aplastic anaemia

Haemolytic anaemia
Hypothyroidism

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11
Q

What are the causes of macrocytic anaemia?

A

Megaloblastic:
B12 or folate deficiency

Due to impaired DNA synthesis

Normoblastic:
Alcohol
Reticulocytosis from haemolytic anaemia, blood loss
Hypothyroidism
Liver disease
Drugs e.g. azathioprine
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12
Q

What are the generic symptoms of anaemia?

A 
Tiredness
SOB
Headaches
Dizziness
Palpitations

Specific to iron deficiency - pica, hair loss

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13
Q

What are the signs of anaemia?

A

Pale skin, conjunctival pallor
Tachycardia, raised RR

Koilonychia - spoon shaped nails indicate iron deficiency
Angulat chelitis - iron defi
Atrophic glossitis - atrophy of papillae, smooth tongue
Brittle hair and nails
Jaundice - haemolytic
Bone deformities - thalassaemia

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14
Q

What are the investigations for anaemia?

A 
FBC, Hb, MCV
Blood film
Reticulocyte count - high count is active production to replace lost cells
Ferritin
B12 and folate
Bilirubin
Direct Coombs
Haemoglobin electrophoresis for haemoglobinopathies
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15
Q

What are the causes of impaired red cell production in children?

A

Red cell aplasia - parvovirus B19 infection, aplastic anaemia, leukaemia, congenital red cell aplasia

Ineffective erythropoiesis - iron def, folic acid def, chronic inflammation, chronic renal failure
Myelodysplasia, lead poisoning

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16
Q

What are the causes of red cell destruction (haemolysis) in children?

A

Red cell membrane disorders - hereditary spherocytosis

Red cell enzyme disorders - G6PD deficiency

Haemoglobinopathies - thalassaemias, sickle cell

Immune - HDN, autoimmune haemolytic anaemia

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17
Q

What are the causes of blood loss leading to anaemia in children?

A

Fetomaternal bleeding

Chronic GI bleed - Meckel diverticulum

Inherited bleeding disorders - von Willebrand disease

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18
Q

What are useful investigations for red cell aplasia?

A

Reticulocytles will be low
Parvovirus serology
Bone marrow aspirate

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19
Q

What are useful investigations for haemolysis?

A

Reticulocytes normal or high
Bilirubin raised

Blood film
Hb HPLC

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20
Q

What are useful investigations for blood loss/ineffective erythropoiesis causing anaemia?

A

Blood film

Serum ferritin

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21
Q

Where does iron intake come from in infants?

A

Breast mild 50% absorbed
Infant formula 10% absorbed
Cow’s milk 10% absorbed
Mixed diet

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22
Q

What are the diagnostic clues that point towards haemolysis?

A 
Raised reticulocyte count - polcythaemia
Unconjugated bilirubinaemia
Increased urinary urobilinogen
Abnormal appearance of RBCs on film
Positive direct antiglobulin test if an immune cause
Increased rbc precursors in bone marrow
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23
Q

What does haemolytic anaemia lead to?

A 
Anaemia
Hepatomegaly
Splenomegaly
Increased blood levels of unconjugated bilirubin
Excess urinary urobilinogen
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24
Q

What are the causes of haemolytic anaemia in children?

A

Haemolysis only leads to anaemia when bone marrow cannot compensate for destruction - RBC lifespan may be reduced to few days, but bone marrow production can increase by eight fold

Immune haemolytic anaemias uncommon in children, unlike neonates

Usually intrinsic abnormalities of the RBC:
Hereditary spherocytosis, red cell enzyme disorder
Haemoglobinopathies

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25
Q

What are the clinical features of hereditary spherocytosis?

A

May be asymptomatic

Jaundice - in childhood, may be intermittent

Anaemia

Mild to mod splenomegaly

Aplastic crisis - uncommon, transient (2-4 wks) caused by parvovirus B19 infection

Gallstones - due to increased bilirubin excretion

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26
Q

What is the management of hereditary spherocytosis?

A

Most are mild, need oral folic acid as have raised requirement due to increased RBC production.

Splenectomy beneficial, indicated in poor growth or troublesome anaemia - tired, loss of vigour
Need to ensure vaccinated against Hib, men C, strep pneumonia
Lifelong daily oral penicillin prophylaxis

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27
Q

Where is iron absorbed?

A

Duodenum and jejunum
Requires acid from stomach to keep iron as soluble ferrous

That is why meds e.g. PPIs can interfere with iron absorption, as less acid

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28
Q

What is total iron binding capacity?

A

The total space on transferrin molecules which iron as ferric irons Fe3+ can bind to the transferrin.

This is measured as transferrin saturation - how much is bound.

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29
Q

What does it mean when ferritin is high or low?

A

Extra ferritin released if inflammation e.g. cancer, infection

Normal or low - iron deficiency anaemia
could be normal if they also have an infection

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30
Q

What does it mean when TIBC and transferrin is high or low?

A

High in iron deficiency

Low in iron overload

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31
Q

How can iron be supplemented?

A

Ferrous sulphate or ferrous fumarate

Can cause constipation and black coloured stools
Unsuitable if malabsorption is the cause

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32
Q

What is G6PD deficiency?

A

Condition where there is a defect in the G6PD enzyme

X linked recessive
Usually affects males

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33
Q

What are G6PD crises triggered by?

A

Infections
Medications e.g. antimalarials
Broad beans/fava beans

Becomes jaundiced and anaemic after e.g. eating broad beans

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34
Q

What does the G6PD enzyme do?

A

Protects cells from damage by reactive oxygen species

Deficiency makes RBCs more vulnerable to ROS, leading to haemolysis

So periods of increased stress can lead to more ros, acute haemolytic anaemia

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35
Q

What is the presentation of G6PD deficiency?

A

Neonatal jaundice

Anaemia
Intermittent jaundice
Gallstones
Splenomegaly

Heinz bodies seen on blood film - denatured Hb

Diagnosis can be made by doing a G6PD enzyme assay

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36
Q

What is the management of G6PD deficiency?

A

Avoid triggers to acute haemolysis - including fava beans and medications
Also napthalene in mothballs

Primaquine - antimalarial
Ciprofloxacin
Nitrofurantoin
Trimethoprim
Sulfonylureas
Sulfasalazine
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37
Q

How can sickle cell be diagnosed?

A

Pregnant women at risk of being carriers offered testing during pregnancy
Newborn screening heel prick at 5 days of age

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38
Q

What is the cause of sickle cell?

A

Autosomal recessive
Abnormal gene on chromosome 11
Two copies needed for trait
Abnormal HbS variant

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39
Q

What are the complications of sickle cell?

A

Anaemia
Increased risk of infection
Avascular necrosis of large joints such as hip
Pulmonary hypertension
Painful and persistent erection - priapism
CKD
Sickle cell crises - vaso-occlusive crises; sickle cells clump together and block small blood vessels
Acute chest syndrome

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40
Q

What is the management of sickle cell crises?

A 
Managed supportively
Have low threshold for admission to hospital
Treat any infection
Keep warm, IV fluids
Simple analgesia
Penile aspiration to treat priapism
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41
Q

What is the general management of sickle cell?

A

Avoid dehydration and other triggers of crises, often have high haematocrit

Ensure vaccines up to date
Antibiotic prophylaxis e.g. penicillin V against infection
Hydroxycarbamide can be used to stimulate HbF
Blood transfusion in severe anaemia
Bone marrow transplant can be curative

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42
Q

What is splenic sequestration crisis?

A

RBCs blocking blood flow in the spleen
Causes acutely enlarged and painful spleen
Pooling of blood in spleen can lead to severe anaemia and circulatory collapse

Emergency
Supportive management with blood transfusions and fluid resuscitation

Splenectomy prevents this
Used in recurrent crises

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43
Q

What is aplastic crises?

A

Temporary loss of creation of new blood cells
Often due to infection with parvovirus B19

Leads to significant anaemia, management supportive with blood transfusions

Resolves spontaneously within a week

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44
Q

What is acute chest syndrome in sickle cell?

A

Fever and resp symptoms, and new infiltrates on CXR

Can be due to infection e.g. pneumonia or bronchiolitis, or non infective causes
e.g. vaso-occlusion or fat emboli

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45
Q

What is the treatment of acute chest syndrome in sickle cell?

A

Abx or antivirals for infection
Blood transfusions for anaemia
Incentive spirometry to encourage effective and deep breathing
Artificial ventilation with NIV or intubation

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46
Q

What is leukaemia?

A

Cancer of a particular line of stem cells in bone marrow

Causes unregulated production of certain blood cells

Classified by chronic (slow) or acute (fast) and cell line affected - myeloid or lymphoid

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47
Q

What are the types of leukaemia that affect children, from most to least common?

A

Most common in acute lymphoblastic leukaemia

Acute myeloid leukaemia

Chronic myeloid leukaemia is rare

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48
Q

At what age does acute lymphoblastic leukaemia peak?

A

2-3 years

49
Q

At what age does acute myeloid leukaemia peak?

A

Under 2 years

50
Q

What occurs in leukaemia - pathophysiology?

A

Mutation leads to excessive production of a type of white blood cell

Overproduction of single type of cell can lead to suppression of other cell lines
Causes underproduction of other cell types

Results in pancytopenia
Low RBCs - anaemia
Low WBCs - leukopenia
Low platelets - thrombocytopenia

51
Q

What are the risk factors for leukaemia?

A

Radiation exposure e.g. AXR in pregnancy, main environmental risk factor for leukaemia

Down’s
Kleinfelter syndrome
Noonan syndrome
Fanconi’s anaemia

52
Q

What is the presentation of leukaemia?

A 
Non-specific
Persistent fatigue
Unexplained fever
Failure to thrive
Weight loss
Night sweats
Pallor - anaemia 
Petechiae
Abnormal bruising - thrombocytopenia
Unexplained bleeding - thrombocytopenia
Abdominal pain
Generalised lymphadenopathy
Unexplained or persistent bone or joint pain
Hepatosplenomegaly
53
Q

When does NICE recommend referral if suspicious of leukaemia?

A

Any child with unexplained petechiae or hepatomegaly for immediate specialist assessment

54
Q

What are the investigations for leukaemia?

A

FBC - anaemia, leukopenia, thrombocytopenia, high numbers of abnormal WBCs
Blood film - blast cells
Bone marrow biopsy
Lymph node biopsy

CXR
CT scan
Lumbar puncture
Genetic analysis and immunophenotyping of abnormal cells

55
Q

What is the management of leukaemia?

A

Chemo

Radio
Bone marrow transplant
Surgery

56
Q

What are the complications of chemotherapy in leukaemia?

A 
Failure to treat
Stunted growth and development
Immunodeficiency and infections
Neurotoxicity
Infertility
Secondary malignancy
Cardiotoxicity
57
Q

How can cancer in a child present?

A

A localised mass
The consequences of disseminated disease e.g. bone marrow infiltration - causes system ill health
Consequences of pressure from a mass on local structures or tissue

58
Q

When is chemotherapy used in malignancy?

A

Primary curative treatment e.g. acute lymphoblastic leukaemia

To control primary or metastatic disease before definitive local treatment with surgery and/or radiotherapy

As adjuvant treatment to deal with residual disease and to eliminate presumed micrometastases e.g. after initial local treatment with surgery in Wilms tumour

59
Q

What are some of the short term side effects of chemotherapy?

A 
Bone marrow suppression
Immunosuppression
Gut mucosal damage
Nausea and vomiting
GI damage, painful mouth ulcers can prevent eating
Anorexia
Alopecia
Drug specific side effects
60
Q

What is a consequence of immunosuppression from chemotherapy?

A

Risk of serious infection

Children with fever and neutropenia admitted for cultures and broad spectrum antibiotics

61
Q

What are some important infections associated with therapy for cancer?

A

Pneumocystis jiroveci pneumonia - especially in children with leukaemia

Disseminated fungal infection - e.g. aspergillosis and candidiasis

Coagulase negative staphylococcal infections of central venous catheters

Measles and chickenpox may have an atypical presentation

Use of live vaccines contraindicated during chemo, and 6 months after

62
Q

What is an example of a treatment scheme for standard risk acute lymphoblastic leukaemia?

A

Induction
Consolidation and CNS protection e.g. methotrexate
Interim maintenance e.g. monthly vincristine and dexamethasone
Delayed intensification
Continuing maintenance - continues for further 2 years in girls, 3 years in boys

63
Q

What is lymphoma?

A

Results from genetic alterations which trigger abnormal proliferation of lymphocytes

64
Q

What is the difference between leukaemia and lymphoma?

A

In lymphoma, the malignant cells are mature lymphocytes
Arise outside of the bone marrow e.g. lymph nodes

Leukaemia is from immature blasts in the bone marrow

EXCEPT
lymphoblastic lymphomas - B and T cell lymphoblastic lymphomas develop from precursors

65
Q

How can lymphoblastic lymphomas be distinguished from lymphoblastic leukaemias?

A

Degree of bone marrow infiltration by blasts

<25% involvement is lymphoma, >25% leukaemia

66
Q

What is the classification of lymphoma?

A

Hodgkin’s:

Classical:
Nodular sclerosis
Mixed cellularity
Lymphocyte rich
Lymphocyte depleted

Non-classical:
Nodular lymphocyte predominant HL (Reed sternberg cells not present)

Non-Hodgkin’s:

Majority are high grade lymphomas (mature cell):

  • B cell
    e.g. Burkitt’s lymphoma
    Large B cell lymphoma
    Primary CNS lymphomas
  • T cell
    Anaplastic large cell lymphoma
    Peripheral T cell lymphoma

Mature cell: low grade:

  • B cell - follicular
  • T cell - rare

Precursor: B and T cell lymphoblastic lymphoma

67
Q

What are the risk factors for lymphoma?

A

Immunodeficiency - post solid organ transplant, ataxia telangiectasia, HIV, immunosuppressive drugs

68
Q

What are the signs and symptoms in a history indicating lymphoma?

A

Painless progressive lymphadenopathy - develops over weeks/months
(could just be due to infection, so requires careful history)

B symptoms: fatigue, drenching night sweats, fever <38, weight loss >10% 6 mnths
Pruritus
Mediastinal involvement (thymus or mediastinal lymph nodes) dyspnoea, cough, chest pain

69
Q

What symptoms of lymphoma indicated extranodal involvement?

A

More common in NHL

Bone marrow - symptoms of anaemia, infection, easy bruising and bleeding

Abdomen - bloating, early satiety, pain, unable to pass stools and vomiting if obstructed

Retroperitoneal lymphadenopathy - urinary retention

Skin - new skin lesions, jaundice

Testicular swelling

CNS - behavioural change, headache, confusion, nausea and vomiting, seizures, weakness, sensory changes

70
Q

What are the clinical findings seen on examination in lymphoma?

A

Non tender, firm, matted lymph nodes
In Hodgkin’s - cervical, supraclavicular, axillary
In NHL - more rapidly growing and bulky

Mediastinal mass - may cause SVC obstruction, effusions, airway obstruction

Abdomen - splenomegaly, hepatomegaly, abdominal mass

Skin - T cell lymphomas inc mycosis fungoides, jaundice

Testicular mass

Neurological weakness, sensory abnormalities, features of raised ICP

71
Q

What are some differentials for lymphadenopathy?

A

Viral infective - URTI, mono, rubella, measles, CMV, adenovirus, HIV

Bacterial infection - TB, typhoid, syphillis, lyme’s, brucellosis

Malignant - leukaemia, neuroblastoma

Autoimmune - JIA, SLE, drug reaxtions

72
Q

What is the most common cause of lymphadenopathy in children?

A

Infection

73
Q

What are the investigations for lymphoma?

A

Bedside:
Pbs, swabs (rule out infection) urine dip, ECG - check before starting cardiotoxic chemo

Bloods:
FBC - pancytopenia or leukaemia, (anaemia, thrombocytopenia, raised WBC in leukaemia)
U&Es - baseline kidney function
LDH and urate - raised in high cell turnover
LFTs, low albumin = worse prognosis
Monospot test - exclude EBV
Hep B/HIV risk of reactivation with rituximab
G6PD def identified as tx can cause haemolytic crisis
ESR - worse prognosis if raised

Imaging:
CXR - mass
CT/MRI/PET - staging
USS liver or spleen

Biopsies of enlarged node
Fine needle aspiration
Excision or partial biopsy

74
Q

What classification is used for lymphoma?

A

Ann Arbor for Hodgkin’s
St Jude’s for non-Hodgkin’s

I - 1 group on 1 side of diaphragm
II - >2 groups same side
III - nodes on both side

IV Hodgkin’s - extranodal sites beyond E

IV NHL - disseminated, multifocal

A: no systemic symptoms
B: systemic symptoms

75
Q

What is the management of Hodgkin’s lymphoma?

A

Chemo

Radio <50% children, PET scan assess response after 2 cycles of chemo and if still going, need adjuvant radiotherapy

Lymphocyte predominant HL has less intensive tx - usually surgery or low dose chemo sufficient

76
Q

What is the management of non-Hodgkin’s lymphoma?

A

Chemo
Regime depends on type and staging

B cell usually 4-6 invasive
T cell NHL less invasive, lasts 2-3 years

Biologics e.g. rituximab
Radio as adjuvant rarely
Bone marrow transplant for relapsed patients
Lymphoblastic lymphoma treated according to ALL

77
Q

What are the short term complications of lymphoma?

A 
SVC obstruction
Bowel obstruction/perforation
Cytopenias
Pericardial or pleural effusions
Pain from tumour invasion
Tumour lysis syndrome
78
Q

What are the short term complications of lymphoma treatment?

A 
Neutropenic sepsis
Mucositis, diarrhoea
Anorexia, weight loss
Alopecia
Nausea and vomiting
Fatigue
Tumour lysis syndrome
79
Q

What are the long term complications of the treatment for lymphoma?

A 
Secondary cancers
Cardiotoxicity
Pulmonary toxicity
Renal impairment
Growth impairment
Infertility
80
Q

What is tumour lysis syndrome?

A

Oncological emergency
caused by lysis of tumour cells
either due to chemo or spontaneously in highly proliferative tumours

81
Q

What can tumour lysis syndrome result in?

A

Hyperphosphataemia
Hyperkalaemia
Hypocalcaemia
Hyperuricaemia

AKI
Cardiac arrhythmias
Nausea and vomiting
Seizures

82
Q

What can help prevent tumour lysis syndrome occurring?

A

Prophylactic hydration
Allopurinol
Prior to chemo

Rasburicase can be used if white cell count >50, breaks down uric acid
(check no G6PD def)
Allopurinol prevents uric acid production

83
Q

What is the treatment of tumour lysis syndrome?

A 
Aggressive hydration
Rasburicase - drug mimics urate oxidase (not present in humans)
Allopurinol
Haemofiltration
Dialysis
84
Q

What is DIC?

A 
Disseminated intravascular coagulation
Systemic activation of blood coagulation
Generates intravascular fibrin
Leads to thrombosis of small and medium sized vessels
Organ dysfunction
85
Q

What are the common causes of DIC?

A

Severe sepsis or shock due to circulatory collapse
e.g. meningococcal sepsis
damage from trauma or burns

May be acute or chronic
Likely initiated through tissue factor pathway

86
Q

What are the predominant features of DIC?

A

Bruising
Purpura
Haemorrhage

Pathophysiological process - microvascular thrombosis, purpura fulminans

87
Q

How can DIC be detected?

A 
No single test
Thrombocytopenia
Prolonged prothrombin time
Prolonged APTT 
Low fibrinogen
Raised fibrinogen degradation products
D-dimers
Microangiopathic haemolytic anaemia
88
Q

What is the management of DIC?

A

Treat underlying cause of DIC, usually sepsis
Intensive care
Provide fresh frozen plasma to replace clotting factors
Cryoprecipitate
Platelets

89
Q

What is the purpose of the spleen?

A 
Spleen contains 
red pulp - filtration of RBCs
white pulp - active in immune response
creation of RBCS if not in bone marrow
storage of RBCs, lymphocytes, platelets in emergency

production and maturation of B and T cells and plasma cells

90
Q

When can splenectomy occur?

A

Planned
Traumatic - accident or surgery
Autosplenectomy - physiological loss of spleen function (hyposplenism)

91
Q

What conditions is hyposplenism associated with?

A 
Sickle cell anaemia - chronic damage to spleen results in atrophy
coeliac disease
dermatitis herpetiformis
essential thrombocythaemia
ulcerative colitis
92
Q

What are the indications for a splenectomy?

A

Trauma
Spontaneous rupture - often in massive splenomegaly e.g. mono with a minor trauma
Hypersplenism - hereditary spherocytosis, elliptocytosis, immune thrombocytopenia
Neoplasia - lymphoma or leukaemia
Cysts, abscesses

93
Q

What on a blood film gives an indication of hyposplenism?

A

Howell-Jolly bodies
Basophilic nuclear remnants in circulating erythrocytes
During maturation, late erythrocytes usually expel nuclei, some do not but are filtered by the spleen
Therefore indicates a damage or absent spleen

94
Q

What are the complications of hyposplenism?

A

Individuals with absent or dysfunctional spleen at increased risk of severe infection - encapsulated bacteria
S pneumonia; pneumococcus
H influenzae Hib
N meningitidis

Increased risk of severe falciparum malaria

95
Q

What is the management of hyposplenic patients?

A

Immunisations against s pneumoniae, n meningitidis, Hib, influenza

Antibiotic prophylaxis - oral phenoxymethylpenicillin or macrolides

If unwell, systemic antibiotics and admit
If at high risk in hyposplenism e.g.:
age <16, or >50 years
Poor response to pneumococcal vaccination
Previous invasive pneumococcal illness
Underlying haematological malignancy resulting in splenectomy

96
Q

What is pancytopenia?

A

Low levels of red blood cells, white blood cells and platelets

97
Q

What are usual causes of pancytopenia in children?

A

Acute leukaemias
Bone marrow failure
Megaloblastic anaemia

Can be due to reduced production:
(Or increased removal - rare)

B12/folate deficiency
Drugs - chemo, abx, anticonvulsants, psychotropic drugs, DMARDs
Viruses
Malignancy
Radiation
Idiopathic aplastic anaemia
Congenital bone marrow failure e.g. Fanconi’s anaemia

98
Q

What are some of the symptoms of pancytopenia?

A 
Tired, weak, dizzy, SOB
Frequent fevers, infection
Pale skin, petechiae
Bleeding 
Bruising easily
Heavy menstruation
Blood in bowel movements
99
Q

How is pancytopenia diagnosed and treated?

A

Bloods, bone marrow biopsy/aspiration

Blood transfusion
Stem cell transplant

100
Q

What drugs and chemicals can cause haemolysis in children with G6PD deficiency?

A

Antimalarials e.g. primaquine, quinine, chloroquine

Abx
Sulphonamides
Quinolones e.g. ciprofloxacin
Nitrofurantoin

Aspirin in high doses

Chemicals
Naphthalene - mothballs
Fava beans - divicine

101
Q

What is HbSC disease?

A

Affected children inherit HbS from one parent, and HbC from another whereas sickle cell anaemia is HbSS and both HbAs replaced with HbS and HbC so no normal HbA - no normal beta globulin genes

Fewer painful crises than those with HbSS
But may develop proliferative retinopathy so have eyes checked

102
Q

What are beta thalassaemias?

A

Beta thalassaemia major - HbA not produced

Beta thalassaemia intermedia - small amount HbA produced, anaemia not bad enough to need blood transfusions

Minor - one normal gene, heterozygous
Small amount of HbA produced

103
Q

What occurs in thalassaemias?

A

Low level of intracellular haemoglobin leads to hypochromic microcytic cells

104
Q

What are alpha thalassaemias?

A

Silent carrier state
Deletion of a single α-globin gene.
It is asymptomatic, without anaemia

α-Thalassemia trait
Deletion of two α-globin genes
There is minimal or no anaemia and no physical signs; findings are identical to those of β-thalassemia minor
(microcytosis and hypochromia)

Haemoglobin H (HbH) disease
Deletion of three α-globin genes.
Tetramers of β-globin, called HbH, are formed
There is moderately severe anaemia, resembling β-thalassemia intermedia (microcytic, hypochromic anaemia
with target cells and Heinz bodies in the blood film)

Hydrops fetalis
Deletion of all four α-globin genes
In the foetus, excess of γ-globin chains form tetramers (Hb Bart) that are unable to deliver the oxygen to
tissues. Usually intrauterine death

105
Q

What are the clinical features of beta thalassaemia major?

A

Severe anaemia, transfusion dependent
Failure to thrive
Extramedullary haemopoesis - prevented by regular transfusions

Pallor
Jaundice
Bossing of skull
Maxillary overgrowth
Splenomegaly
Hepatomegaly
Need for repeated transfusions
106
Q

What are the complications of long term blood transfusion in children?

A

Iron deposition - cardiomyopathy, cirrhosis, diabetes, delayed growth, hyperpigmentation

Alloantibodies makes finding compatible blood hard

Infection - rare
HIV, Hep A B C, prions

Venous access difficult, device may be needed
Could then cause infection

107
Q

What is Fanconi anaemia?

A

Inherited form of aplastic anaemia
Congenital abnormalities - short stature, abnormal thumbs, renal malformations

At high risk of death from bone marrow failure or transformation to acute leukaemia

108
Q

What is aplastic anaemia?

A

Pancytopenia

Hypocellular bone marrow in absence of abnormal infiltrate or marrow fibrosis

109
Q

What is the inheritance of haemophilia A and B?

A

X linked recessive

110
Q

Features of haemophilia?

A

Spontaneous bleeding into joints and muscles
Can lead to crippling arthritis

In neonatal period, risk of intracranial haemorrhage

Haem A - prophylactic FVIII
Haem B - FIX

111
Q

What are the features of vWD?

A

Autosomal dominant
Carriers can still have some deficiency
Defective platelet plug

Bruising
Excessive prolonged bleeding after surgery
Mucosal bleeding e.g. epistaxis, menorrhagia

112
Q

What are examples of acquired disorders of coagulation?

A

Haemorrhagic disease of newborn due to Vit K deficiency
Liver disease
Immune thrombocytopenia
DIC

113
Q

How might a child be deficient in Vit K?

A

Inadequate intake
Malabsorption - coeliac, CF, obstructive jaundice
Vit K antagonists e.g. warfarin

114
Q

What is ITP?

A

Idiopathic thrombocytopenic purpura
Characterised by idiopathic thrombocytopenia (low platelet count) causing a purpuric non-blanching rash

Type II hypersensitivity reaction
Produces antibodies which destroy platelets

115
Q

What is the presentation of ITP?

A

Usually <10s
Hx recent viral illness
Onset of symptoms over 24-48 hrs

Bleeding - gums, epistaxis, menorrhagia
Bruising
Petechial, purpuric rash - bleeding under skin

116
Q

What is ecchymoses?

A

Large area of blood collected under the skin more than 10 mm

Non bllanching lesion

117
Q

What is the management of ITP?

A

FBC, platelet count

Exclude other causes of low platelet count - e.g. heparin induced, or leukaemia

Tx only needed if severe thrombocytopenia - below 10, or patient actively bleeding

Prednisolone
IV immunoglobulins
Blood transfusions

Platelet transfusions work temporarily as antibodies will attack again

118
Q

What is some advice given withITP?

A

Avoid contact sports
Avoid IM injections, procedures such as LPs
Avoid NSAIDs, blood thinners
Advice on managing nosebleeds
Seek help after any injury that could have caused internal bleeding

119
Q

What are the complications of ITP?

A

Chronic ITP
Anaemia
Intracranial and subarachnoid haemorrhage
GI bleeding

Paediatrics (17 decks)

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