Haem + onc Flashcards
1
Q
what is the cause of physiological anaemia?
A
- around 6-9 weeks in healthy term babies, caused by negative feedback prompted by high oxygen delivery seen at birth
- EPO by kidneys suppressed hence Hb reduced by BM
2
Q
what are some other causes of anaemia in children?
A
infants: anaemia of prematurity, blood loss, haemolysis, twin to twin transfusion
neonates - hereditary spherocytosis, G6PD deficiency
older - iron deficiency, blood loss, sickle cell, thalassaemia, leukaemia, helminth infection
low RBC production or high RBC loss
3
Q
what is anaemia of prematurity?
A
- Less time in utero receiving iron from the mother
- Red blood cell creation cannot keep up with the rapid growth in the first few weeks
- Reduced erythropoietin levels
- Blood testsremove a significant portion of their circulating volume
4
Q
what is haemolytic disease of the new born?
A
- incompatibility between rhesus antigens on surface of red blood cells of mother and foetus
- woman rhesus D negative becomes pregnant consider the possibility of foetus becoming rhesus D positive as mothers immune system will recognise this as foreign and and produce antibodies for this
- not a problem during first pregnancy usually, but in second mothers anti-D antibodies will cross placenta and if foetus positive antibodies will cause immune system of foetus to attack its own blood cells by binding to RBC of foetus
- causes anaemia and high bilirubin
- DCT done to assess
5
Q
what are some key examination findings of anaemia?
A
generic: pale skin, conjunctival pallor, tachycardia, raised RR
koilonychia, angular chelitis, atrophic glossitis, brittle hair, jaundice, bone deformities
6
Q
what are some initial investigations for anaemia?
A
- 1st line - FBC, reticulocytes, film, ferritin, CRP/ ESR
- Full blood count forhaemoglobinandMCV
- Blood film
- Reticulocyte count
- Ferritin (low iron deficiency)
- B12 and folate
- Bilirubin (raised in haemolysis)
- Direct Coombs test (autoimmune haemolytic anaemia)
- Haemoglobin electrophoresis (haemoglobinopathies)
- reticulocytes
7
Q
how is anaemia managed?
A
- Management depends on establishing the underlying cause and directing treatment accordingly
- Iron deficiency can be treated with iron supplementation
- Severe anaemia may require blood transfusions
8
Q
what is the pathophysiology of DIC?
A
- new-borns (particularly pre-terms) have low levels of coagulation factors and hence vulnerable to DIC
- causes - sepsis, NEC, HIE, RDS
- the above causes activates the coagulation cascade, promotes fibrin production and deposition and consumption of clotting factors
- consumption of coagulation factors and platelets, inhibition of natural anticoagulants and fibrinolysis, and fibrin deposition result in the clinical picture of DIC
- a bleeding diathesis accompanied by microvascular thrombosis that often leads to end-organ damage
9
Q
how does DIC present?
A
- Bleeding, from many sites in the body
- Blood clots
- Bruising
- Drop in blood pressure
- Shortness of breath
- Confusion, memory loss or change of behavior
- Fever
*petechiae
- bleeding (cutaneous, mucosal, umbilical, GI)
10
Q
what complications are associated with DIC?
A
birth asphyxia, acidosis, respiratory distress syndrome, infection, necrotising enterocolitis, meconium aspiration, aspiration of amniotic fluid, brain injury, hypothermia
11
Q
how is DIC investigated?
A
- platelets low
- schistocytes (fragmented RBC)
- increased INR
- increased APTT
- fibrinogen low
12
Q
how is DIC managed?
A
- get help
- treat cause - NEC, sepsis
- give vitamin K 1mg IV & blood products - platelets, cryoprecipitate etc
- severe cases consider exchange transfusion
13
Q
what is the function of the spleen?
A
- spleen is important in reticuloendothelial system for antibody synthesis and clearance of opsonised organisms by phagocytosis
- Antibody-mediated phagocytosis is the primary mechanism to destroy encapsulated microbes, such as pneumococcus, meningococcus, andHaemophilus
- absence of spleen or reduced activity means the polysaccharide rich capsules of these bacteria protect them from destruction and permit them to create systemic infection
14
Q
when would you suspect hyposplenia?
A
hyposplenia should be suspected in any patient with overwhelming infection with an encapsulated organism
15
Q
How is impaired splenic function investigated?
A
- blood smear - Howell-jolly bodies, Heinz bodies, target cells
- USS with doppler to assess spleen size
- CT/ MRI to detect spleen shape
- radionucleotide (technetium-99m) liver and spleen scan to detect functional reticuloendothelial cells
16
Q
how is impaired splenic function managed?
A
- immunisation with pneumococcal, meningococcal, haemophilus vaccines
- patients with sickle cell and impaired spleen function - antimicrobial prophylaxis
- counselling regarding infections
- MedicAlert bracelets
17
Q
what is leukaemia?
A
- leukaemia is the cancer of stem cells in the bone marrow which leads to unregulated production of certain types of blood cells
- genetic precursor in BM leads to excessive WBC production which suppresses other cell lines causing under production of others
- pancytopenia as a result - anaemia, leukopenia, thrombocytopenia
18
Q
how might leukaemia present?
A
- non specific
- persistent fatigue
- unexplained fever
- failure to thrive
- weight loss
- night sweats
- unexplained bleeding
- abdominal pain
- unexplained bone or joint pain
- pallor
- petechiae and abnormal bruising - thrombocytopenia
- generalised lymphadenopathy
- hepatosplenomegaly
19
Q
what are some complications of chemo?
A
- Failure to treat the leukaemia
- Stunted growth and development
- Immunodeficiency and infections
- Neurotoxicity
- Infertility
- Secondary malignancy
- Cardiotoxicity
20
Q
how is leukaemia investigated?
A
*refer any child with unexplained petechiae, hepatomegaly, if leukaemia suspected FBC within 48h
- Full blood count, which can showanaemia,leukopenia, thrombocytopeniaand high numbers of the abnormal WBCs
- Blood film, which can showblast cells
- Bone marrow biopsy
- Lymph node biopsy
- for staging - CXR, CT, LP, genetic analysis and immunophenotyping
21
Q
how is leukaemia managed?
A
- Treatment of leukaemia will be coordinated by a paediatric oncology multi-disciplinary team
- Leukaemia is primarily treated withchemotherapy
- Other therapies:
- Radiotherapy
- Bone marrow transplant
- Surgery
- The overall cure rate for ALL is around 80%, but prognosis depends on individual factors
- The outcomes are less positive for AML
22
Q
what is lymphoma?
A
- cancer that starts in the lymphatic system divided into Hodgkin’s and non-Hodgkin’s (more)
- accounts for over 10% of childhood cancers and more common in boys and older children
- multi-factorial causes like infection, genetic and environmental
- RF - Epstein-Barr virus, immunosuppressed, other cancer treated
23
Q
when might you suspect lymphoma?
A
- weight loss, night sweats, fevers
- visible or palpable mass
- lethargy
- anorexia
- mediastinal lymphadenopathy - wheeze and cough, SOB
- SVC obstruction and airway compromise!
- non-tender lymphadenopathy
24
Q
how is lymphoma investigated?
A
- FBC - differentiate from infection
- U&E - tumour lysis syndrome
- LDH - elevated
- USS - identify other nodes and assists biopsy
- CXR - mediastinal involvement
- CT full body - extent of disease and staging
- lymph node biopsy - definitive diagnosis
25
What is tumour lysis syndrome?
tumours release their contents into the bloodstream, either spontaneously or in response to therapy, leading to the characteristic findings of hyperuricaemia, hyperkalaemia, hyperphosphataemia, and hypocalcaemia
26
how is lymphoma managed?
immediate
- mediastinal mass high dose steroids
- SVC obstruction
- tumour lysis syndrome hyper-hydration and allopurinol
long term
- chemo
- radiotherapy
27
what may cause pancytopenia in children?
- acute leukaemia's, bone marrow failure syndromes, lupus, infections, medicine side effects, radiation, chemotherapy, autoimmune disorders, FHx of blood disorders can cause
- OR IDIOPATHIC
28
how does pancytopenia present?
- weakness
- fatigue
- easy bruising
- pale skin
- rapid heart rate
- SOB
- bleeding problems like bleeding gums
- infections
- heavy menstruation
- bruises
- tachycardia
- pallor
29
how is pancytopenia managed?
- treat underlying cause
- Drugs that suppress the immune system - autoimmune
- Drugs that stimulate bone marrow - EPO, granulocyte colony-stimulating factor (GCSF)
- Bone marrow transplant
- Blood transfusions
- Allogenic stem cell transplant
- Watchful monitoring - mild
30
what is sickle cell disease?
- inherited haemoglobinopathy caused by mutation in the gene encoding for the beta globin gene
- autosomal recessive affecting beta-globin gene on chromosome 11
- HbS allele results from single nucleic acid substitution from GAG to GTG in beta globin gene
- this affects how haemoglobin polymerises and forms crystals when deoxygenated - sickling of red cells leading to vaso-occlusive crises in sufferers
31
how does sickle cell predispose someone to infection?
splenic dysfunction, reduced opsonisation, adaptive immune dysfunction, neutrophil dysfunction, increased osteomyelitis risk
32
what are some sickle cell crisis types?
- acute exacerbation
- haemolytic
- vaso-occlusive
- sequestration
- aplastic
- acute chest
33
how might vase-occlusive crises present?
- acute pain from vaso-occlusion crises in back, legs, knees, arms, chest and abdomen
- hypoxia
- infection
- strenuous exercise
- dehydration
- acidosis
- Dactylitis - painful inflammation of a digit (finger or toe) which may be first presentation in a child
34
what complications might arise in someone with sickle cell?
- chronic spleen damage by auto-infarction
- pulmonary htn, leg ulcers, priapism, CKD, leg artery ischaemic stroke
- short stature, aplastic crisis
- life expectancy of 58 years
35
what is the most common cause of death associated with sickle cell?
infection, sepsis, meningitis, pneumonia
36
how might sickle cell be investigated?
- hb elecrophoresis
- high performance liquid chromatography
- blood film
- FBC, reticulocytes
- iron studies
- imaging - XR
- antenatal screening
- new born blood spot test
37
when would you consider admission for someone with sickle cell?
- Persistent temperature
- Pallor, lethargy, malaise, abdominal distension.
Severe pain requiring opiate analgesia
- Symptoms and signs suggesting:
* Acute chest syndrome
* Acute cerebrovascular accident
* Sequestration syndrome
* Aplastic crisis
* Fulminant priapism
38
how would you manage an acute pain crisis in sickle cell?
- analgesia - assess pain regularly!! paracetamol, NSAIDs and stronger opioids for severe
- fluid hydration
- oxygen
- antibiotics - consider if any infection, follow local protocol
- red cell transfusion urgent
39
how would you manage sickle cell?
- prophylaxis: hydroxycarbamide, regular transfusions
- education: recognise crises, avoid alcohol and strenuous exercise
general
- avoid triggers like dehydration
- up-to-date vaccinations
- antibiotic prophylaxis
- hydroxycarbamide
- crizanlizumab
- prevents RBC sticking to vessel wall and reduces crises frequency
- BM transplant
- blood transfusions
