Haematology Flashcards
What is vitamin b12 used in ?
For red blood cell development and also maintenance of the nervous system.
Causes of b12 deficiency
- pernicious anaemia = most common cause
- post gastrectomy
- vegan diet or a poor diet
- disorders/surgery of terminal ileum (site of absorption)
- Crohn’s: either diease activity or following ileocaecal resection - metformin (rare)
Features of b12 deficiency
- macrocytic anaemia
- blood film: hypersegmented neutrophils - sore tongue and mouth
- neurological symptoms
- the dorsal column is usually affected first (joint position, vibration) prior to distal paraesthesia - neuropsychiatric symptoms: e.g. mood disturbances
Management of vitamin b12 deficiency
- if no neurological involvement = 1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months
- if a patient is also deficient in folic acid then it is important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cord
Causes of macrocytic anaemia
- vitamin b12 deficiency
- folate deficiency
- Liver disease/alcoholism
- Hypothyroidism
Causes of microcytic anaemia
- Iron deficiency
2. Thalassemia
Causes of normocytic anaemia
- Acute blood loss
2. Chronic renal disease
Features of macrocytic anaemia
- Loss of appetite/weight
- Brittle nails
- Tachycardia
- Diarrhoea
- Fatigue
- Fake skin (lips and eyelids)
- Dyspnoea
- Poor concentration/confusion
- Memory loss
Investigations for macrocytic anaemia
FBC – check for enlarged RBC and anaemia (MCV(high))
Haematocrit levels = low
Haemoglobin levels
Blood film to identify megaloblastic anaemia
–> hypersegmented polymorphoneucleated cells
LFT
TFT
Features of iron deficiency anaemia
- Fatigue
- Shortness of breath on exertion
- Palpitations
- Pallor
- Nail changes: this includes koilonychia (spoon-shaped nails)
- Hair loss
- Atrophic glossitis
- Post-cricoid webs
- Angular stomatitis
Investigations for iron deficiency anaemia
FBC:
- low Hb
- low MCV
- low ferritin
Blood film:
- microcytic hypochromic RBC
- poikilocytosis
- dimorphic RBCs
Endoscopy:
R/O malignancy
Management of iron deficiency
- Oral ferrous sulphate (fumarate, gluconate)
- Iron-rich diet: this includes dark-green leafy vegetables, meat, iron-fortified bread
- treat underlying cause
What is aplastic anaemia?
This type of anaemia occurs when your body fails to produce enough new blood cells
Features of aplastic anaemia
- normochromic, normocytic anaemia
- leukopenia with
thrombocytopenia - features of acute lymphoblastic or myeloid leukaemia
Symptoms:
- fatigue
- SOB
- tachycardia
- pallor
- headache
- fever
- failure to thrive
- jaundice
- murmurs
Investigations for aplastic anaemia
Blood:
- pancytopenia
- reticulocyte
Bone marrrow biopsy
- fewer cells than normal
Management of aplastic anaemia
1st line = immunosuppressants e.g. cyclosporine, corticosteroids
Stem cell transplant
Blood transfusions
What is sickle cell anaemia?
autosomal recessive condition that results for synthesis of an abnormal haemoglobin chain termed HbS
- more common in afro Caribbean decent
When do symptoms develop in sickle cell anaemia?
don’t tend to develop until 4-6 months when the abnormal HbSS molecules take over from fetal haemoglobin.
Features of sickle cell anaemia
- Episodes of pain
- swelling of hands + feet
- frequent infections
- Vision disturbances
- delayed growth/puberty
Investigations for sickle cell anaemia
Definitive diagnosis = haemoglobin electrophoresis
Blood film: crescent moon
Sickle cell crisis management
- analgesia e.g. opiates
- rehydrate
- oxygen
- consider antibiotics if evidence of infection
- blood transfusion
- exchange transfusion: e.g. if neurological complications
Long-term management of sickle cell
- hydroxyurea
- increases the HbF levels and is used in the prophylactic management of sickle cell anaemia to prevent painful episodes - pneumococcal polysaccharide vaccine every 5 years
What is G6PD deficiency anaemia?
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the commonest red blood cell enzyme defect.
- more common = Mediterranean and Africa
- inherited in an X-linked recessive fashion.
- Many drugs can precipitate a crisis as well as infections and broad (fava) beans
Features of G6PD deficiency anaemia
- neonatal jaundice
- intravascular haemolysis
- gallstones are common
- splenomegaly may be present
- Heinz bodies on blood films.
- Bite and blister cells may also be seen
Investigations for G6PD deficiency anaemia
Diagnosis made using G6PD enzyme assay
Drugs causing G6PD deficiency anaemia
- anti-malarials: primaquine
- ciprofloxacin
- sulph- group drugs: sulphonamides, sulphasalazine, sulfonylureas
Management of G6PD deficiency anaemia
Treat cause of symptoms
if anaemia has progressed to haemolytic anaemia = blood transfusion
Define haemolytic anaemia
a disorder in which red blood cells are destroyed faster than they can be made.
Causes of haemolytic anaemia
autoantibodies, medications, and underlying malignancy
hereditiary
Features of haemolytic anaemia
Pallor jaundice Fatigue SOB dizziness splenomegaly
Investigations for haemolytic anaemia
Bloods:
- low hb
- high MCHC
- increase reticulocyte
Film:
- RBC fragment
- schistocytes
- spherocytes
- reticulocyte
- nucleated RBC
Coombs test= positive
- immune mediated
Management of haemolytic anaemia
- Supportive care:
- Folic acid
- transfusion of packed RBCs - Coombs positive:
- remove insult
- corticosteroids
- splenectomy
https://bestpractice.bmj.com/topics/en-gb/98/management-approach
What is idiopathic thrombocytopenic purpura (ITP)?
Immune-mediated reduction in the platelet count.
Symptoms for ITP
- petichae, purpura
- bleeding (e.g. epistaxis)
- catastrophic bleeding (e.g. intracranial)
Blood findings for ITP
Low platelet
Management for ITP
1st line = oral prednisolone
- pooled normal human immunoglobulin (IVIG)
- it raises the platelet count quicker than steroids
- used if active bleeding or an urgent invasive procedure is required - splenectomy is less common