Haematology Flashcards
name 5 causes of microcytic anaemia
- iron-deficiency anaemia
- thalassaemia
- congenital sideroblastic anaemia
- anaemia of chronic disease (more commonly a normocytic, normochromic picture)
- lead poisoning
name 5 causes of normocytic anaemia
- anaemia of chronic disease
- chronic kidney disease
- aplastic anaemia
- haemolytic anaemia
- acute blood loss
name 6 causes of macrocytic anaemia
- B12 deficiency
- folate deficiency
- alcohol
- liver disease
- hypothyroidism
- pregnancy
how will iron studies appear in iron deficiency anaemia
- Hb will be low
- ferritin will be low (unless there is coincidental inflammation)
- transferrin/TIBC will be high
- transferrin saturation will be low
who should be referred urgently for investigation of iron deficiency anaemia
Post-menopausal women with a haemoglobin level ≤10 and men with a haemoglobin level ≤11 should be referred to a gastroenterologist within 2 weeks.
management for iron deficiency anaemia in the community
Oral ferrous sulfate: patients should continue taking iron for 3 months after the iron deficiency has been corrected in order to replenish iron stores.
who is offered FIT testing
- Screening:
- Every 2 years to all men and women aged 60 to 74 years in England.
- Patients aged over 74 years may request screening
- Patients with new symptoms who don’t meet 2wk wait criteria:
- patients >= 50 years with unexplained abdominal pain OR weight loss
- patients < 60 years with changes in their bowel habit OR iron deficiency anaemia
- patients >= 60 years who have anaemia even in the absence of iron deficiency
who should be referred to gastro for 2wk wait
- patients >= 40 years with unexplained weight loss AND abdominal pain
- patients >= 50 years with unexplained rectal bleeding
- patients >= 60 years with iron deficiency anaemia OR change in bowel habit
- those whose tests show occult blood in their faeces (see below)
what is the two level wells score for DVT
what does the well’s score for DVT mean
- two or above: DVT likely
- one or below: DVT unlikely
how do you manage a patient who has a well’s score above 2
how do you manage a patient with a DVT well’s score of 1 or below
in what setting would doac not be the appropriate drug for DVT
if renal impairment is severe (e.g. < 15/min) then LMWH
how long should patients be anticoagulated after
- everyone anticoagulated for three months
- if it was a provoked DVT with a clear precipitating factor (such as leg immobilisation following surgery) then it stops at three months
- if it was unprovoked DVT then continue for further three months
what is the typical blood picture in DIC
- ↓ platelets
- ↓ fibrinogen
- ↑ PT & APTT
- ↑ fibrinogen degradation products
in what four conditions would you see target cells of blood film
- Sickle-cell/thalassaemia
- Iron-deficiency anaemia
- Hyposplenism
- Liver disease
when do you see Howell-Jolly bodies on blood film
hyposplenism
when do you see heinz bodies oh blood film
G6PD deficiency
Alpha Thalassaemia
when do you see pencil poikilocytes on blood film?
iron deficiency anaemia
name 11 types of haemolytic anaemia by cause
- Hereditary causes
- membrane: hereditary spherocytosis
- metabolism: G6PD deficiency
- haemoglobinopathies: sickle cell, thalassaemia
- Acquired: immune causes
- autoimmune: warm/cold antibody type
- alloimmune: transfusion reaction, haemolytic disease newborn
- drug: methyldopa, penicillin
- Acquired: non-immune causes
- microangiopathic haemolytic anaemia (MAHA): TTP/HUS, DIC, malignancy, pre-eclampsia
- prosthetic heart valves
- paroxysmal nocturnal haemoglobinuria
- infections: malaria
- drug: dapsone
compare G6PD deficiency and heredetary spherocytosis with regards to gender, ethnicity, typical history, blood film, and diagnostic tests
what is the most common hereditary haemolytic anaemia in people of northern European descent
heredetary spherocytosis
what is the cause of heredetary spherocytosis
autosomal dominant defect of red blood cell cytoskeleton
what is the management of heredetary spherocytosis
- acute haemolytic crisis:
- treatment is generally supportive
- transfusion if necessary
- longer term treatment:
- folate replacement
- splenectomy
aplastic crisis precipitated by parvovirus infection happens in what disease
heredetary spherocytosis
sickle cell
what is the pathophysiology of G6PD deficiency
↓ G6PD → ↓ reduced NADPH → ↓ reduced glutathione → increased red cell susceptibility to oxidative stress
what are the features of G6PD deficiency
- neonatal jaundice is often seen
- intravascular haemolysis
- gallstones are common
- splenomegaly may be present
- Heinz bodies on blood films. Bite and blister cells may also be seen
what can trigger haemolysis in people with G6PD deficiency
- anti-malarials: primaquine
- ciprofloxacin
- sulph- group drugs: sulphonamides, sulphasalazine, sulfonylureas
- infection
- broad beans
what kind of protection do people who’ve had splenectomy need
- Vaccination
- if elective, should be done 2 weeks prior to operation
- Hib, meningitis A & C
- annual influenza vaccination
- pneumococcal vaccine every 5 years
- Antibiotic prophylaxis
- penicillin V should be continued for at least 2 years and at least until the patient is 16 years of age, although the majority of patients are usually put on antibiotic prophylaxis for life
indications for splenectomy
- Trauma: 1/4 are iatrogenic
- Spontaneous rupture: EBV
- Hypersplenism: hereditary spherocytosis or elliptocytosis etc
- Malignancy: lymphoma or leukaemia
- Splenic cysts, hydatid cysts, splenic abscesses
which bacteria are most likely to cause post-splenectomy sepsis
- encapsulated bacteria such as:
- Strep. pneumoniae
- Haemophilus influenzae
- Neisseria meningitidis
what are the two types of autoimmune haemolytic anaemia
warm and cold based on what temperature the antibodies best cause haemolysis
what is the most common type of autoimmune haemolytic anaemi
warm AIHA
what are the main features of autoimmune haemolytic anaemia
- general features of haemolytic anaemia
- anaemia
- reticulocytosis
- blood film: spherocytes and reticulocytes
- specific features of autoimmune haemolytic anaemia
- positive direct antiglobulin test (Coombs’ test).
what are the causes of warm haemolytic anaemia
- idiopathic
- autoimmune disease: e.g. systemic lupus erythematosus*
- neoplasia
- lymphoma
- chronic lymphocytic leukaemia
- drugs: e.g. methyldopa
what is the management of warm haemolytic anaemia
- treatment of any underlying disorder
- steroids (+/- rituximab) are generally used first-line
what are the features of paroxysmal nocturnal haemoglobinuria
- haemolytic anaemia
- red blood cells, white blood cells, platelets or stem cells may be affected therefore pancytopaenia may be present
- haemoglobinuria: classically dark-coloured urine in the morning (although has been shown to occur throughout the day)
- thrombosis e.g. Budd-Chiari syndrome
- aplastic anaemia may develop in some patients
what is the treatment for paroxysmal nocturnal haemoglobinuria
- blood product replacement
- anticoagulation since they are at increased risk of clotting
how do you diagnose sickle cell anaemia
- definitive diagnosis of sickle cell disease is by haemoglobin electrophoresis
management of sickle cell crisis
- analgesia e.g. opiates
- rehydrate
- oxygen
- consider antibiotics if evidence of infection
- blood transfusion
- exchange transfusion: e.g. if neurological complications
long term managment of sickle cell anaemia
- hydroxyurea
- increases the HbF levels and is used in the prophylactic management of sickle cell anaemia to prevent painful episodes
- NICE CKS suggest that sickle cell patients should receive the pneumococcal polysaccharide vaccine every 5 years
features of beta thalassaemia trait
- usually asymptomatic
- mild hypochromic, microcytic anaemia - microcytosis is characteristically disproportionate to the anaemia
what is the problem in beta thalassaemia major
- absence of beta globulin chains
- chromosome 11