Anaemia - Presentation, Diagnosis and Management Flashcards
What is anaemia ?
A condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal.
BELOW 2SD from the mean
State the range of haemoglobin in adult males
135-175 g/l
State the range of haemoglobin in females
120-155 g/l
State some symptoms of anaemia
Tired all the time
Short of breath
Muscle pain on exertion
Dizzy
Angina
State some clinical signs of anaemia
Pallor in skin and conjunctiva
Tachycardia
Rapid breathing
Peripheral oedema - i.e. leg swelling (if severe anaemia)
Why is tachycardia a symptom of anaemia ?
Cardiac output increases by rises in rate and stroke volume, so more oxygen is delivered.
More symptoms if a sudden fall in Hb
Describe the oxygen dissociation curve for those with anaemia
Right shift
(reduced affinity)
Increased temperature
Increased 2,3 DPG
Increased [H+]
More oxygen extracted from the blood
State the 4 ways in which anaemia can be classified
Under-production or increased loss of RBCs
Congenital or acquired
Acute or chronic
By MCV (mean cell volume) - micro/normo/macro-cytic
Microcytic anaemia
Iron deficiency anaemia, Thalassaemia
MCV 60-80fl
Normocytic anaemia
Blood Loss, Anaemia of Chronic disease, renal impairment
MCV 80-100fl
Macrocytic anaemia
Megaloblastic anaemia, B12/folate deficiency, Myelodysplasia
MCV 100-120fl
MCV
Mean cell volume
MCH
Mean cell haemoglobin
MCHC
Mean cell haemoglobin concentration
RDW
Red cell distribution width
What is RDW a measure of ?
The spread of RBC size
e.g. Retics / Transfusion
MCV 60-80fl
Iron deficiency anaemia, Thalassaemia
MCV 80-100fl
Blood Loss, Anaemia of Chronic disease, renal impairment
MCV 100-120fl
Megaloblastic anaemia, B12/folate deficiency, Myelodysplasia
Describe iron deficiency anaemia
Reduction in MCV to 65-80
Reduction in Hb
Low ferritin
Low transferrin saturation with iron
Causes of iron deficiency anaemia (4)
Poor iron intake
Blood loss (menstrual/ GI tract)
Malabsorption (coeliac disease)
Increased need of iron (for growth spurt/ pregnancy)
State some clinical features of iron deficiency anaemia
Pale
Tachycardia
Koilonychia
Hair loss
Pica
Glossitis/ angular stomatitis
Symptoms of iron deficiency anaemia
Weight loss
Abdominal pain
Bowel change
Heavy periods
Describe investigations for iron deficiency anaemia
Confirmed by LOW ferritin and typical FBC
Screen for coeliac disease (IgA tGA)
Upper and lower endoscopy
Oral treatment for iron deficiency anaemia
Treat the underlying cause
Oral - replacement with sufficient iron for a long enough period
(200mg of ferrous sulphate 1x a day -> 65mg elemental iron per dose)
Why should patients be given oral iron after correction of anaemia ?
IN order to build up iron stores, patients require 3 months of iron.
When is parenteral treatment used over oral treatment for iron deficiency anaemia ?
If oral treatment is ineffective or poorly tolerated
Parenteral treatment for iron deficiency anaemia
(used to be intramuscular - painful, multiple doses, stains skin)
Now administered intravenously
Side effects of iron treatment (IV)
Flu like symptoms
Hypersensitivity reactions
Anaphylaxis
What is the parenteral treatment for iron deficiency anaemia ?
Ferric carboxymaltose - ferinject - over 15-30min : 2 doses
Iron dextran - cosmofer - over 4-6hrs after a test dose
Describe B12 deficiency anaemia
MCV 100-120
Raised bilirubin and LDH levels (due to ineffective erythropoiesis)
Results of B12 deficiency anaemia
What conditions can it cause ?
Can cause peripheral neuropathy - demyelination and posterior column damage
B12 reference range is lower in pregnancy/ oral contraceptive/ on metformin
Pernicious anaemia
Lack of intrinsic factor
(gastric atrophy and auto antibodies to parietal cells and intrinsic factor - preventing absorption)
Inability to absorb B12 from the small intestine
Insufficient creation of healthy RBCs
Treatment for B12 deficiency anaemia
Hydroxocobalamin
1mg intra-muscular alternate days for 5 doses
3 monthly if confirmed ongoing need - pernicious anaemia
What is the treatment for B12 deficiency anaemia caused by a vegan diet ?
Cyanocobalamin orally
Pancytopenia
Deficiency of all three cellular components of the blood (red cells, white cells, and platelets).
Describe the development of folate deficiency
Limited stores of folate and so can develop in weeks.
Poor oral intake
Increased use
Appearance of folate deficiency
Blood count and film appearance is the same as B12 deficiency
What are causes of poor intake / increased use of folate ?
Pregnancy
Haemolysis
Malabsorption
Drugs - anti epileptics / trimethoprim
Treatment of folate deficiency
Oral folic acid - 5mg per day
Function of pre-conception folic acid
0.4mg/day
Reduces neural tube defects
Describe anaemia caused by blood loss
Each 500ml loss gives approx drop of Hb by 10-15 g/l
Drop after fluid replacement or re-distribution
Reticulocyte response within hours
Hb will be normal after blood loss
Describe anaemia of chronic disease
Normocytic anaemia associated with chronic inflammatory disease.
Causes of anaemia of chronic disease
Plentiful iron stores but poor transfer to RBC due to hepcidin and cytokines.
Treatment of anaemia of chronic disease
Treating the underlying condition
Likelihood of getting anaemia of chronic disease
(factors that increase)
History of chronic disease
Inflammatory markers increased e.g. CRP/ESR
Describe anaemia of renal failure
Drop in Hb once creatine clearance drops below 20-30 ml/min chronically
Cause of anaemia of renal failure
Mainly due to a lack of erythropoietin (drives blood production)
Contribution from blood loss at dialysis, inflammatory disease.
Treatment of anaemia of renal failure
Responds well to erythropoietin
e.g. weekly / alternate weeks s/c
Describe anaemia - haemolysis
Increased RBC destruction, marrow can increase production 5-10 fold
Causes of anaemia - haemolysis
Issues to do with :
- RBC membrane
- RBC enzymes
- Globin chains in Hb
Types of anaemia-haemolysis
Acute
Chronic
Congenital
Acquired
Describe haemolysis to do with RBC membrane issue
State conditions
Congenital spherocytosis
Auto-immune haemolysis
Congenital spherocytosis
Autosomal dominant defect in spectrin causing spherical cells - less able to deform, so shortened survival
Auto-immune haemolysis
Auto-antibodies against RBC surface antigens
Fc portion recognised by macrophages in spleen
How is auto-immune haemolysis treated ?
Steroids / Splenectomy / Rituximab
Describe haemolysis to do with RBC enzyme issue
RBC enzyme deficiency - G6PD / pyruvate kinase
Disseminated intravascular coagulation
Prosthetic heart valve
Results of RBC enzyme deficiency
Causes shortened RBC survival
Describe haemolysis to do with globin chains in Hb issue
Haemoglobinopathy
Chronic anaemia and bone/liver/lung/brain ‘‘crisis”
Shortened RBC survival
How is anaemia - abnormal haemoglobin treated ?
Treated by :
- supportive care
- hydroxycarbamide : to increase HbF production
- monoclonal antibody : to prevent red cell-endothelial adhesion
- stem cell transplant
Causes of thalassaemia (anaemia)
Imbalance of globin chain production
Describe beta thalassaemia
As HbF (2alpha, 2gamma) declines after birth - progressive anaemia
Treatment of thalassaemia
Supportive care
Transfusion
Stem cell transplant
Preventative measures for thalassaemia
Antenatal screening for Hb-opathy and thalassaemia
What is myeloma ?
B cell malignancy of mature plasma cells - produce monoclonal immunoglobulin or light chains
What does myeloma present as ?
Presents as a chance finding:
- Anaemia
- Renal failure
- Hypercalcaemia
- Bone pain
- Fracture
Treatment of myeloma
Supportive care
Chemotherapy
Radiotherapy
How is acute leukaemia diagnosed and treated ?
Diagnosed by sampling marrow - pelvis/sternum
Treated by chemotherapy/immunotherapy
Results of anaemia-marrow filtration
Other solid tumours can spread to the marrow e.g. prostate, breast, small cell lung
Examples of haematological malignancy
Lymphoma
Acute leukaemia
Describe myelodysplasia
Marrow becomes increasingly inefficient at producing red cells, white cells and platelets.
Tendency to progress to acute leukaemia.
Treated by supportive care, chemotherapy or stem cell transplant in some.
Describe aplastic anaemia - aka pancytopenia
Expected results post-chemotherapy, but can be drug induced.
e.g. NSAIDs
Treated by supportive care, anti-thymocyte globulin, stem cell transplant
A FBC on a patient with anaemia has a significantly raised reticulocyte count.
What is a specific feature of reticulocytes ?
They indicate the marrows response to anaemia
Anaemia of chronic disease is common both in primary and secondary care.
What is the most effective treatment for this condition ?
Treating the underlying condition
