anaemia in general practice  Â
TRANSCRIPT
Outline
• Signs and symptoms of anaemia
• Classification
• Microcytic
• Normocytic
• Macrocytic
• Data examples
Definition of anaemia
• Anaemia is defined as a reduction in the haemoglobin concentration of the blood
• This results in a decreased oxygen carrying capacity
Symptoms of anaemia
• Shortness of breath on exercise
• Weakness and lethargy
• Palpitations and headaches
• Cardiac failure, angina, intermittent claudication and confusion
• Visual disturbances due to retinal haemorrhages
Factors effecting symptoms of anaemia
• Speed of onset
• Severity of anaemia
• Age
• Haemoglobin O2 dissociation curve
Signs of anaemia
• Pallor
• Hyperdynamic circulation, tachycardia, bounding pulse, cardiomegaly
• Congestive cardiac failure
• Retinal haemorrhages
Classification of Anaemia: Microcytic Hypochromic
• MCV <80fl
• MCH <27pg
Microcytic anaemiaFerritin <25ug/L
• Iron deficiency
Microcytic anaemiaFerritin >25ug/L
• Thalassaemia
• Sideroblastic anaemia (some cases)
• Anaemia of chronic disease (some cases)
• Lead poisoning
Classification of Anaemia: Normocytic Normochromic
• MCV 80-100fl• MCH >26pg
Normochromic normocytic anaemia
• Often incidental finding in systemic disorders• May be first manifestation of a systemic disorder• Many haemolytic anaemias• Anaemia of chronic disease (some cases)• After acute blood loss• Bone marrow failure, e.g. Post-chemotherapy,
infiltration by carcinoma etc
Classification of Anaemia: Macrocytic
• MCV >100fl
• Megaloblastic: vitamin B12 or folate deficiency
• Non-megaloblastic: alcohol, liver disease, myelodysplasia, aplastic anaemia
Iron deficiency anaemia
• Assess for
• Dietary Iron deficiency
• Malabsorption- coeliac
• Chronic blood loss
• Gastrointestinal
• Menorrhagia
Treatment of Iron Deficiency
• Ferrous sulphate 200mg three times a day (cheapest) on an empty stomach
• Continue until stores are replaced-usually 6 months
Follow up-Iron deficiency
• Adolescents and pre-menopausal females
• GI symptoms and no diagnosis
• Menstrual problem
• Follow-up: refer only if specific indication
• Refer to gastroenterologist
• Refer to gynaecologist
Failure of Response to Oral Iron
• Continuing blood loss
• Failure to take tablets
• Wrong diagnosis-thalassaemia trait, sideroblastic anaemia
• Mixed deficiency-associated vitamin B12 or folate deficiency
• Another cause for the anaemia, e.g. malignancy, inflammation
• Malabsorption
• Use of a slow release preparation
Microcytic anaemiaFerritin >25ug/L
• Thalassaemia
• Sideroblastic anaemia • Anaemia of chronic
disease (usually normocytic)
• Lead poisoning (usually normocytic)
• Consider referral to haematologist
• Refer to haematologist
• Assess exposure history: measure urinary lead
Thalassaemia Trait
• Microcytic anaemia
• High red cell count
• Normal MCHC
• Usually non-Caucasian
Treatment of Thalassaemia Trait
• Reassurance
• Evaluation of iron status
• Antenatal/ genetic counselling
Normocytic anaemia
• Often an incidental finding in systemic disorders• May be first manifestation of systemic disorder• May be an early manifestation of a microcytic or
macrocytic anaemia• Detailed history and examination required to guide
investigation/referral• Unexplained normocytic anaemia----refer to
haematologist
Vitamin B12
• Normal daily intake
• Main foods
• Cooking
• Minimal daily requirement
• Body stores
• Absorption
• site
• mechanism
• limit
• Usual therapeutic form
• 7-30g
• Animal produce only
• Little effect
• 1-2g
• 2-3mg (enough for 2-4yrs)
• Ileum
• Intrinsic factor
• 2-3g• Hydroxocobalamin
Pernicious Anaemia
• Autoimmune attack on the gastric mucosa leading to atrophy of the stomach
• Females> males
• Associated autoimmune diseases
• Tends to occur in families
Folic Acid
• Normal daily intake
• Main foods
• Cooking
• Minimal daily requirement
• Body stores
• Absorption
• site
• mechanism
• limit
• Usual therapeutic form
• 200-250g
• Most liver, greens, yeast
• Easily destroyed
• 100-150g
• 10-12mg (4mths supply)
• Duodenum and jejunum
• Converted to methylTHF
• 50-80% of dietary intake
• Folic acid
Causes of Folic Acid Deficiency
• Nutritional -old age, poverty, diet etc
• Malabsorption- tropical sprue, coeliac disease, Crohn’s disease
• Excess utilization
• Physiological-pregnancy, lactation, prematurity
• Pathological-haemolytic anaemia, myelofibrosis, malignant disease, inflammatory disease
• Drugs-anticonvulsants
• Mixed-liver disease, alcoholism, intensive care
Megaloblastic Anaemia: Clinical
• Insidious onset of symptoms and signs of anaemia• Lemon yellow jaundice• Glossitis, angular stomatitis• Purpura• Neuropathy-subacute combined degeneration of
the cord (neuropathy affecting the peripheral sensory nerves and posterior and lateral columns)
Megaloblastic Anaemia: Treatment
• Vitamin B12 1000g/day x 6, intramuscular
• Folic acid 5mg per day, oral• May need folic acid, iron, potassium supplements
and diuretics
• Continue 1000g once every 3 mths for life
Investigation in primary care
• History and examination
• FBP
• Ferritin
• B12 and Folate
Data Interpretation (1)
• Haemoglobin (g/dl)
• Haematocrit (PCV) (%)
• Red cell count (x 1012/L)
• Mean cell haemoglobin (pg)
• Mean cell volume (fl)
• Mean cell haemoglobin concentration (g/dl)
• 7.5 (11.5-16.5)• 30 (0.37-0.47)• 2.35 (3.8-5.8)• 22 (27-32)• 65 (76-100)• 26 (32-36)
Data Interpretation (2)
• Haemoglobin (g/dl)
• Haematocrit (PCV) (%)
• Red cell count (x 1012/L)
• Mean cell haemoglobin (pg)
• Mean cell volume (fl)
• Mean cell haemoglobin concentration (g/dl)
• 11.4 (11.5-16.5)• 0.404 (0.37-0.47)• 6.25 (3.8-5.8)• 20.5 (27-32)• 64.6 (76-100)• 31.7 (32-36)
Further results (2)
• Haemoglobin F- 0.3%• Hb A2 - 2.5%• Ferritin 135ug/L• Homozygous for alpha
3.7 deletion• Homozygous for alpha
+ thalassaemia
• <1%• 1.5-3.5
Data Interpretation (3)
• Haemoglobin (g/dl)
• Haematocrit (PCV) (%)
• Red cell count (x 1012/L)
• Mean cell haemoglobin (pg)
• Mean cell volume (fl)
• Mean cell haemoglobin concentration (g/dl)
• 8.2 (11.5-16.5• 0.25 (0.37-0.47)• 2.7 (3.8-5.8)• 34 (27-32)• 120 (76-100)• 34 (32-36)
Department of Haematology Belfast City Hospital
Anaemia in Adults – Hospital Referral Guidelines:
1. Microcytic anemias (MCV <76 fL): Check serum ferritin (a) Ferritin < 25 ug/L Fe deficiency anaemia: Assess for: Dietary Fe deficiency Malabsorption – esp. coeliac disease Chronic gastrointestinal bleeding Menorrhagia Treat with oral Fe Adolescents & pre-menopausal females: Follow-up
Refer only if specific indication Others - GI symptoms or no diagnosis: Refer to gastroenterologist Menstrual problem: Refer to gynaecologist(b) Ferritin >25 ug/L Thalassaemias } Refer to haematologist Sideroblastic anaemias } Anaemia of chronic disease (usually normocytic) See below Chronic lead poisoning (usually normocytic) Assess exposure history
Measure urinary lead2. Macrocytic anaemias (MCV >100fL): Check serum B12 & folate(a) Normal B12 & folate Assess for: Liver disease
Alcohol excessHypothyroidismPregnancyDrugs
(b) Low B12 or folate Investigate & treat as appropriate Discuss &/or refer to haematologist if difficulties arise(c) All tests normal or no clear diagnosis: Refer to haematologist3. Normocytic anaemia (MCV 76-100 fL): Often an incidental finding in systemic disorders May be the first manifestation of a systemic disorder May be an early manifestation of a microcytic or macrocytic anaemia Detailed history & examination required to guide investigation/referral Unexplained normocytic anaemia: Refer to haematologist
RJG Cuthbert, August 2006
Useful information
• Anaemia in Adults-Hospital referral guidelines
• British Society of Haematology – www.bsg.org.uk
• NHS guidance on the investigation and treatment of anaemias- www.prodigy.nhs.uk/guidance