Dr. Hasan Fahmawi, MRCP (London), FRCP(Edin) Consultant Physician

ANAEMIA

Definition

• Anaemia refers to a state in which haemoglobin in the blood is below the reference range appropriate for age and sex. Other factors like pregnancy and altitude must be taken into consideration. The effects of anaemia reflects decrease oxygen supply to the tissues which is more in acute blood loss. It is mostly in patients with cardiorespiratory disease.

Causes

• Decrease or ineffective marrow production • Lack of iron, vit. B12 or folate. • Myelodysplasia • Invasion of malignant cells • Renal failure • Anaemia of chronic disease • Normal production but increased removal of cells • Blood loss • Haemolysis • Hypersplenism

Symptoms and signs

• Symptoms - tiredness, lightheadedness, breathlessness, development or worsening of ischaemic symptoms.

• Signs - mucous membrane pallor, tachypnoea, raised JVP, tachycardia, flow murmurs, ankle oedema, postural hypotension

Assessment

• Iron deficiency anaemia, menorrhagia, GI malignancy

• A dietary history, pregnancy, rapid growth

• Past medical history, Rh.A., surgery

• Family history, haemolytic anaemia

• A drug history, chloramphenicol, sulfa, methotrexate, aspirin and NSAID

• Investigations CBC, MCV, MCHC, serum ferritin, Vit B12, RBC folate and blood film

MCV

• Low – iron deficiency, thalasaemia, sideroblastic and ACD chronic disease (inflammation, infection and malignancy)

• High – megaloblastic anaemia, pernicious anaemia, liver disease, hyperlipidaemia and pregnancy. (Reticulocytosis)

Iron deficiency anaemia Causes • Blood loss, parasites, GI malignancy, IBD, PUD , gastritis, diverticulosis,

polyposis, angiodysplasia, drugs, menestraution, pregnancy, breast feeding, very rarely chronic haemoptysis or haematuria.

• One third of women of child bearing age have low ferritin level, 3% have iron def.anaemia

• Malabsorption of iron in achlorhyrdria, gastric surgery, Coeliac disease

• Increased demand in puberty, pregnancy and delivery.

• Low ferritin in vit C def., hypothyroidism, and acute phase response up to 100.

• TIBC

• Plasma transferrin receptors can be measured in acute phase response

Management

• HF, Angina, Cerebral hypoxia.-transfusion

• Oral iron, folic acid may be needed.

• IV iron- iron carboxymaltose and iron isomaltose .

• Failure of therapy – non-adherence, continued blood loss, malabsorption and incorrect diagnosis (def. of other factors)

Megaloblastic anaemia

• Deficiency of vit. B12 or folic acid, or disturbance in folic acid metabolism. Folate is an important substrate of, and vit B12 is a co-factor for, the generation of methionine from homocysteine. There is some evidence that giving folic acid in supraphysiologica doses 400mcg daily can reduce the risk of coronary and cerebrovascular disease, by lowering homocysteine levels, accordingly FDA asked for fortification of bread, flour and rice with folic acid.

Vit. B12-

Causes of def.

Gastric pathology - surgery

PERNICIOUS ANAEMIA which is organ specific auto-immune disease leading to gastric atrophy and loss of parietal cells, together with Hashimoto’s thyroiditis, Grave’s disease, Addison disease and vitiligo or with family history of those. Intrinsic factor antibodies in megaloblastic anaemia is diagnostic, anti-parietal cells antibodies are suggestive.

Small bowel pathology, Crohn’s, surgery, motility disorder, hypogammaglobulinaemia, bacterial over growth,

Vegetarians

Symptoms and signs of vit B 12 def. • Malaise (90%)

• Breathlessness (50%)

• Sore mouth (20%) Magenta tongue.

• Signs

• Smooth tongue, angular cheilosis, Vitilgo, skin pigmentation, HF, pyrexia

Neurological manifestations of vit.B12 def.

Peripheral nerves

Spinal cord, subacute combined degeneration of the spinal cord, posterior column and corticospinal tract.

Cerebrum, optic nerve atrophy and dementia.

Autonomic neuropathy.

Folate deficiency • Produced by plants and bacteria, present in liver and kidney as well,

def.in wks.

• Causes – poor intake of vegetables, old people, psychiatric patients, and edentulous patients.

• Malabsorption-Tropical sprue, Coeliac disease, small bowel surgery.

• Cell proliferation – haemolysis.

• Pregnancy

• Anticonvulsants, contraceptives, cytotoxic drugs and alcohol

• Test-RBC folate level, macrocytic dysplastic blood cells, megaloblastic marrow

Treatment

• Vit. B 12- Cyanocobalamine in uncomplicated def. 1000 mcg. IM every 2-3 days, 6 doses followed by maintenance dose, once every 3 months for life.

• In neurological involvement 1000mcg every 2 days, until no further neurological improvement, then maintenance dose

• Folate def. Folic acid 5mg every day for 3 wks, maintenance 5mg every wk, and in case of increased demand, haemolytic anaemia and pregnancy as it prevents neural tube defect as well

Anaemia of chronic disease (ACD),(AI)

• Chronic inflammation, infection or neoplasia, common particularly in hospital admissions, usually mild anaemia, haemoglobin

• 85-115 gm/100ml and normochromic, normocytic, transferrin is low but ferritin is normal or increased.

• Some times low MCV, TIBC his low, soluble transferrin receptors are normal or low.

• Bone marrow may be indicated in difficult cases, and a trial of iron may be given

• Trials of high intravenous iron are underway as trials.

RBC distribution width

• Hb -7.6

• MCV - 75

• MCHC – 26

• RBC distribution width 27

• Hb – 9

• MCV – 73

• MCHC – 26

• RBC distribution width 15

• Hb -7.3

• MCV – 112

• MCHC - 32

• RBC – distribution width 25