Anaemia Flashcards
Anaemia definition in men
Hb <135g/L (13.5g/dL)
Anaemia definition in women
Hb <115g/L (11.5g/dL)
3 causes of anaemia
Reduced production of RBCs
Increased loss of RBCs (haemolytic anaemias)
Increased plasma volume (pregnancy)
Microcytic anaemias
IDA
Anaemia of chronic disease
Sideroblastic anaemia
Thalassaemia
Normocytic anaemias
Acute blood loss Anaemia of chronic disease Bone marrow failure Renal failure Hypothyroidism Haemolysis Pregnancy
Macrocytic anaemias
Fetus (pregnancy) Antifolates (e.g. phenytoin) Hypothyroidism Reticulocytosis (release of larger immature cells e.g. haemolysis) B12/folate deficiency Cirrhosis (EtOH excess/liver disease) Myelodysplastic syndromes
Symptoms of anaemia
Tiredness, shortness of breath, palpitations, headache, tinnitus, anorexia
Signs of anaemia
Pallor, in severe hyperdynamic circulation (tachycardia + flow murmurs (ejection-systolic loudest over apex), heart failure)
Koilonychia Brittle hair and nails Atrophic glossitis Angular cheilosis Post-cricoid webs (Plummer-Vinson syndrome) =?
IDA
IDA blood film
Microcytic, hypochromic
Anisocytosis (varying size)
Poikilocytosis (varying shape)
Pencil cells
Clinically considered cause of IDA
Bleeding until proven otherwise, menorrhagia in young women
5 classifications of IDA
Blood loss Increased utilisation Decreased intake Decreased absorption Intravascular haemolysis
Blood loss-related causes of IDA
Gastrointestinal loss of blood
- peptic ulcers/gastritis
- polypa/colorectal cancer (>50)
- menorrhagia (W <50)
- Meckel’s diverticulum (children)
- hookworm infestation (developing countries)
Increased utilisation-related causes of IDA
Pregnancy/lactation
Growth - infants/children
Decreased intake-related causes of IDA
Prematurity - loss of iron each day foetus isn’t in utero
Infants/children/elderly - suboptimal diet
Decreased absorption-related causes of IDA
Coeliac disease - absence of villi in duodenum
Post-gastric surgery - rapid transit so less acid to aid iron absorption
Intravascular haemolysis-related causes of IDA
Microangiopathic Haemolytic anaemia
PNH (paroxysmal nocturnal haemoglobinuria)
Investigations for IDA
Identify cause
If no obvious cause then OGD + colonoscopy, urine dip, coeliac Ix
IDA treatment
Treat the cause
Oral iron (ferrous sulphate)
IV iron if severe + symptomatic
If septic then blood transfusion instead of iron (fuels infection)
Anaemia of chronic disease causes
Chronic infection (e.g. TB, osteomyelitis)
Vasculitis
Rheumatoid arthritis
Malignancy etc (long-standing illness)
Mechanism of cause for anaemia of chronic disease
Cytokine-driven inhibition of RBC production
1 - Inflammatory markers reduce EPO receptor production (and thus EPO synthesis) by kidneys
2 - Iron metabolism dysregulated, IL6/LPS stimulate production of hepcidin by liver decreasing iron absorption by inhibiting transferrin and causing iron accumulation in macrophages
OR renal failure (EPO deficiency)
Ferritin (intracellular protein indicating iron store) status in ACD
Raised due to iron storage in macrophages
Aetiology of sideroblastic anaemia
Ineffective erythropoiesis - iron loading (accumulation of iron in body) causing haemosiderosis (endocrine, liver, cardiac damage due to iron deposition)
Diagnostic feature for sideroblastic anaemia
Ring sideroblasts seen in marrow
Ring sideroblast description
Erythroid precursors with iron deposited in mitochondria in a ring around nucleus
Sideroblastic anaemia causes
Myelodysplastic disorders Post-chemo Irradiation !!Alcohol excess Lead excess Anti-TB drugs Myeloproliferative disease
Sideroblastic anaemia treatment + drug
Remove cause
Pyroxidine (vit B6 to promote RBC production)
Plasma iron study categories (3)
Serum iron
TIBC (total iron binding capacity)
Ferritin
Iron study results - Dx?
Serum iron - lowered
TIBC - raised
Ferritin - lowered
IDA
Plasma iron study results - Dx?
Serum iron - lowered
TIBC - lowered
Ferritin - raised
Anaemia of chronic disease
Iron study results - Dx?
Serum iron - raised
TIBC - lowered
Ferritin - raised
Chronic haemolytic anaemia