Haem Flashcards
Define microcytic anaemia
Anaemia associated with a decreased MCV
Microcytic (MCV <80 fL).
Haemoglobin (Hb) level <120 g/L in females and <140 g/L in males
Explain the aetiology / risk factors of microcytic anaemia
Iron-deficiency: - Blood loss Anaemia of chronic disease: - Usually normocytic, but can be microcytic Thalassaemia Sideroblastic anaemia: - Abnormal haem synthesis Lead poisoning: - Globin and haem synthesis interference
Summarise the epidemiology of microcytic anaemia
most common cause is iron deficiency anaemia
Recognise the presenting symptoms of microcytic anaemia
Anaemia: lethargy, tiredness, dyspnoea, pallor, weakness
Lead poisoning: anorexia, nausea, vomiting, abdominal pain
Recognise the signs of microcytic anaemia on physical examination
Anaemia: pallor, brittle nails and hair, conjunctival pallor
Tachycardia in severe cases?
Glossitis, cheilitis
Lead poisoning: blue gum line, peripheral nerve lesions, encephalopathy
Identify appropriate investigations for microcytic anaemia and interpret the results
Bloods: FBC, serum iron, iron-binding capacity, serum ferritin, serum lead
Blood film:
- Iron-deficiency: microcytic, hypochromic, anisocytosis, poikilocytosis
- Sideroblastic anaemia: dimorphic blood film
- Lead poisoning: basophilic stripping
If >40/menopausal women:
- Upper GI endoscopy, colonoscopy
Generate a management plan for microcytic anaemia
Iron deficiency: iron supplements, consider parenteral if doesn’t work
Sideroblastic anaemia: treat cause (drugs), pyridoxine in inherited forms
Lead poisoning: remove source of poison, dimercaprol
Identify the possible complications of microcytic anaemia and its management
High-output cardiac failure, complications of cause
Summarise the prognosis for patients with microcytic anaemia
Depends on underlying cause
Define macrocytic anaemia
Anaemiais defined as Hb <120 g/L in females and <140 g/L in males
Macrocytic (MCV >100 fL)
Explain the aetiology / risk factors of macrocytic anaemia
Megaloblastic:
• B12 deficiency (Crohn’s, metformin, omeprazole)
• Folate deficiency (alcoholics, phenytoin)
• Drugs: methotrexate
Non-megaloblastic:
• Alcohol excess, liver disease
Summarise the epidemiology of macrocytic anaemia
More common in elderly and females
Recognise the signs of macrocytic anaemia on physical examination
Anaemia: pallor, tachycardia
Pernicious anaemia: lemon-tinted skin, glossitis, weight loss
B12 deficiency: peripheral neuropathy, ataxia
Recognise the presenting symptoms of macrocytic anaemia
Anaemia: tiredness, lethargy, dyspnoea
Family history of autoimmune disease
Identify appropriate investigations for macrocytic anaemia and interpret the results
Blood: FBC, LFTs, ESR, TFTs, B12, folate
Blood film: large erythrocytes
Schilling’s: radiolabelled B12 measured in urine
Generate a management plan for macrocytic anaemia
Pernicious anaemia: IV hydroxycobalamin
Folate deficiency: oral folic acid (treat B12 deficiency first, folate can worsen neuropathy)
Identify the possible complications of macrocytic anaemia and its management
Risk of gastric cancer, pregnancy + folate deficiency predisposes to spinal cord abnormalities
Summarise the prognosis for patients with macrocytic anaemia
Majority are treatable
Define normocytic anaemia
Anaemia associated with a normal MCV
Anaemiais defined as Hb <120 g/L in females and <140 g/L in males
Normocytic (MCV 80-100 fL
Explain the aetiology / risk factors of normocytic anaemia
Loss of blood cells: • Blood loss (peptic ulcers, oesophageal varices, trauma) • Hypersplenism (RBCs pool in the spleen) • Haemolytic disorders Reduced blood cell formation: • Myelopathies • Renal failure (secondary) Plasma expansion: Pregnancy/overhydration
Summarise the epidemiology of normocytic anaemia
Most common anaemia
Recognise the presenting symptoms of normocytic anaemia
Anaemia: pallor, fatigue, dyspnoea
Anorexia, headache, bowel disturbances
Recognise the signs of normocytic anaemia on physical examination
Koilonychia (iron deficiency), pallor, glossitis, tachycardia, wide pulse pressure, systolic ejection murmur
Identify appropriate investigations for normocytic anaemia and interpret the results
Bloods: FBC, U&Es, eGFR, clotting screen
Pregnancy test
Generate a management plan for normocytic anaemia
Treat underlying cause
Erythropoietin administration
Identify the possible complications of normocytic anaemia and its management
Fatigue
Summarise the prognosis for patients with normocytic anaemia
Dependant on cause
Define aplastic anaemia
Diminished haematopoietic precursors in the bone marrow, and a deficiency of all blood cells (pancytopaenia)
Explain the aetiology / risk factors of aplastic anaemia
Idiopathic (>40%): destruction due to autoimmune mechanisms
Acquired: drugs (chloramphenicol, gold), chemicals, radiation
Inherited: Fanconi’s anaemia
Summarise the epidemiology of aplastic anaemia
Rare, 2-4:1,000,000
Recognise the presenting symptoms of aplastic anaemia
Slow or rapid onset
Anaemia: lethargy, tiredness, dyspnoea Thrombocytopaenia: easy bruising, bleeding gums Leukopenia: increased infections
Recognise the signs of aplastic anaemia on physical examination
Anaemia: pallor
Thrombocytopaenia: bruises, petechiae
Leukopenia: multiple infections
Identify appropriate investigations for aplastic anaemia and interpret the results
Bloods: FBC (everything lowered, normal MCV)
Blood film: exclude leukaemia
Bone marrow trephine biopsy: for diagnosis and exclusion Criteria for severe aplastic anaemia (AA)
- Marrow with <25% normal cellularity
- Neutrophils <0.5 x 109/L
- Platelets <20 x 109/L
- Reticulocytes <40 x 109/L
Define haemolytic anaemia
Shortened erythrocyte life span, due to premature breakdown (<120 days), with anaemia
Explain the aetiology / risk factors of haemolytic anaemia
Hereditary: - Membrane defects - Metabolism defects - Haemoglobinopathies (sickle cell, thalassaemia) Acquired: - Autoimmune - Isoimmune (transfusion reactions) - Drugs (penicillin) - Trauma - Infection (malaria) - Paroxysmal nocturnal haemoglobinuria
Summarise the epidemiology of haemolytic anaemia
Common
