26. GIT Anaemia Flashcards
Define anaemia in women
Hb < 11.5
Define anaemia in men
Hb <13
Where is iron absorbed from?
Stomach and duodenum
Where is folate absorbed from?
Duodenum to jejunum
Where is B12 absorbed from?
Terminal ileum
Must also have intrinsic factor from stomach
What are the causes of hypochromic microcytic anaemia?
Iron deficiency Chronic disease (usually normocytic) Thalassaemia
What are the causes of iron deficiency anaemia?
Dietary
Loss
Malabsorption
What are the clinical features of iron deficiency anaemia?
Mucosal pallor Angular cheilitis Atrophic glossitis Brittle nails, koilonychia Ice pica
What are the lab features of iron deficiency anaemia?
Low Hb and ferritin Low MCV High total iron binding capacity Reduced saturation of iron Hyperplasia of bone marrow
What is the treatment for iron deficiency anaemia?
Iron replacement PO
What are the causes of B12 deficiency?
Lack intrinsic factor
Malabsorption
Increased use
What are the causes of a lack of intrinsic factor?
Pernicious anaemia
Atrophic gastritits
Partial gastrectomy
Give an example of how increased use causes a B12 deficiency
Blind loop bacteria syndrome
What are the lab features of B12 or folate deficient anaemia?
Low Hb
Increased MCV
Reduced serum folate or B12
Marrow hyperplasia
What are the clinical features of B12 deficiency?
Peripheral neuropathy Subacute combined degeneration of the cord Optic atrophy Psychiatric disorders Atrophic glossitis
Why is folate given alongside B12 replacement?
Marrow will start rapidly making new RBCs so folate will be used up
Give common causes of anaemia of chronic disease
IBD
RA, SLE, Sarcoid
Renal failure
Malignancy
What is the pathophysiology of anaemia of chronic disease?
In pro-inflammatory states, the liver releases hepcidin
Causes a reduction in iron absorption and reduced release of iron from macrophages
What are the causes of macrocytic anaemia?
B12 and folate deficiency Alcohol Liver disease Hypothyroidism Reticulocytosis
Why does liver disease result in macrocytic anaemia?
Liver makes lipids for RBC membrane
What investigations can be done if a GIT cause of anaemia is suspected?
Endoscopy and biopsies Check for occult blood in stool TGT antibodies in coeliac disease Antibodies to parietal cells or intrinsic factor Inflammatory markers