anaemia Flashcards
Symptoms of anaemia
tired SOB (normal o2 sats) Light headed/feeling faint Pounding heart/palpitations Pounding in ears Pale
Why do pts become anaemia
Not making enough RbC (reduced Erythropoisis or haematopoiesis)
Losing or breading down RBC too quickly- bleeding hamolysis
Causes of reduced erythropoiesis
Haematinic deficiency
-iron, folate, b12
Bone marrow disorders:
-myeloma, leukaemia, aplastic anaemia. myelodysplasia
Myelosuppressive drugs: chemo, co-trimoxazole, multiple others
CKD (reduced EPO)
Chronic disease/ inflammation- infection, liver disease, autoimmune inflammatory disorders
Endocrine dysfunction
- hypothyroid, reduced testosterone
What can cause pancytopenia
Folate and b12 deficiency
Bone marrow disorders
Myelosuppressive drugs
Low MCV anaemias
Iron deficiency
Thalassaemia
Anaemia of chronic disease
Normal MCV anaemias
Acute blood loss Anaemia of chronic disease Haemolysis Combined deficiency e.g. iron and b12 deficient (e.g things that cause low and high MCV can cancel Out and cause normal MCV) Bone marrow disorders
Raised MCV anaemias
b12 deficiency Folate deficiency Myelodysplasia Alcohol excess Haemolysis Other defects of DNA synthesis e.g. chemo Hypothyroid
Anaemia investigations
B12, folate, ferritin, transferrin saturation
Blood film
Reticulocyte count
LDH (raised in haemolytic), haptoglobin (low), bilirubin (high)
Direct antibody test (positive) if suspect pt is haemolysing
Immunoglobulins, serum free light chains (myeloma screen)
Review medication chart
What is iron bound to in the body
Hb, myoglobin, transferrin, ferritin, haemosiderin
What forms is iron stored in
Ferritin and haemosiderin
Causes of iron deficiency
Inadequate intake
Increased requirements e.g pregnancy
Malabsorption e.g. coeliac, gastrectomy
Chronic haemorrhage - menorrhagia, GI tract
How to diagnose iron deficiency
MCV low
Blood film hypochromic, microcytic, pencil cells
Gold standard would be iron stain on bone marrow
Rather than taking from bone marrow, check ferritin. This roughly correlates with the amount of iron stored in tissues.
Transferrin saturation
Why can ferritin be normal with iron deficiency
What to do I you have a suspicion that ferritin is falsely elevated
ferritin increases in inflammatory conditions e.g. acute or chronic infections, malignancy
Check transferrin saturation
-Iron continually circulates bound to ferritin. If iron levels are low, less transferrin has iron bound to it therefore transferrin saturation is a marker of iron status
Features of b12 deficiency on blood film
OVal macrocyte
Hypersegmented neutrophil
teardrop cell
How is b12 absorbed and transported
B12 in food bound to protein
Pepsi in stomach releases b12 from protein
B12 binds to intrinsic factor (which is produced by gastric parietal cells in stomach)
Function of intrinsic factor is to transport b12 into epithelia cells of the distal half of small intestine
b12 absorbed in ileum
What might pts with b12 deficiency develop
Neurological symptoms e.g. peripheral neuropathy subacute combined degeneration of the cord
Causes of b12 deficiency
Inadequate intake
Inadequate secretion of intrinsic factor
-Pernicious anaemia- antibody against intrinsic factor and/or gastric parietal cells
-Gastrectomy
Malabsorption (crohns, ileal resection)
When may b12 levels measure low
If pt is taking OCP or HRT
Diagnosing b12 deficiency
Raised MCV
Blood film- oval microcytes, hyperhsegmented neutrophils, tear drop cells
Low b12
Test for intrinsic factor antibodies (for pernicious anaemia).
Managemwn of b12 deficiency
If pernicious anaemia- hydroxocobalamin (IM b12) lifelong
If intrinsic factor negative try oral replacement. If doesn’t work then IM required
Where is folate absorbed
duodenum and jejunum
Causes folate deficney
Inadequate intake
Increased requirements- pregnancy, haemolytic anaemia
Malabsorption- coeliac disease, jejunl resection
How to diagnose folate deficiency
Raised MCV
Blood film- microcytes, hyperhsegmented neutrophils,
reduced folate- can measure serum or red cell. (red cell folate more reliable)
Management of folate deficiency
Folic acid
treat underlying cause
Why do b12 and folate deficiency lead to microcytic anaemia
B12 and folate are co-enzymes required for DNA synthesis.
When lacking, DNA synthesis impaired, cells divide more slowly.
RNA synthesis unaffected, cytoplasm builds up and cells become larger
