PB1 Mess Flashcards
what do flecks of blood in stool mean
- this can mean that there is blood in the proximal part of the GIT
what is atrophic glossitis
Soreness, burning of the tongue with loss of taste buds
what does angualar stomatitis mean
- these are sores in the corner of the mouth
what are the cut of points of haemoglobin for anaemia for men and women
Hb <13.5g/dL(m) or <11.5g/dL(f) + MCV <80fL
what are the signs of microcytic anaemia caused by iron deficiency
- Fatigue,
- pica (craving non-food substances),
- koilonychia (spoon-shaped nails),
- hair loss,
- glossitis,
- angular stomatitis
What are the causes of iron deficiency
Decreased intake, decreased absorption, increased loss, increased requirements
Not an end diagnosis – must investigate cause
what is an alternative diagnosis of microcytic anaemia
thalassemia
what is adult haemoglobin made out of
2 alpha and 2 beta
why does low iron cause microcytic anaemia
- iron is needed to make heme - each globin molecules contains a heme moelcule which at its core containins an iorn moelcule
- iron deficiency means that this molecule does not form properly and therefore you generate a low haemoglobin (hypochromic haemoglobin)
how do you diagnose micoryctic anaemia
- history and clinical examination
- haemoglobin decreases and MCV decreases
- peripheral blood smear - this would show small pale red cells, pencil cells (iron deficiency)
how do you diagnose an iron deficiency
- Low serum iron
- increase in total iron binding capacity
- transferrin saturation is less than 16%
- serum ferrtin decreases
what is serum iron
Serum iron = the amount of iron circulating in the blood bound to transferrin (the iron carrying molecule).
what is total iron binding capacity
Total iron binding capacity = how much ‘room’ there is for iron to bind to transferrin. In iron deficiency anaemia, this is raised as a lot of the transferring is unbound.
what is transferrin sautraiotn
Transferrin saturation = the iron carrying molecule in blood. It is not saturated with iron in iron deficiency anaemia.
what is serum ferritin
Serum ferritin = the storage molecule for iron in the tissues
what is the management of microcytic anaemia caused by iron deficency
Oral iron (ferrous sulfate, ferrous gluconate, ferrous fumarate) - +/- asorbic acid for absorption
IV iron replacement
Investigate underlying cause
Patient 1 - colon cancer, diverticulitis etc.
what are the possible things that patient 1 has
- colon cancer
- diverticultiis
what does asorbic acid do for iron deficiency
Asorbic acid = increases the absorption of iron. Often recommended to take iron supplement with vitamin C containing foods e.g. orange juice
what is the proprable cause of patients 1 microcytic anaemia
Colon cancer = given the patient’s age, normal diet and history, her iron deficiency is probably due to increased iron (blood) loss from a colon cancer. It may be invading her colon wall and causing her to bleed, explaining the flecks of blood within the stool.
what are hypersegemented neutrophils
Neutrophils with 6 or more lobed-nuclei
- Neutrophils normally have 2-3 lobed nuclei
Characteristic of megaloblastic anaemia
how many lobes to normal neutrophils have
2-3 lobes
what is the difference between megalobasltic and non megaloblastic anaemia
megaloblastic anaemia
- this is microcytic anaemia that is caused due to the impairment of DNA syntehsis
non megaloblastic anaemia
- anamia forms just macrocytic
what is the haemoglobin and MCV in macrocytic anaemia
Hb <13.5g/dL(m) or <11.5g/dL(f) + MCV >96fL
what are the signs and symptoms of macrocytic anaemia
Shortness of breath
fatigue
palpitations - due to cardiovascular strain of providing enough oxygen to her tissues
pallor
bounding pulse- due to cardiovascular strain of providing enough oxygen to her tissues
how do you diagnose macrocytic anaemia
Hb, MCV, blood film
what are the casues megaloblastic anaemia
vitamin B12 deficiency,
folate deficiency,
pernicious anaemia
what are the causes of non megaloblastic anaemia
alcohol abuse
liver disease,
severe hypothyroidism
what is causes pernicious anaemia
Autoimmune condition with antibodies against parietal cells so intrinsic factor is not produced and B12 cannot be absorbed in the ileum
Causes progressive neurological symptoms as vitamin B12 is an essential co-factor in DNA synthesis
describe how B12 is normally absorbed
Normal vitamin B12 absorption
Bound to intrinsic factor that is released from gastric parietal cells
Absorbed in terminal ileum
what is the management of macrocytic anaemia
Vitamin B12 then folate replacement
Diagnosis and treatment of underlying condition
why is B12 vitamin replaced before folate
Replacing folate will improve the anaemia but will not reverse the lack of DNA synthesis, thus masking the neurological symptoms of the B12 deficiency. Must replace B12 first so that the DNA synthesis pathway can be re-instated properly, thus allowing normal cell and neuronal function.
what is B12 a cofactor for
methionine synthase
- this is the enzyme that catalyses the conversion of homocysteine to methionine
what do you have to have in regulates to haemoglobin and MCV to have normocytic anaemia
Hb <13.5g/dL(m) or <11.5g/dL(f) + MCV 80-96fL
what are the signs and symptoms of normocytic anaemia
Pallor, shortness of breath, exhaustion jaundice bone pain, may be none
what are the casues of normocytic anaemia
Acute blood loss,
haemolytic anaemia,
bone marrow disorder,
anaemia of chronic disease
how do you diagnose normocytic anaemia
Hb, MCV, iron studies, B12 and folate level, blood film
eGFR and electrolytes
what is the pathophysiology in chronic disease that causes normocytic anaemia
Pro-inflammatory state upregulates hepcidin (decreases free iron), low erythropoietin (CKD), decreased survival of circulating RBCs
how do you manage normocytic anameia
Treat underlying condition
RBC transfusion
Erythropoiesis-stimulating agents (e.g. epoetin alfa, darbepoeitin alfa)
What is the characteristic morphology of erythrocytes in iron deficiency anaemia?
pencil cells
What defines megaloblastic anaemia?
There is a defect of RBC development in the bone marrow in which the cell’s nucleus develops at a delayed rate to the cytoplasm.
What is the role of vitamin B12 in DNA synthesis?
B12 is the cofactor for methionine synthase, the enzyme that catalyses the conversion of homocysteine to methionine (a precursor of nucleotide synthesis).
How is vitamin B12 absorbed?
Bound to intrinsic factor, which is released by gastric parietal cells, then absorbed in the terminal ileum.
Where is erythropoietin produced?
in the interstitial fibroblasts of the kidney in response to hypoxia detected in the kidney
