Week 1 - Day 2 - Treatment of anaemia Tutorials (Iron deficiency anaemia, B12/Folate Deficiencies, Subacute combined degeneration of the spinal cord Flashcards
Scenario 1 A 35 year old female presents with menorrhagia and blood results as follows: * Hb 85 g/L * MCV 70 fl * MCH 24 pg - low * Ferritin 3 μg/l - low * Transferrin saturation 5 % Ferritin (male) 30-400 ug/L Ferritin (female) 13-150 ug/L Explain the blood results and the diagnosis made?
Haemoglobin levels are low (Hb <115 g/l in a women is low) - anaemia Mean cell volume is low (MCV <80 is low) - this implies microcytosis The ferritin levels are also low The blood results make for a microcytic anaemia due to iron deficinecy anaemia
What should all people with iron deficiency anaemia be screened for and how? For people who present with iron deficiency anaemia with dyspepsia (indigestion), what should they be referred for?
* Should be screened for coeliac disease * Measure the Anti-endomysial and the anti-transglutaminase antibodies People presenting with iron deficiency anaemia with indigestion - possibility of gastrointestinal cancer and consider urgent referral for further investigations. In all cases, both upper and lower gastrointestinal investigations are recommended, unless the upper GI endoscopy detects gastric cancer or coeliac disease (in which case lower GI investigations are not necessary).
- What is the therapy of choice (include drug names) and the side effects of the chosen drugs? for the female with iron deficiency anaemia
Address underlying causes as necessary (for example treat menorrhagia or stop nonsteroidal anti-inflammatory drugs, if possible). * Therapy of choice would be oral iron supplements -ferrous fumarate preferably (highest iron content per tablet) (if poorly tolerated then ferrous sulphate then ferrous gluconate) Side effects - nausea, constipation, dark stools, abdo discomfort
Iron tablets should be taken on an empty stomach as they will be absorbed better What are alternative treatment options to oral iron tablet therapy? Usually given in patients with non-compliance or oral therapy is not working - extreme circumstances
Parenteral iron preparations, which are only needed in exceptional circumstances, and are usually reserved as a secondary care treatment. Ferric carboxymaltose is an IV iron formula Last line if severe is red cell transfusion
What are red cell indices?
Red blood cell (RBC) indices are part of the complete blood count (CBC) test. They are used to help diagnose the cause of anemia, a condition in which there are too few red blood cells. The indices include: * Average red blood cell size (MCV) * Hemoglobin amount per red blood cell (MCH) * The amount of Hb relative to the size of the cell (Hb concentration) per red blood cell (MCHC)
- How does iron therapy correct anaemia? (ferrous iron – Fe2+, ferric = Fe3+ (ferric is toxic if transported which is why iron binds to transferrin)) What are the red cell indices?
The aim of treatment is to restore haemoglobin levels and red cell indices to normal, and to replenish iron stores Iron will bind to the porphyrin ring after it is absorbed in the entercoytes (it is transported around with transferrin in the blood as Fe2+ and stored bound with ferritin as Fe3+ until it is required for haematopoiesis), once iron binds to porphyrin ring – makes haem molecule
Six weeks later your patient has a repeat blood count: * Hb 89 g/L * MCV 73 fl * MCH 24.5 pg 1. How may this be explained? Origiinal results were: * Hb 85 g/L * MCV 70 fl * MCH 24 pg
This may be explained due to non-compliance to the medication and therefore iron tablets are not having an effect Or the primary problem of menorrhagia has not been treated therefore the iron cannot exact full affect Or Different diagnosis other than iron deificiency anaemia eg, thalassemia or sideroblastic anaemia (usually only have this if the serum ferritin was not measured)
What degree of response to iron therapy would you expect per week?
Would expect Hb to rise by 10g/L per week in a patient on iron treatment
- What simple tests would help you to assess response to therapy?
Would be able to measure thee reticulocytes to see the response to the iron treatment - their level should rise in response to treatment
- Would you now proceed to blood transfusion? * • Could explore why her levels weren’t improving * • Try parenteral before blood transfusion 1st line – ferrous fumrate (then sulphate or gluconate), 2nd line – parenteral iron supplementation, last line Blood transfusion What may help with iron absorption in the proximal small bowel? How long is iron therapy continued?
Abscorbic acid (vitamin C) may help with iron absorption eg drinking orange juice with the tablets Continue until haemoglobin is within normal range and for at least 3 months after to replenish the iron stores
Scenario 2 A 50-year-old man presents with a macrocytic anaemia, positive anti-intrinsic factor antibodies. What is the diagnosis? What is the treatment? How long is treatment continued for?
The patient has pernicious anaemia Anti-intrinsic factor is highly specific for this condition although not very sensitive The treatment would be lifelong B12 injections (IM) for life
Can anti-gastric parietal antibody be used in the diagnosis of pernicious anaemia?
Anti-parietal cell antibody is found in 80% of people with pernicious anaemia, but also in 10% of people without it. However, it has a low specificity of about 50%, which is much lower than that of anti-intrinsic factor antibody If anti-parietal cell antibody is not present it is unlikely that the person has pernicious anaemia, but its presence is not diagnostic as it can occur in other conditions (for example atrophic gastritis, hypothyrodisim) and older people.As a result, it is no longer recommended as a diagnostic test
How is the lifelong vitamin B12 given? Starting dose and continuation? What is the dug name called?
Replenish the B12 stores with 1mg hydrxycobalamin given 6 times over 2 weeks and then give 1mg every 3 months for life
- Are there alternatives for the treatment of pernicious anaemia? rather than lifelong IM B12
High doses oral hydrocobalamin may be affective but not used in tayside
- Discuss the pathogenesis of pernicious anaemia and the mechanism of correction of the anaemia? What is it known as when the gastric parietal cells are affected stopping production of hydrochloric acid?
There is autoimmune destruction of the gastric parietal cells resulting in achlorhydria (absence of HCl in gastric secretions) and lack of gastric intrinsic factor secretions Intrinsic factor is required for the absorption of B12 in the distal ileum and B12 eis required for DNA synthesis – therefore the nuclear divisions are impaired – fewer red cells produced and they are too large therefore megalobastic anaemia Also can cause pancytopenia
Where do upper motor neurone lesions affect? Where do lower motor neurone lesions affect?
UMN lesions affect motor patwhays (corticospinal tract) anwyehere from the precentral gyrus of the frontal cortex to the synapse with the anterior horn cells in the sinal cord LMN lesions are caused by damage anywhere from the anterior horn cells in the cord, nerve roots, plexi or peripheral nerves
