Microcytic Anemias Study Guide PDF

Anemia Overview =============== **Anemia:** - Deficiency in number of healthy RBCs - Deficiency in amount of hemoglobin - Insufficient oxygen to tissues creating condition of hypoxia Decreased: Fe, B12/Folate. Hemopoietic cell defect (chronic/inflammation, aplastic, dysplastic/neoplastic,...

Anemia Overview =============== **Anemia:** - Deficiency in number of healthy RBCs - Deficiency in amount of hemoglobin - Insufficient oxygen to tissues creating condition of hypoxia Decreased: Fe, B12/Folate. Hemopoietic cell defect (chronic/inflammation, aplastic, dysplastic/neoplastic, proliferative anemias) Increased: acute/chronic blood loss, congenital or acquired trauma (hemolytic anemias) **Morphologies**: - Morphologies change based on anemia type and most anemias are centered around increased production while hemolytic anemia focusses on destruction of RBCs - General findings: - Hypochromia - Microcytosis - May see elliptocytes, target cells (severe anemia) - Polychromasia can be seen depending on state of deficiency **Bone Marrow:** - Decreased to no sustainable iron - Increased EPO due to increasing hypoxia - Normal M:E ratio is 2:1 to 5:1 but would become 1:1 **Critical Levels of Hemoglobin** - \< 80 g/L -- Alert - \< 60 g/L -- Critical - Alert = no nee to hospitalize but needs intervention ASAP - Critical = immediate intervention required due to possible complications from hypoxia Considerations When Discussing Anemia ------------------------------------- - Age of onset - Inherited or acquired - Duration of illness - Previous anemia or sudden - Prior treatments for anemia - Is it repeat occurrence? Did pt stop therapy? - Suddenness of anemia: - Increase loss - Increase destruction - Symptoms: dizziness, heart palpitations, etc - Chronic blood loss - Harder to determine cause as pt may not feel effects in slow decline of hgb - Increased menstrual bleeding, GI bleed - Hemolytic episodes - Weakness, icterus in plasma or serum, dark urine - Hemolysis is serious and pt can die within 24 hours - Toxic Exposure - Drugs, hobbies, occupational exposures - Lots of toxins that can cause sudden drops in hgb levels - Dietary history - Alcohol use, unusual diet, changes in diet, prolonged milk injection in infants/toddlers - Family History - Kidney disorders, sickle cell disease, thalassemia, etc. - Underlying disease - Kidney disease, chronic liver disease, hypothyroidism Physical Examination of Symptoms -------------------------------- - Pale and tired - Pallor most noticeable under eyelids, inside of lip - Smooth tongue - Pernicious anemia or severe iron deficiency - Petechiae - Due to thrombocytopenia as seen alongside anemia like aplastic anemia - Heart - Cardiac dilation, tachycardia and murmers - Abdomen - Hepatosplenomegaly if cause is liver disease, leukemia, myelofribrosis Chemical Testing for Anemias ---------------------------- - Analyzer printout helps (CBC) - RDW -- anisocytosis is a good indicator of anemia - Can be macrocytic, normocytic and macrocytic Classification of Anemias ------------------------- Anemia due to decreased production or increased destruction Size Normal RDW High RDW -------------- ------------------------------------------------- ----------------------------------------------------------------------------------- Microcytic Thal minor, ACD, some hemoglobinopathies Fe deficiency, Hgb H ACD, some thal minor, hemolysis Normocytic ACD, hereditary sphero, some hemoglobinopathies Deficiency - treatment SCA Macrocytosis Aplastic anemia, some myelodysplasia Vit B12, folate deficiency, AHA, cold agglutination disorder, alcoholism, thyroid Microcytic Anemia ----------------- See the source image ### Common Findings with Severe Anemia  Punched out water artefact due to slow drying when prepping smear. Severe anemia means there is more plasma on the smear than normal (less RBCs means more plasma) and it takes longer for the slide to dry. If anemia is severe enough, you'll likely see rouleaux as well because you have so much plasma to cell ratio. Iron Deficiency Anemia ---------------------- - Vitamin C promotes iron absorption - Daily iron needs: - Males /infants: 1 mg/day - Females (premenopausal): 0.2-2.0 mg/day - Children: 0.5 mg/day - Fe 3+ "ferr**ic**" non heme iron - Fe 2+ "ferr**ous**" heme iron - Transferrin \~ transports iron - Ferritin \~ stores iron Milk babies: Babies who breastfeed are more likely to get anemia than formula fed babies and often need supplements PLT count commonly increased with IDA To detect iron deficiency in patients, we need to look at both **iron stores and iron levels in the blood**. ### Iron Deficiency Treatment **First Line:** - Oral or infused iron. Wait and see Fe^2+^ - You want ferrous, not ferric, iron. It's is the best supplement (fe^2+^) **Transfusion required when:** - Significant symptoms present (1 unit of blood = 10 g/L hgb) - Alert: Hbg less than 80 g/L. Wait and see with iron supplement. Monitor closely. - Critical: Hgb less than 60 g/L. Usually will give blood until iron treatment catches up. Monitor closely. **Other treatments:** - Synthetic EPO = increase marrow production - Monitor for increased polychromasia; increases retic = increased erythropoiesis or erthyroid hyperplasia in marrow ### Iron In the Body - Most iron is recycled - Adults recycle 95% - Children recycle 70% - When cells die, components break apart and heme molecules break into biliverdin and then bilirubin...heme released iron and goes back into pool **Iron in the body:** - goes through duodenum - converted to Fe^2^ form (the form that we want) - Iron gets transported to bone marrow, liver, and spleen - Converted to ferritin (storage form of iron) - Stored in liver, bone marrow, or spleen and renters circulation when needed Vitamin C reduces ferric iron to it's absorbable form called ferrous iron. This means it goes from Fe^3^ to Fe^2^ Tannins like red wine, nuts, and seeds are iron inhibitors ### Mechanisms of IDA 1. Increased iron loss 2. Malabsorption 3. Decrease in dietary iron 4. Defective utilization of iron #### Increased Iron Loss - GI Bleeds - Menstrual bleeding #### MALABSORPTION - Duodenum surgeries (traumatic or medical such as gastric bypass) - Celiac disease - NOTE: iron absorption sites are in duodenum and proximal jejunum #### Decreases in Dietary Iron - Commonly seen in: - Infants who breastfeed (breastfeeding is 11 times more likely to cause anemia than formula) - Children/adolescence - Pregnancy/breastfeeding women - Elderly (when they don't eat as much or the same quality of food) - Eating disorders - Chronic inflammations like thyroid disorders, chronic renal disease, IBS, Crohn's) - These are more commonly normochromic/normocytic #### Defective Utilization - Sideroblastic anemia - Sometimes -- anemia of chronic inflammation - These occur when a pt has good iron stores but is unable to use the iron. When serum levels fall, nothing there to feed it. A diagram of a liver Description automatically generated ### Testing for IDA Normal - Normal stores, normal in serum Stage 1 - Ferritin storages empty out to feed serum levels - Serum levels still stay normal, storage going down. - Might see Hypochromasia Stage 2 - Serum levels fallen, storage has fallen - Not much of it goes into serum and not enough in marrow for erythropoiesis - RBC count drops (no ingredients to make RBCs) - Some iron left (recycling) and some hgb can be made but it is poor quality and maay be destroyed before even leaving the marrow - Central pallor increased Stage 3 - Almost completely wiped out iron stores, almost complete absence of RBCs being made - Results in sever deficiency - Iron deficiency happened over 120 days ago if severe decrease in cells on slide because the lifespan of cells is 120 days and there has been nothing to replace it - Have to consider this when doing differential (normal \~200 cells/field does not apply) #### Total Iron Binding Capacity TIBC: total iron binding capacity - Ability to bind increases because there is nothing bound to it - Total iron binding capacity tells us how many binding sites are free to bind in the blood #### HISTOGRAMS seen in IDA  State the main population you see then add comment about the secondary population. Don't use dual population. Histograms can take a while to change as cells have 120 day lifespan but when sever you will see a definite shit to the left. Histogram: - Normal = 80-100 fL - Early IDA = \