Year 4 Internal Medicine study notes: Anemia. Full notes on OmpathStudy. Free notes for medical students worldwide.
Anemia Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / I MED BEAUTIFUL NOTES / HEMAT -- Anemia\n435 medicine teamwork\n[ Important Notes Extra Editing file ]\n\nLecture Objectives: \n⇨ Know how to read a CBC (complete blood count)\n⇨ Approach to common causes of anemia\n⇨ Understand the common terminologies\n⇨ Brief overview of investigations and management\n\n Done By: Ibrahim Alkhodiar, Khalid Alghsoon, Abdulaziz\nAlkhodiari.\nEdited by: O\n mar Alsulaiman.\nRevised By: Ahmed Al Yahya\nReferences: Doctors’ Slides+Davidson+Step-up \n\nIntroduction:\nRBCs characteristics:\n- Central pallor 1/3rd of RBC volume\nWhat keep RBC biconcave?\n- The cytoskeleton, proteins that keeps the\nRBC in normal shape.\n- Abnormality in one of them → abnormal\nshape. : Terminology: \nSpherocytosis: loss of Cytoskeletal proteins = Blebs on the surface = Destroyed by splenic\nmacrophages (extravascular hemolysis). on peripheral smear (loss of central pallor).\n\n Elliptocytosis: Cylindrically shaped RBC.\nSpur and Burr cells: Both have spikes.\n\n ●\n●\n●\n●\n●\n●\n●\n●\n● \n\nSchistocytes (Helmet cells): ○ Fragmented RBCs, demarcated by two sharp Ends. ○ Most important cause is microangiopathic hemolytic anemia\n(MAHA) caused by thrombotic thrombocytopenic purpura\n(TTP) = MEDICAL EMERGENCY. ○ Also can be caused by DIC TTP: ○ A fatal disorder with mortality 90% if left untreated. ○ Triad: Low platelet count, anemia, schistocytes. ○ Pentad: above 3 + (+/- neurological1 signs or symptoms, +/- renal failure, +/- fever) ○ Treatment is urgent PLasma EXchange (PLEX) and survival 85% if treated. So, Its highly fatal but\nhighly treatable at the same time. ○ TTP is a true medical emergency! Mean corpuscular volume, or mean cell volume (MCV):\n○ Is a measure of the average volume (=Size) of a red blood corpuscle (or RBC).\n○ MCV is calculated from the distribution of individual RBC volumes. Hematocrit: ○ Automated hematocrit (%) is calculated by multiplying the MCV by the\nRBC number ○ Hematocrit = MCV × red blood cells × 100. ○ It’s the percentage of PRBC to the total volume of blood sample. Mean corpuscular hemoglobin (MCH): ○ Is expressed in picograms. ○ The MCH is calculated by dividing hemoglobin (g/L) by red blood cell count (10^12/L). ○ It’s the average amount OF Hb in ONE CELL. MCH concentration (MCHC): I look at it only when I suspect spherocytosis ○ iIs expressed in grams of hemoglobin per deciliter of packed RBCs. ○ The MCHC is calculated by dividing the hemoglobin concentration (g/dL) by the hematocrit (%) ×\n100. (If Hb is 15.4 g/dL, hematocrit is 44.1%, MCHC = 15.4/0.441= 34.9g/dL). RBC distribution width (RDW): ○ RDW is the coefficient of variation (differences) of RBCs sizes (called anisocytosis). ○ RDW is used in the evaluation of anemia. ○ In microcytic anemias: more frequently elevated with iron deficiency anemia than to thalassemia\nor anemia of chronic disease ○ In macrocytic anemias: more frequently elevated due to vitamin B12 or folate deficiency than to\nliver disease, hypothyroidism. = MOSTLY ELEVATED WITH NUTRITIONAL DEFICIENCIES. ○ Myelodysplastic syndromes, or RBC transfusions to pts with low/high MCV can produce a\ndimorphic RBC pattern2 with a very wide RDW (high RDW value). ○ If all RBCs are large, or all are small, RDW will be normal or even reduced (because although they\nare abnormal, there is no variation between them).\n\n 1\nSeizures, stroke, confusion, and Loss of consciousness\n2\nDimorphic is a term used to describe two circulating red cell populations. One is the patient's basic red cell\npopulation(normal RBCs); the other is a second population with distinct morphological features. \n\nCBC: \nCBC without differential:\n\n CBC with differential:\n- Normal “TOTAL” WBC doesn’t exclude abnormalities. For example, one cell line could be\ndecreased while another is increased which may result in a normal WBC count. So, It’s very\nimportant to order the differential count. Absolute number of differential is more useful\nthan Percentage.\n\n Leukocytosis? Which cell line?\nNeutrophilia:\n○ Acute: bacterial infection, steroids3\n○ Chronic: Chronic myeloid leukemia (CML)\nLymphocytosis:\n○ Acute: viral infections\n○ Chronic: chronic lymphocytic leukemia (CLL)\nMonocytosis:\n○ fungal infection, TB, and malignancy.\nEosinophilia:\n○ allergic conditions, parasite, autoimmune diseases and eosinophilic leukemia\nBasophilia:\n○ very rare, CML (But not isolated basophilia)\n3\nSteroids causes demargination of neutrophils from the endovascular wall to the circulation. \n\n Leukopenia? Which cell line? What degree?\nNeutropenia:\n○ Mild: Absolute neutrophilic count (ANC): 1.5 - 1 “X109 /L”, Risk of infection not increased; no need\nto be investigated (no clinical significance). Mild neutropenia is very common, around 25% of us\nmight have it.\n○ Moderate: ANC: 1 - 0.5 “X109 /L”, Risk of infection not increased. Needs to be inve