🔹introduction:
▪️We generally use the following cutoffs,
• Females – Hb <12 g/dL or hematocrit <36 percent
• Males – Hb <13 g/dL or hematocrit <39 percent
▪️Caveats for normal ranges
⏬ lower values:
• Intense physical activity; dilutional anemia from increased plasma volume, iron deficiency, and/or "march" hemolysis
• pregnancy
• older age
⏫Causes of higher values (may occasionally mask underlying anemia):
• Smoking
• Sleep apnea and other respiratory conditions that cause prolonged hypoxemia
• Medications/drugs
• Hemoconcentration; eg. dehydration or hypovolemia related to vomiting or diarrhea
• High altitude
• Polycythemia vera
▪️Terminology
🔺MCV – Mean corpuscular volume is the average volume (size) of the RBCs; 80–100 fL.
🔺MCH – Mean corpuscular hemoglobin is the average hemoglobin content in an RBC ~ 27–33 pg.
🔺MCHC – Mean corpuscular hemoglobin concentration is the average hemoglobin concentration per RBC ~ 32–36 g/dL
🔺RDW – Red cell distribution width is a measure of the variation in RBC size ~ 11.5–14.5%
🔺Reticulocyte: is a stage in RBC development directly before the mature RBC(and grater than RBC) ~ 1-2% of RBC or absolute count:25,000 to 100,000/microL.
☝🏻The reticulocyte stage of RBC development lasts for approximately four days. In the steady state, reticulocytes generally spend three days in the bone marrow and one day in the circulation. In severe anemia, reticulocytes can leave the bone marrow earlier and can circulate for two to three days,
🔎مثالی از جناب AI برای روشن شدن مبحث ترمینولوژی RBC:
اگر فرض کنیم گلبول‌های قرمز «اتوبوس»، هموگلوبین «مسافر» و مغز استخوان «کارخانه اتوبوس‌سازی» باشد، شاخص‌ها اینگونه تعریف می‌شوند: MCV (حجم) در واقع «اندازه متوسط اتوبوس» شماست (که آیا مینی‌بوس، استاندارد یا اتوبوس کشیده دارید). MCH (مقدار) «تعداد متوسط مسافران» (هموگلوبین) در داخل هر اتوبوس را نشان می‌دهد. MCHC (غلظت/رنگ) به ما می‌گوید که این مسافران چقدر «فشرده و شلوغ» فضای داخل اتوبوس را پر کرده‌اند (که به کم‌رنگ یا پررنگ بودن گلبول مربوط است). در تکمیل این تصویر، RDW «میزان تنوع اندازه‌ها» در کل ناوگان اتوبوسرانی شما (از مینی‌بوس تا اتوبوس بزرگ) و Retic «سرعت تولید اتوبوس‌های نو» توسط کارخانه (مغز استخوان) را نشان می‌دهد.
▪️initial lab tests for unexplained anemia: (other than CBC, RBC indices and WBC with diff) —
• Retic count
• Chemistry panel; AST, ALT, BUN, Cr (and maybe TSH)
• Hemolysis labs esp if retic is increased or clinically suspected; LDH, , bilirubin, and haptoglobin.
• Blood smear – A review of the peripheral blood smear is always desirable in the initial evaluation of anemia
🔺A high reticulocyte count typically indicates
• hemolysis;
• recovery from bleeding;
• removal of a bone marrow insult (drug or infection); or
• repletion of iron, folic acid, or vitamin B12.
▪️When to refer to hematology —
1️⃣Hematologic emergency
• Severe pancytopenia
• Blasts or immature myeloid/lymphoid forms
• Pancytopenia with hemolysis, thrombosis, or bleeding
• Microangiopathic hemolytic anemia with schistocytes on the blood smear.
2️⃣Diagnostic uncertainty
• Anemia with normal or inconclusive laboratory testing
• Pancytopenia or bicytopenia in an older individual with normal vitamin B12, folate, and copper levels.
3️⃣Need for specialized evaluation
• Abnormal lymphocytes (hairy cells, large granular lymphocytes, prolymphocytes)
• Leukoerythroblastosis with or without teardrop cells (dacrocytes) Anemia with leukocytosis not explained by infection or thrombocytosis not explained by iron deficiency or reactive process
• Familial or hereditary anemia
4️⃣Need for specialized treatment
• Iron deficiency that is severe, not responsive to oral iron, occurring in the late second or third trimester of pregnancy, or for which oral iron is not tolerated or would not be absorbed.
• Hemolytic anemia, including microangiopathic hemolysis
• Suspected leukemia or myelodysplastic syndrome.