Type of test Blood

 Normal findings

 Mean corpuscular volume (MCV)

 Adult/elderly/child: 80-95 fL

Newborn: 96-108 fL

Mean corpuscular hemoglobin (MCH)

 Adult/elderly/child: 27-31 pg

Newborn: 32-34 pg

Mean corpuscular hemoglobin concentration (MCHC)

 Adult/elderly/child: 32-36 g/dL (or 32%-36%)

Newborn: 32-33 g/dL (or 32%-33%)

 Red blood cell distribution width (RDW)

 Adult: 11%-14.5%

Test explanation and related physiology

 The RBC indices provide information about the size (MCV and RDW), hemoglobin content (MCH), and hemoglobin concentration (MCHC) of RBCs. This test is routinely performed as part of a CBC. The results of the RBC, hematocrit, and hemoglobin tests are necessary to calculate the RBC indices. When investigating anemia, it is helpful to categorize the anemia according to the RBC indices, as shown in Table 1. Cell size is indicated by the terms normocytic, microcytic, and macrocytic. Hemoglobin content is indicated by the terms normochromic, hypochromic, and hyperchromic. Additional information about RBC size, shape, color, and intracellular structure is described in the blood smear study.

Table1. Categorization of anemia according to red blood cell indices

Mean corpuscular hemoglobin

 The MCH is a measure of the average amount of hemoglobin in an RBC. MCH is calculated as follows:

Because macrocytic cells generally have more hemoglobin and microcytic cells have less hemoglobin, the causes for these values closely resemble those for the MCV value.

Mean corpuscular hemoglobin concentration

 The MCHC is a measure of the average concentration or per centage of hemoglobin in a single RBC. MCHC is calculated as follows:

When values are decreased, the cell has a deficiency of hemoglobin and is said to be hypochromic (frequently seen in iron deficiency anemia and thalassemia). When values are normal, the anemia is said to be normochromic (e.g., hemolytic anemia). RBCs cannot be considered hyperchromic. Only 37 g/dL of hemoglobin can fit into the RBC. Alterations in RBC shape (spherocytosis), RBC agglutination, and a hemolyzed specimen may cause automated counting machines to indicate MCHC levels higher than normal.

Red blood cell distribution width

 The RDW is an indication of the variation in RBC size. It is calculated with a machine by using the MCV and RBC values. Variations in the width of RBCs may be helpful when classifying certain types of anemia. The RDW is essentially an indicator of the degree of anisocytosis, a blood condition characterized by RBCs of variable and abnormal size.

Interfering factors

 • Abnormal RBC size may affect indices.

 • Extremely elevated white blood cell counts may affect RBC indices.

• Large RBC precursors (e.g., reticulocytes) cause an abnormally high MCV.

• Marked elevation in lipid levels (> 2000 mg/dL) causes automated cell counters to indicate high hemoglobin levels. MCHC and MCH will be calculated falsely high.

• The presence of cold agglutinins also falsely elevates MCHC, MCH, and MCV.

* Drugs that may increase MCV results include azathioprine, phenytoin, and zidovudine.

Procedure and patient care

 • See inside front cover for Routine Blood Testing.

• Fasting: no

• Blood tube commonly used: lavender

Abnormal findings

 Increased MCV

- Liver disease

- Antimetabolite therapy

- Alcoholism

- Pernicious anemia (vitamin B12 deficiency)

- Folic acid deficiency

Decreased MCV

- Iron deficiency anemia

- Thalassemia

- Anemia caused by chronic illness

Increased MCH

- Macrocytic anemia

Decreased MCH

- Microcytic anemia

- Hypochromic anemia

Increased MCHC

- Spherocytosis

- Intravascular hemolysis

- Cold agglutinins

Decreased MCHC

- Iron deficiency anemia

- Thalassemia

Increased RDW

- Iron deficiency anemia

- B12 or folate deficiency anemia

- Hemoglobinopathies (e.g., sickle cell disease)

- Hemolytic anemias

- Posthemorrhagic anemias

اخر الاخبار

اخبار العتبة العباسية المقدسة

فرقة العباس تنظم مجلس عزائها السنوي بذكرى شهادة النبي (صلى الله عليه وآله) في النجف

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بالتزامن مع ذكرى شهادته.. قسم الشؤون الفكرية يصدر كتابًا عن النبي الأعظم (صلى الله عليه وآله)

بالصور.. جموع المؤمنين تحيي ذكرى شهادة الرسول الأكرم عند مرقد الإمام علي (صلوات الله عليهما)

المزيد

الآخبار الصحية

لون أسنانك يتحدث عن صحتك.. إليك ما يقول

عادة يومية بسيطة تخفض الكوليسترول وتحمي القلب

الزنجبيل.. دواء سحري لحماية القلب

المشروبات شديدة السخونة.. "خطر خفي" يهدد صحتك

المزيد

الآخبار التكنلوجية

كيف يمكن لعادات القيادة السيئة أن تؤثر على قيمة سيارتك

في طوفان الذكاء الاصطناعي.. نصائح لحجز "تذكرة النجاة"

هكذا يسرق "قراصنة الذكاء الاصطناعي" المليارات بطرق بسيطة

فيديو لانفجار كرة نارية في سماء اليابان.. ما تفسير ذلك؟

المزيد

مواضيع ذات صلة

rheumatoid factor (RF)

reticulocyte count (Retic count)

NGAL

Biomarkers of Tubulo-Interstitial Injury

Low-Molecular-Weight Plasma Proteins

Immunofluorescence Assay (IFA)

Enzyme-Linked Fluorescent Assay (ELFA)

Diagnostic Evaluation of Lyme disease

red blood cell count (RBC count, Erythrocyte count)

rabies-neutralizing antibody test

prothrombin time (PT, Protime, International normalized ratio [INR])

Estimation of the Glomerular Filtration Rate by Equations