Didactic Encyclopedia


SEARCH CONTENTS

Custom Search

Arterial stick | Pathologies of Blood, heart and circulation

ADS BY GOOGLE


Pathologies and health



  • Arterial stick
  • Blood differential
  • Blood smear
  • Blood typing
  • Capillary sample
  • complete blood count (CBC)
  • Cord blood testing
  • RBC count
  • RBC indices
  • Red blood cell production

Arterial stick

An arterial stick is the collection of blood from an artery for laboratory testing.

How the Test is Performed

Usually blood is drawn from an artery in the wrist. It may also be drawn from an artery on the inside of the elbow, groin, or other site. A heartbeat (pulse) is felt by pressing on the area above an artery. If blood is drawn at the wrist, the health care provider will usually check the pulse to make sure blood is flowing into the hand from the main arteries in the forearm (radial and ulnar arteries).
The procedure is as follows:
• The area is cleaned with antiseptic
• A needle is inserted. A small amount of anesthetic may be injected or applied before the needle is inserted.
• Blood flows into a special collecting syringe.
• The needle is removed after enough blood is collected.
• Pressure is applied to the puncture site for 5 - 10 minutes to stop the bleeding. You will be checked during this time to make sure the bleeding stops.

How to Prepare for the Test

Preparation varies with the specific test performed.

How the Test Will Feel

Puncture of an artery may be more uncomfortable than puncture of a vein. This is because arteries are deeper than veins. Arteries also have thicker walls and have more nerves.
When the needle is inserted, there may be some discomfort or pain. Afterward, there may be some throbbing.

Why the Test is Performed

Blood transports oxygen, food, waste products, and other materials within the body. Blood also helps control body temperature, fluids, and the balance of acids and bases.
Blood is made up of a fluid portion (plasma) and a cellular portion. Plasma contains substances dissolved in the fluid. The cellular portion is made up mainly of red blood cells. But it also includes white blood cells and platelets.
Because blood has many functions within the body, tests on the blood or its components may give valuable clues to help health care providers diagnose many medical conditions.
Blood in the arteries (arterial blood) differs from blood in the veins (venous blood) mainly in its content of dissolved gases. Testing arterial blood shows the makeup of the blood before any of its contents are used by the body tissues.

Normal Results

Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An arterial stick is done to get blood samples from arteries. Blood samples are mainly taken to measure gases in the arteris. Abnormal results may point to breathing problems or problems with the body's metabolism. Sometimes arterial sticks are done to get blood culture or blood chemistry samples.

Risks

Veins and arteries vary in size from one person to another. They can also vary from one side of the body to the other. Getting a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Bruising
• Infection (a slight risk any time the skin is broken)
There is a slight risk of damage to nearby tissues when the blood is drawn. Blood can be taken from lower-risk sites, and techniques are used to limit tissue damage.

Considerations

If blood is easier to get from one location or side of your body, let the person who is drawing your blood know before starting the test.

Alternative Names

Blood sample - arterial

References

Milzman D, Janchar T. Arterial puncture and cannulation. In: Roberts JR, Hedges JR, eds.Clinical Procedures in Emergency Medicine

Blood differential

The blood differential test measures the percentage of each type of white blood cell (WBC) that you have in your blood. It also reveals if there are any abnormal or immature cells.
See also:
• Complete blood count (CBC)
• Eosinophil count - absolute

How the Test is Performed

The health care provider will take blood from your vein. The blood collects into an airtight container.
In infants or a young child, blood will be taken from a heel stick or finger stick. The blood is collected in a small glass tube or onto a slide or test strip.
Cotton or a bandage may be applied to stop any bleeding.
A laboratory specialist takes a drop of blood from your sample and smears it onto a glass slide. The smear is stained with a special dye, which helps tell the difference between various types of white blood cells.
Five types of white blood cells, also called leukocytes, normally appear in the blood:
• Neutrophils
• Lymphocytes (B cells and T cells)
• Monocytes
• Eosinophils
• Basophils
A specially designed machine or the health care provider counts the number of each type of cell. The test shows if the number of cells are in proper proportion with one another, and if there is more or less of one cell type.

How to Prepare for the Test

No special preparation is necessary.

How the Test Will Feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed

This test is done to diagnose an infection, anemia, and leukemia. It may also be used to see if treatment for any of these conditions is working.

Normal Results

• Neutrophils: 40% to 60%
• Lymphocytes: 20% to 40%
• Monocytes: 2% to 8%
• Eosinophils: 1% to 4%
• Basophils: 0.5% to 1%
• Band (young neutrophil): 0% to 3%

What Abnormal Results Mean

Any infection or acute stress increases your number of white blood cells. High white blood cell counts may be due to inflammation, an immune response, or blood diseases such as leukemia.
It is important to realize that an abnormal increase in one type of white blood cell can cause a decrease in the percentage of other types of white blood cells.
An increased percentage of neutrophils may be due to:
• Acute infection
• Acute stress
• Eclampsia
• Gout
• Myelocytic leukemia
• Rheumatoid arthritis
• Rheumatic fever
• Thyroiditis
• Trauma
A decreased percentage of neutrophils may be due to:
• Aplastic anemia
• Chemotherapy
• Influenza
• Radiation therapy or exposure
• Viral infection
• Widespread severe bacterial infection
An increased percentage of lymphocytes may be due to:
• Chronic bacterial infection
• Infectious hepatitis
• Infectious mononucleosis
• Lymphocytic leukemia
• Multiple myeloma
• Viral infection (such as mumps or measles)
A decreased percentage of lymphocytes may be due to:
• Chemotherapy
• HIV infection
• Leukemia
• Radiation therapy or exposure
• Sepsis
• Steroid use
An increased percentage of monocytes may be due to:
• Chronic inflammatory disease
• Leukemia
• Parasitic infection
• Tuberculosis
• Viral infection (for example, infectious mononucleosis, mumps, measles)
An increased percentage of eosinophils may be due to:
• Addison's disease
• Allergic reaction
• Cancer
• Collagen vascular disease
• Hypereosinophilic syndromes
• Parasitic infection
An increased percentage of basophils may be due to:
• After splenectomy
• Allergic reaction
• Collagen vascular disease
• Myeloproliferative disease
• Varicella infection
A decreased percentage of basophils may be due to:
• Acute infection
• Cancer
• Severe injury

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Alternative Names

Differential; White blood cell differential count

References

Bain BJ. The peripheral blood smear. In: Goldman L, Schafer AI, eds.Cecil Medicine
Berliner N. Leukopenia and leukocytosis. In: Goldman L, Schafer AI, eds.Cecil Medicine

Blood smear

A blood smear is a blood test that gives information about the number and shape of blood cells.

How the Test is Performed

A blood sample is needed.
The blood sample is sent to a lab. There, the lab technician looks at it under a microscope. Or, the blood may be examined by an automated machine. The smear shows the number and kinds of white blood cells (differential), abnormally-shaped blood cells, and gives a rough estimate of white blood cell and platelet counts.

How to Prepare for the Test

No special preparation is necessary.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

This test may be done as part of a general health exam to help diagnose many illnesses. Or, your doctor may order this test if you have signs of any of the following disorders: Any known or suspected blood disorder
• Cancer
• Hairy cell leukemia
• Monitoring the side effects of chemotherapy

Normal Results

Red blood cells normally are the same in size and color and have a lighter-colored area in the center. The blood smear is considered normal if there is:
• Normal appearance of cells
• Normal white blood cell differential
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results mean there is an abnormality in the size, shape, color, or coating of the red blood cells (RBCs).
Some abnormalities may be graded on a 4-point scale:
• 1+ means 25% of cells are affected
• 2+ means half of cells are affected
• 3+ means 75% of cells are affected
• 4+ means all of the cells are affected
Presence of target cells may be due to:
• Breakdown of red blood cells (decreased osmotic fragility)
• Deficiency of an enzyme called lecithin cholesterol acyl transferase
• Abnormalities of hemoglobin, the protein in red blood cells that carry oxygen (hemoglobinopathies)
• Iron deficiency
• Liver disease
• Spleen removal
Presence of sphere-shaped cells (spherocytes) may be due to:
• Low number of RBCs due to body destroying them (immune hemolytic anemia)
• Low number of RBCs due to some red blood cells shaped like spheres (hereditary spherocytosis)
• Increased osmotic fragility
Presence of elliptocytes may be a sign of hereditary elliptocytosis or hereditary ovalocytosis. These are conditions in which RBCs are abnormally shaped.
Presence of fragmented cells (schistocytes) may be due to:
• Artificial heart valve
• Disorder in which the proteins that control blood clotting become overactive (disseminated intravascular coagulation)
• Infection in the digestive system producing toxic substances that destroy red blood cells, causing kidney injury (hemolytic uremic syndrome)
• Blood disorder that causes blood clots to form in small blood vessels around the body and leads to a low platelet count (thrombotic thrombocytopenic purpura)
Presence of a type of immature red blood cell called a normoblast may be due to:
• Cancer that has spread to bone marrow
• Blood disorder called erythroblastosis fetalis that affects a fetus or newborn
• Tuberculosis that has spread from the lungs to other parts of the body through the blood (miliary tuberculosis)
• Disorder of the bone marrow in which the marrow is replaced by scar (fibrous) tissue (myelofibrosis)
• Removal of spleen
• Severe breakdown of RBCs (hemolysis)
• Disorder in which there is excessive breakdown of hemoglobin (thalassemia)
The presence of burr cells (echinocytes) may indicate:
• Abnormally high level of nitrogen waste products in the blood (uremia)
The presence of spur cells (acanthocytes) may indicate:
• Inability to fully absorb dietary fats through the intestines (abetalipoproteinemia)
• Severe liver disease
The presence of teardrop-shaped cells may indicate:
• Myelofibrosis
• Severe iron deficiency
• Thalassemia major
The presence of Howell-Jolly bodies may indicate:
• Bone marrow does not produce enough healthy blood cells (myelodysplasia)
• Post-splenectomy
• Sickle cell anemia
The presence of Heinz bodies may indicate:
• Alpha thalassemia
• Congenital hemolytic anemia
• Disorder in which red blood cells break down when the body is exposed to certain drugs or the stress of infection (G6PD deficiency)
• Unstable form of hemoglobin
The presence of slightly immature red blood cells (reticulocytes) may indicate:
• Anemia with bone marrow recovery
• Hemolytic anemia
• Hemorrhage
The presence of basophilic stippling may indicate:
• Anemia caused by bone marrow not producing normal blood cells due to toxins or tumor cells (myelophthisic process)
• Lead poisoning
• Myelofibrosis
The presence of sickle cells may indicate sickle cell anemia.

Risks

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Alternative Names

Peripheral smear

References

Bain BJ. The peripheral blood smear. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine
Vajpayee N, Graham SS, Bern S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods

Blood typing

Blood typing is a method to tell what specific type of blood you have. What type you have depends on whether or not there are certain proteins, called antigens, on your red blood cells.
Blood is often grouped according to the ABO blood typing system. This method breaks blood types down into four types:
• Type A
• Type B
• Type AB
• Type O
Your blood type (or blood group) depends on the types that are been passed down to you from your parents.

How the Test is Performed

A blood sample is needed and will be drawn from a vein.
The test to determine your blood group is called ABO typing. Your blood sample is mixed with antibodies against type A and B blood, and the sample is checked to see whether or not the blood cells stick together (agglutinate). If blood cells stick together, it means the blood reacted with one of the antibodies.
The second step is called back typing. The liquid part of your blood without cells (serum) is mixed with blood that is known to be type A and type B. Persons with type A blood have anti-B antibodies, and those with type B blood have anti-A antibodies. Type O blood contains both types of antibodies. These two steps can accurately determine your blood type.
Blood typing is also done to tell whether or not you have a substance called Rh factor on the surface of your red blood cells. If you have this substance, you are considered Rh+ (positive). Those without it are considered Rh- (negative). Rh typing uses a method similar to ABO typing.

How to Prepare for the Test

No special preparation is necessary for this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. These soon go away.

Why the Test is Performed

This test is done to determine a person's blood type. Health care providers need to know your blood type when you get a blood transfusion or transplant, because not all blood types are compatible with each other. For example:
• If you have type A blood, you can only receive types A and O blood.
• If you have type B blood, you can only receive types B and O blood.
• If you have type AB blood, you can receive types A, B, AB, and O blood.
• If you have type O blood, you can only receive type O blood.
Type O blood can be given to anyone with any blood type. That is why people with type O blood are called universal blood donors.
Blood typing is especially important during pregnancy. If the mother is found to be Rh-, the father should also be tested. If the father has Rh+ blood, the mother needs to receive a treatment to help prevent the development of substances that may harm the unborn baby. See: Rh incompatibility
If you are Rh+, you can receive Rh+ or Rh- blood. If you are Rh-, you can only receive Rh- blood.

Normal Results

ABO typing:
If your blood cells stick together when mixed with:
• Anti-A serum, you have type A blood
• Anti-B serum, you have type B blood
• Both anti-A and anti-B serums, you have type AB blood
If your blood cells do not stick together when anti-A and anti-B are added, you have type O blood.
Back typing:
• If the blood clumps together only when B cells are added to your sample, you have type A blood.
• If the blood clumps together only when A cells are added to your sample, you have type B blood.
• If the blood clumps together when either types of cells are added to your sample, you have type O blood.
Lack of blood cells sticking together when your sample is mixed with both types of blood indicates you have type AB blood.
RH typing:
• If your blood cells stick together when mixed with anti-Rh serum, you have type Rh-positive blood.
• If your blood does not clot when mixed with anti-Rh serum, you have type Rh-negative blood.

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
• Fainting or feeling light-headed
• Multiple punctures to locate veins
• Excessive bleeding
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Considerations

There are many antigens besides the major ones (A, B, and Rh). Many minor ones are not routinely detected during blood typing. If they are not detected, you may still have a reaction when receiving certain types of blood, even if the A, B, and Rh antigens are matched.
A process called cross-matching followed by a Coombs test can help detect these minor antigens and is done before transfusions, except in emergency situations.

Alternative Names

Cross matching; Rh typing; ABO blood typing

References

Davenport RD. Transfusion medicine. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods
Goodnough LT. Transfusion medicine. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine

Capillary sample

A capillary sample is a blood sample collected by pricking the skin. Capillaries are tiny blood vessels near the surface of the skin.

Alternative names

Blood sample - capillary; Fingerstick; Heelstick

How the Test is Performed

• The area is cleansed with antiseptic.
• The skin of the finger, heel or another area is pricked with a sharp needle or a lancet.
• The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container.
• Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

How the Test Will Feel

Some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed

Blood transports oxygen, food, waste products, and other materials within the body. It also helps regulate body temperature. Blood is made up of cells and a fluid called plasma. Plasma contains various dissolved substances. The cells are mainly red blood cells, white blood cells and platelets.
Because blood has many functions, tests on the blood or its components provide valuable clues in the diagnosis of medical conditions.
Capillary blood sampling offers several advantages over drawing blood from a vein:
• It is easy to obtain (it can be difficult to obtain blood from the veins, especially in infants).
• There are several collection sites on the body and these can be rotated.
• Testing can be done at home and with little training. For example, persons with diabetes must check their blood sugar several times a day using capillary blood sampling.
Disadvantages to capillary blood sampling include:
• Only a limited amount of blood can be drawn using this method.
• The procedure has some risks (see below).
• Capillary blood sampling may result in inaccurate results, such as falsely elevated sugar, electrolyte, and blood count values.

Normal results

Results vary depending on the test done. Your health care provider can tell you more.

What Abnormal Results Mean

Results vary depending on the test done. Your health care provider can tell you more.

Risks

• Excessive bleeding
• Fainting or feeling light-headed
• Infection (a slight risk any time the skin is broken)
• Scarring (occurs when there have been multiple punctures in the same area)
• Calcified nodules (sometimes occurs in infants, but usually disappear by 30 months of age)
• Damage to blood cells from this method of collection can sometimes cause inaccurate test results and the need to repeat the test with blood drawn from a vein.

References

Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In:McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods

complete blood count (CBC)

A complete blood count (CBC) test measures the following:
• The number of red blood cells (RBC count)
• The number of white blood cells (WBC count)
• The total amount of hemoglobin in the blood
• The fraction of the blood composed of red blood cells (hematocrit)
The CBC test also provides information about the following measurements:
• Average red blood cell size (MCV)
• Hemoglobin amount per red blood cell (MCH)
• The amount of hemoglobin relative to the size of the cell (hemoglobin concentration) per red blood cell (MCHC)
The platelet count is also usually included in the CBC.

How the Test is Performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to Prepare for the Test

There is no special preparation needed.

How the Test will Feel

When the needle is inserted to draw blood, you may feel moderate pain, though most people feel only a prick or a stinging sensation. Afterward there may be some throbbing or bruising.

Why the Test is Performed

A complete blood count (CBC) is used to detect or monitor many different health conditions. It may be used to:
• Diagnose infections or allergies
• Detect blood clotting problems or blood disorders, including anemia
• Evaluate red blood cell production or destruction

Normal Results

Blood counts may vary with altitude. In general, normal results are:
RBC count:
• Male: 4.7 to 6.1 million cells/mcL
• Female: 4.2 to 5.4 million cells/mcL
WBC count:
• 4,500 to 10,000 cells/mcL
Hematocrit:
• Male: 40.7 to 50.3%
• Female: 36.1 to 44.3%
Hemoglobin:
• Male: 13.8 to 17.2 gm/dL
• Female: 12.1 to 15.1 gm/dL
Red blood cell indices:
• MCV: 80 to 95 femtoliter
• MCH: 27 to 31 pg/cell
• MCHC: 32 to 36 gm/dL
Note:
• cells/mcL = cells per microliter
• gm/dL = grams per deciliter;
• pg/cell = picograms per cell
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

A high RBC or hematocrit may be due to:
• Dehydration (such as from severe diarrhea)
• Kidney disease with high erythropoietin production
• Low oxygen level in the blood for a long time due to heart or lung disease
• Polycythemia vera
• Smoking
A low RBC or hematacrit is a sign of anemia, which can result from:
• Autoimmune diseases such as lupus erythematosus or rheumatoid arthritis
• Blood loss (hemorrhage)
• Bone marrow failure (for example, from radiation, infection, or tumor)
• Chronic kidney disease
• Hemolysis (red blood cell destruction)
• Leukemia and other blood cancers
• Long-term infections such as hepatitis
• Poor diet and nutrition, causing too little iron, folate, vitamin B12, or vitamin B6
• Multiple myeloma
A lower than normal white blood cell count is called leukopenia. A decreased WBC count may be due to:
• Autoimmune diseases (such as systemic lupus erythematosus)
• Bone marrow failure (for example, due to infection, tumor, radiation, or fibrosis)
• Disease of the liver or spleen
High numbers of WBCs is called leukocytosis. It can result from:
• Infectious diseases
• Inflammatory disease (such as rheumatoid arthritis or allergy)
• Leukemia
• Severe emotional or physical stress
• Tissue damage (such as burns)
Low hemoglobin values may be due to:
• Anemia (various types)
• Blood loss

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Considerations

RBCs transport hemoglobin which, in turn, carries oxygen. The amount of oxygen received by body tissues depends on the amount and function of RBCs and hemoglobin.
WBCs are mediators of inflammation and the immune response. There are various types of WBCs that normally appear in the blood:
• Neutrophils (polymorphonuclear leukocytes)
• Band cells (slightly immature neutrophils)
• T-type lymphocytes (T cells)
• B-type lymphocytes (B cells)
• Monocytes
• Eosinophils
• Basophils

Alternative Names

Complete blood count

References

Goldman L, Schafer AI, eds.Cecil Medicine

Cord blood testing

Cord blood refers to a sample of blood collected from the umbilical cord when a baby is born. The umbilical cord is the cord connecting the baby to the mother's womb.
Cord blood testing can be done to evaluate a newborn's health.

How the Test is Performed

Right after the birth of your baby, the umbilical cord is clamped and cut. If cord blood is to be drawn, another clamp is placed 8 to 10 inches away from the first. The section between the clamps is cut and a blood sample is collected into a specimen tube.

How to Prepare for the Test

No special steps are needed to prepare for this test.

How the Test will Feel

You will not feel anything beyond the normal birthing process.

Why the Test is Performed

Cord blood testing is done to measure the following in your baby’s blood:
• Bilirubin levels
• Blood culture (if an infection is suspected)
• Blood gases (to evaluate the oxygen, carbon dioxide, and pH levels)
• Blood sugar level
• Blood type and Rh
• Complete blood count (CBC)
• Platelet count

Normal Results

Normal values mean that all items checked are within normal range.

What Abnormal Results Mean

A low pH (less than 7.04 to 7.10) means there are higher levels of acids in the baby's blood. This might occur when the baby does not get enough oxygen during labor. One reason for this could be that the umbilical cord was compressed during labor or delivery.
A blood culture that is positive for bacteria means you have a blood infection (septicemia).
High levels of blood sugar (glucose) in the cord blood may be found if the mother has diabetes. The newborn will be watched for hypoglycemia (low blood sugar) after delivery.
High levels of bilirubin could be due to infections that the baby gets before birth, including:
• Congenital CMV
• Congenital hepatitis
• Congenital rubella
• Congenital toxoplasmosis
Other possible causes include:
• Dubin-Johnson syndrome
• Jaundice in the mother
• Mother taking sulfa drugs during pregnancy
• Rh incompatibility
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Considerations

Most hospitals routinely collect cord blood for testing at birth. The process is fairly easy and this is the only time when this type of blood sample can be collected.
You can also decide to bank or donate cord blood at the time of your delivery. Cord blood can be used to treat certain types of bone marrow-related cancers. Some parents may choose to save (bank) their child's cord blood for this and other, future medical purposes.
Cord blood banking for personal use is done by private companies. There is a charge for the service. Cord blood can also be donated to your local blood bank for use by others as needed for cancer treatment.

References

Umbilical Cord Blood Banking. ACOG Committee Opinion No. 399. American College of Obstetricians and Gynecologists.Obstet Gynecol
American Academy of Pediatrics Section on Hematology/Oncology, American Academy of Pediatrics Section on Allergy/Immunology, Lubin BH, Shearer WT. Cord blood banking for potential future transplantation. Pediatrics
Carlo WA. The fetus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds.Nelson Textbook of Pediatrics

RBC count

An RBC count is a blood test that measures how many red blood cells (RBCs) you have.
RBCs contain hemoglobin, which carries oxygen. How much oxygen your body tissues get depends on how many RBCs you have and how well they work.
Watch this video about:Red blood cell production

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary for adults.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

The RBC count is almost always part of the CBC (complete blood count) test.
The test can help diagnose different kinds of anemia (low number of RBCs) and other conditions affecting red blood cells.
Additional conditions under which an RBC count may be performed:
• Disease that damages kidney blood vessels (Alport syndrome)
• White blood cell cancer (macroglobulinemia of Waldenstrom)
• Disorder in which red blood cells break down earlier than normal (paroxysmal nocturnal hemoglobinuria)
• Bone marrow disorder in which the marrow is replaced by scar tissue (myelofibrosis)

Normal Results

Normal RBC range is:
• Male: 4.7 to 6.1 million cells per microliter (cells/mcL)
• Female: 4.2 to 5.4 million cells/mcL
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Higher-than-normal numbers of RBCs may be due to:
• Cigarette smoking
• Problem with heart's structure and function that is present at birth (congenital heart disease)
• Failure of the right side of the heart (cor pulmonale)
• Dehydration (such as from severe diarrhea)
• Kidney tumor (renal cell carcinoma)
• Low blood oxygen level (hypoxia)
• Scarring or thickening of the lungs (pulmonary fibrosis)
• Bone marrow disease that causes abnormal increase in RBCs (polycythemia vera)
Your RBC count will increase for several weeks when you move to a higher altitude.
Drugs that can increase the RBC count include:
• Gentamicin
• Methyldopa
Lower-than-normal numbers of RBCs may be due to:
• Anemia
• Bleeding
• Bone marrow failure (for example, from radiation, toxins, or tumor)
• Deficiency of a hormone called erythropoietin (caused by kidney disease)
• RBC destruction (hemolysis) due to transfusion, blood vessel injury, or other cause
• Leukemia
• Malnutrition
• Bone marrow cancer called multiple myeloma
• Nutrition deficiencies of iron, copper, folic acid, vitamin B6, or vitamin B12
• Overhydration
• Pregnancy
Drugs that can decrease the RBC count include:
• Chemotherapy drugs
• Chloramphenicol
• Hydantoins
• Quinidine

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Alternative Names

Erythrocyte count; Red blood cell count

References

Bunn HF. Approach to the anemias. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine
Mathur SC, Schexneider KI, Hutchison RE. Hematopoiesis. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods

RBC 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 hemoglobin relative to the size of the cell (hemoglobin concentration) per red blood cell (MCHC)

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

RBCs transport hemoglobin which, in turn, transports oxygen. The amount of oxygen tissues receive depends on the amount and function of RBCs and hemoglobin.
The MCV reflects the size of red blood cells. The MCH and MCHC reflect the hemoglobin content of red blood cells. These RBC measures are used to diagnose types of anemia.
Anemias are defined based on cell size (MCV) and amount of Hgb (MCH).
• MCV less than lower limit of normal: microcytic anemia
• MCV within normal range: normocytic anemia
• MCV greater than upper limit of normal: macrocytic anemia
• MCH less than lower limit of normal: hypochromic anemia
• MCH within normal range: normochromic anemia
• MCH greater than upper limit of normal: hyperchromic anemia

Normal Results

• MCV: 80 - 100 femtoliter
• MCH: 27 - 31 picograms/cell
• MCHC: 32 - 36 grams/deciliter
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

This test is used to diagnose the cause of anemia. The following are the types of anemia and their causes:
• Normocytic/normochromic (NC/NC) anemia is caused by sudden blood loss, prosthetic heart valves, blood infection (sepsis), tumor, long-term disease, aplastic anemia, or deficiency of the hormone erythropoietin caused by kidney failure.
• Microcytic/hypochromic anemia is caused by iron deficiency, lead poisoning, blood disorder called thalassemia, or inflammation.
• Macrocytic/normochromic or hyperchromic anemia results from chemotherapy, folate deficiency, or vitamin B12 deficiency.

Risks

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Alternative Names

Erythrocyte indices; Blood indices; Mean corpuscular hemoglobin (MCH); Mean corpuscular hemoglobin concentration (MCHC); Mean corpuscular volume (MCV); Red blood cell indices

References

Bunn HF. Approach to the anemias. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine
Hutchison RE, McPherson RA, Schexneider KI. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods

Red blood cell production

Following application region is j w player plays ADAM health video about Red blood cell production

Overview

Blood carries various substances that must be brought to one part of the body or another. Red blood cells are an important element of blood. Their job is to transport oxygen to the body’s tissues in exchange for carbon dioxide, which is carried to and eliminated by the lungs.
Red blood cells are formed in the red bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts give rise to all of the formed elements in blood. If a hemocytoblast commits to becoming a cell called a proerythroblast, it will develop into a new red blood cell.
The formation of a red blood cell from hemocytoblast takes about 2 days. The body makes about two million red blood cells every second.
Blood is made up of both cellular and liquid components. If a sample of blood is spun in a centrifuge, the formed elements and fluid matrix of blood can be separated from each other. Blood consists of 45% red blood cells, less than 1% white blood cells and platelets, and 55% plasma.

Published for educational purposes from the website: MedlinePlus
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

SEARCH CONTENTS

Custom Search

ADD THIS