Bilirubin - blood

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Transcript of Bilirubin - blood

Bilirubin - bloodBlood test
Bilirubin is a yellowish pigment found in bile, a fluid produced by the liver.
This article discusses the laboratory test done to measure bilirubin in the blood. Total and direct bilirubin are usually measured to screen for or to monitor liver or gallbladder problems. Large amounts of bilirubin in the body can lead to jaundice.
A test may also be done to measure bilirubin in a urine sample. For information on that test, see: Bilirubin - urine.
How the Test is Performed
A blood sample is needed. For information on how this is done, see: Venipuncture .
The laboratory specialist spins the blood in a machine called a centrifuge, which separates the liquid part of the blood (serum) from the cells. The bilirubin test is done on the serum.
How to Prepare for the Test
You should not eat or drink for at least 4 hours before the test. Your health care provider may instruct you to stop taking drugs that affect the test.
Drugs that can increase bilirubin measurements include allopurinol, anabolic steroids, some antibiotics, antimalaria medications, azathioprine, chlorpropamide, cholinergics, codeine, diuretics, epinephrine, meperidine, methotrexate, methyldopa, MAO inhibitors, morphine, nicotinic acid, birth control pills, phenothiazines, quinidine, rifampin, steroids, sulfonamides, and theophylline.
Drugs that can decrease bilirubin measurements include barbiturates, caffeine, penicillin, and high-dose salicylates such as aspirin.
Why the Test is Performed
This test is useful in determining if a patient has liver disease or a blocked bile duct.
Bilirubin metabolism begins with the breakdown of red blood cells in many parts of the body. Red blood cells contain hemoglobin, which is broken down to heme and globin. Heme is converted to bilirubin, which is then carried by albumin in the blood to the liver.
In the liver, most of the bilirubin is chemically attached to another molecule before it is released in the bile. This "conjugated" (attached) bilirubin is called direct bilirubin; unconjugated bilirubin is called indirect bilirubin. Total serum bilirubin equals direct bilirubin plus indirect bilirubin.
Conjugated bilirubin is released into the bile by the liver and stored in the gallbladder, or transferred directly to the small intestines. Bilirubin is further broken down by bacteria in the intestines, and those breakdown products contribute to the color of the feces. A small percentage of these breakdown compounds are taken in again by the body, and eventually appear in the urine.
Normal Results
Direct bilirubin: 0 to 0.3 mg/dL Total bilirubin: 0.3 to 1.9 mg/dL
Note: mg/dL = milligrams per deciliter
Normal values may vary slightly from laboratory to laboratory.
What Abnormal Results Mean
Jaundice is a yellowing of the skin and the white part of the eye, which occurs when bilirubin builds up in the blood at a level greater than approximately 2.5 mg/dL. Jaundice occurs because red blood cells are being broken down too fast for the liver to process. This might happen due to liver disease or bile duct blockage.
If the bile ducts are blocked, direct bilirubin will build up, escape from the liver, and end up in the blood. If the levels are high enough, some of it will appear in the urine. Only direct bilirubin appears in the urine. Increased direct bilirubin usually means that the biliary (liver secretion) ducts are obstructed.
Increased indirect or total bilirubin may be a sign of:
Crigler-Najjar syndrome Erythroblastosis fetalis Gilbert's disease Healing of a large hematoma (bruise or bleeding under the skin) Hemolytic anemia Hemolytic disease of the newborn Hepatitis Physiological jaundice (normal in newborns) Sickle cell anemia Transfusion reaction
Bile duct obstruction Cirrhosis Dubin-Johnson syndrome (very rare) Hepatitis Intrahepatic cholestasis (buildup of bile in the liver) due to any cause
Additional conditions under which the test may be performed:
Biliary stricture Cholangiocarcinoma Cholangitis Choledocholithiasis Hemolytic anemia due to G6PD deficiency Hepatic encephalopathy Idiopathic aplastic anemia Idiopathic autoimmune hemolytic anemia Immune hemolytic anemia (including drug-induced immune hemolytic
anemia) Secondary aplastic anemia Thrombotic thrombocytopenic purpura Wilson's disease
Considerations
Factors that interfere with bilirubin testing are:
Hemolysis (breakdown) of blood will falsely increase bilirubin levels Lipids in the blood will falsely decrease bilirubin levels Bilirubin is light-sensitive; it breaks down in light
Alternative Names
References
Berk PD, Korenblat KM. Approach to the patient with jaundice or abnormal liver test results. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 150.
Update Date: 2/23/2009
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of
Newborn jaundice
Exchange transfusion - series
Newborn jaundice is a condition marked by high levels of bilirubin in the blood. The increased bilirubin cause the infant's skin and whites of the eyes (sclera) to look yellow.
Causes
Bilirubin is a yellow pigment that's created in the body during the normal recycling of old red blood cells. The liver processes bilirubin in the blood so that it can be removed from the body in the stool.
Before birth, the placenta -- the organ that nourishes the developing baby -- removes the bilirubin from the infant so that it can be processed by the mother's liver. Immediately after birth, the baby's own liver begins to take over the job, but this can take time. Therefore, bilirubin levels in an infant are normally a little higher after birth.
High levels of bilirubin in the body can cause the skin to look yellow. This is called jaundice. Jaundice is present to some degree in most newborns. Such "physiological jaundice" usually appears between day 2 and 3, peaks between days 2 and 4, and clears by 2 weeks. Physiological jaundice usually causes no problems.
Breast milk jaundice is another common, usually non-harmful form of newborn jaundice. Breast milk may contain a substance that increases reuse of bilirubin in the intestines. Such jaundice appears in some healthy, breastfed babies after day 7 of life, and usually peaks during weeks 2 and 3. It may last at low levels for a month or more.
Breastfeeding jaundice is a type of exaggerated physiological jaundice seen in breastfed babies in the first week, especially in those that are not nursing often enough. It is different than breast milk jaundice in that it occurs later and is caused by the milk itself.
Sometimes jaundice can be a sign of a serious underlying problem. Higher levels of bilirubin can be due to:
An event or condition that increases the number of red blood cells that needs to be processed
Anything that interferes with the body’s ability to process and remove bilirubin
The following increase the number of red blood cells that need to be processed:
Abnormal blood cell shapes o Congenital spherocytic anemia o Elliptocytosis
Blood type incompatibilities o ABO incompatibility (Mother has type O blood, baby does not) o Rh incompatibility (Mother is Rh negative, baby is not)
Cephalohematoma or other birth injury Glucose-6-phosphate dehydrogenase deficiency High levels of red blood cells (polycythemia)
o More common in small for gestational age babies o More common in some twins
Infection Prematurity Pyruvate kinase deficiency Transfusions
The following interfere with the body's ability to process and remove bilirubin:
Alpha-1 antitrypsin deficiency Biliary atresia Certain medications Congenital cytomegalovirus (CMV) infection Congenital herpes Congenital hypothyroidism Congenital rubella Congenital syphilis Congenital toxoplasmosis Crigler-Najjar syndrome Cystic fibrosis Gaucher's disease Gilbert syndrome Hypoxia Infections (such as sepsis) Lucey-Driscol syndrome Neonatal hepatitis
Niemann-Pick disease Prematurity
In otherwise healthy babies born at 35 weeks gestation or greater, those most likely to eventually develop signs of newborn jaundice are those who have:
A brother or sister who needed phototherapy for jaundice A high bilirubin level for their age, even if they are not yet jaundiced Been exclusively breastfeed, especially if weight is excessive Blood group incompatibility or other known red blood cell disease Cephalohematoma or significant bruising East Asian ancestry Jaundice in the first 24 hours of life
Symptoms
The main symptom is a yellow color of the skin. The yellow color is best seen right after gently pressing a finger onto the skin. The color sometimes begins on the face and then moves down to the chest, belly area, legs, and soles of the feet.
Sometimes, infants with significant jaundice have extreme tiredness and poor feeding.
Exams and Tests
All newborns should be examined for jaundice at least every 8 to 12 hours for the first day of life.
Any infant who appears jaundiced in the first 24 hours should have bilirubin levels measured immediately. This can be done with a skin or blood test.
Babies should be assigned a risk for later developing jaundice before they leave the hospital. Babies are classified as low risk, low intermediate risk, high intermediate risk, or high risk. Many hospitals do this by routinely checking total bilirubin levels on all babies at about 24 hours of age.
Further testing varies on the infant's specific situation and test results. For example, the possible cause of the jaundice should be sought for babies who require treatment or whose total bilirubin levels are rising more rapidly than expected.
Tests that will likely be done include:
Complete blood count Coomb's test Measurement of levels of specific types of bilirubin Reticulocyte count
The level of albumin in the baby's blood may also be checked. Low albumin levels may increase the risk of damage from excessive jaundice.
Treatment
Treatment is usually not necessary. Keep the baby well-hydrated with breast milk or formula. Frequent feedings encourage frequent bowel movements, which helps remove bilirubin through the stools. (Bilirubin is what gives stool a brown color).
Sometimes special blue lights are used on infants whose levels are very high. This is called phototherapy. These lights work by helping to break down bilirubin in the skin. The infant is placed naked under artificial light in a protected isolette to maintain constant temperature. The eyes are protected from the light. The American Academy of Pediatrics recommends that breastfeeding be continued through phototherapy, if possible.
In the most severe cases of jaundice, an exchange transfusion is required. In this procedure, the baby's blood is replaced with fresh blood. Treating severely jaundiced babies with intravenous immunoglobulin may also be very effective at reducing bilirubin levels.
Outlook (Prognosis)
Usually newborn jaundice is not harmful. For most babies, jaundice usually resolves without treatment within 1 to 2 weeks. However, if significant jaundice is untreated, very high levels of bilirubin can damage the brain. For babies who require treatment, the treatment is usually quite effective.
Possible Complications
Rare, but serious, complications from high bilirubin levels include:
Cerebral palsy Deafness Kernicterus -- brain damage from very high bilirubin levels
When to Contact a Medical Professional
All babies should be seen by a health care provider in the first 5 days of life to check for jaundice.
Those who spend less than 24 hours in a hospital should be seen by age 72 hours.
Infants sent home between 24 and 48 hours should be seen again by age 96 hours.
Infants sent home between 48 and 72 hours should be seen again by age 120 hours.
Jaundice is an emergency if the baby has a fever, has become listless, or is not feeding well. Jaundice may be dangerous in high-risk newborns.
Jaundice is generally NOT dangerous in term, otherwise healthy newborns. Call the infant's health care provider if jaundice is severe (the skin is bright yellow), if jaundice continues to increase after the newborn visit, lasts longer than 2 weeks, or if other symptoms develop. Also call the doctor if the feet, particularly the soles, are yellow.
Prevention
In newborns, some degree of jaundice is normal and probably not preventable. The risk of significant jaundice can often be reduced by feeding babies at least 8 to 12 times a day for the first several days and by carefully identifying infants at highest risk.
All pregnant women should be tested for blood type and unusual antibodies. If the mother is Rh negative, follow-up testing on the infant's cord is recommended. This may also be done if the mother blood type is O+, but it not necessarily required if careful monitoring takes place.
Careful monitoring of all babies during the first 5 days of life can prevent most complications of jaundice. Ideally, this includes:
Considering a baby's risk for jaundice Checking bilirubin level in the first day or so Scheduling at least one follow-up visit the first week of life for babies sent
home from the hospital in 72 hours
Alternative Names
References
American Academy of Pediatrics (AAP). Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2004 Jul;114(1):297-316.
Mercier CE, Barry SE, Paul K, et al. Improving Newborn Preventive Services at the Birth Hospitalization: A Collaborative, Hospital-Based Quality-Improvement Project. Pediatrics. 2007 Sep;120(3):481-488.
Moerschel SK, Cianciaruso LB, Tracy LR. A practical approach to neonatal jaundice. American Family Physician. 2008 May;77(9).
Update Date: 12/1/2008
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by
David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Previously reviewed by Alan Greene, MD, FAAP, Department of Pediatrics, Stanford University School of Medicine, Lucile Packard Children's Hospital; Chief of Future Health, A.D.A.M., Inc., September 2007.
Rh incompatibility
Antibody Hemoglobin Bilirubin - blood Jaundice - yellow skin Anemia Heart failure Poor feeding in infants Seizures
Rh incompatibility is a condition that develops when a pregnant woman has Rh- negative blood and the baby in her womb has Rh-positive blood.
During pregnancy, red blood cells from the fetus can get into the mother's bloodstream as she nourishes her child through the placenta. If the mother is Rh-negative, her system cannot tolerate the presence of Rh-positive red blood cells.
In such cases, the mother's immune system treats the Rh-positive fetal cells as if they were a foreign substance and makes antibodies against the fetal blood cells. These anti-Rh antibodies may cross the placenta into the fetus, where they destroy the fetus's circulating red blood cells.
First-born infants are often not affected -- unless the mother has had previous miscarriages or abortions, which could have sensitized her system -- as it takes time for the mother to develop antibodies against the fetal blood. However, second children who are also Rh-positive may be harmed.
Hemoglobin changes into bilirubin, which causes an infant to become yellow (jaundiced). The jaundice of Rh incompatibility, measured by the level of bilirubin in the infant's bloodstream, may range from mild to dangerously high levels of bilirubin.
Rh incompatibility develops only when the mother is Rh-negative and the infant is Rh-positive. Special immune globulins, called RhoGAM, are now used to prevent this sensitization. In developed countries such as the US, hydrops fetalis and kernicterus have decreased markedly in frequency as a result of these preventive measures.
Symptoms
Rh incompatibility can cause symptoms ranging from very mild to fatal. In its mildest form, Rh incompatibility causes destruction of red blood cells.
Symptoms may include:
Exams and Tests
There may be:
A positive direct Coombs test result Higher-than-normal levels of bilirubin in the baby's cord blood Signs of red blood cell destruction in the infant's blood
Mild Rh incompatibility may be treated with:
Aggressive hydration Phototherapy using bilirubin lights
Outlook (Prognosis)
Possible Complications
hearing loss, speech disorder, and seizures
When to Contact a Medical Professional
Call your health care provider if you think or know you are pregnant and have not yet seen a doctor.
Prevention
Rh incompatibility is almost completely preventable. Rh-negative mothers should be followed closely by their obstetricians during pregnancy.
If the father of the infant is Rh-positive, the mother is given a mid-term injection of RhoGAM and a second injection within a few days of delivery.
These injections prevent the development of antibodies against Rh-positive blood. This effectively prevents the condition.
Alternative Names
Update Date: 10/15/2007
Updated by: Deirdre O’Reilly, MD, MPH, Neonatologist, Division of Newborn Medicine, Children’s Hospital Boston and Instructor in Pediatrics, Harvard Medical School, Boston, Massachusetts. Review Provided by VeriMed Healthcare Network.
Antibodies
ABO incompatibility is a reaction of the immune system that occurs if two different and not compatible blood types are mixed together.
Causes
A, B, and O are the three major blood types. The types are based on small substances (molecules) on the surface of the blood cells. In people who have different blood types, these molecules act as immune system triggers (antigens).
Each person has a combination of two of these surface molecules. Type O lacks any molecule. The different blood types are:
Type A (AA or AO molecules) Type B (BB or BO molecules) Type AB Type O
People who have one blood type form proteins (antibodies) that cause their immune system to react against other blood types. Being exposed to another type of blood can cause a reaction. This is important when a patient needs to receive blood (transfusion) or have an organ transplant. The blood types must be matched to avoid an ABO incompatibility reaction.
For example:
A patient with type A blood will react against type B or type AB blood A patient with type B blood will react against type A or type AB blood A patient with type O blood will react against type A, type B, or type AB
blood
Because type O lacks any surface molecules, type O blood does not cause an immune response. This is why type O blood cells can be given to patients of any blood type. People with type O blood are called "universal donors." However, people with type O can only receive type O blood.
Symptoms
The following are symptoms of transfusion reactions:
Back pain Blood in urine Feeling of "impending doom" Fever Yellow skin (jaundice)
Exams and Tests
Bilirubin level is high Complete blood count (CBC) shows damaged red blood cells, may also
show mild anemia Lab testing of patient's and donor's blood shows that they are not
compatible
Treatment
Treatment may include:
Drugs used to treat allergic reactions (antihistamines) Drugs used to treat swelling and allergies (steroids) Fluids given through a vein (intravenous) Medicines to raise blood pressure if it drops too low
Outlook (Prognosis)
This can be a very serious problem which can even result in death. With the right treatment, a full recovery is likely.
Possible Complications
When to Contact a Medical Professional
Call your health care provider if you have recently had a blood transfusion or transplant and you have the symptoms listed above.
Prevention
Careful testing of donor and patient blood types before transfusion or transplant can prevent this problem.
McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders; 2006.
Hoffman R, Benz E, Shattil S, Furie B, Cohen H. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, Pa: Churchill Livingstone; 2004.
Update Date: 5/13/2008
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Stuart I. Henochowicz, MD, FACP, Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
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