hyperbilirubinemia


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hyperbilirubinemia

 [hi″per-bil″ĭ-roo″bĭ-ne´me-ah]
an excess of bilirubin in the blood, occurring as a result of liver or biliary tract dysfunction or with excessive destruction of red blood cells. It is classified as conjugated or unconjugated, according to the type of bilirubin present. Jaundice is manifested when excess bilirubin is deposited in the skin and mucous membranes.
hyperbilirubinemia I Gilbert disease.
hyperbilirubinemia II a chronic idiopathic jaundice, transmitted as an autosomal recessive trait, that affects the excretory function of the liver. The resulting increase in serum conjugated bilirubin is caused by defective transport of conjugated bilirubin into the biliary tract. The condition is generally harmless. Called also Dubin-Johnson syndrome.
conjugated hyperbilirubinemia, Type III a form of conjugated hyperbilirubinemia; probably the result of a primary defect in the storage or hepatic uptake of bilirubin.
hyperbilirubinemia in the newborn excess serum bilirubin in the newborn due either to overproduction of bilirubin, as in excessive destruction of erythrocytes, or to reduction in glucuronide conjugation in the liver. If a high level of bilirubinemia is left untreated, kernicterus may occur as a result of free unconjugated bilirubin entering the brain tissue and causing neurotoxic damage. The exact level at which kernicterus will occur in individual newborns has not been established. There is evidence that bilirubin levels as low as 6 to 9 mg/dl in very-low-birth-weight and preterm infants puts them at risk for kernicterus and brain damage.
Treatment. The goal of therapy is to reduce serum bilirubin and prevent kernicterus, which virtually disappears when bilirubin levels are controlled. Phototherapy is the standard treatment for nonhemolytic hyperbilirubinemia. It may be used prophylactically in newborns at high risk, for example, in preterm, low-birth-weight, and very-low-birth-weight newborns. Exchange transfusions are used for treatment of moderate to severe hemolytic disease, or when excessive bilirubinemia in preterm newborns is not controlled by phototherapy.
Patient Care. Newborns most at risk for hyperbilirubinemia are those who are preterm, who display bruising, or who have blood incompatibilities, an enclosed hemorrhage such as cephalhematoma, polycythemia, an intrauterine infection, congenital red blood cell abnormality, or congenital hypothyroidism or galactosemia.

Observation of the newborn for jaundice is of primary importance, especially those predisposed to hyperbilirubinemia. Yellowing of the skin is first apparent on the face, progressing downward as it increases in severity. The time at which jaundice is first noticed also is significant. Laboratory data can provide information on the levels of direct and indirect serum bilirubin, the hematocrit, variations in red cell morphology, reticulocyte count, Coombs' test and crossmatching of the infant's cells and maternal serum to detect abnormal antibodies when infant and mother are of the same blood type, and special tests for enzyme deficiencies and galactosemia.

Clinical jaundice is investigated when the jaundice appears in the first 12 hours of life and serum bilirubin levels rise at the rate of more than 3 mg per hour. These signs are indicative of hemolytic jaundice, which may require an exchange transfusion. Physiologic jaundice, which is due to immature liver function, rarely becomes apparent before the third day of life or persists beyond the first week and does not exceed 12 mg in term infants.

Other observations include noting any bruising, which causes hemolysis of erythrocytes and release of the bilirubin component, and assessment for cephalhematoma, which has the same effect as bruising because accumulated red blood cells are broken down. Intestinal obstruction also can lead to a buildup of serum bilirubin. The unevacuated stool contains bile which is broken down by intestinal flora into its basic components, thus allowing the release of bilirubin into the blood stream.

Care of the newborn receiving phototherapy includes protection of the skin and eyes from ultraviolet radiation. Care of the newborn receiving an exchange transfusion is discussed under that topic.

hy·per·bil·i·ru·bi·ne·mi·a

(hī'pĕr-bil'i-rū-bi-nē'mē-ă),
An abnormally high level of bilirubin in the circulating blood, resulting in clinically apparent icterus or jaundice when the concentration is sufficient.

hyperbilirubinemia

(hī′pər-bĭl′ĭ-ro͞o′bə-nē′mē-ə)
n.
An abnormally high concentration of bilirubin in the blood.

hyperbilirubinemia

Hepatology An ↑ of BR in the peripheral circulation; BR is either unconjugated, or conjugated to glucuronic acid, which ↑ BR's water solubility and facilitates its entry into the bile; hyperbilirubinemia in neonates is due to ↓ metabolism, clearance, and liver immaturity. See Jaundice.

hy·per·bil·i·ru·bi·ne·mi·a

(hī'pĕr-bil'i-rū-bi-nē'mē-ă)
An abnormally large amount of bilirubin in the circulating blood, resulting in clinically apparent icterus or jaundice when the concentration is sufficient.
Synonym(s): hyperbilirubinaemia.

Hyperbilirubinemia

A condition where there is a high level of bilirubin in the blood. Bilirubin is a natural by-product of the breakdown of red blood cells, however, a high level of bilirubin may indicate a problem with the liver.

hy·per·bil·i·ru·bi·ne·mi·a

(hī'pĕr-bil'i-rū-bi-nē'mē-ă)
Abnormally high level of bilirubin in circulating blood, resulting in clinically apparent icterus or jaundice when concentration is sufficient.
Synonym(s): hyperbilirubinaemia.
References in periodicals archive ?
In the newborn, the auditory pathway is vulnerable to damage from moderate to severe hyperbilirubinemia, resulting in sensorineural hearing loss (23).
Hyperbilirubinemia in African American neonates: clinical issues and current challenges.
One hundred and ten infants who were treated due to hyperbilirubinemia were included in the present study.
This same cut-off point was also obtained by calculating the value that gave approximately 25 false-positive results for every one false-negative result given the prevalence of hyperbilirubinemia in this study.
In the case of vitamin B12 deficiency, erythrocytes cannot mature with consequent hemolysis and hyperbilirubinemia.3
In the neonatal period, it is especially important to prevent hyperbilirubinemia in order to protect the brain from kernicterus.
For the 1 h results, there was no statistically significant difference between the groups in terms of age, body mass index (BMI), multiparity, neonatal hypoglycemia, hyperbilirubinemia, intensive care unit admission, birth weight, abnormal results, and LGA rates; however, the rate of SGA infants was statistically significantly higher in group 2 compared with group 3 (Table 1).
In most cases, it does not require treatment; however, elevated bilirubin levels in the blood (hyperbilirubinemia) can be toxic and may potentially lead to neurologic complications, including encephalopathy or irreversible brain damage, concluded the company.
This is most likely due to the clinical relationship between longer duration of labour and cephalohematoma, a known risk factor for severe hyperbilirubinemia [17,18].
Based on the kidney biopsy results and significant hyperbilirubinemia, testing was done for bacteremia, influenza, tuberculosis, HIV, tick-borne diseases, Hantavirus infection, acute viral hepatitis (A, B, C, E, CMV, EBV, and VZV) and vasculitis, which were all negative or normal.
Indirect hyperbilirubinemia is a known clinical presentation of urinary tract infection- (UTI-) associated urosepsis in infancy.