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Introduction ⬇

In newborns, signs of jaundice may indicate hemolytic anemia or congenital icterus. If bilirubin levels reach a critical point in the infant, damage to the CNS may occur in a condition known as kernicterus. Therefore, in these infants, the level of bilirubin is the deciding factor in whether or not to perform an exchange transfusion.

Neonatal bilirubin is used to monitor erythroblastosis fetalis (hemolytic disease of the newborn), which usually causes jaundice in the first 2 days of life. All other causes of neonatal jaundice, including physiologic jaundice, hematoma or hemorrhage, liver disease, and biliary disease, should also be monitored. Normal, full-term neonates experience a normal, neonatal, physiologic, transient hyperbilirubinemia by the 3rd day of life, which rapidly falls by the 5th–10th day of life.

Normal Findings ⬆ ⬇

Newborns (0–7 days):

Cord Blood Total:

Clinical Alert

Critical Value for Neonatal Bilirubin>15 mg/dL or >256 mol/L (intellectual disability can occur)

See Table 6.4 for a comparison of premature and full-term infants.

Procedure ⬆ ⬇

  1. Draw blood from heel of newborn using a capillary pipette and amber Microtainer tube; 0.5 mL of serum is needed. Cord blood may also be used.

  2. Protect sample from light.

Clinical Implications ⬆ ⬇

  1. Elevated total bilirubin (neonatal) is associated with the following conditions:

    1. Erythroblastosis fetalis occurs as a result of blood group incompatibility between mother and fetus.

      1. Rh (D) antibodies and other Rh factors

      2. ABO antibodies

      3. Other blood groups, including Kidd, Kell, and Duffy (see Chapter 8)

    2. Galactosemia

    3. Sepsis

    4. Infectious diseases (e.g., syphilis, toxoplasmosis, cytomegalovirus)

    5. RBC enzyme abnormalities:

      1. Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency

      2. Pyruvate kinase deficiency

      3. Spherocytosis (autohemolytic anemia causing the RBCs to become sphere-shaped and not the typical biconcave shape)

    6. Subdural hematoma, hemangiomas

  2. Elevated unconjugated (indirect) neonatal bilirubin is associated with the following conditions:

    1. Erythroblastosis fetalis

    2. Hypothyroidism

    3. Crigler–Najjar syndrome

    4. Obstructive jaundice

    5. Infants of mothers with diabetes

  3. Elevated conjugated (direct) neonatal bilirubin is associated with the following conditions:

    1. Biliary obstruction

    2. Neonatal hepatitis

    3. Sepsis

Interventions ⬆

Pretest Patient Care

  1. Explain test purpose and procedure and its relation to jaundice to the mother.

  2. See Chapter 1 guidelines for safe, informed, effective pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed.

  2. For slight elevations (i.e., <10.0 mg/dL or <170 μmol/L), phototherapy may be initiated.

  3. Monitor neonatal bilirubin levels to determine indications for exchange transfusion. Tests should be done every 12 hours in jaundiced newborns. See Table 6.5 for exchange transfusion indications.

  4. Transfuse at one step earlier in the presence of the following conditions:

    1. Coombs test positive

    2. Serum protein <5 g/dL

    3. Metabolic acidosis (pH <7.25)

    4. Respiratory distress (with O2<50 mm Hg or 6.6 kPa)

    5. Certain clinical findings (e.g., hypothermia, CNS or other clinical deterioration, sepsis, hemolysis)

Other criteria for exchange transfusion are suddenness and rate of bilirubin increase and when such an increase occurs; for example, an increase of 3 mg/dL (51 μmol/L) in 12 hours, especially after bilirubin has already leveled off, must be followed by frequent serial determinations, especially if it occurs on the first or seventh day of life rather than on the third day. Be cognizant of a rate of bilirubin increase of more than 1 mg/dL (more than 17 μmol/L) during the first day of life. Serum bilirubin of 10 mg/dL (170 μmol/L) after 24 hours or 15 mg/dL (256 μmol/L) after 48 hours despite phototherapy usually indicates that serum bilirubin will reach 20 mg/dL (342 μmol/L).