Bilirubin is a yellowish pigment resulting from the normal breakdown of old red blood cells. During this process, hemoglobin is broken down into heme, which is then converted into unconjugated bilirubin. This form is not water-soluble and must be transported to the liver bound to the protein albumin.
Once in the liver, the unconjugated bilirubin is “conjugated,” making it water-soluble so it can be mixed into bile and excreted through the intestines. Elevated bilirubin levels in the blood, known as hyperbilirubinemia, often cause the skin and eyes to turn yellow, a condition called jaundice. High bilirubin is a symptom indicating an imbalance between production and excretion, and treatment depends entirely on the patient’s age and the underlying cause.
Identifying the Source of High Bilirubin
Lowering bilirubin requires accurately determining the cause, as the source dictates the treatment strategy. Causes are broadly categorized based on where the problem occurs in the body’s processing pathway.
In newborns, high bilirubin is common because developing livers are slower to conjugate the pigment, leading to physiological jaundice. Other causes in infants include breast milk jaundice, a benign condition, and pathological jaundice. Pathological cases may be due to blood type incompatibility, genetic conditions, or infection, often involving the rapid breakdown of red blood cells that overwhelms the liver.
In adults, causes are classified into three categories: pre-hepatic, hepatic, and post-hepatic. Pre-hepatic causes occur before the liver, such as hemolytic anemia, where red blood cells are destroyed too quickly. Hepatic causes involve the liver itself, including diseases like hepatitis, cirrhosis, or Gilbert’s syndrome. Post-hepatic causes involve an obstruction after the liver, preventing conjugated bilirubin from being excreted. This is often caused by gallstones, tumors, or inflammation blocking the bile ducts. A medical evaluation, including blood tests to measure both unconjugated and conjugated bilirubin, is necessary to pinpoint the specific problem.
Standard Medical Interventions for Neonatal Jaundice
Interventions for high bilirubin in infants focus on rapidly reducing levels to prevent kernicterus, a severe form of brain damage. The most common treatment is phototherapy, which uses blue-green light. The light penetrates the skin and converts unconjugated bilirubin molecules into water-soluble compounds called photoisomers.
These photoisomers are easily excreted in the bile and urine without requiring further processing by the infant’s liver. Phototherapy can be delivered using overhead lights, fiber-optic blankets, or pads to maximize the exposed skin surface area. Treatment effectiveness depends on the light’s intensity, the surface area exposed, and the distance from the light source.
For infants with extremely high or rapidly rising levels that do not respond to intensive phototherapy, exchange transfusion is used. This procedure is a last-resort therapy to avoid neurological damage. It involves repeatedly withdrawing small amounts of the infant’s blood and replacing it with donor blood, which dilutes the circulating bilirubin and antibodies.
If jaundice is due to a specific pathological condition, such as infection or blood type incompatibility, the underlying cause is treated concurrently. Intravenous immunoglobulin (IVIg) may be administered to infants with blood type incompatibility to reduce maternal antibodies causing red blood cell destruction. The goal is a swift and sustained reduction of bilirubin to a safe level.
Addressing Hyperbilirubinemia in Adults
Treating elevated bilirubin in adults differs significantly from infants because the goal is resolving the underlying condition, not directly lowering the bilirubin. Phototherapy is rarely used in adults because their mature livers manage the pigment, and skin thickness limits light penetration. Bilirubin levels return to normal only once the function of the liver or bile ducts is restored.
If the cause is pre-hepatic, such as hemolytic anemia, treatment manages the condition destroying red blood cells. Medications like phenobarbital may enhance the liver’s ability to conjugate and excrete the pigment in specific cases. For hepatic causes, such as viral hepatitis or cirrhosis, management involves antiviral medications, lifestyle changes like alcohol cessation, or drugs like ursodeoxycholic acid (UDCA) to improve bile flow.
In cases of post-hepatic obstruction, where bile flow is blocked, treatment is typically surgical or endoscopic. This may involve removing gallstones or placing a stent to bypass a tumor or stricture in the bile duct. Diagnostic tools like abdominal ultrasound and Liver Function Tests guide the targeted treatment plan.
Monitoring and Follow-Up Care
Diligent monitoring is necessary after any intervention to ensure bilirubin levels remain safe and the underlying cause is resolved. For infants treated with phototherapy, follow-up testing is required 6 to 24 hours after treatment stops to check for rebound hyperbilirubinemia. Total serum bilirubin levels are plotted on specialized nomograms to determine the need for further treatment.
Parents should ensure adequate feeding, as dehydration contributes to rising bilirubin levels. In adults, follow-up involves repeating blood work, including liver function tests, to track the underlying disease progression.
For both age groups, certain symptoms require immediate medical attention, indicating dangerously high levels or a worsening condition. These urgent warning signs include:
- Lethargy, difficulty feeding, or high-pitched crying in an infant.
- Confusion, severe abdominal pain, or unexplained weight loss in an adult.
Managing hyperbilirubinemia often involves managing a chronic condition, such as liver disease. Long-term care may require regular specialist appointments and adherence to a treatment regimen to prevent recurrence.