Bilirubin Levels: Understanding Danger Signs In Newborns

Bilirubin is a yellow substance produced when red blood cells break down. While in the womb, a baby's liver is immature and cannot remove bilirubin, so the placenta does this job. After birth, the liver takes over, but it may take some time for it to do so efficiently. This causes a build-up of bilirubin, leading to jaundice, a yellowing of the skin and eyes. While jaundice is common and usually harmless, very high levels of bilirubin can be dangerous and lead to severe complications such as brain damage.

Bilirubin levels above 15 mg/dL in the first 48 hours

Bilirubin is a brownish-yellow substance that forms when red blood cells break down. Normally, it is metabolised by the liver and gallbladder. However, when bilirubin levels rise above 15 mg/dL in newborns within the first 48 hours, it is considered dangerous and medical treatment is recommended.

High bilirubin levels can be harmful, especially in newborns, as it can lead to a condition called kernicterus. Kernicterus can cause seizures, irreversible brain damage, and even death. This occurs when excess unconjugated bilirubin crosses the blood-brain barrier and harms the developing brain.

There are various factors that can lead to elevated bilirubin levels, including:

• Hemolytic anemia: Rapid destruction of red blood cells due to cancer, autoimmune diseases, or certain medications.
• Lack of digestive bacteria in newborns: This can cause jaundice in newborns due to impaired breakdown of bilirubin.
• Gilbert syndrome: A genetic disorder that causes the liver to process bilirubin slowly.
• Liver disease: Impaired blood flow through the liver or conditions such as cirrhosis or liver cancer can affect bilirubin processing.
• Bile duct obstruction: Blockage due to gallstones, pancreatitis, or tumours can prevent bilirubin from being delivered to the small intestine in bile.
• Medications: Certain drugs, such as antibiotics, anticonvulsives, and over-the-counter medications, can impair liver function and lead to high bilirubin levels.

Treatment Options:

When bilirubin levels exceed 15 mg/dL in newborns within the first 48 hours, treatment is recommended to prevent potential harm to the brain. Treatment options include:

• Phototherapy: Newborns are placed under special blue lights to help break down bilirubin molecules.
• Intravenous immunoglobulin: This prevents the rapid breakdown of red blood cells.
• Exchange transfusion: In rare cases, some of the newborn's blood is replaced with fresh, donated blood.

Bilirubin levels above 20 mg/dL after 72 hours

Bilirubin is a yellow substance that is created when red blood cells break down. In newborns, jaundice is a common condition that occurs when there is a build-up of bilirubin in the blood. This happens because a newborn's liver is not yet developed enough to get rid of the bilirubin. While jaundice usually goes away on its own within a couple of weeks, it is important for a healthcare provider to check the bilirubin levels of newborns to ensure that they do not get too high.

If bilirubin levels rise above 20 mg/dL after 72 hours, healthcare providers will recommend treatment for the newborn to reduce the bilirubin levels. Phototherapy is the standard treatment, which involves placing the infant under a lamp that emits fluorescent white or blue-spectrum light. This helps break down the bilirubin into a water-soluble form, allowing the body to excrete it without conjugating it in the liver. This prevents unconjugated bilirubin from depositing in the newborn's brain tissue. In rare cases, when phototherapy is not effective, an exchange transfusion may be recommended, where some of the newborn's blood is replaced with fresh, donated blood.

It is important to monitor bilirubin levels in newborns and seek medical attention if levels rise too high, as this can help prevent serious health complications and ensure the newborn's health and well-being.

Kernicterus

In newborn babies with very high levels of bilirubin in the blood, the bilirubin can cross the thin layer of tissue that separates the brain and blood (the blood-brain barrier). This can lead to irreversible neurological damage. The risk of kernicterus is higher in newborns because their still-developing livers are heavily exercised by the breakdown of fetal hemoglobin as it is replaced with adult hemoglobin, and the blood-brain barrier is not yet fully developed.

The initial symptoms of kernicterus in babies include lethargy (sleepiness) and brief pauses in breathing (apnoea). As the condition progresses, additional symptoms can include fits (seizures) and muscle spasms that can cause arching of the back and neck. If significant brain damage occurs before treatment, a child can develop serious and permanent problems, such as cerebral palsy, hearing loss, learning disabilities, involuntary twitching, problems with eye movements, and poor development of the teeth.

Healthcare providers recommend treatment for newborns when bilirubin levels rise above 15 mg/dL in the first 48 hours or 20 mg/dL after 72 hours. Treatment options include phototherapy, exchange transfusion, and intravenous immunoglobulins.

Phototherapy treatment

Phototherapy is the standard treatment to reduce bilirubin levels in newborns. It is recommended when bilirubin levels rise above 15 mg/dL in the first 48 hours or 20 mg/dL after 72 hours. During phototherapy, the newborn is placed under a lamp that emits fluorescent white or blue-spectrum light. The baby will be undressed, wearing only a diaper and a mask to protect their eyes. The light helps break down the bilirubin into a water-soluble form so that the body can excrete it without conjugating it in the liver. This prevents unconjugated bilirubin from depositing in the newborn's brain tissue, which can cause brain damage.

The ideal configuration for phototherapy is four special blue bulbs placed centrally, with two daylight fluorescent tubes on either side. The lights should be 15 to 20 cm from the infant. For double phototherapy, a fiber-optic pad can be placed under the newborn, which is twice as effective as standard phototherapy. The treatment usually takes one to two days, and the baby's bilirubin levels should be checked again in 24 hours to ensure they are not rising again.

Phototherapy can be done in a hospital or at home, depending on the severity of the newborn's condition. In rare cases, when phototherapy does not work, a double volume blood exchange transfusion may be necessary. This procedure replaces some of the baby's blood with fresh, donated blood.

Possible Side Effects of Phototherapy

• Watery diarrhea
• Dehydration
• Skin rash
• Burns
• Retinal damage
• Thermoregulatory instability
• Loose stools
• Tanning of the skin

Exchange transfusion

During an exchange transfusion, a physician inserts a plastic tube called a catheter through the umbilical vein of the infant to slowly remove their blood and replace it with donor blood that contains normal bilirubin levels. The donor blood is warmed to 37 degrees Celsius and can be inserted through the same umbilical catheter (known as the push-pull technique) or through a peripheral vein in the abdomen. The amount of blood removed from the infant at each interval must equal the amount of blood infused back in to prevent complications within the cardiovascular system, such as cardiac arrest.

The success of exchange transfusion therapy is accompanied by some risks, including cardiac arrest, irregular beating of the heart, the formation of air bubbles in the blood vessels, and infections at the transfusion site. According to a 1976 study by the National Institute of Child Health and Human Development, the death rate from exchange transfusion is 0.53 per 100 infants, or 0.3 per 100 procedures.

Since the 1980s, the use of exchange transfusion treatment has been in decline due to the development of prenatal treatments and alternative postnatal treatments, such as phototherapy. Phototherapy, which uses light wavelengths to break down bilirubin, is now the most common postnatal treatment for jaundiced infants. It is less invasive and has extremely low risks associated with the procedure.

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