Jaundice is a common condition in newborns, characterized by a yellow discoloration of the skin and eyes. This yellowing occurs due to elevated levels of bilirubin, a byproduct of the normal breakdown of red blood cells. In newborns, jaundice can occur when the liver is not mature enough to efficiently process and eliminate bilirubin from the bloodstream.
Phototherapy is a well-established treatment method for neonatal jaundice. It involves exposing the baby’s skin to specific wavelengths of light, which helps to break down bilirubin in the blood into forms that can be more easily excreted by the liver and kidneys.
Types of Lights Used
1.Fluorescent Lights and Bili-lights
Phototherapy for neonatal jaundice primarily uses fluorescent light sources. These lights, often referred to as bili-lights, emit light in the blue-green spectrum. The most effective wavelengths for breaking down bilirubin are in the range of 430-490 nanometers (nm). This specific range of light effectively converts bilirubin into its water-soluble isomers that can be excreted through urine and stool.
2.Light-emitting Diodes (LEDs)
In recent years, LED lights have become increasingly popular for phototherapy due to their efficiency and longevity. LEDs can be precisely tuned to emit light at the desired wavelengths, making them highly effective for phototherapy. Moreover, they generate less heat compared to traditional fluorescent lights, reducing the risk of overheating the baby.
3.Halogen Lamps and Compact Fluorescent Lamps (CFLs)
Halogen lamps and compact fluorescent lamps (CFLs) are also used in conventional phototherapy units. Halogen lamps, while effective, produce more heat and require careful monitoring to avoid overheating. CFLs, similar to fluorescent lights, emit light in the blue-green spectrum and are often used in combination with other light sources to enhance effectiveness.
Mechanism of Action
The mechanism by which phototherapy works is based on the photochemical reactions that occur when bilirubin absorbs light. When the baby’s skin is exposed to the therapeutic light, the bilirubin in the skin absorbs the light energy. This energy causes a photochemical
reaction that converts bilirubin into two forms:
1.Structural Isomers: These are converted through a process called photoisomerization, which rearranges the molecular structure of bilirubin into a water-soluble form known as **lumirubin**. Lumirubin can be excreted through the baby’s urine and stool without needing to be processed by the liver.
2.Photo-oxidation Products: Light exposure also leads to **photo-oxidation**, a process that adds oxygen to bilirubin, further increasing its solubility and facilitating its excretion.
These photochemical changes reduce the levels of bilirubin in the blood, alleviating the symptoms of jaundice and preventing the potential complications associated with high bilirubin levels, such as **kernicterus** (a form of brain damage).
Types of Phototherapy
There are several types of phototherapy used to treat neonatal jaundice, each with specific advantages:
1.Conventional Phototherapy Overhead Lamps: This is the most common form of phototherapy. It involves placing the baby under a set of overhead lights, typically fluorescent, halogen, or LED. The baby is placed in an open bassinet or incubator with their skin exposed to the light. Eye protection, such as an eye mask, is used to shield the baby’s eyes from the bright light.
2.Intensive Phototherapy: Intensive phototherapy increases the light exposure by using multiple light sources or higher-intensity lamps. This method is often used for babies with higher bilirubin levels that need rapid reduction.
Preparation and Setup
The procedure for phototherapy involves several steps to ensure the baby’s safety and the treatment’s effectiveness:
1. Positioning: The baby is placed on their back in an open crib, bassinet, or incubator. The baby’s clothing is removed to maximize skin exposure to the light, but the diaper may remain on to protect the genital area.
2. Eye Protection: An eye mask or shield is placed over the baby’s eyes to prevent potential damage from the bright light.
3. Monitoring Temperature: The baby’s temperature is regularly monitored to prevent overheating. Some phototherapy units include built-in temperature control systems to help maintain a safe environment.
Exposure Duration
The duration of exposure to phototherapy varies depending on the severity of jaundice and the baby’s response to treatment. Typically, the baby may need to remain under the lights for several hours to days, with periodic breaks for feeding, diaper changes, and bonding time with parents.
Monitoring Bilirubin Levels
Regular blood tests are conducted to measure bilirubin levels and assess the effectiveness of the treatment. The frequency of these tests depends on the initial bilirubin levels and how quickly they decrease with phototherapy.
Hydration and Nutrition
Ensuring the baby remains well-hydrated and fed is crucial during phototherapy. Frequent breastfeeding or formula feeding helps maintain hydration and supports the elimination of bilirubin through urine and stool.
Safety and Side Effects
While phototherapy is generally safe, there are potential side effects and complications to be aware of:
1. Hyperthermia: Overheating can occur if the baby is exposed to high-intensity lights for extended periods. Regular temperature monitoring and proper ventilation can help mitigate this risk.
2. Dehydration: Increased fluid loss can occur due to the heat generated by the lights. Ensuring adequate hydration through regular feedings is essential。
3. Skin Rash: Some babies may develop a mild skin rash due to prolonged light exposure. This typically resolves once phototherapy is discontinued.
4. Temporary Bronze Skin Syndrome: In rare cases, babies may develop a temporary bronze discoloration of the skin. This condition is harmless and resolves after treatment.
5. Eye Protection: Proper use of eye protection is crucial to prevent potential damage to the baby’s eyes. The eye mask or shield should be checked regularly to ensure it is in place and not causing irritation.
When Phototherapy is Recommended
Phototherapy is recommended based on specific guidelines related to bilirubin levels, the baby’s age, and the presence of risk factors. The American Academy of Pediatrics (AAP) provides guidelines for initiating phototherapy in newborns:
1. Bilirubin Levels: The decision to start phototherapy is primarily based on the total serum bilirubin (TSB) level. These levels are evaluated in relation to the baby’s age in hours and the presence of risk factors such as prematurity or hemolytic disease.
2. Age and Risk Factors: For term infants without risk factors, phototherapy is typically initiated at higher bilirubin levels compared to preterm infants or those with risk factors. For example, a healthy term infant might start phototherapy at a TSB level of around 15 mg/dL, while a preterm infant may start at lower levels.
3. Clinical Assessment: In addition to bilirubin levels, clinical assessment of the baby’s overall health, feeding patterns, and weight gain is considered when deciding on phototherapy.
Additional Considerations
1. Early Discharge: For babies discharged early from the hospital, follow-up visits or home phototherapy may be recommended if there is a high risk of developing significant jaundice.
2. Parental Involvement: Educating parents about the signs of worsening jaundice and the importance of follow-up appointments ensures timely intervention if bilirubin levels rise.
Conclusion
Phototherapy is a cornerstone treatment for neonatal jaundice, utilizing specific wavelengths of light to safely and effectively reduce elevated bilirubin levels in newborns. Understanding the types of lights used, the mechanism of action, and the procedural details helps ensure the safe application of this therapy. By addressing key points such as the effectiveness, safety, and guidelines for initiating treatment, caregivers can be well-informed about this essential therapeutic intervention.
Ensuring comprehensive and clear communication about phototherapy not only alleviates parental concerns but also supports the optimal health and well-being of newborns undergoing treatment for jaundice.
