Value of Transcutaneous Bilirubin Devices

Neonatal jaundice, commonly found in 60% of normal newborns, is normally a self-resolving episode ending 72 to 96 h after birth. Transient elevation of blood bilirubin occurs by combination of an increase in red blood cell destruction and concomitant decrease in hepatic bilirubin conjugation. (1) Visible jaundice is present in most term and near-term newborns during the first week of life. Although it is mostly a benign condition, healthcare professionals should keep in mind rare but severe adverse outcomes of serious hyperbilirubinemia (2). Newborn infants must be monitored to identify those who might develop severe hyperbilirubinemia and, in rare cases, acute bilirubin encephalopathy or kernicterus.Kernicterus is associated with a high mortality rate and survivors usually suffer from complications such as athetoid cerebral palsy, highfrequency hearing loss and intellectual disability(3).

Severe neonatal hyperbilirubinemia and its sequelae can be prevented with appropriate serum bilirubin monitoring and early treatment involving phototherapy or exchange blood transfusion (4). In the 2004 American Academy of Pediatrics Subcommittee on Hyperbilirubinemia guideline, total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) measurement is recommended before discharge from the maternity hospital to evaluate the risk of subsequent severe hyperbilirubinemia in all newborns (5). To measure bilirubin levels, the total serum bilirubin (TSB) measured by the biochemical laboratory is still considered a gold standard, but it is invasive, requiring needle pricks that carry the risk for iatrogenic anemia, puncture site infection, bacteremia, and osteomyelitis, and cause pain and stress to the neonates(6). The turn around time for bilirubin test results may delay the initiation of therapy for neonatal hyperbilirubinemia. In recent years, the transcutaneous bilirubinometer, which uses photometry to detect bilirubin levels, has been used as an alternative to estimate the bilirubin levels(4). TcB meters estimate total serum or plasma bilirubin using multiwave length spectral reflection from the skin surface.(7) Transcutaneous bilirubinometry (TcB) developed due to several converging influences and factors as the recognition that yellow skin color is due to the deposition of bilirubin,1 a chromophore molecule that, with advancements in optical science, could be quantitatively measured(8). Transcutaneous bilirubinometry (TcB) has the following advantages ease of use, non-invasive nature and reduction in the number of inpatient TSB determinations reduced expense when compared to a serum bilirubin, immediate results, and superior performance over visual assessment of jaundice. The first attempt at non-invasive measurement of bilirubin goes back to the 1960's when the icterometer was introduced. This device, based on reflectance, had poor analytical specificity and sensitivity, and poor reproducibility with coefficient of variations ranging between 20 and 40%. In the past years, bilirubinometers have gradually been improved and are now based on simultaneous multiple wavelength analysis (9)