文本框: Advances in Transcutaneous Bilirubin Measurements
Finn Ebbesen, Department of Pediatrics, University Hospital of Aalborg, Denmark
Transcutaneous bilirubin measurement as a screening method for neonatal hyperbilirubinemia is a well established method in healthy term infants using Minolta/Air Shields' apparatus. When using this apparatus in infants in the neonatal intensive care unit (NICU) we found, that the transcutaneous bilirubin conc. (TcB) measured in the forehead was significantly and positively correlated to the plasma bilirubin conc. (TSB) and the presence of respiratory distress syndrome, and negatively to the gestational age and the postnatal age. Due to these factors it was impossible to derive simple criteria for detection of hyperbilirubinemia by this jaundice meter.
Now a new transcutanous bilirubinometer, BiliCheck, has been developed. With this apparatus we found a good correlation between TcB and TSB, both in healthy term and near term infants and in  NICU-infants, though the TcB was on average about 20% lower than TSB.  In the NICU infants, TcB, other things being equal, was lower in males than in females, and decreased with increasing postnatal age. Further, sick infants had a higher TcB than healthy infants for the same TSB level. The differences were statistical significant, but small and of minor clinical significance. Blood hemoglobin conc., gestational age and ethnic origin were not found to influence TcB, i.e. BiliCheck corrects sufficiently  for these factors.
By retrospective analysis of our data, a screening model is presented whereby TcB can be used to screen infants who require phototherapy. We found that using screening limits for TcB, which are 70% of the currently used phototherapy limits for TSB., 80% of blood samples in healthy term and near term infants, and 42% of NICU infants with a gestational age </= 32 weeks, could be avoided. 
It can be concluded, that the new second generation transcutaneous bilirubinometer is suitable for screening both NICU and healthy newborn infants with jaundice, with regard to phototherapy. We recommend using a TcB limit which is 70% of the currently recommended TSB limits for phototherapy, in order to decide wheather TSB needs to be measured.