Study On The Relationship Between The Dose,Time And Bilirubin Changes Of Phototherapy For Jaundice In Neonates

Purpose:The purpose of the study was to explore the hourly trend of changes in bilirubin in neonates with jaundice during phototherapy,and to explore whether the trend was identical in neonates with different characteristics（gestational age）.To explore the influencing factors of the efficacy of phototherapy at different time,including irradiance,hemoglobin,intravenous fluid intake per hour,milk intake per hour,and the use of probiotics through multiple linear regression analysis.Methods:Exploratory and repeated measures descriptive study.Collect the hourly bilirubin values and other relevant data of hospitalized neonates with jaundice during the first time phototherapy.The mixed effect model and multiple linear regression model were used for data analysis.Results:A total of 306 subjects were included in this study,with a median gestational age of260 days.Among them,190 were males,116 were females,107 were under 35 weeks of gestational age,and 199 were with gestational age of 35 weeks and above.Mixed effect model found that,in neonates with gestational age≥35 weeks and<35 weeks,bilirubin value decreased rapidly within the first 5-6 hours of phototherapy,and thereafter,although bilirubin continued to decline,the decline slowed down.Hemoglobin value,initial bilirubin value,using of probiotics,and milk intake were factors that affected the changes in bilirubin during phototherapy.In neonates with gestational age of 35 weeks or more,the initial bilirubin value T0（β=0.712,p<0.001）,the volume of first hour milk intake（β=-0.025,p<0.001）and hemoglobin（β=0.012,p=0.033）were influencing factors of the bilirubin at the first hour of phototherapy,and the bilirubin at the first hour T1（β=0.807,p<0.001）,using of probiotics（β=-0.944,p=0.001）wer influencing factors of the second hour bilirubin.In neonates with gestational age less than 35 weeks,hemoglobin was influencing factor of bilirubin value at the 6^th（β=0.015,p=0.026）,8^th（β=0.014,p=0.044）and 9^th（β=0.022,p<0.001）hour of phototherapy.Conclusions:During the nine hours of phototherapy in neonates with jaundice,bilirubin decreases rapidly within the first 5-6 hours of phototherapy,and then,the rate slow down.In neonates with gestational age≥35 weeks,the volume of milk intake in the first hour after the start of phototherapy can accelerate the decline in bilirubin values.Using of probiotics at the beginning of phototherapy,the decline in bilirubin values is greater at the second hour of phototherapy.In neonates with gestational age<35 weeks,the higher the hemoglobin value,the higher the bilirubin value at the sixth,eighth,and ninth hours of phototherapy.