Correlation Research Between Bilirubin Levels In Cerebrospinal Fluid, Skull MRI, BAEP, NBNA And Bilirubin Encephalopathy In Newborns

ObjectiveTo explore the clinical value of cerebrospinal fluid bilirubin levels in the diagnosis ofbilirubin encephalopathy by determining of the cerebrospinal fluid bilirubin levels inneonatal and to analyze the relationship between MRI signal and brainstem auditoryevoked potential changes and bilirubin encephalopathy by examining the skull MRIand brainstem auditory evoked potential, and to provide an important basis for earlydiagnosis and prognosis predication of neonatal bilirubin encephalopathy.Methods134cases with bilirubin encephalopathy and37cases with non-bilirubinencephalopathy as control group were chosen from February2011to October2012.Compare with the concentrations of unconjugated bilirubin in cerebrospinal fluid andunconjugated bilirubin in serum of two groups. According to the ROC curve, analyzetheir critical value, sensitivity, specificity, positive predictive value and negativepredictive value in the diagnosis of bilirubin encephalopathy.2According to the skull MRI and BAEP examination, the subjects were divided intonormal MRI group and abnormal MRI group, BAEP normal group and abnormalBAEP group, and to compare the differences in birth weight, age, weight, gestationalage, cerebrospinal fluid bilirubin levels and serum bilirubin levels between the groupsand to analyze the relationship between the bilirubin encephalopathy and skullMRI changes, as well as BAEP changes. 3To compare the differences of NBNA scores between the bilirubin encephalopathygroup and non-bilirubin encephalopathy group.4SPSS13.0software was employed for statistical analysis of data, the measurementdatas were expressed in mean±standard deviation(x±S), the comparison between thetwo groups employed independent sample t-test, the sample composition ratio or ratecompared emoployed the chi-square test, P <0.05was considered to be statisticalsignificant. To determine the critical value, sensitivity, specificity, positive predictivevalue and negative predictive value of cerebrospinal fluid unconjugated bilirubin levelsand serum unconjugated bilirubin levels in the diagnosis of bilirubin encephalopathyby drawing the ROC curve. The pearson correlation analysis was performed for theindirect bilirubin levels in cerebrospinal fluid and in serum.Result1The cerebrospinal fluid unconjugated bilirubin in the bilirubin encephalopathygroup,(13.88±5.03) μmol/L, was significantly higher than what in the controlgroup,(5.83±4.30) μmol/L, the difference was statistical significant (t=6.957,P<0.01).According to the ROC curve, the area under the ROC curve of cerebrospinalfluid unconjugated bilirubin (0.909) was greater than that of serum unconjugatedbilirubin (0.692). When the critical value was9.55μmol/L, the diagnostic sensitivityand specificity of cerebrospinal fluid unconjugated bilirubin for bilirubinencephalopathy was86.7%and93.9%, respectively. There was no correlation betweenthe cerebrospinal fluid indirect bilirubin level and serum indirect bilirubinlevel (r=0.142,P>0.05).2Basic clinical information comparison between the normal MRI group and abnormalMRI group, there were no statistical differences found in the in birth weight, age,admission weight, gestational age. Compared with normal skull MRI group, all thelevels of cerebrospinal fluid indirect bilirubin, cerebrospinal fluid total bilirubin, serum indirect bilirubin, serum total bilirubin in the abnormal skull MRI group were higher,and the differences were statistical significant (t=3.874,4.523,3.074,3.104,all P<0.05)The incidence rate of abnormal skull MRI in the bilirubin encephalopathy group washigher than that in the non-bilirubin encephalopathy group,the difference was statisticalsignificant(P<0.05).3Basic clinical information comparison between the normal BAEP group andabnormal group, there were no statistical differences found in the in birth weight, age,admission weight, gestational age. Compared with normal BAEP group, all the levelsof cerebrospinal fluid indirect bilirubin, cerebrospinal fluid total bilirubin, serumindirect bilirubin, serum total bilirubin in the abnormal BAEP group were higher, andthe differences were statistical significant(t=3.015,3.641,4.424,4.475,all P<0.05). Theincidence rate of abnormal BAEP in the bilirubin encephalopathy group was higherthan that in the non-bilirubin encephalopathy group, the difference was statisticalsignificant (P <0.05).4Newborn NBNA score comparison between the bilirubin encephalopathy group andnon-bilirubin encephalopathy group, we found that the NBNA scores of bilirubinencephalopathy group was less than that in the non-bilirubin encephalopathy group,and the difference was statistical significant(t=-3.132,P<0.05).ConclusionThe cerebrospinal fluid unconjugated bilirubin levels could be used as a sensitiveindicator for early diagnosis of neonatal bilirubin encephalopathy, and to combinewith BAEP and skull MRI examination, there will be conducive to the early diagnosisand prompt treatment of bilirubin encephalopathy and to reduce the sequelaes ofbilirubin encephalopathy.