Research for critical concentration
of serum bilirubin on nerval toxicity in premature infants
Lu H, Chen KZ, Huang XH, Zhang Z
Guangzhou Children's Hospital,
Guangzhou, China
Objective: to explore the critical
value of serum bilirubin (SB) impairing center nerve cell, and these
factors of influencing critical value of SB.
Methods: 129 premature infants with
hyperbilirubinemia were admitted in our hospital between Jan. 1997 and Dec.
1999. With rise of value of SB, that brainstem auditor induced potential
(BAP) became abnormal, it was the mark of impairment of center nerve cell.
Concentration of SB was assayed and BAP was detected, when these infants
were admitted. Then that were monitored once every day untill the patient's
BAP was abnormal, the value of SB was recorded, meanwhile, gestation age
(GA), birth weight, concentration of serum albumin and pH were recorded.
Results: For all of 129 infants, the
critical value of total SB was 189.36±24.29umol/L, the critical value of serum unconjugated bilirubin
(SUB) was 177.41±27.23umol/L. For these infants whose GA was lower than 32 weeks,
~34 weeks, ~<37 weeks, the critical value of SUB were respectively 154.67±28.92 umol/L, 161.61±16.06 umol/L and 173.76±19.22 umol/L. Bivariate
correlate analysis indicated that GA, birth weight, concentration of serum
albumin and pH correlative significantly with the critical value. While
partial correlative analysis indicated other three factors correlate
significantly with the critical value, besides GA.
Conclusion: Results showed the
critical value of SB is lower distinctly than the traditional diagnostic
criterion of pathologic jaundice. The GA was lower, the critical value was
lower. That suggested we should interfere as early as possible in premature
infant with hyperbilirubinemia, for preventing bilirubin-cncephalopathy.
Low birth weight, hypoalbuminemia and acidosis could increase the risk of
nerval toxicity of bilirubin. Besides to control the concentration of SB,
the best method to decrease the
incidence of bilirubin-cncephalopathy is to reduce incidence of
premature delivery, low birth weight infant and asphyxia.