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.

 
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