Role of surfactant inhibitors in amniotic fluid in respiratory distress syndrome

Total serum bilirubin levels during the first 2 days of life and subsequent neonatal morbidity in very low birth weight infants: a retrospective review

To determine the relationship between total serum bilirubin (TSB) during the first 2 days of life and subsequent neonatal morbidity in very low birth weight (VLBW, less than 1500 g) infants. We performed a prospective study of 582 VLBW infants born between July 1, 2005 and December 31, 2009. TSB was measured in umbilical cord blood (UCB), at 24 and 48 h after birth. Demographic and clinical characteristics of infants in hospital were recorded. The interaction between TSB variables during the first 48 h of life and subsequent neonatal morbidity were assessed in logistic regression analyses adjusted for multiple risk factors. It was found that TSB in UCB was in a negative correlation with occurrence of respiratory distress syndrome (RDS) [OR 0.626, 95% confidence interval (95% CI): 0.446-0.879, p = 0.007], and there was also a negative correlation between TSB in UCB and occurrence of intraventricular hemorrhage (IVH) [OR 0.695, 95% CI 0.826-0.981, p = 0.020]. However, TSB in UCB positively correlated with hyperbilirubinemia [OR 2.471, 95% CI 1.326-3.551, p = 0.012], and TSB at 24 h after birth was also in a positive correlation with early onset sepsis (EOS) [OR 1.299, 95% CI 1.067-1.582, p = 0.011]. VLBW infants with low TSB levels in UCB were more likely to develop RDS and IVH, and those with low TSB levels in UCB were less likely to develop hyperbilirubinemia. Infants with high TSB levels at 24 h after birth were more likely to develop EOS. The protective effect of raised TSB in UCB with respect to RDS and IVH warrants further investigation.

Total serum bilirubin level in umbilical cord blood and respiratory distress syndrome in very low birth weight infants

AIMS

To explore the association between total serum bilirubin (TSB) level in umbilical cord blood (UCB) and the occurrence and/or severity of respiratory distress syndrome (RDS) in very low birth weight (VLBW) infants.

METHODS

We performed a prospective study of 579 VLBW infants. The mean TSB level in UCB (1.8 mg/dL) was used to divide the cohort into two groups: neonates with levels <1.8 mg/dL and those with levels >1.8 mg/dL. Demographic and clinical characteristics of the 2 groups, including diagnosis of RDS, need for ventilation, peak fraction of inspired oxygen (FiO2), oxygenation index (OI), and duration of respiratory support, were compared.

RESULTS

Three hundred and twenty-four infants were included in the low-TSB group and 255 infants were included in the high-TSB group. RDS was less frequent in the high TSB group than in the low one (46.3% vs. 56.6%, P=0.01). A negative association between TSB level in UCB and the occurrence of RDS [odds ratio (OR)=0.620; 95% confidence interval (CI) 0.440-0.873, P=0.006] was observed. However, lower TSB in UCB was not associated with the maximum FiO2, OI, or duration of mechanical ventilation.

CONCLUSIONS

VLBW infants with low TSB levels in UCB were more likely to develop RDS. However, in conjunction with surfactant replacement therapy, no correlation was found between TSB levels in UCB and the severity of RDS. The negative association between high TSB in UCB and RDS warrants further investigation.