OBJECTIVETo investigate the value of urinary S100B protein and lactate/creatinine ratio determination in early identification of neonatal hypoxic-ischemic encephalopathy (HIE).

METHODSThe levels of urinary S100B protein and urinary lactate/creatinine ratio were detected in 58 full-term newborn infants with HIE on the first, second and third day after birth. The severity of clinical manifestations, including the degree of encephalopathy, was assessed within 7 days after birth. Twenty five normal neonates were enrolled into the control groups.

RESULTS(1) The urinary S100B level of HIE neonates was significantly higher in samples collected throughout the monitoring period than those of the normal control groups (all P < 0.001). The urinary lactate/creatinine ratio of the HIE neonates was also significantly higher than that of normal control groups within the first day (P < 0.001). (2) A significantly positive correlation was found between the level of urinary S100B protein within three days and the urinary lactate/creatinine ratio within the first day and between the level of urinary S100B protein within three days and clinical degree (P < 0.05). (3) When S100B concentration was 0.47 microg/L and urinary lactate/creatinine ratio was 0.55, the sensitivity and specificity of detecting the third day urinary S100B alone, were respectively 90.4%, 91.9%. Detecting it associated with the first day urinary lactate/creatinine ratio could increase the sensitivity and specificity (respectively 98.8% and 97.4%) for predicting development of HIE.

CONCLUSIONOn the basis of clinical manifestations of asphyxic neonatals, detecting the level of urinary S100B within three days and the first day urinary lactate/creatinine ratio may be of important value in early diagnosis and grading of HIE.