Significance of umbilical cord blood gas analysis in evaluating the prognosis of neonates and correlated factors

Abstract

Objective To investigate the value of umbilical artery blood gas analysis on judging neonatal asphyxia and prognosis.Methods Four hundred and fifty-one newborn infants from October 2009 to November 2011 were chose.Blood gas analysis of umbilical artery at birth and radial artery at 1 hour after birth were accessed in all 541 cases ; The arterial blood gas was rechecked if necessary.Clinical data including the gestational age,birth weight,maternal and neonatal conditions,family history,information of occurrence and development of diseases were recorded.The clinical manifestation and laboratory examination to determine the organ dysfunction due to pefinatal asphyxia was observed.Results The reference value of umbilical arterial blood gas analysis:pH 7.21 ± 0.10,PCO2 (59 ± 13)mm Hg(1 mm Hg =0.133 kPa),PO2(14 ±8)mm Hg,HCO3-(23.7 ±2.9) mmol/L,BE(-4.1 ± 3.8)mmoL/L,SO2(15.0 ± 14.6)％.Correlation analysis of high risk factors and umbilical arterial pH indicated that neonates with fetal distress and perverse labor had a significantly lower pH value; preterm infants had a significantly higher pH value.Significant correlation was found between Apgar score at 1 minute after birth and all the parameters of umbilical arterial blood gas.No correlation was found between Apgar score at 5 minute after birth and the parameters of umbilical arterial blood gas except PO2 and SO2.The analytic result indicated that there was correlation between nervous system impairment and all parameters of umbilical arterial blood gas.Impairment of kidney,heart and metabolism was correlated with umbilical arterial pH and PCO2 value.Impairment of lung,digestion and hematological system was only correlated with umbilical arterial pH value.Conclusions There was significant correlation between Apgar score at 1 minute after birth and the umbilical cord blood gas analysis.Both umbilical cord blood gas analysis and Apgar score have diagnostic value in assessing asphyxia-related organs dysfunction,but the sensitivity and specificity were unsatisfied.Combination of umbilical arterial pH value and Apgar score may elevate the predictive value. Key words: Umbilical artery ; Blood gas ; Asphyxia; Neonate ; Prognosis