| BackgroundAt present,it is common in China to diagnose neonatal asphyxia by Apgar score alone,and its limitation has become increasingly obvious,and the diagnostic status is far from that of developed countries.Combined with the international guidelines for resuscitation of neonatal asphyxia,the diagnostic standard of neonatal asphyxia is based on Apgar score combined with umbilical artery pH value(potential of hydrogen,pH).At present,there are few studies on umbilical artery and vein blood gas in China.Umbilical vein blood gas analysis can be combined with neonatal asphyxia to provide a basis for finding the cause of neonatal asphyxia.This study further studied the characteristics of umbilical artery and vein blood gas analysis and its relationship with neonatal asphyxia in order to provide a basis for the diagnosis of neonatal asphyxia and analysis of the cause of asphyxia.Objective1.To study the statistical reference range of umbilical artery and vein blood gas analysis and its clinical application in neonatal asphyxia.2.To study the correlation between umbilical artery and vein blood gas analysis and Apgar score,and to study the risk factors and diagnostic criteria of neonatal asphyxia and prognosis of neonatal asphyxia.MethodsThis study retrospectively analyzed 424 cases of parturients and 427 cases of newborns delivered in the obstetrics department of the sixth affiliated Hospital of Guangzhou Medical University from January 2020 to March 2021,including 427 cases of umbilical artery blood gas analysis and 87 cases of umbilical artery and vein blood gas analysis.To analyze the parameter range of umbilical artery and vein pH(potential of hydrogen,pH),PO2(partial pressure of oxygen,PO2),PCO2(partial pressure of carbon dioxide,PCO2)BE(Buffer excess,BE),Lac(lactic acid,Lac)and HCO3-(bicarbonate radical,HCO3-)in 1 minute Apgar>7 minutes,to study the relationship between umbilical artery and vein blood gas analysis,1 minute Apgar score and neonatal asphyxia,and to study the risk factors of neonatal asphyxia by multivariate logistic regression analysis.The consistency of 1 minute Apgar score,umbilical artery pH,1 minute Apgar score combined with umbilical artery pH was analyzed to study the best diagnostic criteria of neonatal asphyxia;study the prognosis of neonatal asphyxia.Results1.Umbilical artery and vein blood gas analysis of newborns with 1 minute Apgar score>7.1.1 The results of umbilical artery blood gas analysis in 385 patients with 1 minute Apgar score>7 were as follows:pH:7.25±0.09(mmHg),PaO2:24.43±11.21(mmHg)PaCO2a:55.27±13.82(mmHg),BE:-3.37±4.22(mmol/L),Lac:4.57±2.57(mmol/L),HCO3-:24.16±4.13(mmol/L).1.2 The results of umbilical vein blood gas analysis in 82 patients with 1 minute Apgar score>7 were as follows:pH:7.31±0.06,PaO2:33.10±11.21(mmHg),PaCO2:44.87±10.10(mmHg),BE:-2.94±4.35(mmol/L),HCO3-:24.26±4.97(mmol/L).2.Relationship between umbilical artery and vein blood gas analysis and neonatal asphyxia.2.1 In 427 cases of umbilical artery blood gas analysis,neonatal asphyxia was diagnosed by 1 minute Apgar score<7 and umbilical artery pH<7.20,including 29 cases in asphyxia group and 398 cases in non-asphyxia group.The pH and BE of umbilical artery in asphyxia group were smaller than those in non-asphyxia group(pH:7.07±0.08 vs.7.26±0.07;BE:-10.06±3.61 vs.-2.87±3.87,P<0.05),and the Lac and PC02 of umbilical artery in asphyxia group were larger than those in non-asphyxia group(Lac:8.71±3.10 vs.4.26±2.26;PCO2:71.88±18.05 vs.54.32±12.63,P<0.05).2.2 Among the 87 cases of umbilical vein blood gas analysis,neonatal asphyxia was diagnosed by 1 minute Apgar score ≤7 and umbilical artery pH<7.20,including 4 cases in asphyxia group and 83 cases in non-asphyxia group.The pH and BE of umbilical vein in asphyxia group were smaller than those in non-asphyxia group(pH:7.18±0.03 vs.7.31±0.06;BE:-7.15±3.42 vs.-2.61±4.21,P<0.05),and the Lac and PCO2 of umbilical vein in asphyxia group were larger(Lac:7.62±1.10 vs.3.67±2.30;PCO2:57.23±11.48 vs.44.46+9.50,P<0.05)than those in non-asphyxia group.2.3 Among the 87 cases of umbilical artery and vein blood gas analysis,15 cases were asphyxiated group(umbilical artery pH<7.20)and 72 cases were non-asphyxiated group(umbilical artery pH≥7.20).The pH of umbilical vein in asphyxia group was smaller than that in non-asphyxia group(7.22±0.04 vs.7.32±0.05,P<0.05).The difference of pH and PCO2 in asphyxia group was larger than that in asphyxia group(pH difference:0.10±0.09 vs.0.02±0.05;PCO2 difference:19.89±14.30 vs.5.70±11.36,P<0.05).3.Relationship between 1 minute Apgar and umbilical artery and vein blood gas analysis.3.1 Umbilical artery blood gas analysisAmong the 427 cases of umbilical artery blood gas analysis in this study,asphyxia group(n=47)was asphyxiated according to 1 minute Apgar score ≤7,and non-asphyxia group was defined as 1 minute Apgar score>7(n=380).The pH and BE of umbilical artery in asphyxia group were smaller than those in non-asphyxia group(pH:7.14±0.11 vs.7.27±0.08;BE:-8.03±4.52 vs.-2.78±3.85,P<0.05),and the Lac and PCO2 of umbilical artery in asphyxia group were larger than those in asphyxia group(Lac:7.56±3.22 vs.4.19±2.22;PC02:64.67±18.45 vs.54.38±12.65,P<0.05).3.2 Umbilical vein blood gas analysisIn this study,87 cases of umbilical vein blood gas analysis were divided into asphyxia group with 1 minute Apgar score ≤7(n=6)and non-asphyxia group with 1 minute Apgar score>7(n=81).The pH and BE of umbilical vein in asphyxia group were smaller than those in non-asphyxia group(pH:7.21±0.06 vs.7.31±0.06,P<0.05;BE:-6.50±3.10 vs.-2.55±4.22,P<0.05).The PCO2 of asphyxia group was larger than that of non-asphyxia group(Lac:6.70±2.32 vs.3.64±2.28,P<0.05).3.3 The correlation between 1 minute Apgar and umbilical artery blood gas analysis1 minute Apgar was positively correlated with umbilical artery pH,BE,HCO3-by Spearman analysis(r=0.36,r=0.34,r=0.23,all P<0.05),negatively correlated with Lac and PCO2(r=0.32,r=0.18,P<0.04),and had no correlation with PO2 and SO2(r=0.36,r=0.34,r=0.23,P<0.05),but had no correlation with PO2 and SO2(P>0.05).4.Relationship between mode of delivery,fetal distress and umbilical artery and vein blood gas analysis.4.1 The results of umbilical artery blood gas analysis during fetal distressIn 427 cases of umbilical artery blood gas analysis,there were 168 cases of fetal distress and 259 cases of non-fetal distress.The umbilical artery pH and BE in the fetal distress group were smaller than those in the non-fetal distress group(pH:7.23±0.10 vs.7.27±0.08;BE:-3.93±5.05 vs.-2.99±3.61,P<0.05).The umbilical artery Lac in the fetal distress group was larger(5.23±2.86 vs.4.13±2.28,P<0.05).The incidence of umbilical artery pH<7.2 in the fetal distress group was higher(33.93%vs.20.08%,P<0.05).4.2The results of umbilical vein blood gas analysis in fetal distress.In this study,there were 87 cases of umbilical vein blood gas analysis,41 cases in fetal distress group and 46 cases in non-fetal distress group.There was no significant difference in pH and BE between the two groups.4.3 The effect of delivery mode on umbilical artery blood gas analysisIn 427 cases of fetal distress in this study,there were 168 cases of fetal distress,96 cases of cesarean section,50 cases of vaginal delivery and 22 cases of forceps delivery.The pH and BE of umbilical artery in cesarean section group were larger than those in vaginal spontaneous delivery group and forceps delivery group(pH:7.26±0.08 vs.7.19±0.09,7.20±0.12;BE:-1.99±4.23 vs.-5.97±5.29,-7.75±3.81,P<0.05).The Lac in cesarean section group was smaller than that in cesarean section group(3.87±2.30 vs.7.06±2.80,7.02±1.77,P<0.05).There was no significant difference in pH,BE and Lac of umbilical artery between vaginal spontaneous delivery group and forceps delivery group.5.Comparative analysis of umbilical artery pH,1 minute Apgar and general condition of newborn.Among the 427 cases of umbilical artery blood gas analysis,there were 95 cases of premature rupture of membranes,132 cases of amniotic fluid opacity,82 cases of gestational diabetes mellitus,25 cases of gestational hypertension and 167 cases of umbilical cord around neck.5.1Umbilical artery pHThe group of umbilical artery pH<7.20 was asphyxia group,and the group of umbilical artery pH≥ 7.20 was non-asphyxia group(n=318).The incidence of turbid amniotic fluid,premature rupture of membranes,gestational diabetes mellitus,gestational hypertension and umbilical cord around neck had no significant difference between asphyxia group and non-asphyxia group(P>0.05).5.2 1 minute ApgarIn this study,umbilical artery blood gas analysis showed that 47 patients were asphyxiated in 1 minute Apgar score ≤7,and 380 patients in non-asphyxia group were classified as non-asphyxia group according to 1 minute Apgar score>7.The incidence of amniotic fluid turbidity and gestational hypertension in asphyxia group was higher than that in non-asphyxia group(44.68%vs.29.21%;14.89%vs.4.74%,P<0.05).6.Relationship between risk factors of neonatal asphyxia and umbilical artery blood gas analysis.Umbilical artery blood gas analysis of 427 newborns,1 minute Apgar score ≤7 and umbilical artery pH<7.20 as asphyxia group.Logistic regression analysis show that gestational age is the risk factor of neonatal asphyxia,but umbilical cord factor,premature rupture of membranes,gestational hypertension,gestational diabetes mellitus,turbid amniotic fluid,and preterm delivery are not risk factors(P>0.05).7.Diagnostic criteria for neonatal asphyxia.7.1 1 minute Apgar≤7 combined with umbilical artery pH<7.20 is the diagnostic criteria for asphyxia:1 minute Apgar Kappa value is 0.74,umbilical artery pH<7.20 Kappa value is 0.35,umbilical artery pH<7.15 Kappa value is 0.53(P<0.05).Apgar has the largest Kappa value,the highest specificity and positive predictive value,which is close to the umbilical artery pH<7.15,and the umbilical artery pH<7.20 Kappa value is the smallest,the lowest specificity and positive predictive value;Apgar has the highest Youden index,which is similar to that of the umbilical artery pH<7.20,while the umbilical artery pH<7.15 has the lowest(P<0.05).7.2 1 minute Apgar ≤7 combined with umbilical artery pH<7.15 is the diagnostic criteria for asphyxia,umbilical artery pH<7.20 Kappa value is 0.27,umbilical artery pH<7.15 Kappa value is 0.60,1 minute Apgar score Kappa value is 0.61(P<0.05).1 minute Apgar’s Kappa value,specificity,positive predictive value and Youden index were similar to those of the umbilical artery pH<7.15(P<0.05),umbilical artery pH<7.20 Kappa value,specificity,positive predictive value and Youden index were the lowest(P<0.05).7.3 1 minute Apgar combined with umbilical artery pH<7.15 has higher accuracy and objectivity in diagnosing neonatal asphyxia.The lower the umbilical artery pH,the higher the specificity and the lower the sensitivity.8.Prognosis of neonatal asphyxiaAmong the 427 cases of umbilical artery blood gas analysis,there were 109 cases with umbilical artery pH<7.20,29 cases of asphyxia(1 minute Apgar ≤7 combined with umbilical artery pH<7.20),40 cases of organ damage,425 cases of cured prognosis,and 2 cases of unhealed prognosis,the prognosis was 0 neonatal deaths.In this study,a comparative analysis of neonatal asphyxia,umbilical artery pH<7.20 with organ damage,hospitalization days(hospital days due to neonatal asphyxia and/or organ damage),and prognostic outcome showed that,in the neonatal asphyxia group the incidence of the organs damage and the length of hospital stay were higher than those in the non-asphyxia group(P<0.05);the incidence of organ damage and the number of hospital stays in the umbilical artery pH<7.20 group were higher than those in the umbilical artery pH≥7.20 group(P<0.05);the prognosis of neonatal asphyxia was cured compared with the non-asphyxia group,there was no significant difference between the rate and the non-asphyxia group(P>0.05);the prognostic cure rate of the umbilical artery pH<7.20 group was not significantly different from that of the umbilical artery pH≥7.20 group(P>0.05).Conclusions1.In this study,umbilical cord blood gas analysis pH,PaO2,PaCO2,BE,HCO3-the results of each index are basically the same as those of many large samples at home and abroad.Umbilical cord blood gas analysis has a high Lac,which can be used to diagnose neonatal asphyxia and find the cause of neonatal asphyxia..2.1 minute Apgar is positively correlated with pH,BE,HCO3-of the umbilical artery;negatively correlated with Lac and PCO2;and has no correlation with PO2 and SO2.3.The accuracy and objectivity of the diagnosis of neonatal asphyxia in 1 minute Apgar≤7 combined with umbilical artery pH<7.15 is higher.The lower the umbilical artery pH,the higher the specificity and the lower the sensitivity.The age of pregnant women is a risk factor for neonatal asphyxia;the incidence of organ damage increases during neonatal asphyxia,and the length of hospital stay is prolonged.Neonatal asphyxia is a risk factor for organ damage. |
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