Analysis Of Amplitude-integrated EEG Changes Before And After Mild Hypothermia In Moderate And Severe Hypoxic-ischemic Encephalopathy

Objective:To analyze the background patterns and sleep-wake cycles(SWC)on amplitude-integrated electroencephalography(a EEG)neonates with moderate and severe hypoxic-ischemic encephalopathy(HIE)before and after mild hypothermia,in order to explore the efficacy of mild hypothermia(MH)in treating the neonates and to evaluate the severity of HIE.Methods:Totally 79 neonates with moderate to severe HIE in Neonatal Intensive Care Unit(NICU)from Mar.2015 to Feb.2017 were retrospectively analyzed.Neonates of HIE were divided into 2 groups according to the clinical graduation of HIE,namely the moderate HIE group(41cases)and the severe HIE group(38cases),and then they were divided into the conventional treatment group of the moderate HIE group(Group A 19cases),MH treatment group of the moderate HIE group(Group B 21cases),the conventional treatment group of the severe HIE group(Group C 20cases),MH treatment group of the severe HIE group(Group D 18cases)according to before and after MH therapeutic apparatus was used by NICU of The first hospital of Jilin University.The patients in each group were measured respectively by using the amplitude integrated electroencephalography(a EEG)before MH treatment and on one week after MH treatment.Results:1.There were no statistical differences between Group A,group B,group C and group D in gestational age,birth weight,sex,delivery mode,1-minute Apgar score,5-minute Apgar score,mechanical ventilation,amniotic fluid,placenta,umbilical cord,risk factors for antepartum and intrapartum period(p> 0.05).2.In the moderate HIE group,the continuous voltage in the background activity increased and the sleep awakening cycle was more mature than that before the conventional treatment(p<0.05).In the moderate HIE group,the continuous voltage increased,the incidence of SA decreased,the SWC was more mature,the amplitude of the lower border was shifted,and the total score of a EEG were higher than those before mild hypothermia(p <0.05).3.Compared with the moderate group,there was significant difference in the background activities in severe HIE group(p <0.05),but there was no significant difference in the other aspects of a EEG.In the severe HIE group,the incidence of the continuous voltage increased,and the incidence of the discontinuous voltage decreased,and the SWC was more mature(p <0.05).4.Compared with the moderate group,the continuous voltage reduced,partial continuous voltage,discontinuous voltage,FT,SA and the loss rate of SWC increased(p <0.05)in the severe group.5.In the a EEG score,the SWC,the lower border amplitude,total score of the moderate group increased after conventional treatment(p <0.05).In group B,after mild treatment,the continuous voltage,SWC and bandwidth combined with lower boundary and the total score were higher than those before treatment(p <0.05).In Group C,the continuous voltage,SWC and total score were significantly higher than those before treatment(p <0.05).The continuous voltage,SWC,the lower border amplitude and bandwidth combined with lower boundary were significantly higher than those before treatment(P <0.05).6.The SWC,bandwidth combined with lower boundary,the total score of the severe group before treatment were significantly lower than those of the moderate HIE group(p <0.05).Conclusions:1.The abnormal a EEG changes of neonates with moderate and severe HIE show a decreased continuity in voltage,a lack of SWCs and a high rate of SA.2.There is an association between the changes of background patterns,SWCs and the extent of HIE in neonates.With the higher degree of HIE,discontinuous voltage pattern,loss rate of SWCs and SA increased obviously,even repeated or persistent seizures appeared,and the incidence of FT and CLV increased.3.a EEG scores are associated with the severity of HIE,and neonates with severe HIE have lower a EEG scores.4.In neonates with moderate HIE,a EEG got improved in terms of the background activity,SA and SWC after mild hypothermia,and the improvement in background activity is superior to conventional therapy.In neonates with severe HIE,a EEG improved in the background activity and SWC after mild hypothermia,but there is little difference in a EEG improvement.5.In neonates with moderate hypoxic-ischemic encephalopathy,the voltage continuity,sleep arousal cycle,bandwidth bound,total score got improved after mild hypothermia,and the improvement in sleep awakening cycle and total score is superior to conventional therapy.In neonates with severe hypoxic-ischemic encephalopathy,the items all got improved after mild hypothermia,and the improvement in the lower border amplitude is higher than conventional treatment.