The Changes Rule Of Amplitude-integrated Electroencephalography In Very Preterm/Extremely Preterm Infants

Objective:To study the changes of amplitude-integrated electroence-phalography?aEEG?in premature infants under 32 weeks,and to analyze the relationship between postmenstrual gestational age?PMA?and brain developmental maturity.Methods:A total of 46 premature infants born at 26-32 weeks gestation:who are admitted to neonatal intensive care unit from January 2018 to December 2018 were recruited in this study,grouped them according to PMA.Divided into 4 groups:PMA 26-28⁺⁶ weeks?n=22?;PMA 29-30⁺⁶ weeks?n=63?;PMA 31-32⁺⁶ weeks?n=75?;PMA 33-35⁺⁶ weeks?n=45?,46 cases of premature infants born under 32 weeks of gestational age record a total of 205aEEG waveforms.The changes of aEEG waveforms in each group were analyzed to explore the changes with PMA.Re-grouping the preterm infants with the same gestational age and postmenstrual gestational age,divided into3 groups,namely gestational age 26-27⁺⁶ weeks,28-29⁺⁶ weeks and 30-31⁺⁶weeks.Comparing the scores of aEEG,and to judge the relationship between the PMA and the maturity of brain development.Results:?1?The changes of aEEG in preterm infants with gestational age less than 32 weeks:?1?Continuity and Sleep-wake cycle:with the increase of PMA,the proportion of continuous voltage and sleep-wake cycle gradually increased.?2?Amplitude of lower border and Bandwidth:As the PMA increasing,the amplitude of the lower bound gradually increased and the bandwidth gradually narrowed.Among them,the amplitude less than 3?V results showed that the PMA 26-28⁺⁶ weeks compared with the PMA 29-30⁺⁶weeks showed a statistically significant difference?P<0.05?,and the other two groups showed P>0.05,no statistical significance.The amplitude 3-5?V results showed that PMA 26-28⁺⁶ weeks and PMA 29-30⁺⁶ weeks,PMA 31-32⁺⁶weeks compared with PMA 33-35⁺⁶ weeks,the difference was statistically significant?P<0.05?.The amplitude greater than 5?V results showed that there was statistical significance between the groups?P<0.05?.When the bandwidth was greater than 20?V,the difference between PMA 26-28⁺⁶ weeks and PMA29-30⁺⁶ weeks,PMA 29-30⁺⁶ weeks and PMA 31-32⁺⁶ weeks was statistically significant?P<0.05?.The results of bandwidth of 15-20?V and less than 15?V showed no significant difference between the week of PMA 26-28⁺⁶ and PMA29-30⁺⁶?P>0.05?,and the results of the other two groups were statistically significant?P<0.05?.?2?The relationship between PMA and brain developmental maturity:?1?With the increase of PMA,the brain development gradually matured.The aEEG results showed that the score of every parameter and total scores of aEEG gradually increased,and there was a significant positive correlation between each parameter and PMA?P<0.05?.?2?The preterm infants enrolled in the same birth gestational age and postmenstrual gestational age were regrouped into three groups,namely gestational age 26-27⁺⁶ weeks,28-29⁺⁶weeks and 30-31⁺⁶ weeks,and their aEEG total scores were compared.The results showed that in the three groups,the total score of aEEG in the premature infants of the postmenstrual gestational age group was higher than that in the gestational age group,and the aEEG scores between the two groups were statistically significant at 28 weeks or more?P<0.05?.Conclusions:?1?The changes of aEEG in very preterm/extremely preterm infants have a certain regularity.With the increase of PMA,the voltage continuity increasing,the sleep-wake cycle appearing,the lower boundary amplitude increasing,and the bandwidth narrowing.?2?In very preterm/extremely preterm infants,continuous voltage and sleep-wake cycle can be observed at 26 weeks of PMA.Before PMA 29weeks,EEG activity is inhibited to varying degrees,showing lower boundary voltage??5?V?or low amplitude??15?V?,after 33 weeks of PMA,EEG activity tends to mature.?3?For the determination of brain maturity in very preterm/extremely preterm infants,it is necessary to comprehensively consider the four indicators of continuity,sleep-wake cycle,lower boundary amplitude and bandwidth.The interpretation of single index may lead to error in results.?4?PMA and the scores and total scores of aEEG have a good positive correlation.The brain developmental maturity of very preterm/extremely preterm infants is closely related to PMA.?5?Extrauterine life can accelerate the brain development in very preterm/extremely preterm infants.It can improve the extrauterine survival environment,reduce brain damage,and improve the prognosis of very preterm/extremely preterm infants.