Amplitude-integrated EEG In Critically Ill Patients With Hypoxic-ischemic Encephalopathy

[Objective]: The study aimed at exploring the application of amplitude integratedelectroencephalography(aEEG) in evaluating the neurological function ofhypoxic-ischemic encephalopathy(HIE) with cardiopulmonary resuscitation(CPR),thecorrelation between the scores of cerebral function, coma and other factors and cerebralcerebral performance category(CPC) in different period, and the contribution withdifferent factors for the score of CPC. At last, we intend to supply an effective andobjective method for monitoring cerebral function in intensive care unit (ICU).[Method]: The experiment is designed with three groups, which are normal controlgroup, abnormal group and study group. The normal group: There are sixty volunteersare recruited to make cerebral function monitoring. Everyong is monitored30minutesand observed the response of open-closing eyes. We choose20pairs coordinate data ofeach channel to analyze. There are8channels to monitor different regions of brain,including frontal, temporal, parietal and central and occipital lobe. We make statisticalanalysis and bulid the range of referenc value.Abnormal group: The group includes23cases, including13cases of viral encephalitis,6tuberculous encephalitis and3dementia. On the basis of results with CEEG, these casesare divided into two groups, including mild-middle group with13cases and severe groupwith10cases. And the time is from30minutes to1hour. At the end, we choose20pairscoordinate data of each channel to make statistical analysis. Contrasting the normalcontrol group, we get the reference value of different diffusion abnormal aEEG, and wemake the standard to evaluate the aEEG,which is prepared for the further study.Study group: There are25hypoxic-ischemic encephalograph patients with CPR. Wemonitor the cerebral function in bedside at the first day, the third day and the seventh dayafter the patients admitted to ICU of the hospital. And each time, we record the scores ofaEEG and GCS-P and the clinical information of each patient. We do follow-upobservation after first and third month, recording the score of CPC. In contrast of thenormal and abnormal group, we make classification for the aEEG of the study group.5means normal,4means mild-middle abnormal,3means severe abnormal,1meanselectrical silence which the worst event and2means other untypical types which isexcluded by above-mentioned,including status epileptics and so on. Recording theresustitation time, age, gender, respiration, the scores of aEEG and GCS-P and the scoreof CPC, we use the SPSS software to make statistic analysis. [Results]:1. In normal group, the comparison between leftside and rightside ofdifferent regions of brain has no statistical difference, and the value of p is larger than0.05. And we get the same result in comparison with different gender. There is statisticaldifference between upper limit within frontal, temporal, parietal and central, andoccipital lobe, which is accounted by analysis of variance, the value of p following F isboth less than0.05. And the same result between lower limit. There is statistical sensebetween the four regions. After opening the eyes, the phenomenon of alpha-suppressionis occurrence.2. In mild and middle abnormal group, there is no significant difference betweenleftside and rightside of the same region of the brain, and all of the value of p is largerthan0.05. And we get the same result in severe group. We use analysis of variance toanalyze the difference of upper limit of the four regions in the same group, and we getthe value of p are both less than0.05, and the same result of lower limit. There is statisticvariance. In contrast of the three groups, there is significant difference, and the value of pis less than0.001.3. We make three months follow-up observation for the patients of the study group.There are14cases of clinical death, and the survival group has four cases with electricsilence, and others have brain waves with abnormal. The three scores of aEEG are notsignificant difference in the analysis of variance, and the value of p is0.485. The threescores of GCS-P have no significant difference yet with p is equal to0.785. Comparativeanalysis of the score of CPC between the first month and the third month, there is nodifference, and the value of p is0.327. And between any two groups comparativeanalysis, the difference has no sense with the p being larger than0.05. There is nostatistical difference between the different groups.4. In the comparative analysis between resuscitation time, age, gender and CPC, weuse the method of Spearman correlation. The result shows that there is no significantcorrelation between the three factors and the score of CPC of the first month and thethird month, and the p is larger than0.05. However, the aEEG, GCS-P and respirationhave correlation with CPC, the value of p is less than0.05. And then we make analysis ofvariance, the p is less than0.05, which means there is linear correlation between theupper three factors and CPC. And then we get the multiple linear regression equation. Wemake multiple regression equation for hypothesis testing, and analyze the coefficient of determination R2and the standard error of regression estimate S. The R2of the equationwith CPC1as the dependent variable is0.601,0.757and0.728respectively. And the S is0.616,0.481and0.509. So, there is60.1percent change of CPC1can be explained by thescores of aEEG, GCS-P and respiration in the first day. So the scores of the third day andthe seventh day can explain the75.7percent and72.8percent of the change of CPC1respectively. And in the same method, we get the R2and S of the equation with CPC3asthe dependent variable. The R2is0.648,0.832and0.696respectively, and the S is0.581,0.401and0.540. So the independent variable can explain64.8percent,83.2percent and69.6percent change of CPC3in different period.[Conclusion]:1. The aEEG within different regions of normal adult are different,and there is significantly stastical variance, and the occipital lobe amplitude is the highest.Both of the frequency and amplitude are changed in diffuse abnormal electrical activity,and we can explain the cerebral function with the change of aEEG.2. The heartresuscitation time is important to patients’ survival status, the sooner recovery ofspontaneous heart rate, the higher the survival rate. However, the resuscitation time hasno significant effect for the neurological function. There is no linear correlation betweenthem.3. There are linear correlation between aEEG, GCS-P and respiration with the CPC.And we can make a forecast of neurological function with the scores of aEEG, GCS-Pand respiration to those who has hypoxic-ischemia encephalopathy after the CPR.4.aEEG is an objective and reliable tool for cerebral function monitoring, which is suitablefor bedside cerebral function monitoring in ICU. And combination of various method canimprove the accuracy of cerebral function monitoring.