研究背景 意识水平、麻醉深度和疼痛水平很难在儿科患者中进行客观真实的表达和评估。随着神经生物和脑电技术的发展，儿科患者的脑电监测有了新的研究进展。作为可以直接反映大脑皮层电活动的监测方式，经处理的脑电监测在评估意识水平、监测麻醉深度和反映疼痛水平方面有了新的舞台。患者状态指数PSI、爆发抑制率SR和睡眠脑电监测PSG开始逐渐在儿科人群中应用和推广。但由于缺乏基础的人群数据，针对儿科患者的相关研究受到较大的影响和限制。

研究目的 研究一：观察不同年龄组的儿科患者全麻过程中PSI的变化规律，评估PSI作为辨别不同麻醉阶段观察指标的可行性，比较不同年龄组间PSI的差异，并分析全麻下儿科患者PSI的影响因素。研究二：观察爆发抑制在学龄前患儿全麻过程中的发生和分布情况，比较不同年龄组间SR的差异，分析全身麻醉下儿科患者SR的影响因素。研究三：比较儿科患者术后不同镇痛方案对术后当晚的脑电睡眠分期的影响，评估术后睡眠脑电反映儿科患者的术后镇痛效果的可行性。

研究方法 研究一：242名全身麻醉下行择期手术的学龄前儿童分为0-3月、3-12月和1-7岁三组，记录患儿的一般情况，包括身高、体重、性别、年龄、手术类型及ASA分级。从入手术室后即刻开始全程监测PSI。使用七氟烷吸入诱导，七氟烷复合瑞芬太尼麻醉维持。全麻过程按“清醒”、“诱导”、“浅麻醉”（0.2-0.5MAC）、“中麻醉”（0.6-1MAC）、“停药”、“自主呼吸恢复”和“拔管”分为7个事件段，记录相应的事件段内的心率、血压均值和PSI的均值、最大值、最小值和变化范围（最大值与最小值的差值）。在三个年龄组内，分别比较不同事件段内的PSI的均值、最大值、最小值和变化范围，相邻事件间的PSI进行ROC曲线分析并计算曲线下面积。在三个年龄组间比较相同事件段内的PSI的均值、最大值、最小值和变化范围。建立多水平模型分析学龄前儿童全麻下PSI的影响因素。

研究二：对0-3月、3-12月和1-7岁三组共242名患者在七氟烷全身麻醉下的择期手术中全程进行SR监测。使用七氟烷吸入诱导，七氟烷复合瑞芬太尼麻醉维持。按照“清醒”、“诱导”、“浅麻醉”（0.2-0.5MAC）、“中麻醉”（0.6-1MAC）、“停药”、“自主呼吸恢复”和“拔管”7个事件分段，计算相应事件段内的心率、血压均值和SR的均值和最大值。在三个年龄组内，比较各个事件段内的SR值，分析不同事件段内SR>2即‘爆发抑制持续超过1秒’的发生率，并对麻醉事件内出现SR最大值的发生率进行统计。在三个年龄组间，比较相同事件段内的SR最大值。建立多水平模型分析学龄前儿童全麻下SR的影响因素。

研究三 全麻下行择期手术，术后需要使用静脉镇痛泵的56名1-10岁儿童进行随机分为两组，术后静脉持续泵注右美托咪定0.3 ug/kg/h加舒芬太尼0.04 ug/kg/h镇痛的DEX组和单纯泵注舒芬太尼0.04 ug/kg/h镇痛的SUF组。患儿术后转到外科重症监护室，即刻行心电图、血压和脉搏血氧饱和度的持续监测和记录，直到转至普通病房。从手术当天晚上8:00到第二天早上8:00，使用SONMO手表的脑电图（EEG）记录系统（SOMNO medicis GmbH）进行多导睡眠监测（PSG）。记录所有术后镇痛的并发症包括呼吸抑制、低氧血症、心动过缓、低血压、恶心和呕吐。比较两组患儿间PSG睡眠结构的差异和不良反应的发生情况。

研究结果 研究一：三个年龄组内，PSI在不同麻醉事件中的均值和最小值差异显著，可反映全麻变化趋势。1-7岁患儿从“停药”开始，PSI判断不同麻醉状态的准确性较高。三个年龄组间，相同事件内的PSI均值、最大值、最小值以及变化范围的差异有统计学意义。年龄越小，相同事件下PSI的数值越小，变化范围越大。多水平模型分析PSI的影响因素包括心率、体重和不同麻醉事件即药物不同浓度。

研究二：三个年龄组内，0-3月组全程无SR的患儿为6.5%，不同麻醉事件间的SR差异显著，91.3%的患儿在“中麻醉”期出现SR>2的情况，而SR最大值出现在“中麻醉”事件中的发生率最高，占到64.5%。SR呈现出随药物浓度增加而升高的趋势。3-12月组全程无SR的患儿占47.5%，“中麻醉”期的SR值与其他事件段差异显著，35.4%的患儿在“中麻醉”期出现SR>2的情况，SR最大值发生率最高出现在“中麻醉”期，占到34.3%。1-7岁无SR的患儿占比为74.5%，“诱导”期的SR与其他事件段差异显著，12.5%的患儿在“诱导”期出现SR>2的情况，而SR最大值发生率最高也在“诱导”期，占12.2%。 不同年龄组间相同事件段内SR>2和SR最大值的发生率均有显著差异。

研究三：与单纯泵注舒芬太尼的SUF组相比，术后镇痛为右美托咪定复合舒芬太尼的DEX组患儿术后当晚的睡眠结构浅睡眠和深睡眠的时长延长，快速动眼睡眠的时长和占比减少。睡眠碎片时长和碎片指数更高。睡眠脑电监测可间接反映儿科患者术后镇痛效果。

结论 研究一：全麻过程中的PSI指数变化趋势可反映麻醉深度的变化，在监测麻醉深度和指导临床用药方面有一定的优势。但在不同年龄段内呈现不同的数值分布和变化特点，在临床应用中的影响因素较多，因此在精确反映麻醉深度方面尚需更细的混杂因素和年龄分组研究。

研究二：爆发抑制在全麻的儿科患者中普遍存在，不同年龄段的患儿SR有显著差异，且分布规律不同。年龄越大，全麻下SR发生率越低，SR值越小。1岁以下患儿SR可能随麻醉药物浓度增大而升高，1岁以上的患儿在诱导期更易出现SR>2。因此对于1岁以下的婴幼儿应更关注麻醉药物用量。

研究三：睡眠脑电监测可观察到术后各个睡眠周期的时长和占比的改变、觉醒次数、碎片时长和指数等情况的变化。复合右美托咪定的术后镇痛方案对儿科患者手术当晚的睡眠分期可产生一定影响。提示可通过术后的睡眠脑电监测间接评估儿科患者术后镇痛效果，帮助进一步优化镇痛方案。

总结：脑电监测在儿科麻醉中的应用前景非常广阔，应引起更多关注并进行更多的基础观察和大样本对照研究。

Background It is difficult to express and evaluate the levels of consciousness, anesthesia depth, and pain in pediatric patients objectively and truthfully. With the development of neurobiology and  technology, there has been new research progress in electroencephalogram EEG monitoring of pediatric patients. As a monitoring method that can directly reflect the electrical activity of the cerebral cortex, the application of processed EEG monitoring has a new stage in assessing the level of consciousness, monitoring the depth of anesthesia and reflecting the level of pain. Patient status index (PSI), burst suppression rate (SR), and polysomnography (PSG) are gradually being promoted in the pediatric population. However, due to the lack of basic population data, research on pediatric patients has been greatly affected and limited.

Purpose Study 1: Observe the changes in PSI during general anesthesia in pediatric patients of different age groups, evaluate the feasibility of PSI as an observational indicator for distinguishing different stages of anesthesia. Compare the differences in PSI between age groups and analyze the influencing factors of PSI under general anesthesia.

Study 2: Observing the occurrence and distribution of burst suppression during general anesthesia in preschool children, comparing the differences in SR among different age groups, and analyzing the influencing factors of SR during general anesthesia.

Study 3: Compare the effects of different postoperative analgesic prescriptions on the PSG of pediatric patients on the night after surgery and analyze the feasibility of reflecting the analgesic effect of pediatric patients through postoperative PSG monitoring.

Methods Study 1: 242 preschool children undergoing elective surgery under general anesthesia were divided into three groups: 0-3 months, 3-12 months, and 1-7 years old. The general information including height, weight, gender, age, surgical type, and ASA grade, was recorded. Monitor PSI throughout the entire process immediately after entering the operating room. Sevoflurane inhalation induction was used, and sevoflurane combined with remifentanil was mainly used to maintain anesthesia. The general anesthesia process is divided into 7 event segments according to "awake", "induction", "shallow anesthesia" (0.2-0.5MAC), "moderate anesthesia" (0.6-1MAC), "withdrawal", "spontaneous respiratory recovery", and "extubation". The corresponding event segments are recorded for the mean in heart rate and blood pressure ,and the mean, maximum, minimum, and range of changes(the difference between the maximum and minimum values) in PSI. Compare the mean, maximum, minimum, and range of changes of PSI within different event segments within three age groups. Perform ROC curve analysis on PSI between adjacent events and calculate the area under the curve. Compare PSI within the same event segments among three age groups. Establish a multi-level model to evaluate the influencing factors of PSI under general anesthesia in preschool children.

Study 2: 242 patients in three groups of 0-3 months, 3-12 months, and 1-7 years old underwent SR monitoring throughout the elective surgery under general anesthesia. Sevoflurane inhalation induction and sevoflurane combined with remifentanil maintenance was used. Calculate the mean values of heart rate and blood pressure, the mean  and maximum vales of SR within the corresponding event segments based on 7 event segments: "awake", "induction", "shallow anesthesia" (0.2-0.5MAC), "moderate anesthesia" (0.6-1MAC), " withdrawal", "spontaneous respiratory recovery", and "extubation". Within three age groups, analyze the incidence of SR>2 in different event segments, compare the SR values within each event segment, and analyze the anesthesia events corresponding to the SRmax value. Compare the SRmax values within the same event segments among three age groups. Establish a multi-level model to evaluate the influencing factors of SR under general anesthesia in  preschool children.

Study 3: 56 children aged 1-10 years who used intravenous analgesia pump after elective surgery under general anesthesia were randomly divided into two groups: continuous intravenous infusion of dextrometomidine 0.3 ug/kg/h plus sufentanil 0.04 ug/kg/h analgesia and  intravenous infusion of sufentanil 0.04 ug/kg/h analgesia. After the operation, children were transferred to the surgical intensive care unit, the ECG, blood pressure and pulse oxygen saturation were continuously monitored and recorded until transferred to the general ward. From 8:00 pm on the day of surgery to 8:00 am the next day, polysomnography (PSG) was performed using the SONMO watch's electroencephalogram recording system (SOMNO media GmbH). All complications of postoperative analgesia including respiratory depression, hypoxemia, bradycardia, hypotension, nausea and vomiting were recorded. Compare the differences in the sleep structure of PSG and the occurrence of adverse reactions between the two groups of children.

Results Study 1: There were significant differences in the mean and minimum values of PSI among different anesthesia events in three age groups, which can reflect the trend of general anesthesia changes. The accuracy of PSI as an index for guiding different anesthesia states is relatively high in children aged 1-7y, starting from "withdrawal" event. There are statistically significant differences in the mean, maximum, minimum, and numerical range of PSI within the same event among the three age groups. The younger the age, the smaller the value of PSI under the same event, and the larger the range of variation. The influencing factors of PSI analyzed by a multi-level model include heart rate, body weight, and different anesthetic events, i.e. different concentrations of drugs.

Study 2: Within the three age groups, 6.5% in the 0-3month group had no SR throughout the entire process, and there was a significant difference in SR between different anesthesia events. 91.3% of children experienced SR>2 during the "moderate anesthesia", with the highest incidence of SR occurring during the "moderate anesthesia", accounting for 64.5%. 47.5% of children in the 3-12month group had no SR. The SR value during the "moderate anesthesia" was significantly different from other event segments, with 35.4% of children experiencing SR>2 during the "moderate anesthesia", and the highest incidence of SR occurred during the "moderate anesthesia" event, accounting for 34.3%. SR in children under 1 year old shows a trend of variation with changes in drug concentration. 74.5% of children aged 1-7 had no SR, and there was a significant difference in SR between the "induction" period and other event segments. 12.5% of children had SR>2 during the "induction", and the highest incidence of SR was in the "induction", accounting for 12.2%. There were significant differences in the incidence of SR>2 and SRmax within the same event segments among different age groups.

Study 3: When the postoperative analgesia was dextmedetomidine combined with sufentanil, the duration of light sleep and deep sleep was prolonged, and the duration and proportion of REM sleep were reduced. Sleep fragmentation duration and fragmentation index are higher.

Conclusion Study 1: The trend of PSI index changes during general anesthesia can reflect the changes in anesthesia depth and has certain advantages in monitoring depth and guiding clinical medication. However, there are different numerical distributions and changes within different age groups, and there are many influencing factors in clinical applications. Therefore, more detailed confounding factors and age grouping studies are needed to accurately reflect the depth of anesthesia.

Study 2: Burst suppression is commonly present in pediatric patients under general anesthesia, with significant differences in SR among different age groups and varying distribution patterns. The older the age, the lower the incidence and value of SR under general anesthesia. Children under 1 year old may experience SR as the concentration of anesthetic drugs increases, while children over 1 year old are more likely to experience SR>2 during the induction period. Therefore, for infants and young children under 1 year old, more attention should be paid to the dosage of anesthetic drugs.

Study 3: PSG monitoring can observe changes in the duration and proportion of each sleep cycle, awakening frequency, fragment duration, and index of pediatric patients after surgery. The postoperative analgesic regimen of compound dexmedetomidine can have a certain impact on the sleep staging of pediatric patients on the night of surgery. It is suggested that postoperative PSG monitoring can indirectly evaluate the effectiveness of postoperative analgesia in pediatric patients, helping to further optimize the analgesic plan.