Heart rate variability as a predictor of intraoperative autonomic nervous system homeostasis.

The aim of the proof-of-concept study is to investigate the level of concordance between the heart rate variability (HRV), the EEG-based Narcotrend Index as a surrogate marker for the depth of hypnosis, and the minimal alveolar concentration (MAC) of the inhalation anesthetic sevoflurane across the entire course of a surgical procedure. This non-blinded cross-sectional study recorded intraoperative HRV, Narcotrend Index, and MAC in 31 male patients during radical prostatectomy using the Da-Vinci robotic-assisted surgical system at Mannheim University Medical Center. The degree of concordance was calculated using repeated measures correlation with the R package (rmcorr) and presented using the rmcorr coefficient (rrm). The Narcotrend Index correlates significantly across all measures with the time-dependent parameter of HRV, the standard deviation of the means of RR intervals (SDNN) (rrm = 0.2; p < 0.001), the frequency-dependent parameters low frequency (LF) (rrm = 0.09; p = 0.04) and the low frequency/high frequency ratio (LF/HF ratio) (rrm = 0.11; p = 0.002). MAC correlated significantly negatively with the time-dependent parameter of heart rate variability, SDNN (rrm = -0.28; p < 0.001), the frequency-dependent parameter LF (rrm = -0.06; p < 0.001) and the LF/HF ratio (rrm = -0.18; p < 0.001) and the Narcotrend Index (rrm = -0.49; p < 0.001) across all measures. HRV mirrors the trend of the Narcotrend Index used to monitor depth of hypnosis and the inhibitory influence of the anesthetic sevoflurane on the autonomic nervous system. Therefore, HRV can provide essential information about the homeostasis of the autonomic nervous system during general anesthesia. DRKS00024696, March 9th, 2021.

How Is the Nociceptive Withdrawal Reflex Influenced by Increasing Doses of Propofol in Pigs?

The nociceptive withdrawal reflex (NWR) is a physiological, polysynaptic spinal reflex occurring in response to noxious stimulations. Continuous NWR threshold (NWRt) tracking has been shown to be possibly useful in the depth of anesthesia assessment. The primary aim of this study was to describe how propofol modulates the NWRt over time in pigs. Five juvenile pigs (anesthetized three times) were included. An intravenous (IV) infusion of propofol (20 mg/kg/h) was started, and boli were administered to effect until intubation. Afterwards, the infusion was increased every ten minutes by 6 mg/kg/h, together with an IV bolus of 0.5 mg/kg, until reaching an electroencephalographic suppression ratio (SR) of between 10% and 30%. The NWRt was continuously monitored. For data analysis, the time span between 15 min following intubation and the end of propofol infusion was considered. Individual durations of propofol administration were divided into five equal time intervals for each pig (TI1-TI5). A linear regression between NWRt and TI was performed for each pig. Moreover, the baseline NWRt and slopes of the linear regression (b1) were compared among days using a Friedman Repeated Measures Analysis of Variance on Ranks. The NWRt always increased with the propofol dose (b1 = 4.71 ± 3.23; mean ± standard deviation). No significant differences were found between the baseline NWRt and the b1 values. Our results suggest that the NWRt may complement the depth of anesthesia assessment in pigs receiving propofol.

Tracheal extubation under Narcotrend EEG monitoring at different depths of anesthesia after tonsillectomy in children: a prospective randomized controlled study.

Objective: This study aims to investigate whether tracheal extubation at different depths of anesthesia using Narcotrend EEG (NT value) can influence the recovery quality from anesthesia and cognitive function of children who underwent tonsillotomy. Methods: The study enrolled 152 children who underwent tonsillotomy and were anesthetized with endotracheal intubation in our hospital from September 2019 to March 2022. These patients were divided into Group A (conscious group, NT range of 95-100), Group B (light sedation group, NT range of 80-94), and Group C (conventional sedation group, NT range of 65-79). A neonatal pain assessment tool, namely, face, legs, activity, cry, and consolability (FLACC), was used to compare the pain scores of the three groups as the primary end point. The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scales were used to evaluate the cognitive function of children in the three groups before and after surgery as the secondary end points. Results: Differences were observed in the awakening time and FLACC scores after awakening among the three groups (P < 0.05). Among them, Group A exhibited a significantly shorter awakening time and higher FLACC score after awakening than those in Groups B and C (both P < 0.05). The total incidence of adverse reactions in Group B was significantly lower than that in Groups A and C (P < 0.05). No significant difference was observed in MMSE and MoCA scores before the operation and at 7 days after the operation among the three groups (P > 0.05), but a significant difference was found in MMSE and MoCA scores at 1 day and 3 days after the operation among the three groups (P < 0.05). In addition, MMSE and MoCA scores of the three groups decreased significantly at 1 day and 3 days after the operation than those at 1 day before the operation (P < 0.05). Conclusion: When the NT value of tonsillectomy is between 80 and 94, tracheal catheter removal can effectively improve the recovery quality and postoperative cognitive dysfunction of children.

Alternative sensor montage for Index based EEG monitoring. A systematic review.

The main objective of this systematic review is to assess the reliability of alternative positions of processed electroencephalogram sensors for depth of anesthesia monitoring and its applicability in clinical practice. A systematic search was conducted in PubMed, Embase, Cochrane Library, Clinical trial.gov in accordance with reporting guidelines of PRISMA statement together with the following sources: Google and Google Scholar. We considered eligible prospective studies, written in the English language. The last search was run on the August 2023. Risk of bias and quality assessment were performed. Data extraction was performed by two authors and results were synthesized narratively owing to the heterogeneity of the included studies. Thirteen prospective observational studies (438 patients) were included in the systematic review after the final assessment, with significant diversity in study design. Most studies had a low risk of bias but due to lack of information in one key domain of bias (Bias due to missing data) the overall judgement would be No Information. However, there is no clear indication that the studies are at serious or critical risk of bias. Bearing in mind, the heterogeneity and small sample size of the included studies, current evidence suggests that the alternative infraorbital sensor position is the most comparable for clinical use when the standard sensor position in the forehead is not possible.

Overview and Clinical Applications of Artificial Intelligence and Machine Learning in Cardiac Anesthesiology.

Artificial intelligence- (AI) and machine learning (ML)-based applications are becoming increasingly pervasive in the healthcare setting. This has in turn challenged clinicians, hospital administrators, and health policymakers to understand such technologies and develop frameworks for safe and sustained clinical implementation. Within cardiac anesthesiology, challenges and opportunities for AI/ML to support patient care are presented by the vast amounts of electronic health data, which are collected rapidly, interpreted, and acted upon within the periprocedural area. To address such challenges and opportunities, in this article, the authors review 3 recent applications relevant to cardiac anesthesiology, including depth of anesthesia monitoring, operating room resource optimization, and transthoracic/transesophageal echocardiography, as conceptual examples to explore strengths and limitations of AI/ML within healthcare, and characterize this evolving landscape. Through reviewing such applications, the authors introduce basic AI/ML concepts and methodologies, as well as practical considerations and ethical concerns for initiating and maintaining safe clinical implementation of AI/ML-based algorithms for cardiac anesthesia patient care.

Assessment of seizure duration and utility of using SedLine® EEG tracing in veterans undergoing electroconvulsive therapy: a retrospective analysis.

BACKGROUND: Electroconvulsive therapy (ECT) endures as a definitive treatment for refractory depression and catatonia and is also considered an effective treatment for a number of other severe psychiatric disorders (Lisanby, N Engl J Med 357:1939-1945, 2007)(Weiner and Prudic, Biol Psychiatry 73:105-106, 2013). GA is an essential component of the ECT procedure for various reasons (Lee, Jenkins and Sparkle, Life 11, 2021). Monitoring anesthetic effects on the brain is desirable as anesthetic agents affect seizure duration and recovery (Rasulo, Hopkins, Lobo, et al,  Neurocrit Care 38:296-311, 2023) (Jones , Nittur , Fleming and Applegate,  BMC Anesthesiol 21:105, 2021) (Soehle , Kayser , Ellerkmann and Schlaepfer,  BJA 112:695-702, 2013). Perioperative anesthetic effects on consciousness can be assessed with brain function monitoring using raw electroencephalogram (EEG) traces and processed EEG indices. OBJECTIVE: We examined the usefulness and utility of the SedLine® anesthetic effect monitor during ECT procedures. We hypothesized that the seizure duration as measured by the EEG tracing of the ECT machine is equivalent to the duration assessed by the SedLine® EEG tracing. A secondary objective was to describe the SedLine® patient state indices (PSI) at different phases of treatment. METHODS: Following IRB approval, we analyzed the data of the electronic medical records of 45 ECT treatments of 23 patients in an urban VA medical center between July 01, 2021, and March 30, 2022. We compared the seizure duration in minutes and seconds as measured either by the ECT machine EEG tracing or the SedLine® EEG tracing. We then collected SedLine® processed EEG indices at four different stages during the treatment. Appropriate comparative and observational statistical analyses were applied. RESULTS: There was no significant difference in measured seizure duration between the two methods examined (p < 0.05). We observed a lag of the SedLine PSI value at the time before stimulus delivery and limited PSI utility during the course of ECT. CONCLUSION: The SedLine® EEG tracing can be an alternative to the machine EEG tracing for the determination of seizure duration. The SedLine® processed EEG indices are not consistently useful before and after ECT delivery. Anesthetic effect monitoring during ECT is feasible.

Comparison of post-auricular and frontal bispectral index values obtained during renal surgeries.

BACKGROUND: The bispectral index (BIS) monitor is one of the EEG-derived monitoring techniques and well-established devices used to measure the depth of anesthesia. This study aimed to assess the agreement of BIS values based on the positions of either post-auricular or frontal sensors in individual patients undergoing renal surgeries while lateral positions at various stages of anesthesia. PATIENTS AND METHODS: 12 patients older than 18 years, ASA I-III patients scheduled for elective renal operations, two BIS were placed on each patient, one on each side of the post-auricular region and one across the forehead, and each sensor was connected to a different BIS monitor. We gathered three pieces of data at each of the six-time points: BIS score, signal quality index (SQI) score calculating the signal's strength and electromyography (EMG) score: before the onset of anesthesia (awake) when the eyelash reflex is lost (LOC), after intubation (intubation), following the initial surgical incision, each 30 min throughout the procedure (maintenance), and at the moment the patient's eyes open naturally after waking up from anesthesia (emergence). RESULTS: The overall BIS value at the frontal position was significantly higher than the post-auricular position (52.5 ± 22.2 and 52.1 ± 22.1, respectively, P = 0.010). On the other hand, the BIS value was comparable between the frontal and post-auricular positions at LOC, intubation, 60, 120, and 80 min and at emergence. A strong link between the two sensor positions, as indicated by the correlation coefficient (r = 0.607, P < 0.001), and the Bland-Altman analysis revealed a small mean difference (-1.8) and a low (9.0/- 12.5) limit of agreement, with just 4.3% of the readings falling outside of it during the anesthetic maintenance period. CONCLUSION: Acceptable variation in BIS data was observed when obtained from the two different sensor positions for clinical usage. The post-auricular BIS sensor system may be a suitable substitute for an impractical frontal setup. PROTOCOL REGISTRATION: The study was registered in clinicaltrials.gov on 11/07/2022 (trial registration number: NCT05451823).

Changes of anesthetic drug concentration in plasma during isolation of autologous blood with acute isovolumic hemodilution and its influence on anesthetic effect after reinfusion / 中国临床药理学与治疗学

To investigate the changes of anesthetic drug concentration in plasma during isolation of autologous blood with acute normovolemic hemodiluti-on and its influence on the depth of anesthesia, muscle relaxant effect and blood drug concentration after reinfusion. METHODS: Forty patients of both sexes, aged 20-60 yr, American Society of Anesthesiologists physical status or Ⅱ, hemoglobin (Hb) >120 g / L, hematocrit (Hct) >35%, undergoing eletive multilevel spinal surgery were included, were divided into 2 groups (n=20 each) using a random number table. ANH group (group A): ANH was performed after stable induction of anesthesia, the target Hct value was 28%-30%, and autologous blood was reinfused after the main operation steps. Control group (group C): routine transfusion and infusion treatment. The bispectral index (BIS) and Train-of-Four stimulation (TOF) were observed and recorded at the stable induction of anesthesia (T1), 30 minutes of stable induction (T2), the end of operation (T3), 30 minutes after the end of the operation (T4), 1 hour after the end of the operation (T5) and 2 hours after the end of the operation (T6). The concentrations of propofol and cisatracurium besylate in plasma at T1-T6, stored blood at 1 h (TS1), 2 h (TS2), and before reinfusion (TS3) were detected by Liquid Chromatography-tandem Mass Spectrometry. The extubation time and recovery score at T4-6 hours were recorded. RESULTS: There was no significant difference in propofol between the two groups at each time point (P > 0.05). The plasma concentration of cisatracurium besylate in group A was higher than that in group C at T3 (P0.05). The BIS value at T4 and TOF value at T3 in group A were significantly lower than those in group C. The recovery score of group A was lower than that of group C at T4 (P0.05). CONCLUSION: The plasma concentrations of propofol and cisatracurium besylate were basically unchanged during the in vitro isolation of ANH autologous blood. The plasma concentrations of cisatracurium besylate were only temporarily affected after the main operation steps, but the postoperative muscle relaxation recovery and recovery quality were not significantly affected.

Research progress of anesthesia-related neural network in depth of anesthesia monitoring / 中国临床药理学与治疗学

Improper control of depth of anesthesia is not only detrimental to the rapid and stable recovery of anesthesia, but also affects the postoperative outcome of patients. Therefore, accurate control of anesthesia depth is an urgent clinical and scientific problem in the field of anesthesiology. At present, different algorithm models derived from electroencephalogram (EEG) signals are used to monitor the depth of anesthesia, but they cannot meet the requirements of anesthesiologists to accurately evaluate the depth of anesthesia. In recent years, the research on the mechanism and modulation of anesthesia-related neural network suggests that it has potential value as a method to monitor depth of anesthesia. Anesthesia-related neural networks mainly include sleep-wake circuit, thalamic-cortical circuit and corticocortical network. A thorough understanding of the neural network involved in the loss of consciousness caused by anesthesia will guide the depth of anesthesia monitoring more accurately and provide possibility for improving the quality of clinical anesthesia resuscitation.

An Adaptive Method for Detecting and Removing EEG Noise / 中国医疗器械杂志

To solve the problem of real-time detection and removal of EEG signal noise in anesthesia depth monitoring, we proposed an adaptive EEG signal noise detection and removal method. This method uses discrete wavelet transform to extract the low-frequency energy and high-frequency energy of a segment of EEG signals, and sets two sets of thresholds for the low-frequency band and high-frequency band of the EEG signal. These two sets of thresholds can be updated adaptively according to the energy situation of the most recent EEG signal. Finally, we judge the level of signal interference according to the range of low-frequency energy and high-frequency energy, and perform corresponding denoising processing. The results show that the method can more accurately detect and remove the noise interference in the EEG signal, and improve the stability of the calculated characteristic parameters.

An anesthesia depth computing method study based on wavelet transform and artificial neural network / 生物医学工程学杂志

General anesthesia is an essential part of surgery to ensure the safety of patients. Electroencephalogram (EEG) has been widely used in anesthesia depth monitoring for abundant information and the ability of reflecting the brain activity. The paper proposes a method which combines wavelet transform and artificial neural network (ANN) to assess the depth of anesthesia. Discrete wavelet transform was used to decompose the EEG signal, and the approximation coefficients and detail coefficients were used to calculate the 9 characteristic parameters. Kruskal-Wallis statistical test was made to these characteristic parameters, and the test showed that the parameters were statistically significant for the differences of the four levels of anesthesia: awake, light anesthesia, moderate anesthesia and deep anesthesia (

Research status of influence of hemodilution on anesthetics and depth of anesthesia / 中国临床药理学与治疗学

Perioperative autotransfusion and blood protection has become a hot issue in modern medicine. Hemodilution, as an effective method of saving blood, has been widely used in clinical practice. It can reduce the clinical demand for allogeneic blood source and relieve the tension of clinical blood use to a certain extent. However, hemodilution itself will also have a certain impact on human physiological functions; especially it can affect the pharmacokinetics and pharmacodynamics of anesthetics and the depth of anesthesia. This paper focuses on the effects of hemodilution on anesthetics and anesthesia depth.

Effect of anesthesia depth on stress response during single-lung ventilation in thoracic surgery / 肿瘤研究与临床

Objective@#To study the effects of different anesthesia depths on stress response during single-lung ventilation in patients with thoracoscopic lobectomy.@*Methods@#Sixty patients selected for elective thoracoscopic lobectomy in the Second Hospital of Shanxi Medical University from September 2018 to May 2019 were randomly divided into three groups according to the digital random table method, with 20 patients in each group. Group A maintained deep anesthesia with the bispectral index (BIS) 36-45, group B maintained moderate anesthesia with BIS 46-55, and group C did not undergo BIS monitoring. The changes of heart rate, mean arterial pressure (MAP), stress indexes cortisol and blood glucose before anesthesia induction (T0), immediately after one-lung ventilation (T1), 60 min after one-lung ventilation (T2) and immediately after skin suture (T3) in the three groups were compared.@*Results@#The concentration of blood glucose in group A at T1, T2 and T3 was (5.28±0.49) mmol/L, (5.34±0.49) mmol/L and (5.40±0.47) mmol/L, and the cortisol was (142.75±31.45) ng/ml, (181.36±19.62) ng/ml and (153.81±33.92) ng/ml; the blood glucose in group B was (5.63±0.35) mmol/L, (6.06±0.19) mmol/L and (5.79±0.44) mmol/L, and the cortisol was (168.45±31.16) ng/ml, (171.09±25.28) ng/ml and (159.39±18.77) ng/ml; the blood glucose in group C was (6.35±0.56) mmol/L, (7.04±0.26) mmol/L and (6.17±0.54) mmol/L, and the cortisol was (191.13±46.00) ng/ml, (283.25±30.07) ng/ml and (183.01±19.71) ng/ml, respectively. The blood glucose and cortisol levels in group C at T1, T2 and T3 were higher than those in group A and group B (all P < 0.05). The MAP in group A at T1, T2 and T3 were (69±5) mmHg (1 mmHg= 0.133 kPa), (67±6) mmHg and (75±7) mmHg, respectively, and group B was (80±8) mmHg, (79±4) mmHg and (84±9) mmHg, the differences between the two groups were statistically significant (all P < 0.05). There was significant difference in cortisol between group A and group B at T1 (P < 0.05). The heart rate and MAP at T1, T2 and T3 in group A and group C were significantly different from those at T0 (all P < 0.05). The heart rate and MAP at T1 and T2 in groups B were significantly different from those at T0 (all P < 0.05).@*Conclusion@#BIS anesthesia depth monitoring should be performed during single-lung ventilation in thoracic surgery, and BIS should be maintained at 46-55, which can not only inhibit the stress response but also have a slight effect on hemodynamics.

Evaluation of Bispectral Index time delay in response to anesthesia induction: an observational study / Avaliação do tempo de atraso do índice bispectral na resposta à indução da anestesia: estudo observacional

Abstract Background and objectives According to the manufacturer, the Bispectral Index (BIS) has a processing time delay of 5-10 s. Studies addressing this have suggested longer delays. We evaluated the time delay in the Bispectral Index response. Methods Based on clinical data from 45 patients, using the difference between the predicted and the real BIS, calculated during a fixed 3 minutes period after the moment the Bispectral Index dropped below 80 during the induction of general anesthesia with propofol and remifentanil. Results The difference between the predicted and the real BIS was in average 30.09 ± 18.73 s. Conclusion Our results may be another indication that the delay in BIS processing may be much longer than stated by the manufacture, a fact with clinical implications.

Resumo Justificativa e objetivos De acordo com o fabricante, o índice bispectral (BIS) tem um tempo de processamento de cinco a dez segundos. Estudos que avaliaram esse tempo de processamento sugeriram atrasos mais longos. Nós avaliamos o tempo de atraso na resposta do BIS. Métodos Com base em dados clínicos de 45 pacientes, calculamos a diferença entre o tempo de atraso previsto e real do índice bispectral durante um período fixo de três minutos após o momento em que o BIS caiu abaixo de 80 durante a indução da anestesia geral com propofol e remifentanil. Resultados A diferença entre o BIS previsto e real foi em média 30,09 ± 18,73 segundos. Conclusão Nossos resultados sugerem que o atraso no processamento do índice bispectral pode ser muito maior do que o declarado pelo fabricante, um fato com implicações clínicas.

Use of the Bispectral Index to Predict Eye Position of Children during General Anesthesia

PURPOSE: To assess the relationship between eye position and anesthesia depth using the bispectral index (BIS) value, a parameter derived from electroencephalography data. METHODS: We investigated the relationship between BIS value and eye position in 32 children who underwent surgery for epiblepharon under general anesthesia. BIS values were recorded continuously throughout the procedure (from induction to awakening). Eye positions were video-recorded and analyzed after surgery. The vertical position of each eye was scored according to its height in relation to the medial canthus. An eye position in which the upper eyelid covered one-third of the cornea was defined as a significant ocular elevation. RESULTS: The BIS value correlated inversely with the end-tidal concentration of each anesthetic agent, whereas it correlated positively with the eye elevation score (eye position = 0.014 × BIS + 0.699, p = 0.011). The mean eye position score was significantly greater in patients whose BIS values were over 65. Eleven patients (34.4%) had significant ocular elevation; their mean concurrent BIS value was 61.6. Two of these patients had elevation during surgery and 9 had elevation during emergence from anesthesia. CONCLUSIONS: We found that high BIS values were correlated with low levels of anesthetic concentration and high eye position, suggesting that BIS monitoring may be useful for predicting eye position during anesthesia. Particular attention must be given to eye position during ophthalmic surgery. Anesthesia depth can be maintained by assuring that the BIS value remains below 65.

PICCO monitoring heart rate variability and cardiac output vs. narcotrend anesthetic depth monitoring / 实用医学杂志

Objective To explore the correlation of heart rate variability(HRV)and cardiac output by PICCO with anesthetic depth by Narcotrend monitoring. Methods 60 patients with radical resection of esophageal cancer were enrolled in the study. PICCO was used to monitor ECG and Narcotrend was use to monitor anesthetic depth.The NT value,NT grade,Cardiac index(CI),heart rate(HR),mean arterial pressure(MAP),cardiac output(CO),Poincare scattergram Scatter plot minor axis(SD1)and scatter plot major axis(SD2)were recorded and measured at the time points of pre-anesthesia induction(T1),post-successful intubation(T2),tracheal intu-bation moment(T3),lung collapse for 30 min(T4),post-lung ventilation(T5)and 10min after operation(T6). Results Person's correlation analysis showed that during the monitoring period(T1-T6),CI,CO,SD1 and NT showed a low linear correlation(P < 0.001);SD2 was significantly correlated with NT(P <0.001). There was a low linear correlation between CI,CO,SD1,SD2 and NT at the operation time(T2-T5). Conclusion During general anesthesia,heart rate variability(SD1,SD2)and cardiac output(CO)are correlated with the NT value of anesthesia depth.Collaborative monitoring could help to enhance the safety of anesthesia.

Effects of different anesthesia levels on perioperative cerebral oxygen metabolism and postoperative cogni-tive function in elderly patients / 实用医学杂志

Objective To investigate the effects of different levels of anesthesia on perioperative cerebral oxygen metabolism and postoperative cognitive function in the elderly patients. Methods One hundred elderly pa-tients receiving gastric cancer surgery were divided into two groups:group D(BIS value 30-39) and group L(BIS value 50-59). Blood samples were collected at T0,T1,T2,T3 and T4. Da-jvO2 and CERO2 were calculated at the same time.MMSE score was recorded at the time point of 1,3 and 7 d after operation.Results Compared with the T0,Da-jvO2 and CERO2 were both decreased in the two groups at T2-T4(P<0.05).Compared with the group L, the group D were decreased more obviously(P < 0.05). Compared with preoperative score,MMSE score was de-creased at the time point of 1,3d in the group L as well as 1d in the group D(P<0.05).Compared with the group L,group D was significantly increased at the time point of 1 and 3 d(P < 0.05). Conclusion BIS value was maintained at 30-39 can decrease perioperative cerebral oxygen metabolism and improve postoperative cognitive function in the elderly patients.

Effect of anesthesia at different depths on postoperative cognitive disfunction and inflammatory response in the elderly patients undergoing abdominal operation / 新乡医学院学报

Objective To investigate the effect of anesthesia at different depths on postoperative cognitive disfunction (POCD) and inflammatory response in the elderly patients undergoing abdominal operation.Methods A total of 90 elderly patients who underwent abdominal operation in the Affiliated Hospital of Shaanxi University of Chinese Medicine from June 2014 to June 2016 were divided into observation group and control group according to the depth of anesthesia,45 cases in each group.The patients in the two groups were performed with combined intravenous and inhalation anesthesia,the bispeetral index (BIS) value was maintained at 30-39 during the operation in the observation group,and the BIS value was maintained at 50-59 during the operation in the control group.The mean arterial pressure (MAP) and heart rate(HR) of patients in the two groups were recorded at the time points of entering the operation room(T0),5 minutes after tracheal cannula(T1),opening abdominal cavity (T2),closing abdominal cavity (T3) and tracheal cannula extubation (T4).The mini-mental state examination (MMSE) score of the patients in the two groups was performed before operation and the first,third,seventh day after operation;and the incidence of POCD was recorded.The levels of serum interleukin-6(IL-6) and S-100β protein were detected at the time points of before operation,the end of the operation and the first,third day after operation in the two groups.Results Five cases in the control group and six cases in the observation group were eliminated,39 cases in the observation group and 40 cases in the control group were evaluated finally.The MAP at T1 and T2 was significantly lower than that at T0 in the two groups (P ＜ 0.05).There was no significant difference in the MAP between T3,T4 and T0 in the two groups(P ＜ 0.05).There was no significant difference in the HR each time point in each group(P ＜ 0.05).There was no significant difference in the MAP and HR between the two groups at each time point(P ＜ 0.05).There was no significant difference in the MMSE score between the two groups before operation(P ＜ 0.05).The MMSE score of patients at the first and third day after operation was significantly lower than that before operation and the seventh day after operation in the two groups (P ＜ 0.05).There was no significant difference in the MMSE score between before operation and the seventh day after operation in the two groups(P ＜0.05).The MMSE score in the observation group was significantly higher than that in the control group at the first and third day after operation (P ＜ 0.05).There was no significant difference in the MMSE score between the two groups at the seventh day after opera tion(P ＜ 0.05).The incidences of POCD at the first,third and seventh day after operation in the observation group were 28.21％ (11/39),15.38％ (6/39) and 7.69％ (3/39) respectively;and they were 50.00％ (20/40),37.50％ (15/40) and 20.00％ (8/40) respectively in the control group.The incidence of POCD in the observation group was significantly lower than that in the control group at the first and third day after operation (x =3.934,4.949;P ＜ 0.05).There was no significant difference in the incidence of POCD between the two groups at the seventh day after operation(x2 =2.496,P ＜ 0.05).There was no significant difference in the levels of serum IL-6 and S-100β protein between the two groups before operation (P ＜0.05).The levels of serum IL-6 and S-100β protein at the end of operation and the first,third day after operation were significantly higher than those before operation in the two groups(P ＜ 0.05).The levels of serum IL-6 and S-100β protein in the observation group were significantly lower than those in the control group at the end of operation and the first,third day after operation (P ＜ 0.05).Conclusion Deep anesthesia (BIS value is maintained at 30-39) can reduce the levels of inflammatory factors,the incidence of POCD after operation and the brain damage in the elderly patients with abdominal operation.

Effects of different depths of anesthesia on postoperativecognitive dysfunction:a meta-analysis / 实用医学杂志

Objective To investigate the effects of different depths of anesthesia on incidence of postopera-tive cognitive dysfunction (POCD). Methods We systematically retrievedPubmed,OVID,CNKI,CBM and Wanfang database and VIP database for randomized controlled trials(RCTs)from inceptionto December 312016, comparing different depths of anesthesia for their impacts on incidence of early POCD. After data extraction and quality evaluation,Revman 5.3 software was used for statistical data analysis. Results A total of 714 patients in 8 eligible RCTs were identified. Results of meta-analysis were as follows.(1)Incidence of POCD of depth anesthesia (NTS=E0-E1)was lower than general anesthesia(NTS=D0-D1)1 d after surgery(OR=0.21,95%CI 0.13~0.35,P < 0.00001).(2)Incidence of POCD of depth anesthesia(NTS = E1)was lower than general anesthesia (NTS=D0)7 d after surgery(OR=0.45,95%CI 0.23~0.91,P=0.03).(3)Incidence of POCD of NTS=E1 was lower than NTS=D07d after surgery(OR=0.42,95%CI 0.24~0.71,P=0.001). Conclusion Comparedwith general anesthesia,depth anesthesia is associated with a lower incidence of early POCD.

Effects of different depths of anesthesia on postoperativecognitive dysfunction:a meta-analysis / 实用医学杂志

Objective To investigate the effects of different depths of anesthesia on incidence of postopera-tive cognitive dysfunction (POCD). Methods We systematically retrievedPubmed,OVID,CNKI,CBM and Wanfang database and VIP database for randomized controlled trials(RCTs)from inceptionto December 312016, comparing different depths of anesthesia for their impacts on incidence of early POCD. After data extraction and quality evaluation,Revman 5.3 software was used for statistical data analysis. Results A total of 714 patients in 8 eligible RCTs were identified. Results of meta-analysis were as follows.(1)Incidence of POCD of depth anesthesia (NTS=E0-E1)was lower than general anesthesia(NTS=D0-D1)1 d after surgery(OR=0.21,95%CI 0.13~0.35,P < 0.00001).(2)Incidence of POCD of depth anesthesia(NTS = E1)was lower than general anesthesia (NTS=D0)7 d after surgery(OR=0.45,95%CI 0.23~0.91,P=0.03).(3)Incidence of POCD of NTS=E1 was lower than NTS=D07d after surgery(OR=0.42,95%CI 0.24~0.71,P=0.001). Conclusion Comparedwith general anesthesia,depth anesthesia is associated with a lower incidence of early POCD.