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Anesthesia depth assessment

Edited by:

Sean Coeckelenbergh, Université Libre de Bruxelles, Belgium

Ashraf Dahaba, Suez Canal University, Egypt

Anesthesia depth assessment remains a fundamental topic in perioperative medicine. Despite a plethora of clinical signs and available tools, monitoring the hypnotic and antinociceptive components of anesthesia poses particular difficulties. Neuromuscular blockade monitoring, often done with train-of-four count and ratio, remains fundamental to good clinical practice and also has its challenges.

Monitoring the hypnotic component of anesthesia has greatly evolved over the past three decades. Processed electroencephalograms (EEG) are available but the algorithms they use have been validated in adult populations within limited anesthetic conditions. Consequently, two challenges exist regarding the processed EEG:

1. Extremes in age can affect the EEG during general anesthesia. The growing elderly population is principally affected by this limitation as they are often at risk of postoperative cognitive adverse events;

2. The use of multimodal anesthesia utilizes different anesthetic agents that have variable impact on the EEG. Their use can therefore cause the processed EEG value to display aberrant information.

However, several monitors now display the spectrogram, which may be part of the solution to these challenges. This three dimensional display of the EEG breaks down its signal by wave frequency, intensity, and time. This tool may be useful to identify both elderly patients with a “vulnerable brain” phenotype and individual components of multimodal anesthesia.

Over the past decade, several new tools have also shown potential in assessing the antinociception component. The majority of the available monitors focuses on assessing the sympathetic response to a noxious stimulus and consequently offers an elegant, but surrogate, measure of nociception. Although several goal-directed approaches coupled with these monitors have shown promise, there remains a need to clarify the impact of guiding antinociception with these tools on patient outcome.

In order to recognize the significant advancements in anesthesia depth assessment, we launched a BMC Anesthesiology collection that focused on the potential tools and associated therapies.

This collection comprises submissions from all aspects of this developing field including, for example:

-Clinical outcomes (e.g., impact on postoperative delirium or intraoperative hemodynamics)

-The use of the spectrogram to guide anesthesia depth

-Identification of high risk populations that can benefit from anesthetic depth monitoring (e.g., “vulnerable brain”)

-Potential applications and impact of nociception monitoring

-Simulation, skills, and training on optimizing anesthetic depth

-State-of-the-art reviews on monitoring each component

If you would like to know more about this collection, you can email to the Editor of BMC Anesthesiology at

Our Guest Editors:

Sean Coeckelenbergh

New Content ItemSean Coeckelenbergh is a dynamic young anesthesiologist associated with the Université Libre de Bruxelles. He is highly active in perioperative research and has a particular interest for guiding goal-directed strategies with monitors, including those of anesthetic depth and nociception. He is currently interested in evaluating the autonomic response to surgery and using the spectrogram to guide anesthetic titrations.

Ashraf Dahaba

New Content ItemProfessor Ashraf Dahaba has 55 publications as first author in top impact factor Journals with a total impact factor of 180 Impact Factor Points (IP). He has a unique Hirsch Index as first author (H-Index) =20. Professor Dahaba has more than 240 presentations in International Congresses where he was often the Keynote speaker of the congress. Professor Dahaba is currently dedicated to developing readily available stand alone tablet-operated  (with no laptop cable connections) Artificial Intelligence (AI) Autonomous/Augmented Anesthesia gadgets that could take the burden off the practicing anesthesiologists from calculating complicated infusion rates adjustments and giving anesthesiologists 2 free hands. 


  1. Anesthesiologists are required to maintain an optimal depth of anesthesia during general anesthesia, and several electroencephalogram (EEG) processing methods have been developed and approved for clinical use ...

    Authors: Yurie Obata, Tomomi Yamada, Koichi Akiyama and Teiji Sawa
    Citation: BMC Anesthesiology 2023 23:125
  2. Dexmedetomidine has analgesic properties, but the intraoperative analgesic effect of dexmedetomidine is often masked by the effects of other general anaesthetics. Therefore, the degree to which it reduces intr...

    Authors: XiaoHua Wang, SiYuan Zhang, Chunxiu Wang, Yi Huang, Hao Wu, Guoguang Zhao and TianLong Wang
    Citation: BMC Anesthesiology 2023 23:68
  3. Assessment of appropriate anesthetic depth is crucial to prevent harm to patients. Unnecessary deep anesthesia can be harmful, potentially causing acute renal failure, myocardial injury, delirium, and an incre...

    Authors: Hilde Strand, Ann Charlott Elshaug, Øyvind Bernersen and Randi Ballangrud
    Citation: BMC Anesthesiology 2022 22:57
  4. In this study, we aimed to analyse survey data to explore two different hypotheses; and for this purpose, we distributed an online survey to Chinese anaesthesiologists. The hypothetical questions in this surve...

    Authors: Jian Zhan, Ting-Ting Yi, Zhuo-Xi Wu, Zong-Hong Long, Xiao-Hang Bao, Xu-Dong Xiao, Zhi-Yong Du, Ming-Jun Wang and Hong Li
    Citation: BMC Anesthesiology 2021 21:294
  5. Radiofrequency catheter ablation (RFCA) as a safe and effective method has been widely used in ventricular tachycardia (VT) patients, and with which anesthesiologists frequently manage their perioperative care...

    Authors: Hongquan Dong, Nana Li and Zhaochu Sun
    Citation: BMC Anesthesiology 2021 21:285
  6. The anatomical dimensions of the lumbar dural sac determine the sensory block level of spinal anesthesia; however, whether they show the same predictive value during continuous epidural anesthesia (CEA) remain...

    Authors: Chen-yang Xu, Can Liu, Xiao-ju Jin, Fan Yang, Fang Xu, Wan-Di Qian and Wen-jun Guo
    Citation: BMC Anesthesiology 2021 21:268
  7. Better protection can be provided during neurosurgery due to the establishment of somatosensory-evoked potential (SEP) and motor-evoked potential (MEP) monitoring technologies. However, some studies have showe...

    Authors: Bingbing Xiang, Shulan Jiao, Yulong Zhang, Lu Wang, Yuting Yao, Feng Yuan, Rui Chen and Qijun Zhou
    Citation: BMC Anesthesiology 2021 21:240
  8. Continuous infusion of propofol has been used to achieve sedation in children. However, the relationship between the effect-site concentration (Ce) of propofol and sedation scale has not been previously examined....

    Authors: Young-Eun Jang, Sang-Hwan Ji, Ji-Hyun Lee, Eun-Hee Kim, Jin-Tae Kim and Hee-Soo Kim
    Citation: BMC Anesthesiology 2021 21:222
  9. Administration of an optimal dose of anesthetic agent to ensure adequate depth of hypnosis with the lowest risk of adverse effects to the fetus is highly important in cesarean section. Sodium thiopental (STP) ...

    Authors: Golnar Sabetian, Farid Zand, Fatemeh Mirhadi, Mohammad Reza Hadavi, Elham Asadpour, Laleh Dehghanpisheh, Zeinabsadat Fattahi Saravi and Seyed Mostajab Razavi
    Citation: BMC Anesthesiology 2021 21:201
  10. Intraoperative brain function monitoring with processed electroencephalogram (EEG) indices, such as the bispectral index (BIS) and patient state index (PSI), may improve characterization of the depth of sedati...

    Authors: James Harvey Jones, Vinay Ravikumar Nittur, Neal Fleming and Richard L. Applegate II
    Citation: BMC Anesthesiology 2021 21:105
  11. Estimating the depth of anaesthesia (DoA) is critical in modern anaesthetic practice. Multiple DoA monitors based on electroencephalograms (EEGs) have been widely used for DoA monitoring; however, these monito...

    Authors: Jian Zhan, Zhuo-xi Wu, Zhen-xin Duan, Gui-ying Yang, Zhi-yong Du, Xiao-hang Bao and Hong Li
    Citation: BMC Anesthesiology 2021 21:66
  12. The Analgesia Nociception Index (ANI) has been suggested as a non-invasive guide for analgesia. Our objective was to compare the efficacy of ANI vs. standard pharmacokinetic pattern for guiding intraoperative ...

    Authors: Sirirat Tribuddharat, Thepakorn Sathitkarnmanee, Pornlada Sukhong, Maneerat Thananun, Parinda Promkhote and Duangthida Nonlhaopol
    Citation: BMC Anesthesiology 2021 21:50