Electroencephalogram-Guided Anesthesia Care in Children
Jerry Chao MD, Ian Yuan MD, and Myron Yaster MD
In 2023, I don’t think any one of us would feel comfortable or safe using a vapor anesthetic without end-tidal gas monitoring. Indeed, anything less would be akin to flying blind and is probably malpractice. And yet, flying blind is essentially what we do whenever we use total intravenous anesthesia (TIVA), even with target controlled infusion pumps and software (and, to be honest, even when we use vapor anesthetics targeting an end tidal concentration to a minimum alveolar concentration [MAC)). Remember that MAC was determined by movement to surgical stimulation and not (un)consciousness. MAC awake is significantly less than MAC for movement to surgical stimulation. What “value” should we be targeting, particularly in an era in which we routinely use adjuvants like opioids and muscle relaxants?
Wouldn’t it be game changing if there was a reliable and useful way to titrate our general anesthetic agents (whether IV or inhalational) to the therapeutic endpoints of loss of consciousness (“sedation-hypnosis”) and amnesia using real-time data returned from the end organ of interest: the brain? As regular readers of the PAAD know, this technology already exists, namely, using electroencephalogram (EEG) guidance. In today’s PAAD, our EEG “mavens” (gurus), Drs. Jerry Chao and Ian Yuan will guide us through today’s article by Bong et al.1
Finally, for those who are teaching new students, today’s PAAD and the issues it raises would be great intraoperative discussion/teaching points. Myron Yaster MD
Original article
Bong CL, Balanza GA, Khoo CE, Tan JS, Desel T, Purdon PL. A Narrative Review Illustrating the Clinical Utility of Electroencephalogram-Guided Anesthesia Care in Children. Anesth Analg. 2023 Jul 1;137(1):108-123. Doi: 10.1213/ANE.0000000000006267. Epub 2023 Jun 16. PMID: 36729437.
Determining the depth of anesthesia (hypnosis, amnesia, analgesia, and immobility) in children has been challenging because of their “wide range of ages, developmental stages, and body sizes, as well as their concomitant differences in physiology and pharmacology.”1 Using weight based dosing, age, and vital sign responses to surgical stimulation alone are inadequate for determining the patient’s precise state of sedation-hypnosis. Today’s PAAD summarizes what is known about EEG monitoring in pediatric anesthesia care and provides a narrative review illustrating “how the EEG spectrogram can be used to visualize, in real time, brain responses to anesthetic drugs in relation to hemodynamic stability, surgical stimulation, and other interventions such as cardiopulmonary bypass. The spectrogram allows visualization of precise changes in EEG frequency and amplitude with the progression of time, and can be used to assess the child’s depth of consciousness. Further, this review discusses anesthetic management principles in a variety of clinical scenarios, including in infants and children with altered conscious levels, atypical neurodevelopment, hemodynamic instability, and those undergoing total intravenous anesthesia and/or cardiopulmonary bypass. Each scenario is accompanied by practical illustrations of how the spectrogram can be taken into account to assess the brain state in that moment in order to guide anesthetic titration in order to avoid over- or underdosing. Overall, this review illustrates how well-established clinical management principles in children can be significantly complemented and supported by the addition of EEG monitoring, thus enabling personalized anesthesia care to enhance patient safety and experience.”1
As Bong et al. repeatedly point out: “The relationship between general anesthesia, brain function, and consciousness is complex, and it is not easy to predict anesthetic requirements based on cardiopulmonary vital signs alone. EEG monitoring during clinical anesthesia in children allows visualization of the complex interactions between brain response, hemodynamic response to anesthesia, and dynamic levels of surgical stimulation in real time. EEG-guided anesthesia provides insight into each individual child’s brain response, which is not necessarily predictable based on age, sex, and weight. In addition, special patient groups, including neuroatypical patients, those with altered levels of consciousness, and preemies undergoing complex surgeries may have unpredictable requirements, which vary according to changing surgical stimuli. EEG monitoring facilitates more precise and nuanced titration of anesthetic agents, personalized to each child’s needs at any given moment in time.”1 Finally, continued collection of EEG data will help narrow knowledge gaps in the neuroscience of early anesthetic effects, inform our understanding of neurodevelopment, and help innovate our clinical practice.
If we assume, based on recent literature 2-5, that EEG monitoring of anesthetic depth in pediatric patients is currently available and can be used to improve patient safety, then why isn’t it routinely used? Like all new technology introduced into anesthetic clinical care, there are 5 stages of adoptation: innovators, early adopters, the early majority, the late majority and laggards. With pediatric EEG monitoring, we are now in the early adopter phase, soon to hopefully transition to the early majority phase. Similar to the adoptation of ultrasound for vascular access and neural blockade, staying up-to-date of the medical literature and learning the technology at annual meetings at SPA, ASA, and the European Society of Anaesthesiology, etc… will be pivotal in creating a majority of users familiar with pediatric EEG monitoring.
Are you using EEG in your practice? If yes tell us some stories as to how it has changed your practice. If you aren’t, tell us why not and the obstacles you are trying to overcome to incorporate into your practice? Send your responses to Myron who will post in a Friday Reader Response. Finally, over the next few weeks we will be discussing in the PAAD some revolutionary changes coming to American specialty Board certification process. Developing competency will be fundamental. Stay tuned.
References
1. Bong CL, Balanza GA, Khoo CE, Tan JS, Desel T, Purdon PL. A Narrative Review Illustrating the Clinical Utility of Electroencephalogram-Guided Anesthesia Care in Children. Anesthesia and analgesia. Jul 1 2023;137(1):108-123. doi:10.1213/ane.0000000000006267
2. Yuan I, Xu T, Skowno J, et al. Isoelectric Electroencephalography in Infants and Toddlers during Anesthesia for Surgery: An International Observational Study. Anesthesiology. Aug 1 2022;137(2):187-200. doi:10.1097/aln.0000000000004262
3. Yuan I, Missett RM, Jones-Oguh S, et al. Implementation of an electroencephalogram-guided propofol anesthesia education program in an academic pediatric anesthesia practice. Paediatric anaesthesia. Jul 6 2022;doi:10.1111/pan.14520
4. Yuan I, Xu T, Kurth CD. Using Electroencephalography (EEG) to Guide Propofol and Sevoflurane Dosing in Pediatric Anesthesia. Anesthesiology clinics. Sep 2020;38(3):709-725. doi:10.1016/j.anclin.2020.06.007
5. Xu T, Kurth CD, Yuan I, Vutskits L, Zhu T. An approach to using pharmacokinetics and electroencephalography for propofol anesthesia for surgery in infants. Paediatric anaesthesia. Dec 2020;30(12):1299-1307. doi:10.1111/pan.14021