Processed Electroencephalogram in Pediatric Patients: A Survey Among Portuguese Anesthesiologists

Processed electroencephalogram (pEEG) monitoring in pediatric anesthesia presents complex challenges, primarily due to the complexities of interpreting EEG signals in immature, developing brains, where factors such as brain architecture, synaptogenesis, neuronal differentiation, glucose metabolism, and cortical myelination significantly differ from those in adults [1]. While the need for monitoring is heightened due to the elevated risk of awareness or burst suppression as models for dosing are population-derived pharmacokinetic models, numerical indices from parameterized mathematical algorithms present limitations in pediatric patients [2-5]. Instead, combining raw EEG, density spectral array (DSA), and spectral edge frequency (SEF) presents as a more robust alternative, although visual EEG analysis is complex, requiring specialized training and time, contributing to varied pEEG use across institutions and age groups [1-4, 6-8]. This study presents a cross-sectional survey assessing the frequency, preferences, and barriers to pEEG use among Portuguese anesthesiologists, particularly in children under 10 years of age. The survey, sent to anesthesiologists in public and private institutions practising pediatric anesthesia, achieved a 70% response rate (133 respondents, with 123 included in the analysis). The questionnaire included items on the frequency of pEEG use during general and intravenous anesthesia, factors influencing its use, and the specific pEEG parameters considered most clinically relevant. A full questionnaire is available in the Supporting Information. Among respondents, 41.5% reported consistent use of pEEG during general anesthesia in pediatric patients, while 37.3% used it depending on the surgical procedure and patient characteristics. A smaller subset (15.5%) reported selective use during intravenous anesthesia. The use of pEEG increased with patient age (as shown in Figure 1); however, approximately half of the anesthesiologists (45.2%) used pEEG regardless of age. Notably, pEEG was “never” or “rarely” used by 17.1% and 14.6% of anesthesiologists, respectively, in children under 1 year of age. Barriers to pEEG use primarily involved equipment availability and challenges in data interpretation. Limited access to equipment was the main reason for infrequent pEEG use in children over 1 year. Conversely, for children under 1 year, 50% of anesthesiologists cited a lack of confidence in interpreting pEEG data as the primary barrier. Additionally, 17.4% and 13.0% of anesthesiologists attributed the infrequent use of pEEG to limited clinical value in children aged 0–12 months and 1–3 years, respectively. This decline in usage for younger children reflects both the inherent difficulties of interpreting pEEG in immature brains and a lack of confidence in its relevance for infants and toddlers. Surveyed anesthesiologists expressed clear preferences for specific pEEG parameters in clinical practice. The spectrogram or DSA was favored by 33.7% of respondents, followed by the numerical EEG value (31.0%), electromyography (19.0%), and SEF (16.3%). These findings align partially with the 2018 survey by the European Society of Pediatric Anesthesiologists (ESPA), where depth-of-hypnosis monitors were used in 98% of adolescents and 25% of neonates. In the ESPA study, 49% of professionals who did not use these monitors, considered the parameters unreliable or not validated in pediatric patients [9]. Conversely, 70% of respondents routinely utilized EEG monitoring during anesthesia with propofol, and nearly 50% used it during sevoflurane anesthesia [9]. So, while routine pEEG monitoring in children under anesthesia is common in other parts of Europe, especially with intravenous agents such as propofol, our survey suggests that in Portugal, barriers such as equipment access and interpretative confidence still limit widespread application, especially among younger age groups. In our study, DSA and numerical indices of pEEG were rated as the most valuable parameters, followed by electromyography and SEF. Proprietary EEG indices, developed for healthy adults, may be unreliable for children and infants. Although much research is still needed, raw EEG parameters, such as SEF or DSA, seem to offer more reliable insights than conventional numerical indices [1, 8]. Long et al. [10] recently published the first randomized controlled trial about sevoflurane requirements during DSA-guided anesthesia versus standard care, which showed reduced sevoflurane requirements in EEG-guided anesthesia care in children. Given the lack of clarity on how different proprietary numerical indices are computed and how they relate to neurophysiological properties of the developing brain, it is important to learn to interpret the EEG waveform and spectrogram. Several authors have published recommendations on the use of nonproprietary EEG parameters to guide anesthetic dosing in infants [1, 2, 8, 11]. Nearly all respondents (95.9%) believed that increased training in pediatric pEEG interpretation is necessary indicating, a demand for targeted professional development in EEG monitoring for young patients. Various studies have demonstrated the benefits of training in this area, with some recommending self-guided learning through e-learning platforms such as www.icetap.org and https://eegforanesthesia.iars.org/ and foundational readings [1, 12-14]. Currently, there are no established guidelines that precisely determine how EEG parameters should be applied in pediatric anesthesia. Although studies highlight the pros and cons of different parameters, few offer specific protocols for various clinical scenarios. Consequently, there is a pressing need for refined guidelines, age-specific algorithms, and comprehensive training modules for pEEG in pediatric anesthesia. This study provides insight into the current practices, preferences, and obstacles surrounding pEEG monitoring in Portuguese pediatric anesthesia. As the first national survey examining pEEG use in pediatric patients, it underscores an underutilization of pEEG in children under one year, largely due to interpretive uncertainties and logistical constraints. Future research should aim to improve the evidence on the usefulness and benefits of pEEG monitoring in pediatric anesthesia, particularly its role in enhancing patient safety and optimizing anesthetic dosing. Simultaneously, future efforts should focus on developing training resources that build anesthesiologists' confidence in pediatric EEG interpretation, creating guidelines that address the unique aspects of EEG in the developing brain, and increasing availability of age-appropriate monitoring technology. In conclusion, while pEEG has the potential to enhance safety and efficacy in pediatric anesthesia, its effective application in young patients is hindered by resource and training limitations. Addressing these challenges is essential to ensuring that anesthesiologists can leverage this tool to optimize anesthetic depth in pediatric patients confidently. The authors have nothing to report. Informed consent was obtained from all the participants. The first question of the questionnaire was, “I authorize the use of the information collected in this questionnaire for presentations at congresses, meetings, or in publications: yes/no.” Participants who did not provide informed consent were excluded. The authors declare no conflicts of interest. The datasets used and/or analyzed in this study are available from the corresponding author upon reasonable request. Data S1. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.