Intraoperative brain monitoring has advanced significantly, with both unprocessed electroencephalogram (EEG) and density spectral array (DSA) playing key roles in modern anesthetic practice. However, the debate over their relative utility remains ongoing.
From a neuroscientific perspective, these tools are complementary rather than competing:
- Raw EEG:Provides direct, detailed, real-time insights into brain activity.Research has demonstrated that specific EEG patterns, such as burst suppression, alpha rhythms, or theta waves, are critical markers for tailoring anesthesia and avoiding adverse outcomes like intraoperative awareness.However, interpreting raw EEG requires advanced training, as not all anesthesiologists are familiar with neurophysiological patterns.
- DSA (Density Spectral Array):A processed representation of EEG that converts complex patterns into an easily interpretable spectrogram.Studies, such as those by Emery Brown, highlight how DSA simplifies trend recognition, such as transitions between anesthetic states or changes in anesthetic depth.The value of this approach lies in its rapid and accessible representation, which facilitates decision-making in the operating room.
- Recent work shows that combining raw EEG with DSA enhances the precision of monitoring brain states during anesthesia.
- For example, Akeju and Brown (2017) propose that raw EEG patterns can be visually corroborated using DSA, which serves to reinforce interpretation and reduce the probability of errors.
In my Opinion: This is not about choosing one over the other. Both tools are indispensable and complementary. While raw EEG allows for deep and specific analysis, DSA provides a broader view that facilitates efficiency in the OR. Integrating both represents the future of more Personalized and Safer Anesthesia, aligned with principles of applied neuroscience.
📣 Let’s reflect together: How are you integrating these tools in your daily practice? What challenges do you face when combining them in your clinical workflow?
- Brown, E. N., Lydic, R., & Schiff, N. D. (2010). General anesthesia, sleep, and coma. The New England Journal of Medicine, 363(27), 2638–2650.
- Akeju, O., & Brown, E. N. (2017). Neural oscillations demonstrate that general anesthesia and sedative states are neurophysiologically distinct from sleep. Current Opinion in Neurobiology, 44, 178–185.
- Kim MC, Fricchione GL, Brown EN, Akeju O. Role of electroencephalogram oscillations and the spectrogram in monitoring anaesthesia. BJA Educ. 2020 May;20(5):166-172. doi: 10.1016/j.bjae.2020.01.004. Epub 2020 Feb 20. Erratum in: BJA Educ. 2020 Jul;20(7):249. doi: 10.1016/j.bjae.2020.04.001. PMID: 33456946; PMCID: PMC7807831.
LivaNova Clinical Field Engagement Specialist
9moAgree Carolina - both tools are critical
Visiting Professor of Anesthesia Assiut University Egypt. former professor of Anesthesia Riyadh KSA
9moI think DSA is easier to interpret in OR setting. It reflects the amplitude and frequency pattern of EEG waves.
MD - Ph.D - Presidente da Sociedade Brasileira de Anestesiologia - Gestão 2020 - Pós-graduado em Engenharia Clínica. Pós-graduação em Gestão de Pessoas e Liderança de Equipes.
9moDevemos sempre analisar como como complementares. Por exemplo: A morfologia do padrão surto-supressão, o tempo em supressão assim como se o padrão é reativo ou não são importantes. Além disso, o EEG bruto é de registro imediato enquanto o espectrograma, no BIS, tem um delay de 9s.
Strategic Clinical and Regulatory Consultant; Vice President, Clinical & Regulatory at Health Data Analytics Institute
10moHas there ever been a RCT showing any outcome benefit of using raw EEG or DSA monitoring versus standard clinical practice? Why are these alternate approaches not held to the same standards of evidence that were demanded of processed EEG measures such as BIS?
CEO at Nimbelle Medical Systems
10moCarolina Frederico. MD, EDAIC Thank you for highlighting this important issue. It seems obvious to me that researchers within intraoperative brain monitoring need both the raw EEG and the DSA for the development of the science in this very promising area. But maybe further down the road when the science has evolved, we could manage without the raw EEG for the non-researcher/regular anesthesiologists? Burst suppressions for example can be analyzed by software and presented in a more comprehensible manner added to the DSA. We could still have the option of the raw EEG displayed by the push of a button for those who so desire but maybe we could avoid it on the regular screen? Today's anesthesia environment is highly complex and anesthesiologists complain about information overload while new features and new monitored parameters are continuously introduced. As a product owner in anesthesia workstations I am always concerned with information overload for the regular anesthesiologist and the raw EEG seems to me as quite an extra burden for the intraoperative brain monitoring non-expert. What do you think? Philippe Picard, Milan Hrobský