Optimal bispectral index exists in healthy patients undergoing general anesthesia: A validation study

• Published in: Journal of clinical monitoring and computing Vol. 38; no. 4; pp. 791 - 802
• Main Authors: Froese, Logan, Gomez, Alwyn, Sainbhi, Amanjyot Singh, Vakitbilir, Nuray, Marquez, Izabella, Amenta, Fiorella, Park, Kangyun, Stein, Kevin Y., Berrington, Neil, Dhaliwal, Perry, Zeiler, Frederick A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2024; Springer Nature B.V
• Subjects: Adult; Aged; Anestesi och intensivvård; Anesthesia; Anesthesia, General; Anesthesiology; Blood Pressure; Cerebrovascular Circulation; Consciousness Monitors; Critical Care - methods; Critical Care Medicine; Electroencephalography - methods; Female; General anesthesia; Health Sciences; Healthy Volunteers; Humans; Injuries; Intensive; Klinisk medicin; Male; Medicin och hälsovetenskap; Medicine; Medicine & Public Health; Medicinska och farmaceutiska grundvetenskaper; Middle Aged; Monitoring, Intraoperative - methods; Neurovetenskaper; Original Research; Populations; Reproducibility of Results; Statistics for Life Sciences; Wakefulness; Young Adult; Cerebral autoregulation; High frequency data assessment; Pressure reactivity
• ISSN: 1387-1307; 1573-2614; 1573-2614
• DOI: 10.1007/s10877-024-01136-3

Purpose Continuous cerebrovascular reactivity monitoring in both neurocritical and intra-operative care has gained extensive interest in recent years, as it has documented associations with long-term outcomes (in neurocritical care populations) and cognitive outcomes (in operative cohorts). This has sparked further interest into the exploration and evaluation of methods to achieve an optimal cerebrovascular reactivity measure, where the individual patient is exposed to the lowest insult burden of impaired cerebrovascular reactivity. Recent literature has documented, in neural injury populations, the presence of a potential optimal sedation level in neurocritical care, based on the relationship between cerebrovascular reactivity and quantitative depth of sedation (using bispectral index (BIS)) – termed BISopt. The presence of this measure outside of neural injury patients has yet to be proven. Methods We explore the relationship between BIS and continuous cerebrovascular reactivity in two cohorts: (A) healthy population undergoing elective spinal surgery under general anesthesia, and (B) healthy volunteer cohort of awake controls. Results We demonstrate the presence of BISopt in the general anesthesia population (96% of patients), and its absence in awake controls, providing preliminary validation of its existence outside of neural injury populations. Furthermore, we found BIS to be sufficiently separate from overall systemic blood pressure, this indicates that they impact different pathophysiological phenomena to mediate cerebrovascular reactivity. Conclusions Findings here carry implications for the adaptation of the individualized physiologic BISopt concept to non-neural injury populations, both within critical care and the operative theater. However, this work is currently exploratory, and future work is required.