EEG response of dexmedetomidine during drug induced sleep endoscopy

Lichy Han; David R Drover; Marianne C Chen; Amit R Saxena; Sarah L Eagleman; Vladimir Nekhendzy; Angelica Pritchard; Robson Capasso

doi:10.3389/fnins.2023.1144141

EEG response of dexmedetomidine during drug induced sleep endoscopy

Front Neurosci. 2023 Jul 14:17:1144141. doi: 10.3389/fnins.2023.1144141. eCollection 2023.

Authors

Lichy Han¹, David R Drover¹, Marianne C Chen¹, Amit R Saxena¹, Sarah L Eagleman², Vladimir Nekhendzy¹, Angelica Pritchard¹, Robson Capasso³

Affiliations

¹ Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA, United States.
² Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States.
³ Department of Otolaryngology, Head and Neck Surgery, Stanford University, Stanford, CA, United States.

Abstract

Introduction: Dexmedetomidine is one of the anesthetics of choice for drug induced sleep endoscopy (DISE), with advantages including limited respiratory depression, analgesia, and decreased incidence of emergence delirium. However, challenges with determining sedation levels and prolonged recovery have limited its usage. An improved understanding of the effect of dexmedetomidine on the level of sedation and the corresponding electroencephalographic (EEG) changes could help overcome these barriers.

Methods: Fifty-one patients received dexmedetomidine sedation with Richmond Agitation-Sedation Scale (RASS) score assessment and continuous EEG monitoring via SedLine for DISE. We constructed a pharmacokinetic model to determine continuous dexmedetomidine blood concentration. From the SedLine, we extracted the patient state index (PSI), and from the EEG we calculated the spectral edge frequency 95% (SEF95) and the correlation dimension (CD), a type of fractal dimension used to assess the complexity of a system. These metrics were subsequently compared against one another and with the dexmedetomidine concentration.

Results: Our pharmacokinetic model yielded a two-compartment model with volumes of 51.8 L and 106.2 L, with clearances of 69.5 and 168.9 L/h, respectively, and a time to effect of 9 min, similar to prior studies. Based on this model, decreasing RASS score, SEF95, CD, and PSI were all significantly associated with increasing dexmedetomidine concentration (p < 0.001, p = 0.006, p < 0.001 respectively). The CD, SEF95, and PSI better captured the effects of increasing dexmedetomidine concentration as compared to the RASS score. Simulating dexmedetomidine concentration based on titration to target levels derived from CD and PSI confirmed commonly used dexmedetomidine infusion dosages.

Conclusion: Dexmedetomidine use for DISE confirmed previous pharmacokinetic models seen with dexmedetomidine. Complex EEG metrics such as PSI and CD, as compared to RASS score and SEF95, better captured changes in brain state from dexmedetomidine and have potential to improve the monitoring of dexmedetomidine sedation.

Keywords: dexmedetomidine; drug induced sleep endoscopy; electroencephalography; level of sedation; pharmacology.