Neurophysiologic Correlates of Ketamine Sedation and Anesthesia
| Autor: | Hyoungkyu Kim, Duan Li, UnCheol Lee, George A. Mashour, Paul Picton, Vijay Tarnal, Amy M. McKinney, Adrian Pichurko, Phillip E. Vlisides, Ellen Janke, Tarik Bel-Bahar, Bryan S Kunkler |
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| Rok vydání: | 2017 |
| Předmět: |
medicine.diagnostic_test
medicine.drug_class business.industry Sedation Electroencephalography 03 medical and health sciences Dose–response relationship 0302 clinical medicine Anesthesiology and Pain Medicine Bolus (medicine) 030202 anesthesiology Anesthesia Sedative Anesthetic Healthy volunteers medicine Ketamine medicine.symptom business 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Anesthesiology. 127:58-69 |
| ISSN: | 0003-3022 |
| DOI: | 10.1097/aln.0000000000001671 |
| Popis: | Background Previous studies have demonstrated inconsistent neurophysiologic effects of ketamine, although discrepant findings might relate to differences in doses studied, brain regions analyzed, coadministration of other anesthetic medications, and resolution of the electroencephalograph. The objective of this study was to characterize the dose-dependent effects of ketamine on cortical oscillations and functional connectivity. Methods Ten healthy human volunteers were recruited for study participation. The data were recorded using a 128-channel electroencephalograph during baseline consciousness, subanesthetic dosing (0.5 mg/kg over 40 min), anesthetic dosing (1.5 mg/kg bolus), and recovery. No other sedative or anesthetic medications were administered. Spectrograms, topomaps, and functional connectivity (weighted and directed phase lag index) were computed and analyzed. Results Frontal theta bandwidth power increased most dramatically during ketamine anesthesia (mean power ± SD, 4.25 ± 1.90 dB) compared to the baseline (0.64 ± 0.28 dB), subanesthetic (0.60 ± 0.30 dB), and recovery (0.68 ± 0.41 dB) states; P < 0.001. Gamma power also increased during ketamine anesthesia. Weighted phase lag index demonstrated theta phase locking within anterior regions (0.2349 ± 0.1170, P < 0.001) and between anterior and posterior regions (0.2159 ± 0.1538, P < 0.01) during ketamine anesthesia. Alpha power gradually decreased with subanesthetic ketamine, and anterior-to-posterior directed connectivity was maximally reduced (0.0282 ± 0.0772) during ketamine anesthesia compared to all other states (P < 0.05). Conclusions Ketamine anesthesia correlates most clearly with distinct changes in the theta bandwidth, including increased power and functional connectivity. Anterior-to-posterior connectivity in the alpha bandwidth becomes maximally depressed with anesthetic ketamine administration, suggesting a dose-dependent effect. |
| Databáze: | OpenAIRE |
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