Victoria Windmann1, Claudia Spies1, Emery N Brown2, Devika Kishnan3, Gregor Lichtner1, Susanne Koch4. 1. Department of Anesthesiology and Intensive Care Medicine, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. 2. Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Institute for Medical Engineering and Science, USA; Institute for Data, Systems and Society, USA; Picower Institute for Learning and Memory, USA; Department of Brain and Cognitive Sciences, USA; Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. 3. Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA. 4. Department of Anesthesiology and Intensive Care Medicine, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: susanne.koch@charite.de.
Abstract
OBJECTIVE: To investigate the influence of midazolam premedication on the EEG-spectrum before and during general anesthesia in elderly patients. METHODS: Patients aged ≥65 years, undergoing elective surgery were included in this prospective observational study. A continuous pre- and intraoperative frontal EEG was recorded in patients who received premedication with midazolam (Mid, n = 15) and patients who did not (noMid, n = 30). Absolute power within the delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta (12-25 Hz) frequency-bands was analyzed in EEG-sections before (pre-induction), and after induction of anesthesia with propofol (post-induction), as well as during general anesthesia with either propofol or volatile-anesthetics (intra-operative). RESULTS: Pre-induction, α-power of Mid patients was lower compared with noMid-patients (α-power: Mid: -10.75 dB vs. noMid: -9.20 dB; p = 0.036). After induction of anesthesia Mid-patients displayed a stronger increase of frontal α-power resulting in higher absolute α-power at post-induction state, (α-power: Mid -3.56 dB vs. noMid: -6.69 dB; p = 0.004), which remained higher intraoperatively (α-power: Mid: -2.12 dB vs. noMid: -6.10 dB; p = 0.024). CONCLUSION: Midazolam premedication alters the intraoperative EEG-spectrum in elderly patients. SIGNIFICANCE: This finding provides further evidence for the role of GABAergic activation in the induction of elevated, frontal α-power during general anesthesia. TRIAL REGISTRY NUMBER: NCT02265263. 23 September 2014. Principal investigator: Prof. Dr. med. Claudia Spies. (https://clinicaltrials.gov/ct2/show/NCT02265263).
OBJECTIVE: To investigate the influence of midazolam premedication on the EEG-spectrum before and during general anesthesia in elderly patients. METHODS:Patients aged ≥65 years, undergoing elective surgery were included in this prospective observational study. A continuous pre- and intraoperative frontal EEG was recorded in patients who received premedication with midazolam (Mid, n = 15) and patients who did not (noMid, n = 30). Absolute power within the delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta (12-25 Hz) frequency-bands was analyzed in EEG-sections before (pre-induction), and after induction of anesthesia with propofol (post-induction), as well as during general anesthesia with either propofol or volatile-anesthetics (intra-operative). RESULTS: Pre-induction, α-power of Midpatients was lower compared with noMid-patients (α-power: Mid: -10.75 dB vs. noMid: -9.20 dB; p = 0.036). After induction of anesthesia Mid-patients displayed a stronger increase of frontal α-power resulting in higher absolute α-power at post-induction state, (α-power: Mid -3.56 dB vs. noMid: -6.69 dB; p = 0.004), which remained higher intraoperatively (α-power: Mid: -2.12 dB vs. noMid: -6.10 dB; p = 0.024). CONCLUSION:Midazolam premedication alters the intraoperative EEG-spectrum in elderly patients. SIGNIFICANCE: This finding provides further evidence for the role of GABAergic activation in the induction of elevated, frontal α-power during general anesthesia. TRIAL REGISTRY NUMBER: NCT02265263. 23 September 2014. Principal investigator: Prof. Dr. med. Claudia Spies. (https://clinicaltrials.gov/ct2/show/NCT02265263).
Authors: Stephan Kratzer; Michael Schneider; David P Obert; Gerhard Schneider; Paul S García; Matthias Kreuzer Journal: Front Syst Neurosci Date: 2020-12-03