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BACKGROUND: The electroencephalographic (EEG) provides the anesthesiologist with information regarding the level of anesthesia. Processed EEG indices are available that reflect the level of anesthesia as a single number. Strong oscillatory EEG activity in the alpha-band may be associated with an adequate level of anesthesia and a lower incidence of cognitive sequelae. So far, we do not know how the processed indices would react to changes in the alpha-band activity. Hence, we modulated the alpha-oscillatory activity of intraoperative EEG to assess possible index changes. METHODS: We performed our analyses based on data from 2 studies. Intraoperative EEG was extracted, and we isolated the alpha-band activity by band-pass filtering (8-12 Hz). We added or subtracted this activity to the original EEG in different steps with different amplifications of the alpha signal. We then replayed these signals to the bispectral index (BIS), the Entropy Module (state entropy [SE]), the CONOX (qCON), and the SEDLine (patient state index [PSI]); and evaluated the alpha-band modulation's impact on the respective index. RESULTS: The indices behaved differently to the modulation. In general, indices decreased with stronger alpha-band activity, but the rate of change was different with SE showing the strongest change (9% per step) and PSI and BIS (<5% per step) showing the weakest change. A simple regression analysis revealed a decrease of 0.02 to 0.09 index points with increasing alpha amplification. CONCLUSIONS: While the alpha-band in the intraoperative EEG seems to carry information regarding the quality of anesthesia, changes in the alpha-band activity do neither strongly nor uniformly influence processed EEG indices. Hence, to assess alpha-oscillatory activity's strength, the user needs to focus on the raw EEG or its spectral representation also displayed on the monitoring systems.
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Introduction: During general anesthesia, frontal electroencephalogram (EEG) activity in the alpha frequency band (8-12 Hz) correlates with the adequacy of analgesia. Transcranial direct current stimulation (tDCS) and auditory stimulation, two noninvasive neuromodulation techniques, can entrain alpha activity in awake or sleeping patients. This study evaluates their effects on alpha oscillations in patients under general anesthesia. Methods: 30 patients receiving general anesthesia for surgery were enrolled in this two-by-two randomized clinical trial. Each participant received active or sham tDCS followed by auditory stimulation or silence according to assigned group (TDCS/AUD, TDCS/SIL, SHAM/AUD, SHAM/SIL). Frontal EEG was recorded before and after neuromodulation. Patients with burst suppression, mid-study changes in anesthetic, or incomplete EEG recordings were excluded from analysis. The primary outcome was post-stimulation change in oscillatory alpha power, compared in each intervention group against the change in the control group SHAM/SIL by Wilcoxon Rank Sum testing. Results: All 30 enrolled participants completed the study. Of the 22 included for analysis, 8 were in TDCS/AUD, 4 were in TDCS/SIL, 5 were in SHAM/AUD, and 5 were in SHAM/SIL. The median change in oscillatory alpha power was +4.7 dB (IQR 4.4, 5.8 dB) in SHAM/SIL, +2.8 dB (IQR 1.5, 8.9 dB) in TDCS/SIL (p = 0.730), +5.5 dB in SHAM/AUD (p = 0.421), and -6.1 dB (IQR -10.2, -2.2 dB) in TDCS/AUD (p = 0.045). Conclusion: tDCS and auditory stimulation can be administered safely intraoperatively. However, these interventions did not increase alpha power as administered and measured in this pilot study.
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Anestesia , Electroencefalografía , Humanos , Anestesia/métodos , Monitoreo Intraoperatorio/métodosRESUMEN
BACKGROUND: Frontal electroencephalography (EEG) monitoring can be useful in guiding the titration of anesthetics, but it is not always feasible to place electrodes in the standard configuration in some circumstances, including during neurosurgery. This study compares 5 alternate configurations of the Masimo Sedline Sensor. METHODS: Ten stably sedated patients in the intensive care unit were recruited. Frontal EEG was monitored in the standard configuration (bifrontal upright) and 5 alternate configurations: bifrontal inverse, infraorbital, lateral upright, lateral inverse, and semilateral. Average power spectral densities (PSDs) with 95% CIs in the alternate configurations were compared to PSDs in the standard configuration. Two-one-sided-testing with Wilcoxon signed-rank tests assessed equivalence in the spectral edge frequency (SEF-95), EEG power, and relative delta (0.5 to 3.5 Hz), alpha (8 to 12 Hz), and beta (20 to 30 Hz) power between each alternate and standard configurations. RESULTS: After the removal of unanalyzable tracings, 7 patients were included for analysis in the infraorbital configuration and 9 in all other configurations. In the lateral upright and lateral inverse configurations, PSDs significantly differed from the standard configuration within the 15 to 20 Hz band. The greatest decrease in EEG power was in the lateral inverse configuration (median: -97 dB; IQR: -130, -62 dB). The largest change in frequency distribution of EEG power was in the infraorbital configuration; median SEF-95 change of -1.4 Hz (IQR: -2.8, 0.7 Hz), median relative delta power change of +7.3% (IQR: 1.4%, 7.9%), and median relative alpha power change of -0.6% (IQR: -5.7%, 0.0%). CONCLUSIONS: These 5 alternate Sedline electrode configurations are suitable options for monitoring frontal EEG when the standard configuration is not possible.
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Monitoring brain activity and associated physiology during the administration of general anesthesia (GA) in mice is pivotal to guarantee postanesthetic health. Clinically, electroencephalogram (EEG) monitoring is a well-established method to guide GA. There are no established methods available for monitoring EEG in mice (Mus musculus) during surgery. In this study, a minimally invasive rodent intraoperative EEG monitoring system was implemented using subdermal needle electrodes and a modified EEG-based commercial patient monitor. EEG recordings were acquired at three different isoflurane concentrations revealing that surgical concentrations of isoflurane anesthesia predominantly contained burst suppression patterns in mice. EEG suppression ratios and suppression durations showed strong positive correlations with the isoflurane concentrations. The electroencephalographic indices provided by the monitor did not support online monitoring of the anesthetic status. The online available suppression duration in the raw EEG signals during isoflurane anesthesia is a straight forward and reliable marker to assure safe, adequate and reproducible anesthesia protocols.
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Anestésicos por Inhalación , Isoflurano , Humanos , Ratones , Animales , Anestesia General , Electroencefalografía , Monitoreo IntraoperatorioRESUMEN
BACKGROUND: Intraoperative alpha-band power in frontal electrodes may provide helpful information about the balance of hypnosis and analgesia and has been associated with reduced occurrence of delirium in the postanesthesia care unit. Recent studies suggest that narrow-band power computations from neural power spectra can benefit from separating periodic and aperiodic components of the electroencephalogram. This study investigates whether such techniques are more useful in separating patients with and without delirium in the postanesthesia care unit at the group level as opposed to conventional power spectra. METHODS: Intraoperative electroencephalography recordings of 32 patients who developed perioperative neurocognitive disorders and 137 patients who did not were considered in this post hoc secondary analysis. The power spectra were calculated using conventional methods and the "fitting oscillations and one over f" algorithm was applied to separate aperiodic and periodic components to see whether the electroencephalography signature is different between groups. RESULTS: At the group level, patients who did not develop perioperative neurocognitive disorders presented with significantly higher alpha-band power and a broadband increase in power, allowing a "fair" separation based on conventional power spectra. Within the first third of emergence, the difference in median absolute alpha-band power amounted to 8.53 decibels (area under the receiver operator characteristics curve, 0.74 [0.65; 0.82]), reaching its highest value. In relative terms, the best separation was achieved in the second third of emergence, with a difference in medians of 7.71% (area under the receiver operator characteristics curve, 0.70 [0.61; 0.79]). The area under the receiver operator characteristics curve values were generally lower toward the end of emergence with increasing arousal. CONCLUSIONS: Increased alpha-band power during emergence in patients who did not develop perioperative neurocognitive disorders can be traced back to an increase in oscillatory alpha activity and an overall increase in aperiodic broadband power. Although the differences between patients with and without perioperative neurocognitive disorders can be detected relying on traditional methods, the separation of the signal allows a more detailed analysis. This may enable clinicians to detect patients at risk for developing perioperative neurocognitive disorders in the postanesthesia care unit early in the emergence phase.
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Delirio , Electroencefalografía , Humanos , Estudios Prospectivos , Electroencefalografía/métodos , Anestesia General/efectos adversos , Anestesia General/métodos , Delirio/diagnóstico , Delirio/psicologíaRESUMEN
BACKGROUND: Monitoring the electroencephalogram (EEG) during general anesthesia can help to safely navigate the patient through the procedure by avoiding too deep or light anesthetic levels. In daily clinical practice, the EEG is recorded from the forehead and available neuromonitoring systems translate the EEG information into an index inversely correlating with the anesthetic level. Electrode placement on the forehead can lead to an influence of electromyographic (EMG) activity on the recorded signal in patients without neuromuscular blockade (NMB). A separation of EEG and EMG in the clinical setting is difficult because both signals share an overlapping frequency range. Previous research showed that indices decreased when EMG was absent in awake volunteers with NMB. Here, we investigated to what extent the indices changed, when EEG recorded during surgery with NMB agents was superimposed with EMG. METHODS: We recorded EMG from the flexor muscles of the forearm of 18 healthy volunteers with a CONOX monitor during different activity settings, that is, during contraction using a grip strengthener and during active diversion (relaxed arm). Both the forehead and forearm muscles are striated muscles. The recorded EMG was normalized by z-scoring and added to the EEG in different amplification steps. The EEG was recorded during anesthesia with NMB. We replayed these combined EEG and EMG signals to different neuromonitoring systems, that is, bispectral index (BIS), CONOX with qCON and qNOX, and entropy module with state entropy (SE) and response entropy (RE). We used the Friedman test and a Tukey-Kramer post hoc correction for statistical analysis. RESULTS: The indices of all neuromonitoring systems significantly increased when the EEG was superimposed with the contraction EMG and with high EMG amplitudes, the monitors returned invalid values, representative of artifact contamination. When replaying the EEG being superimposed with "relaxed" EMG, the qCON and BIS showed significant increases, but not SE and RE. For SE and RE, we observed an increased number of invalid values. CONCLUSIONS: With our approach, we could show that EMG activity during contraction and resting state can influence the neuromonitoring systems. This knowledge may help to improve EEG-based patient monitoring in the future and help the anesthesiologist to use the neuromonitoring systems with more knowledge regarding their function.
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BACKGROUND: Processed electroencephalography (EEG) is used to monitor the level of anesthesia, and it has shown the potential to predict the occurrence of delirium. While emergence trajectories of relative EEG band power identified post hoc show promising results in predicting a risk for a delirium, they are not easily transferable into an online predictive application. This article describes a low-resource and easily applicable method to differentiate between patients at high risk and low risk for delirium, with patients at low risk expected to show decreasing EEG power during emergence. METHODS: This study includes data from 169 patients (median age, 61 yr [49, 73]) who underwent surgery with general anesthesia maintained with propofol, sevoflurane, or desflurane. The data were derived from a previously published study. The investigators chose a single frontal channel, calculated the total and spectral band power from the EEG and calculated a linear regression model to observe the parameters' change during anesthesia emergence, described as slope. The slope of total power and single band power was correlated with the occurrence of delirium. RESULTS: Of 169 patients, 32 (19%) showed delirium. Patients whose total EEG power diminished the most during emergence were less likely to screen positive for delirium in the postanesthesia care unit. A positive slope in total power and band power evaluated by using a regression model was associated with a higher risk ratio (total, 2.83 [95% CI, 1.46 to 5.51]; alpha/beta band, 7.79 [95% CI, 2.24 to 27.09]) for delirium. Furthermore, a negative slope in multiple bands during emergence was specific for patients without delirium and allowed definition of a test for patients at low risk. CONCLUSIONS: This study developed an easily applicable exploratory method to analyze a single frontal EEG channel and to identify patterns specific for patients at low risk for delirium.
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Delirio , Propofol , Humanos , Persona de Mediana Edad , Periodo de Recuperación de la Anestesia , Anestesia General , Delirio/inducido químicamente , Propofol/efectos adversos , Sevoflurano/efectos adversos , Electroencefalografía/métodosRESUMEN
Telemetric electroencephalography (EEG) recording, using subdermal needle electrodes, is a minimally-invasive method to investigate mammalian neurophysiology during anesthesia. These inexpensive systems may streamline experiments examining global brain phenomena during surgical anesthesia or disease. We utilized the OpenBCI™ Cyton board with subdermal needle electrodes to extract EEG features in six C57BL/6J mice undergoing isoflurane anesthesia. Burst suppression ratio (BSR) and spectral features were compared for a verification of our method. Following an increase from 1.5% to 2.0% isoflurane, the BSR increased (Wilcoxon-signed-rank statistic; p = 0.0313). Furthermore, although the absolute EEG spectral power decreased, the relative spectral power remained comparable (Wilcoxon-Mann-Whitney U-Statistic; 95% CI exclusive AUC=0.5; p < 0.05). Compared to tethered systems, this method confers several improvements for anesthesia specific protocols: 1-Avoiding electrode implant surgical procedures, 2-Anatomical non-specificity for needle electrode placement to monitor global cortical activity representative of anesthetic state, 3-Facility to repeat recordings in the same animal, 4-User-friendly for non-experts, 5-Rapid set-up time, and 6-Lower costs.â¢Minimally-invasive telemetric EEG recording systems ergonomically improve tethered systems for anesthesia protocols.â¢Using this method, we verified that higher isoflurane concentrations resulted in an increased EEG burst suppression ratio and decreased EEG absolute spectral power, with no change in frequency distribution.
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Background: An optimized anesthesia monitoring using electroencephalographic (EEG) information in the elderly could help to reduce the incidence of postoperative complications. Processed EEG information that is available to the anesthesiologist is affected by the age-induced changes of the raw EEG. While most of these methods indicate a "more awake" patient with age, the permutation entropy (PeEn) has been proposed as an age-independent measure. In this article, we show that PeEn is also influenced by age, independent of parameter settings. Methods: We retrospectively analyzed the EEG of more than 300 patients, recorded during steady state anesthesia without stimulation, and calculated the PeEn for different embedding dimensions m that was applied to the EEG filtered to a wide variety of frequency ranges. We constructed linear models to evaluate the relationship between age and PeEn. To compare our results to published studies, we also performed a stepwise dichotomization and used non-parametric tests and effect sizes for pairwise comparisons. Results: We found a significant influence of age on PeEn for all settings except for narrow band EEG activity. The analysis of the dichotomized data also revealed significant differences between old and young patients for the PeEn settings used in published studies. Conclusion: Based on our findings, we could show the influence of age on PeEn. This result was independent of parameter, sample rate, and filter settings. Hence, age should be taken into consideration when using PeEn to monitor patient EEG.
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BACKGROUND: Devices monitoring the hypnotic component of general anesthesia can help to guide anesthetic management. The main purposes of these devices are the titration of anesthesia dose. While anesthesia at low doses can result in awareness with intraoperative memory formation, excessive administration of anesthetics may be associated with an increased risk of postoperative neurocognitive disorder. We have previously shown for various indices that they are significantly influenced by the patient's age and that the monitors have a significant time delay. Here, we evaluated the influence of patient's age and time delay on the patient state index (PSI) of the SEDLine monitor. METHODS: To analyze the influence of the patient's age, we replayed 2 minutes of electroencephalography (EEG) of 141 patients (19-88 years, ASA I-IV) undergoing general anesthesia maintained with desflurane, sevoflurane, or propofol to the SEDLine monitor. We extracted the PSI as well as the spectral edge frequency (SEF) and performed a linear regression analysis. For evaluation of the time delay, we replayed 5 minutes of EEG of stable episodes of adequate anesthesia (PSI between 25 and 50) or light sedation/wake (PSI >70) in different orders to the SEDLine to simulate sudden changes between the states. Time delays were defined as the required time span of the monitor to reach the stable target index. RESULTS: PSI and SEF increased significantly with the patient's age. These findings did not depend on the administered anesthetic. The evaluation of the correlation between SEF and PSI showed a strong correlation with Spearman's correlation coefficient of ρ = 0.86 (0.82; 0.89). The time delays depended on the type of transition. We found a median time delay of 54 (Min: 46; Max: 61) seconds for the important transition between adequate anesthesia and awake and 55 (Min: 50; Max: 67) seconds in the other direction. CONCLUSIONS: With our analyses, we show that the indices presented on the SEDLine display, the PSI and the SEF, increase with age for patients under general anesthesia. Additionally, a delay of the PSI to react to sudden neurophysiologic changes due to dose of the maintenance anesthetic is of a time course that is clinically significant. These factors should be considered when navigating anesthesia relying on only the proprietary index for the SEDLine monitor.
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Anestésicos , Propofol , Humanos , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Hipnóticos y Sedantes , Anestesia General/efectos adversos , Sevoflurano , ElectroencefalografíaRESUMEN
Advanced age, American Society of Anesthesiologists physical status (ASA) classification and the presence of cognitive impairment are associated with an elevated risk of postoperative morbidity and mortality. The visual paired comparison (VPC) task, which relies on recognition of novel images, examines declarative memory. VPC scores have demonstrated the ability to detect mild cognitive impairment and track progression of neurodegenerative disease. Quantitative pupillometry may have similar value. We evaluate for associations between these variables of interest and the feasibility of performing these tests in the preoperative clinic. Prospective data from 199 patients seen in the preoperative clinic at a tertiary academic center were analyzed. A 5 min VPC task (Neurotrack Technologies, Inc, Redwood City, CA) was administered during their scheduled preoperative clinic visit. Pupillary light reflexes were measured at the same visit (PLR-3000™, Neuroptics Corp, Irvine, California).Thirty-four percent of patients were categorized as ASA 2 and 58% as ASA 3. Median age was 57 (IQR: 44-69). Associations were demonstrated between age and ASA physical status (Mann-Whitney U Test, p < 0.0001), maximum pupil size (Spearman Rank Correlation, r = - 0.40, p < 0.0001), and maximum constriction velocity (Spearman Rank Correlation, r = - 0.39, p < 0.0001). Our data also revealed an association between VPC score and age (Spearman Rank Correlation, p = 0.0016, r = - 0.21) but not ASA score (Kruskal-Wallis Test, p = 0.14). When compared to a nonsurgical cohort with no history of memory impairment, our population scored worse on the VPC task (Mann-Whitney U Test, p = 0.0002). A preoperative 5 min VPC task and pupillometry are feasible tests in the preoperative setting and may provide a valuable window into an individual's cognition prior to elective surgery.
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Disfunción Cognitiva , Tecnología de Seguimiento Ocular , Enfermedades Neurodegenerativas , Humanos , Persona de Mediana Edad , Estudios Prospectivos , PupilaRESUMEN
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) negatively impacts the central nervous system, and studies using a full montage of electroencephalogram (EEG) electrodes have reported nonspecific EEG patterns associated with coronavirus disease 2019 (COVID-19) infection. The use of this technology is resource-intensive and limited in its implementation. In this descriptive pilot study, we report neurophysiological patterns and the potential prognostic capability of an abbreviated frontal EEG electrode montage in critically ill COVID-19 patients. MATERIALS AND METHODS: Patients receiving mechanical ventilation for SARS-CoV-2 respiratory failure were monitored with Sedline Root Devices using EEG electrodes were placed over the forehead. Qualitative EEG assessments were conducted daily. The primary outcome was mortality, and secondary outcomes were duration of endotracheal intubation and lengths of intensive care and hospitalization stay. RESULTS: Twenty-six patients were included in the study, and EEG discontinuity was identified in 22 (84.6%) patients. The limited sample size and patient heterogeneity precluded statistical analysis, but certain patterns were suggested by trends in the data. Survival was 100% (4/4) for those patients in which a discontinuous EEG pattern was not observed. The majority of patients (87.5%, 7/8) demonstrating activity in the low-moderate frequency range (7 to 17 Hz) survived compared with 61.1% (11/18) of those without this observation. CONCLUSIONS: The majority of COVID-19 patients showed signs of EEG discontinuity during monitoring with an abbreviated electrode montage. The trends towards worse survival among those with EEG discontinuity support the need for additional studies to investigate these associations in COVID-19 patients.
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COVID-19 , Humanos , SARS-CoV-2 , Enfermedad Crítica , Proyectos Piloto , ElectroencefalografíaRESUMEN
Having a healthy sleep pattern plays a vital role in one's overall health. Sleep in the elderly is characterized by decreased slow-wave sleep and an increase of REM sleep. Furthermore, quantitative electroencephalographic (qEEG) studies have shown an age-related attenuation of total EEG power in sleep. However, exercise has been shown to improve sleep across all age groups. In this study, we used the Sleep Profiler™ EEG Sleep Monitor to observe EEG changes occurring during sleep following an aerobic exercise intervention. This study was done on older adults (N = 18, with only five subjects containing both pre- and post-data of sufficient quality for analysis) with an age range 60-85 years. The aerobics regimen was performed three times weekly for 12-weeks commencing with 20-min sessions. The time of each session progressed by 1-2 min/session as needed to a maximum time of 45 min per session. The macro-architecture (sleep stages) and microarchitecture (EEG) results were analyzed using MATLAB. For the microarchitecture, our results showed more deep sleep following the aerobic exercise regimen. Furthermore, for the microarchitecture, out results shows an increase in total EEG power post-exercise in both light (N1 and L1) and deep sleep (N2 and N3). These preliminary changes in sleep the microarchitecture suggest that non-pharmacologic methods might mitigate age-related EEG changes with potential implications for neurocognitive health.
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The course of neuro-cognitive recovery following anaesthesia and surgery is distinctive and poorly understood. Our objective was to identify patterns of neuro-cognitive recovery of the domains routinely assessed for delirium diagnosis in the post anaesthesia care unit (PACU) and to compare them to the cognitive recovery patterns observed in other studies; thereby aiding in the identification of pathological (high risk) patterns of recovery in the PACU. We also compared which of the currently available tests (3D-CAM, CAM-ICU, and NuDESC) is the best to use in PACU. This was a post hoc secondary analysis of data from the Alpha Max study which involved 200 patients aged over 60 years, scheduled for elective surgery under general anaesthesia lasting more than 2 h. These patients were assessed for delirium at 30 min following arrival in the PACU, if they were adequately arousable (Richmond Agitation Sedation Score ≥ -2). All tests for delirium diagnosis (3D-CAM, CAM-ICU, and NuDESC) and the sub-domains assessed were compared to understand temporal recovery of neurocognitive domains. These data were also analysed to determine the best predictor of PACU delirium. We found the incidence of PACU delirium was 35% (3D-CAM). Individual cognitive domains were affected differently. Few individuals had vigilance deficits (6.5%, n = 10 CAM-ICU) or disorganized thinking (19% CAM-ICU, 27.5% 3D-CAM), in contrast attention deficits were common (72%, n = 144) and most of these patients (89.5%, n = 129) were not sedated (RASS ≥ -2). CAM-ICU (27%) and NuDESC (52.8%) detected fewer cases of PACU delirium compared to 3D-CAM. In conclusion, return of neurocognitive function is a stepwise process; Vigilance and Disorganized Thinking are the earliest cognitive functions to return to baseline and lingering deficits in these domains could indicate an abnormal cognitive recovery. Attention deficits are relatively common at 30 min in the PACU even in individuals who appear to be awake. The 3D CAM is a robust test to check for delirium in the PACU.
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Considerable evidence from mouse models and human postmortem brain suggests loss of Muscleblind-like protein 2 (MBNL2) function in brain is a major driver of CNS symptoms in Myotonic dystrophy type 1 (DM1). Increased hypersomnia, fatigue, and surgical complications associated with general anesthesia suggest possible sensitivity to GABAergic inhibition in DM1. To test the hypothesis that MBNL2 depletion leads to behavioral sensitivity to GABAA receptor (GABAA-R) modulation, Mbnl2 knock-out (KO) and wild-type (WT) littermates were treated with the anesthetic sevoflurane, the benzodiazepine diazepam, the imidazopyridine zolpidem, and the benzodiazepine rescue agent, flumazenil (Ro 15-1788), and assessed for various behavioral metrics. Mbnl2 KO mice exhibited delayed recovery following sevoflurane, delayed emergence and recovery from zolpidem, and enhanced sleep time at baseline that was modulated by flumazenil. A significantly higher proportion of Mbnl2 KO mice also loss their righting reflex [loss of righting reflex (LORR)] from a standard diazepam dose. We further examined whether MBNL2 depletion affects total GABAA-R mRNA subunit levels and validated RNA-sequencing data of mis-spliced Gabrg2, whose isoform ratios are known to regulate GABA sensitivity and associated behaviors. While no other GABAA-R subunit mRNA levels tested were altered in Mbnl2 KO mouse prefrontal cortex, Gabrg2S/L mRNA ratio levels were significantly altered. Taken together, our findings indicate that loss of MBNL2 function affects GABAergic function in a mouse model of myotonic dystrophy (DM1).
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Distrofia Miotónica , Animales , Diazepam/farmacología , Modelos Animales de Enfermedad , Flumazenil/farmacología , Humanos , Ratones , Ratones Noqueados , Distrofia Miotónica/genética , Distrofia Miotónica/metabolismo , ARN , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Receptores de GABA-A , Sevoflurano , Zolpidem , Ácido gamma-AminobutíricoRESUMEN
STUDY OBJECTIVE: Postoperative neurocognitive disorders (PND) are common complications after surgery under general anesthesia. In our aging society the incidence of PND will increase. Hence, interdisciplinary efforts should be taken to minimize the occurrence of PND. Electroencephalographic (EEG) monitoring of brain activity during anesthesia or emergence from anesthesia is a promising tool to identify patients at risk. We therefore investigated whether we could identify specific EEG signatures during emergence of anesthesia that are associated with the occurrence of PND. DESIGN AND PATIENTS: We performed a prospective observational investigation on 116 patients to evaluate the EEG features during emergence from general anesthesia dominated by slow delta waves in patients with and without delirium in the postoperative care unit (PACU-D) as assessed by the CAM-ICU and the RASS. MAIN RESULTS: During emergence both the frontal and global EEG of patients with PACU-D were significantly different from patients without PACU-D. PACU-D patients had lower relative alpha power and reduced fronto-parietal alpha coherence. CONCLUSIONS: With our analysis we show differences in EEG features associated with anesthesia emergence in patients with and without PACU-D. Frontal and global EEG alpha-band features could help to identify patients with PACU-D. CLINICAL TRIAL NUMBER: NCT03287401.
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Periodo de Recuperación de la Anestesia , Delirio del Despertar , Envejecimiento , Anestesia General/efectos adversos , Electroencefalografía , Delirio del Despertar/diagnóstico , Delirio del Despertar/etiología , Humanos , Cuidados PosoperatoriosRESUMEN
BACKGROUND: Ketamine is typically used by anesthesiologists as an adjunct for general anesthesia and as a nonopioid analgesic. It has been explored for prevention of postoperative delirium, although results have been contradictory. In this study, we investigated the association of ketamine with postoperative delirium and specific encephalographic signatures. Furthermore, we examined these associations in the context of baseline neurocognition as measured by a validated assessment. METHODS: We conducted a prospective observational study from January 2019 to December 2020. Ninety-eight patients aged ≥65 years and undergoing spine surgery scheduled for ≥3 hours were included in the study. All participants who completed the University of California San Francisco (UCSF) Brain Health Assessment preoperatively and postoperatively were assessed with the confusion assessment method for intensive care unit (CAM-ICU) and/or the Nursing Delirium Screening Scale (NuDESC). Patients had frontal electroencephalogram (EEG) recordings (SedLine Root, Masimo, Corp) quantitatively analyzed. We used 60 seconds of artifact-free EEG (without burst suppression) extracted from the middle of the maintenance period to calculate the normalized power spectral density (PSD). Comparisons were made between those who did or did not receive ketamine and according to results from neurocognitive assessments. RESULTS: Ninety-eight patients (of a total of 155, enrolled and consented) had EEG of sufficient quality for analysis (42 women). Overall, we found a significant increase in the EEG power in the moderate frequency range (10-20 Hz) in patients that received ketamine. When the patients were divided by their preoperative cognitive status, this result in the ketamine group only held true for the cognitively normal patients. Patients that were cognitively impaired at baseline did not demonstrate a significant change in EEG characteristics based on ketamine administration, but impaired patients that received ketamine had a significantly higher rate of postoperative delirium (52% ketamine versus 20% no ketamine) (odds ratio [OR], 4.36; confidence interval [CI], 1.02-18.22; P = .048). In patients determined to be preoperatively cognitively normal, the incidence of postoperative delirium was not significantly associated with ketamine administration (19% ketamine versus 17% no ketamine) (OR, 1.10; CI, 0.30-4.04; P = .5833). CONCLUSIONS: Ketamine-related changes in EEG are observed in a heterogeneous group of patients receiving spine surgery. This result was driven primarily by the effect of ketamine on cognitively normal patients and not observed in patients that were cognitively impaired at baseline. Furthermore, patients who were cognitively impaired at baseline and who had received ketamine were more likely to develop postoperative delirium, suggesting that cognitive vulnerability might be predicted by the lack of a neurophysiologic response to ketamine.