Emergence delirium in children is related to epileptiform discharges during anaesthesia induction: An observational study

Electroencephalographic insights into the pathophysiological mechanisms of emergence delirium in children and corresponding clinical treatment strategies

Emergence delirium is a common postoperative complication in patients undergoing general anesthesia, especially in children. In severe cases, it can cause unnecessary self-harm, affect postoperative recovery, lead to parental dissatisfaction, and increase medical costs. With the widespread use of inhalation anesthetic drugs (such as sevoflurane and desflurane), the incidence of emergence delirium in children is gradually increasing; however, its pathogenesis in children is complex and unclear. Several studies have shown that age, pain, and anesthetic drugs are strongly associated with the occurrence of emergence delirium. Alterations in central neurophysiology are essential intermediate processes in the development of emergence delirium. Compared to adults, the pediatric nervous system is not fully developed; therefore, the pediatric electroencephalogram may vary slightly by age. Moreover, pain and anesthetic drugs can cause changes in the excitability of the central nervous system, resulting in electroencephalographic changes. In this paper, we review the pathogenesis of and prevention strategies for emergence delirium in children from the perspective of brain electrophysiology-especially for commonly used pharmacological treatments-to provide the basis for understanding the development of emergence delirium as well as its prevention and treatment, and to suggest future research direction.

Intraoperative pediatric electroencephalography monitoring: an updated review

Intraoperative electroencephalography (EEG) monitoring under pediatric anesthesia has begun to attract increasing interest, driven by the availability of pediatric-specific EEG monitors and the realization that traditional dosing methods based on patient movement or changes in hemodynamic response often lead to imprecise dosing, especially in younger infants who may experience adverse events (e.g., hypotension) due to excess anesthesia. EEG directly measures the effects of anesthetics on the brain, which is the target end-organ responsible for inducing loss of consciousness. Over the past ten years, research on anesthesia and computational neuroscience has improved our understanding of intraoperative pediatric EEG monitoring and expanded the utility of EEG in clinical practice. We now have better insights into neurodevelopmental changes in the developing pediatric brain, functional connectivity, the use of non-proprietary EEG parameters to guide anesthetic dosing, epileptiform EEG changes during induction, EEG changes from spinal/regional anesthesia, EEG discontinuity, and the use of EEG to improve clinical outcomes. This review article summarizes the recent literature on EEG monitoring in perioperative pediatric anesthesia, highlighting several of the topics mentioned above.

Association between emergence delirium and brain status parameters in children undergoing general anesthesia: A prospective observational study

INTRODUCTION

Emergence delirium is a common postoperative neurological complication in children after general anesthesia. There is no valid tool to predict emergence delirium. Wavelet index, pain threshold index, anxiety index, and comfort index are real-time brain status parameters extracted from the electroencephalogram, which have recently been developed. The aim is to evaluate the association between real-time brain status parameters during emergence and emergence delirium in children undergoing general anesthesia.

METHODS

One hundred and thirty patients between 3 and 6 years of age undergoing dental surgery under general anesthesia were enrolled in the study. Real-time electroencephalogram data were recorded at four different time points from end of anesthetics administration (T1), end of surgery (T2), extubation (T3), and response (eye opening, movement) to verbal stimulation (T4). Each patient was assessed for emergence delirium using the Pediatric Anesthesia Emergence Delirium scale. Receiver operating characteristics curves and the associated areas under the curves were computed to analyze the ability of wavelet index, pain threshold index, anxiety index, and comfort index to predict emergence delirium.

RESULTS

One hundred and sixteen patients were included for final analysis. During recovery from general anesthesia, brain status parameters increased significantly from T1 (wavelet index, 59.5 ± 6.2; pain threshold index, 61.7 ± 5.3; anxiety index, 9.2 ± 2.5; comfort index, 21.6 ± 8.7) to T4 (wavelet index, 67.4 ± 9.4; pain threshold index, 73.2 ± 9.1; anxiety index, 38.6 ± 11.2; comfort index, 66.1 ± 16.5; p < .001). To predict emergence delirium, areas under the curves [95% CI] for anxiety index were 0.84 [0.75-0.93] (p < .001), and comfort index was 0.89 [0.81-0.96] (p < .001). The Pediatric Anesthesia Emergence Delirium scale scores of 37 patients were higher than 10 indicating emergence delirium, and the incidence of emergence delirium was 31.90%. The sensitivity and specificity of anxiety index with corresponding cutoff values in predicting emergence delirium were 73.0% and 89.9%, and the sensitivity and specificity of comfort index in predicting emergence delirium were 91.9% and 83.5%. The best cutoff values for anxiety index and comfort index to predict emergence delirium were 46.5 and 68.5, respectively. The areas under the curves [95% CI] of wavelet index to predict emergence delirium were 0.43 [0.31-0.35] (p = .27), while the areas under the curves [95% CI] of pain threshold index to predict emergence delirium were 0.49 [0.37-0.62] (p = .73).

DISCUSSION

Both anxiety index and comfort index derived from electroencephalogram wavelet analysis were associated with emergence delirium in pediatric patients undergoing general anesthesia for dental surgery. Wavelet index and pain threshold index were not associated with emergence delirium during general anesthesia for dental surgery in children.

CONCLUSIONS

AnXi and CFi might be used to guide anesthesiologists to identify and intervene ED in children.

Analysis of the relationship between EEG burst suppression and poor prognosis in children under general anaesthesia: study protocol for a prospective, observational, single-centre study

BACKGROUND

Emergence delirium (ED) in children refers to the immediate postoperative period when children experience decreased perception of their surroundings, accompanied by disorientation and altered perception. Burst suppression (BS) is recognised as periods longer than 0.50 s during which the EEG does not exceed approximately + 5.0 mV, which is an electroencephalographic state associated with profound inactivation of the brain. Our primary objective was to determine the association between BS on electroencephalogram (EEG) under general anaesthesia with postoperative wake-up delirium and multiple adverse outcomes, such as prolonged awakening and extubation.

METHODS

In this prospective, observational cohort study at Beijing Children's Hospital, Capital Medical University, Beijing, China, children aged 6 months to 9 years who underwent surgery under general anaesthesia and underwent EEG monitoring between January 2022 and January 2023 were included. Patients' prefrontal EEGs were recorded intraoperatively as well as analysed for the occurrence and duration of BS and scored postoperatively for delirium by the PAED scale, with a score of no less than 10 considered as having developed wake-up delirium.

DISCUSSION

This study identified a relationship between EEG BS and postoperative awakening delirium under general anaesthesia in children and provides a novel preventive strategy for postoperative awakening delirium and multiple adverse outcomes in paediatric patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2200055256. Registered on January 5, 2022.

Desflurane is risk factor for postoperative delirium in older patients' independent from intraoperative burst suppression duration

Background

Postoperative Delirium (POD) is the most frequent neurocognitive complication after general anesthesia in older patients. The development of POD is associated with prolonged periods of burst suppression activity in the intraoperative electroencephalogram (EEG). The risk to present burst suppression activity depends not only on the age of the patient but is also more frequent during propofol anesthesia as compared to inhalative anesthesia. The aim of our study is to determine, if the risk to develop POD differs depending on the anesthetic agent given and if this correlates with a longer duration of intraoperative burst suppression.

Methods

In this secondary analysis of the SuDoCo trail [ISRCTN 36437985] 1277 patients, older than 60 years undergoing general anesthesia were included. We preprocessed and analyzed the raw EEG files from each patient and evaluated the intraoperative burst suppression duration. In a logistic regression analysis, we assessed the impact of burst suppression duration and anesthetic agent used for maintenance on the risk to develop POD.

Results

18.7% of patients developed POD. Burst suppression duration was prolonged in POD patients (POD 27.5 min ± 21.3 min vs. NoPOD 21.4 ± 16.2 min, p < 0.001), for each minute of prolonged intraoperative burst suppression activity the risk to develop POD increased by 1.1% (OR 1.011, CI 95% 1.000-1.022, p =  0.046). Burst suppression duration was prolonged under propofol anesthesia as compared to sevoflurane and desflurane anesthesia (propofol 32.5 ± 20.3 min, sevoflurane 17.1 ± 12.6 min and desflurane 20.1 ± 16.0 min, p < 0.001). However, patients receiving desflurane anesthesia had a 1.8fold higher risk to develop POD, as compared to propofol anesthesia (OR 1.766, CI 95% 1.049-2.974, p =  0.032).

Conclusion

We found a significantly increased risk to develop POD after desflurane anesthesia in older patients, even though burst suppression duration was shorter under desflurane anesthesia as compared to propofol anesthesia. Our finding might help to explain some discrepancies in studies analyzing the impact of burst suppression duration and EEG-guided anesthesia on the risk to develop POD.

Association of electroencephalogram epileptiform discharges during cardiac surgery with postoperative delirium: An observational study

Background

Delirium is a frequent and serious complication following cardiac surgery involving cardiopulmonary bypass (CPB). Electroencephalography reflects the electrical activity of the cerebral cortex. The impact of electroencephalographic epileptiform discharges during cardiac surgery on postoperative delirium remains unclear. This study was designed to investigate the relationship between intraoperative epileptiform discharges and postoperative delirium in patients undergoing cardiac surgery.

Methods

A total of 76 patients who underwent cardiac surgery under CPB were included. The baseline cognitive status was measured before surgery. Electroencephalograms were monitored continuously from entry into the operating room to the end of surgery. The presence of delirium was assessed through the Confusion Assessment Method or the Confusion Assessment Method for the Intensive Care Unit on the first 3 days after surgery. Univariate and multivariate logistic regression analyses were performed to evaluate the association between epileptiform discharges and delirium.

Results

Delirium occurred in 31% of patients and epileptiform discharges were present in 26% of patients in the study. Patients with delirium had a higher incidence of epileptiform discharges (52.63% vs. 13.95%, P &lt; 0.001) and longer durations of anesthesia and CPB (P = 0.023 and P = 0.015, respectively). In addition, patients with delirium had a longer length of hospital stay and a higher incidence of postoperative complications. Multivariate logistic regression analysis showed that age and epileptiform discharges were significantly associated with the incidence of postoperative delirium [odds ratio, 4.75 (1.26–17.92), P = 0.022; 5.00 (1.34–18.74), P = 0.017, respectively].

Conclusions

Postoperative delirium is significantly related to the occurrence of epileptiform discharges during cardiac surgery.

EEG-Parameter-Guided Anesthesia for Prevention of Emergence Delirium in Children

Background: Emergence delirium (ED) usually occurs in children after surgery with an incidence of 10−80%. Though ED is mostly self-limited, its potential injuries cannot be ignored. Whether electroencephalography (EEG)-parameter-guided anesthesia could reduce the incidence of ED in pediatric surgery has not been fully discussed to date. Methods: Fifty-four boys aged 2−12 years undergoing elective hypospadias surgery under sevoflurane anesthesia were selected. In the EEG-parameter-guided group (E group), sevoflurane was used for anesthesia induction and was maintained by titrating the spectral edge frequency (SEF) to 10−15 and combining the monitoring of density spectral array (DSA) power spectra and raw EEG. While in the control group (C group), anesthesiologists were blinded to the SedLine screen (including SEF, DSA, and raw EEG) and adjusted the intraoperative drug usage according to their experience. Patients with a Pediatric Anesthesia Emergence Delirium (PAED) score > 10 were diagnosed with ED, while patients with a PAED score > 2 were diagnosed with emergence agitation (EA). Results: Finally, a total of 37 patients were included in this trial. The incidence of ED in the E group was lower than in the C group (5.6% vs. 36.8%; p = 0.04), while the incidence of EA was similar in the two groups (61% vs. 78.9%; p = 0.48). Intraoperative parameters including remifentanil dosage and the decrease in mean arterial pressure (MAP) were not different between the two groups (p > 0.05), but the mean end-tidal sevoflurane concentration (EtSevo) was lower in the E group than in the C group (p > 0.05). Moreover, during PACU stay, the extubation time and discharge time of the groups were similar, while the PAED scores within 5 min from extubation and the Face, Legs, Activity, Cry, and Consolability (FLACC) scores within 30 min from extubation were lower in the E group than in the C group. Conclusion: EEG-parameter-guided anesthesia management reduced the incidence of ED in children. Studies with larger sample sizes are needed to obtain more convincing results.

Epileptiform EEG discharges during sevoflurane anesthesia in children: A meta-analysis

OBJECTIVE

To investigate the overall incidence and associated factors of epileptiform discharges in children during sevoflurane anesthesia.

METHODS

Our group systematically searched the PubMed, Cochrane library (Central) and EMBASE for the relevant trials from their inception until September 2020. The primary endpoint was the incidence of epileptiform discharges during sevoflurane induction. The secondary endpoints were the incidence of different types of epileptiform discharges, factors associated with these epileptiform events, and other adverse events such as seizure-like movements.

RESULTS

After screening of 713 records, eleven studies involving 448 participants were included into the final analysis. Meta-analysis indicated that the overall incidence of Epileptiform EEG discharges was 38.1% (95%confidence interval [CI], 19.1%-59.2%) during sevoflurane anesthesia in children. Subgroup analysis showed that the incidence of these EEG patters was lower when participants were inducted by using the low initial concentration of sevoflurane, compared with the high initial concentration sevoflurane (1.7%, 95%CI, 0.0% to 8.4% versus 47.7%, 95%CI, 25.5% to 70.3%, P < 0.05). The longer exposure (>3 min) of high concentration sevoflurane during induction showed higher rate of epileptiform discharges than a shorter exposure (≤3 min) (48.4%, 95%CI, 20.1% to 77.3% versus 5.7%, 95%CI, 0.00% to 23.5%; P < 0.05). No significant difference for the incidence of epileptiform discharges was observed in subgroup analysis of addition of nitrous oxide (69.2%, 95%CI, 34.0% to 95.7% versus 41.3%, 95%CI, 15.6% to 69.7%, P﹥0.05) and type of EEG monitoring (26.9%, 95%CI, 3.8% to 60.7% versus 53.1%, 95%CI, 25.4% to 79.8%, P﹥0.05).

CONCLUSIONS

The incidence of epileptiform EEG events in children during sevoflurane anesthesia varied from 19.1%-59.2%. The low initial concentration technique and shorter exposure time of high concentration sevoflurane may be associated with a decreased incidence of these epileptiform discharges in EEG.

SIGNIFICANCE

Epileptiform EEG discharges during sevoflurane anesthesia in children should arouse clinicians' attention. The use of low initial concentration technique and shorter exposure time of high concentration sevoflurane may be associated with a lower occurrence of these paradoxical events.

Urinary Aromatic Amino Acid Metabolites Associated With Postoperative Emergence Agitation in Paediatric Patients After General Anaesthesia: Urine Metabolomics Study

Background: Emergence agitation (EA) is very common in paediatric patients during recovery from general anaesthesia, but underlying mechanisms remain unknown. This prospective study was designed to profile preoperative urine metabolites and identify potential biomarkers that can predict the occurrence of EA.

Methods: A total of 224 patients were screened for recruitment; of those, preoperative morning urine samples from 33 paediatric patients with EA and 33 non-EA gender- and age-matched patients after being given sevoflurane general anaesthesia were analysed by ultra-high-performance liquid chromatography (UHPLC) coupled with a Q Exactive Plus mass spectrometer. Univariate analysis and orthogonal projection to latent structures squares-discriminant analysis (OPLS-DA) were used to analyse these metabolites. The least absolute shrinkage and selection operator (LASSO) regression was used to identify predictive variables. The predictive model was evaluated through the receiver operating characteristic (ROC) analysis and then further assessed with 10-fold cross-validation.

Results: Seventy-seven patients completed the study, of which 33 (42.9%) patients developed EA. EA and non-EA patients had many differences in preoperative urine metabolic profiling. Sixteen metabolites including nine aromatic amino acid metabolites, acylcarnitines, pyridoxamine, porphobilinogen, 7-methylxanthine, and 5′-methylthioadenosine were found associated with an increased risk of EA, and they all exhibited higher levels in the EA group than in the non-EA group. The main metabolic pathways involved in these metabolic changes included phenylalanine, tyrosine and tryptophan metabolisms. Among these potential biomarkers, L-tyrosine had the best predictive value with an odds ratio (OR) (95% CI) of 5.27 (2.20–12.63) and the AUC value of 0.81 (0.70–0.91) and was robust with internal 10-fold cross-validation.

Conclusion: Urinary aromatic amino acid metabolites are closely associated with EA in paediatric patients, and further validation with larger cohorts and mechanistic studies is needed.

Clinical Trial Registration:clinicaltrials.gov, identifier NCT04807998

Emergence agitation in paediatric day case surgery: A randomised, single-blinded study comparing narcotrend and heart rate variability with standard monitoring

BACKGROUND

Postoperative emergence agitation remains a significant challenge in paediatric anaesthesia. Although short-lived, it may cause harm to the patient and negative experiences for all. Differentiating agitation, delirium and pain is difficult. Electroencephalography allows precise titration of anaesthetic depth, and heart rate variability monitoring permits immediate intervention regarding nociception and pain. We examined if one of these measures could be used to reduce postoperative agitation in an unselected paediatric day surgical population.

OBJECTIVE

The primary outcome was postoperative agitation with a Richmond Agitation-Sedation Scale greater than 0. Secondary outcomes were: length of stay, postoperative nausea and vomiting, fentanyl and propofol consumption, pain scores and use of postoperative analgesics.

DESIGN

A randomised, single-blinded study constituting children aged 1 to 6 years, undergoing minor general day surgical procedures.

SETTING

Paediatric day surgical department 29th March 2019 to 12th June 2020.

PATIENTS

Ninety-eight children (ASA 1 or 2) were enrolled, and 93 children were included in the final analysis.

INTERVENTIONS

Children received standard monitoring (n=31), standard monitoring plus either Narcotrend (n=31), or Anaesthesia Nociception Index monitoring (n=31). Sevoflurane or fentanyl was titrated immediately according to monitor thresholds.

RESULTS

Kaplan-Meier analysis yielded a statistically significant difference between the groups (P = 0.016) with the lowest agitation levels in the Anaesthesia Nociception Index group, intermediate levels in the control group and the highest agitation levels in the Narcotrend monitored group. Intergroup pairwise comparison however, showed no difference. The Anaesthesia Nocioception Index group received slightly more fentanyl (P = 0.277). The control group patients had the highest pain scores despite receiving more caudal blocks and the Narcotrend group had more sevoflurane adjustments. Other secondary outcomes were comparable.

CONCLUSION

Children in the Anaesthesia Nociception Index group were the least agitated with the highest fentanyl doses, without increasing the length of stay in the PACU or postoperative nausea and vomiting.

CLINICAL REGISTRATION

The study was registered in RedCAP online trial database 1/11/2018 trial registration nr. OP720. https://open.rsyd.dk/OpenProjects/openProject.jsp?openNo=720&lang=da.

[Intraoperative Neuromonitoring: Electroencephalography]

Intraoperative neuromonitoring using electroencephalography (EEG) enables anaesthesiologists to monitor the depth of anaesthesia. It is intended to reduce the occurrence of intraoperative wakefulness, postoperative delirium and postoperative cognitive deficits and to shorten process times in the operating room. This article shows how to interpret the raw EEG, spectrograms and processed indices for different age groups and anaesthetics and summarizes the resulting clinical benefits. While propofol and volatile anesthetics produce characteristic frontal EEG signatures with a high activity of coherent α- and δ-waves, ketamine triggers an increase in rapid γ-waves, which leads to incorrectly high indices (BIS, PSI, NI) despite deep anaesthetic levels.In children, frontal α-waves do not appear until the age of approx. 6 months and valid indices (BIS, PSI, NI) can only be derived starting at an age of approx. 12 months. Furthermore, children of preschool and elementary school age often show epileptiform discharges in the EEG during induction of anaesthesia, what is linked to emergence delirium. In adults, the intraoperative frontal α-power decreases significantly with increasing age and older patients tend to have an increased occurrence of burst suppression patterns during anaesthesia. Clinical benefits of EEG-based neuromonitoring comprise reduced doses of anaesthesia, shorter wake-up times after surgery and a lower incidence of intraoperative awareness during total intravenous anaesthesia. Moreover, anaesthesia guided by processed EEG indices can reduce the incidence of postoperative delirium and postoperative cognitive deficits in older patients. In-depth knowledge about intraoperative EEG changes that go beyond the interpretation of processed indices could lead to a further reduction in intra- and postoperative complications in the future.

Tracheal intubation with or without a neuromuscular blocking agent for a short surgical procedure in children: Prospective, randomized, double-blind trial

BACKGROUND

Although a neuromuscular blocking agent during induction of anesthesia is the standard of care in adults, some pediatric anesthesiologists remain concerned about their use for several reasons. Therefore, propofol and short-acting opioids with a moderate concentration of sevoflurane have been used as alternatives to a neuromuscular blocking agent.

AIMS

This study compared propofol, alfentanil, and rocuronium to determine the optimal anesthetic agent for intubation conditions as well as emergence in a short pediatric procedure.

METHODS

In this prospective, randomized, double-blind study, 114 pediatric patients, aged 1-9 years, were randomly assigned to one of three groups receiving either propofol 2 mg kg^-1 (propofol group), alfentanil 14 mcg kg^-1 (alfentanil group), or rocuronium 0.3 mg kg^-1 (rocuronium group). The primary outcome was intubating conditions, which were evaluated 90 s after test drug administration. Vital signs were recorded during the intubation period. Complications during and after emergence, time to recovery, airway-related complications, and severity of emergence agitation were recorded.

RESULTS

Compared with the propofol group (60%), significantly more excellent intubating conditions were observed in the alfentanil group (97%, percent difference -37, 95% confidence interval (CI) -54.4--21.0, p < .001) and the rocuronium group (87%, percent difference -27, 95% CI -46.5--8.2, p = .041). Hemodynamic responses were different between the rocuronium and alfentanil groups, although the incidence of adverse events was not different among the three groups. The emergence duration was only statistically different between the rocuronium group [9.9 ± 3.2 min] and the propofol group [11.7 ± 2.2 min] (difference 95% CI 0.667-3.583, p = .001), while that of the alfentanil group [10.9 ± 2.4 min] was comparable with the other groups.

CONCLUSIONS

Both 0.3 mg kg^-1 rocuronium and 14 µg kg^-1 alfentanil are superior adjuncts for tracheal intubation in children undergoing frenulectomy in comparison with 2 mg kg^-1 propofol. Hemodynamic adverse events and recovery profiles were comparable among the three groups.

Investigating how electroencephalogram measures associate with delirium: A systematic review

Delirium is a common neurocognitive disorder in hospital settings, characterised by fluctuating impairments in attention and arousal following an acute precipitant. Electroencephalography (EEG) is a useful method to understand delirium pathophysiology. We performed a systematic review to investigate associations between delirium and EEG measures recorded prior, during, and after delirium. A total of 1,655 articles were identified using PsycINFO, Embase and MEDLINE, 31 of which satisfied inclusion criteria. Methodological quality assessment was undertaken, resulting in a mean quality score of 4 out of a maximum of 5. Qualitative synthesis revealed EEG slowing and reduced functional connectivity discriminated between those with and without delirium (i.e. EEG during delirium); the opposite pattern was apparent in children, with cortical hyperexcitability. EEG appears to have utility in differentiating those with and without delirium, but delirium vulnerability and the long-term effects on brain function require further investigation. Findings provide empirical support for the theory that delirium is a disorder of reduced functional brain integration.

Frontal electroencephalogram activity during emergence from general anaesthesia in children with and without emergence delirium

BACKGROUND

Emergence delirium (ED) in children after general anaesthesia causes significant distress in patients, their family members, and clinicians; however, electroencephalogram (EEG) markers predicting ED have not been fully investigated.

METHODS

This prospective, single-centre observational study enrolled children aged 2-10 yr old under sevoflurane anaesthesia. ED was assessed according to Diagnostic and Statistical Manual of Mental Disorders (DSM) IV or 5 criteria. The relative power of low-frequency (delta and theta) and high-frequency (alpha and beta) EEG waves during the emergence period was compared between the children with and without ED. The linear relationships between the relative power and peak Paediatric Assessment of Emergence Delirium (PAED) score were investigated.

RESULTS

Among the 60 patients, 22 developed ED (ED group), whereas the other 38 did not (non-ED group). The relative power of the delta wave was higher (mean [standard deviation], 0.579 [0.083] vs 0.453 [0.090], respectively, P<0.001) in the ED group, whereas that of the alpha and beta waves was lower in the ED group, than in the non-ED group (0.155 [0.063] vs 0.218 [0.088], P=0.005 and 0.114 [0.069] vs 0.186 [0.070], P<0.001, respectively). The areas under the receiver operating characteristic curves of the relative power of the delta wave, low-to-high frequency power ratio, and delta-to-alpha ratio were 0.837 (95% confidence interval, 0.737-0.938), 0.835 (0.735-0.934), and 0.768 (0.649-0.887), respectively. The relative power of the delta wave and the two ratios had a positive linear relationship with the peak PAED scores.

CONCLUSIONS

Paediatric patients developing ED have increased low-frequency (delta) frontal EEG activity with reduced high-frequency (alpha and beta) activity during emergence from general anaesthesia.

CLINICAL TRIAL REGISTRATION

NCT03797274.

Epileptiform EEG discharges and sevoflurane in children: Protocol of a systematic review and meta-analysis

BACKGROUND

Epileptiform discharges in electroencephalogram (EEG) have been frequently reported in children undergoing sevoflurane mask induction. However, the incidence, characteristics and risk factors of these epileptiform patterns during sevoflurane anesthesia in children are poorly understood. The aim of this study is to systematically review the epileptic potential of sevoflurane in children with the EEG monitoring.

METHODS

PubMed, EMBASE, Cochrane library (Central) will be systematically searched from inception to December 2018. The effect of sevoflurane on epileptic EEG patters in children will be studied. The primary outcome will be the incidence of epileptic discharges, the characteristics and risk factors of these epileptic discharges. Meta-analysis will be calculated using R software 3.5.1.

RESULTS

This study will offer new evidence of the incidence, characteristics and risk factors of EEG epileptic discharges during sevoflurane anesthesia.

CONCLUSION

The conclusion drawn from this systematic review will benefit the children with or without epilepsy undergoing sevoflurane anesthesia.

ETHICS AND DISSEMINATION

Ethics approval is unnecessary because data of individual patients will not be included and no privacy will be involved. The results of this review will be published in a peer-reviewed journal or a conference report. Amendments of the basic protocol will be documented in the comprehensive review.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD 42019122008.

Emergence delirium in children is not related to intraoperative burst suppression - prospective, observational electrography study

BACKGROUND

Emergence-delirium is the most frequent brain dysfunction in children recovering from general anaesthesia, though the pathophysiological background remains unclear. The presented study analysed an association between emergence delirium and intraoperative Burst Suppression activity in the electroencephalogram, a period of very deep hypnosis during general anaesthesia.

METHODS

In this prospective, observational cohort study at the Charité - university hospital in Berlin / Germany children aged 0.5 to 8 years, undergoing planned surgery, were included between September 2015 and February 2017. Intraoperative bi-frontal electroencephalograms were recorded. Occurrence and duration of Burst Suppression periods were visually analysed. Emergence delirium was assessed using the Pediatric Assessment of Emergence Delirium Score.

RESULTS

From 97 children being analysed within this study, 40 children developed emergence delirium, and 57 children did not. Overall 52% of the children displayed intraoperative Burst Suppression periods; however, occurrence and duration of Burst Suppression (Emergence delirium group 55% / 261 + 462 s vs. Non-emergence delirium group 49% / 318 + 531 s) did not differ significantly between both groups.

CONCLUSIONS

Our data reveal no correlation between the occurrence and duration of intraoperative Burst Suppression activity and the incidence of emergence delirium. Burst Suppression occurrence is frequent; however, it does not seem to have an unfavourable impact on cerebral function at emergence from general anaesthesia in children.

TRAIL REGISTRATION

NCT02481999, June 25, 2015.

Neuromonitoring in the elderly

PURPOSE OF REVIEW

To summarize recent recommendations on intraoperative electroencephalogram (EEG) neuromonitoring in the elderly aimed at the prevention of postoperative delirium and long-term neurocognitive decline. We discuss recent perioperative EEG investigations relating to aging and cognitive dysfunction, and their implications on intraoperative EEG neuromonitoring in elderly patients.

RECENT FINDINGS

The incidence of postoperative delirium in elderly can be reduced by monitoring depth of anesthesia, using an index number (0-100) derived from processed frontal EEG readings. The recently published European Society of Anaesthesiology guideline on postoperative delirium in elderly now recommends guiding general anesthesia with such indices (Level A). However, intraoperative EEG signatures are heavily influenced by age, cognitive function, and choice of anesthetic agents. Detailed spectral EEG analysis and research on EEG-based functional connectivity provide new insights into the pathophysiology of neuronal excitability, which is seen in elderly patients with postoperative delirium.

SUMMARY

Anesthesiologists should become acquainted with intraoperative EEG signatures and their relation to age, anesthetic agents, and the risk of postoperative cognitive complications. A working knowledge would allow an optimized and individualized provision of general anesthesia for the elderly.