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Background: Excessive workload may impact the anaesthetists' ability to adequately process information during clinical practice in the operation room and may result in inaccurate situational awareness and performance. This exploratory study investigated heart rate (HR), linear and non-linear heart rate variability (HRV) metrics and subjective ratings scales for the assessment of workload associated with the anaesthesia stages induction, maintenance and emergence.Methods: HR and HRV metrics were calculated based on five min segments from each of the three anaesthesia stages. The area under the receiver operating characteristics curve (AUC) of the investigated metrics was calculated to assess their ability to discriminate between the stages of anaesthesia. Additionally, a multiparametric approach based on logistic regression models was performed to further evaluate whether linear or non-linear heart rate metrics are suitable for the assessment of workload.Results: Mean HR and several linear and non-linear HRV metrics including subjective workload ratings differed significantly between stages of anaesthesia. Permutation Entropy (PeEn, AUC=0.828) and mean HR (AUC=0.826) discriminated best between the anaesthesia stages induction and maintenance. In the multiparametric approach using logistic regression models, the model based on non-linear heart rate metrics provided a higher AUC compared with the models based on linear metrics.Conclusions: In this exploratory study based on short ECG segment analysis, PeEn and HR seem to be promising to separate workload levels between different stages of anaesthesia. The multiparametric analysis of the regression models favours non-linear heart rate metrics over linear metrics. [ABSTRACT FROM AUTHOR]

Background: Fluoro-D-deoxyglucose positron emission tomography (FDG-PET) is a standard procedure for interictal assessment and accurate pre-surgical evaluation of presumed epileptogenic zone localization. Profound sedation or general anesthesia is frequently required to reduce movement artefacts in young or cognitively impaired patients during image acquisition. This study compares the impact of propofol and sevoflurane anesthesia on overall quality of PET images, detectability of a hypometabolic lesion and demarcation of the detected lesion in pediatric patients suffering from focal epilepsia., Methods: Pediatric patients with focal epilepsia were anesthesized using propofol (N.=37) or sevoflurane (N.=43). Two independent blinded investigators rated the PET-scans on a 3-point Likert scale with respect to overall quality of PET images, detectability of a hypometabolic lesion and demarcation of the detected lesion. Mann-Whitney-U-Test was conducted to compare the rating results between the two anesthesia regimes. Inter-rater reliability was calculated using Cohen's Kappa., Results: Anesthesia was throughout uneventful and there was no clinical evidence for peridiagnostic seizures. Differences in neither single dimension ratings nor in sum scores (mean 5.8 ± SD 1.5 for propofol, and 5.7 ± SD 1.5 for sevoflurane; P=0.567) were statistically significant. Cohen's Kappa was between 0.428 and 0.499., Conclusion: For surgical planning in patients with epilepsy, FDG-PET imaging is an indispensable functional imaging technique to detect hypometabolism. We conclude that both, sevoflurane and propofol based anesthetic regimes are suitable to detect hypometabolic cerebral lesions during FDG-PET.

Background: New cardiopulmonary resuscitation (CPR) guidelines have been published in 2010 emphasizing the importance of minimizing interruptions during chest compression. The aim of our study was to compare the simulator-based CPR training performance of physicians not specialized in anaesthesia and intensive care nurses before and after implementation of new resuscitation guidelines., Methods: In autumn 2010, a total of 74 scenarios during six 1.5 day simulation-based CPR trainings were performed. Four of them were conducted after the implementation of the 2010 guidelines. During each simulated scenario a programmed script standardized the conditions of the simulator and its reactions on the trainees' actions. CPR relevant parameters were extracted on the basis of the simulator's log files and no-flow-time fraction and median cardiac output of the simulator were calculated. Results before and after the guideline implementation were compared using the Wilcoxon Two Sample Test., Results: Thirty-four out of 74 scenarios were included into the analysis. During training according to the 2010 guidelines, the no-flow-time fraction was lower (median: 21.8% [IQR: 16.1-27.1%] vs. 29.1 % [IQR: 25.0-30.9 %]; P=0.04). The median cardiac output increased from 1.60 L/min-1 [IQR: 1.50-1.65 L/min-1] to 1.90 L/min-1 [IQR: 1.80-2.10 L/min-1]; P<0.001) when the CPR training was conducted according to the 2010 resuscitation guidelines., Conclusion: Non-anesthesiological physicians and intensive care nurses training demonstrated an improved CPR performance in a high-fidelity human patient simulator with respect to the median cardiac output and duration of no-flow-time when 2010 CPR guidelines were applied.