Midlatency auditory evoked potentials during anesthesia in children: A narrative review.

The brain is considered as the major target organ of anesthetic agents. Despite that, a reliable means to monitor its function during anesthesia is lacking. Mid latency auditory evoked potentials are known to be sensitive to anesthetic agents and might therefore be a measure of hypnotic state in pediatric patients. This review investigates the available literature describing various aspects of mid latency auditory evoked potential monitoring in pediatric anesthesia.

The predictive value of the Pleth Variability Index on fluid responsiveness in spontaneously breathing anaesthetized children-A prospective observational study.

BACKGROUND: In children, the preoperative hydration status is an important part of the overall clinical assessment. The assumed preoperative fluid deficit is often routinely replaced during induction without knowing the child's actual fluid status. AIM: We investigated the predictive value of the Pleth Variability Index as a measure of fluid responsiveness in spontaneously breathing anesthetized children. METHODS: Pleth Variability Index, stroke volume and Cardiac Index, measured by electrovelocimetry, mean blood pressure, and heart rate were recorded during anesthesia induction in 50 pediatric patients <6 years. Baseline values were compared to values recorded after administration of 10 mL/kg of Ringer's lactate and during two passive leg raising tests (before and after fluid administration). Fluid responsiveness was defined as an increase of ≥10% in stroke volume. RESULTS: Only in fluid responsive patients, Pleth Variability Index values were higher before fluid administration than thereafter (21.4 ± 5.9% vs 15.0 ± 9.4%, 95% CI of difference 1.1 to 11.8%, P = .02). Pleth Variability Index values at baseline were higher in fluid responders (21.4 ± 5.9%) than in fluid nonresponders (15.3 ± 7.7%), 95% CI of difference 1.6 to 10.6%, P = .009. The area under the receiver operating curve indicating fluid responsiveness was 0.781 (95% CI 0.623 to 0.896, P = .0002), with the highest sensitivity (82%) and specificity (70%) at a Pleth Variability Index of >15% (Positive predictive value 2.71 (95% CI: 1.4 to 5.2)). Only in fluid responders, the Pleth Variability Index decreased during passive leg raising, while stroke volume increased. CONCLUSIONS: The Pleth Variability Index may be of additional value to predict fluid responsiveness in spontaneously breathing anesthetized children. A significant overlap in baseline Pleth Variability Index values between fluid responsive and nonfluid responsive patients does not allow a reliable recommendation as to a cut off value.

Electroencephalographic density spectral array monitoring during propofol/sevoflurane coadministration in children, an exploratory observational study.

INTRODUCTION: Propofol and sevoflurane have a long history in pediatric anesthesia. Combining both drugs at low dose levels offers new opportunities. However, monitoring the hypnotic effects of this drug combination in children is challenging, because the currently available processed EEG-based systems are insufficiently validated in young children and the co-administration of anesthetics. This study investigated electroencephalographic density spectral array monitoring during propofol/sevoflurane coadministration with fixed sevoflurane- and variable propofol dosages. PATIENTS AND METHODS: We analyzed the density spectral array pattern recorded during propofol/sevoflurane anesthesia in pediatric patients from birth to 11 years of age. Data from 78 patients were suitable for analysis. The primary outcome parameter of this study was the correlation between variable propofol dosages and the expression of the four electroencephalogram frequency bands ß, α, θ, and δ. The main secondary outcome parameters were the intra-operative total EEG power and the prevalence of burst suppression. RESULTS: In patients above the age of 1 year, a dose-dependent correlation between the propofol dosage and the relative percentage of ß (-12.2%, p < 0.001) and δ (5.1%, p < 0.001) was found. There was an age-dependent trend toward increasing mean EEG power, with the most significant increase in the first year of life. In 14.1% of our patients, at least one episode of burst suppression occurred. CONCLUSION: DSA-guided augmentation of propofol anesthesia with sevoflurane provides sufficient depth of anesthesia at doses usually considered sub-anesthetic in children, leading to less anesthetic drug exposure for the individual child.

Electroencephalographic Density Spectral Array monitoring in pediatric anesthesia: clinical background and practical applications.

Depth of hypnosis monitoring using numerical index based processed electroencephalography is part of the standard anesthesia equipment in many operating rooms. Unfortunately, this method has its limitations, especially in pediatric patients. Therefore, there is an increasing interest in raw electroencephalography parameters. Electroencephalographic density spectral array (DSA) monitoring is a real-time technique that can be used in all age groups and with all common anesthetics. We present a practice-oriented introduction to the principle of DSA monitoring in pediatric anesthesia for pediatric anesthesiologists and two algorithms for using this technology in children under sevoflurane and propofol anesthesia.

Electroencephalographic density spectral array monitoring during propofol sedation in teenagers, using the narcotrend electroencephalographic monitor.

BACKGROUND: Recently published articles address concerns about the safe use of currently available index-based depth of hypnosis monitors. Electroencephalographic Density Spectral Array monitoring facilitates the interpretation of unprocessed electroencephalogram data, providing the anesthesiologist with real-time drug-specific information on hypnotic depth. The primary aim of this study was to investigate the clinical applicability of Density Spectral Array with a commercially available monitor as the Narcotrend EEG monitor in teenagers under procedural sedation using propofol. METHODS: We performed a secondary analysis of EEG data. Unprocessed electroencephalogram data from 37 patients, aged 12-18 years, scheduled for gastrointestinal endoscopy under propofol sedation, were used for analysis. The relationship between non-steady state propofol concentrations and Density Spectral Array, represented by the four electroencephalographic frequency bands ß, α, θ and δ was investigated. RESULTS: Increasing propofol concentration caused augmentation in the amplitude of frontal δ oscillations and a decrease in the amplitude of frontal ß oscillations. The expression of α oscillations showed a biphasic pattern related to increasing the propofol concentration. Spearman correlation analysis showed a significant correlation between propofol concentration and relative EEG power in ß (r -0.84, P<0.0001), θ (r 0.50, P=0.004) and δ (r 0.63, P<0.0001). CONCLUSIONS: We were able to show that DSA displayed in real time, on a commercially available DoA monitor (the Narcotrend EEG monitor), can provide the anesthesiologist with understandable information regarding the dose-dependent EEG effects of propofol in teenagers.