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This study evaluated the effectiveness of the essential oil of Hesperozygisringens (EOHR) for anesthesia of Colossomamacropomum by documenting hematological and blood biochemical responses after biometric handling. In Experiment 1, juveniles (14.12 ± 3.53 g) were exposed to different concentrations of EOHR: 0 (control), 75, 150, 300 and 450 µL L-1 (n=10 fish for each concentration), to determine times for induction and recovery from anesthesia, as well as its effects on ventilatory frequency (VF). Based on these results, Experiment 2 evaluated the effects of 0 (control), 75 (with induction and recovery times outside that recommended for fish anesthesia) and 150 µL L-1 EOHR (within recommended times) on hematological and biochemical variables of juveniles (20.52 ± 3.47 g) after anesthesia and after 24 h of recovery (n = 6 fish for each concentration and collection time). Survival was 100%. Induction time showed a quadratic effect of EOHR concentration. Recovery time did not differ among EOHR concentrations. Concentrations between 150 and 450 µL L-1 EOHR caused rapid induction (< 3 min) and recovery (< 5 min). EOHR concentration affected VF. The concentration of 150 µL L-1 EOHR had little influence on hematological and biochemical parameters of C. macropomum of 20 g. RESUMO: Este estudo avaliou a eficiência do óleo essencial de Hesperozygis ringens (EOHR) para anestesia de Colossoma macropomum, documentando as respostas hematológicas e bioquímicas do sangue após o manuseio biométrico. No experimento 1, juvenis (14,12 ± 3,53 g) foram expostos a diferentes concentrações de EOHR: 0 (controle), 75, 150, 300 e 450 µL L-1 (n = 10 peixes para cada concentração), para determinar os tempos de indução e recuperação da anestesia, bem como seus efeitos na frequência ventilatória (VF). Com base nesses resultados, o experimento 2 avaliou os efeitos de 0 (controle), 75 (com tempos de indução e recuperação fora do recomendado para anestesia de peixes) e 150 µL L-1 EOHR (dentro dos tempos recomendados) sobre variáveis hematológicas e bioquímicas de juvenis (20,52 ± 3,47 g) após a anestesia e após 24h de recuperação (n = 6 peixes para cada concentração e tempo de coleta). A sobrevivência foi de 100%. O tempo de indução mostrou efeito quadrático da concentração de EOHR. O tempo de recuperação não diferiu entre as concentrações de EOHR. Concentrações entre 150 e 450 µL L-1 EOHR causaram rápida indução (< 3 min) e recuperação (< 5 min). As concentrações de EOHR afetaram a VF. A concentração de 150 µL L-1 de EOHR teve pouca influência nos parâmetros hematológicos e bioquímicos de C. macropomum de 20 g.

Purpose of review Major adverse cardiovascular and cerebrovascular events (MACCE) significantly affect the surgical outcomes. Electrocardiogram (ECG) has been a standard intraoperative monitor for 30 years. Electroencephalogram (EEG) can provide valuable information about the anesthetized state and guide anesthesia management during surgery. Whether EEG should be a standard intraoperative monitor is discussed in this review. Recent findings Deep anesthesia has been associated with postoperative delirium, especially in elderly patients. Intraoperative EEG monitoring has been demonstrated to reduce total anesthesia drug use during general anesthesia and postoperative delirium. Summary Unlike ECG monitoring, the EEG under general anesthesia has not been designated as a standard monitor by anesthesiologist societies around the world. The processed EEG technology has been commercially available for more than 25 years and EEG technology has significantly facilitated its intraoperative use. It is time to consider EEG as a standard anesthesia monitor during surgery.

Slow oscillations are the coordinated activity of large neuronal populations consisting of alternating active (Up states) and silent periods (Down states). These oscillations occur in the corticothalamocortical network during slow-wave sleep and deep anesthesia. They also spontaneously occur in isolated cortical slices or in disconnected ‘cortical islands’ in brain damage. This rhythmic activity emerges in the cortical network when there are no other driving inputs and is considered its default activity pattern. During Up states, neocortical neurons receive barrages of synaptic inputs and fire action potentials. During Down states, neurons remain silent; rather they are hyperpolarized, and synaptic activity is almost nonexistent. From a dynamic perspective, this pattern is often referred to as a state-dependent bistability. During Up states, the activity expresses coherent oscillations at high frequencies in the beta and gamma ranges, sharing properties with wakefulness. The impact of Up/Down states on synaptic transmission and plasticity and its relationship with sleep are discussed.

Background Consciousness during surgical procedure is associated with adverse psychological effects and postoperative complications. The aim of this study is to evaluate the depth of anesthesia using brain function index (BFI) among patients undergoing elective laparotomy. Materials and methods In this cross-sectional study, 256 patients referred to (XXX) for elective laparotomy were included. BFI values using published studies were used to measure the depth of anesthesia in response to propofol, atracurium and propofol induction: deeply anesthetized (BFI Results The average dose of propofol administered/propofol infusion was 111.67 ± 78.87 and 104.88 ± 76.20, respectively, atracurium 67.04 ± 40.06 and fentanyl was 33.61 ± 9.137. Deep anesthesia and light anesthesia were significantly different at various time intervals, p Conclusion The outcomes of our study show that brain function index might be helpful to determine the level of anesthesia among patients undergoing elective laparotomy. However, further comparative studies, including other parameters are required.

During deep anesthesia, the electroencephalographic (EEG) signal of the brain alternates between bursts of activity and periods of relative silence (suppressions). The origin of burst-suppression and its distribution across the brain remain matters of debate. In this work, we used functional magnetic resonance imaging (fMRI) to map the brain areas involved in anesthesia-induced burst-suppression across four mammalian species: humans, long-tailed macaques, common marmosets, and rats. At first, we determined the fMRI signatures of burst-suppression in human EEG-fMRI data. Applying this method to animal fMRI datasets, we found distinct burst-suppression signatures in all species. The burst-suppression maps revealed a marked inter-species difference: in rats the entire neocortex engaged in burst-suppression, while in primates most sensory areas were excluded—predominantly the primary visual cortex. We anticipate that the identified species-specific fMRI signatures and whole-brain maps will guide future targeted studies investigating the cellular and molecular mechanisms of burst-suppression in unconscious states.

Fish may warrant euthanasia for a variety of reasons, but euthanasia may be difficult to accomplish or confirm because fish can recover from deep anesthesia even after cardiac and respiratory arrest. The efficacies of three types of anesthetics were evaluated to compare their suitability for euthanasia of Unga cichlids (Sarotherodon linellii). Thirty cichlids were randomly assigned to be immersed in one of the three anesthetic solutions: tricaine methanesulfonate (MS-222), 2-phenoxyethanol (2-PE), and clove oil (CO) at doses of 1,000 mg/L, 2 mL/L, and 500 mg/L respectively. The opercular rates and caudal fin stroke rates were quantified, and the time to cessation of physiological measures (CPM) including caudal fin strokes, the reaction to external stimuli, the righting reflex, swimming, and operculation were recorded. Varying anesthetic induction times were observed with all three euthanasia solutions; the time to CPM in the 2-PE group occurred at a significantly slower rate than in the MS-222 group (P 0.05). The cost of euthanasia per cichlid was calculated, with the most economically viable option being 2-PE; at more than seven times the price of 2-PE, MS-222 was the most expensive. After a 60-min immersion in the euthanasia solution, the presence of an audible heartbeat was identified in 100% of the cichlids immersed in 2-PE, 100% immersed in CO, and 90% in MS-222, indicating that they were not reliably euthanized. Therefore, a two-step protocol is recommended in cichlids for euthanasia: heavy anesthesia via immersion followed by an intravenous or intracardiac injection of euthanasia solution, or other secondary method of euthanasia.

Neben tiefen Narkoseindexwerten wurden insbesondere Burst-Suppression-Muster und deren Zusammenhang mit postoperativem Delir und postoperativer Mortalitat untersucht. Dreizehn der im Folgenden beschriebenen Studien aus dem letzten Jahrzehnt liefern Hinweise, dass dokumentierte tiefe Narkoseindizes oder Burst-Suppression-Muster das Risiko fur entweder ein postoperatives kognitives Defizit oder die Mortalitat erhohen. Es handelt sich jedoch uberwiegend um sekundare Datenanalysen oder retrospektive Observationsstudien. Die erste prospektive Interventionsstudie zu „triple low“ konnte diesen Zusammenhang nicht nachweisen. Derzeit werden die ersten prospektiven Interventionsstudien zur Vermeidung exzessiver EEG-Suppression durchgefuhrt. Die Ergebnisse wurden nicht nur die Formulierung evidenzbasierter Empfehlungen ermoglichen, sondern sollen auch Hinweise und Anhaltspunkte liefern, ob es sich bei den oben genannten Beobachtungen um einen kausalen Zusammenhang oder ein Epiphanomen handelt.

espanolEvaluar los efectos de las nanoparticulas de luteolina en el proceso de cicatrizacion de las cavidades dentales en conejos. Diseno: Este estudio incluyo cinco conejos asignados al azar para controlar animales y animales experimentales. Inmediatamente despues de la extraccion de un incisivo maxilar superior, los alveolos alveolares de los animales experimentales se trataron con luteolina topica, mientras que los alveolos alveolares del grupo control permanecieron sin tratamiento. Los animales fueron sacrificados por decapitacion con anestesia profunda siete dias despues de la extraccion del diente. Las cavidades de los dientes se seccionaron y se tineron con hematoxilina y eosina. Resultados: la evaluacion histologica revelo que el tratamiento con luteolina indujo una curacion mas temprana de los alveolos extraidos. Conclusion: estos hallazgos sugieren que la luteolina acelera el proceso de curacion en las cuencas de los conejos. EnglishTo evaluate the effects of luteolin nanoparticles on the process tooth socket healing in rabbits. Design: This study comprised five rabbits randomly assigned to control animal and experimental animals. Immediately after the extraction of an upper maxillary incisor, the alveolar sockets of experimental animals were treated with topical luteolin while alveolar sockets of the control group remained without treatment. The animals were sacrificed by decapitation with deep anesthesia seven days post tooth extraction. The tooth sockets were sectioned and stained with hematoxylin and eosin stains. Results: Histological evaluation revealed that luteolin treatment induced earlier healing of extracted tooth sockets. Conclusion: These findings suggest that luteolin accelerates the healing process in tooth sockets of rabbits.

Previous studies have reported the usefulness of intraoperative corticocortical evoked potentials (CCEPs) for preserving language function during brain surgery.This study aimed to assess the influence of depth of anesthesia on CCEP to establish its clinical utility.Twenty patients with brain tumors or epilepsy who underwent awake craniotomy were included in this study. Before resection, the electrode plates were placed on the frontal and temporoparietal cortices, and 1-Hz alternating electrical stimuli were delivered to the pars opercularis/pars triangularis in a bipolar fashion. Electrocorticograms from the temporoparietal cortices time-locked to stimuli were averaged to obtain CCEP responses from a state of deep anesthesia until the awake state. The correlation between CCEP waveforms and bispectral index (BIS) was evaluated.CCEP amplitude increased with the increase in the BIS level. CCEP latency decreased in 5 patients and increased in 15 patients under anesthesia compared with the awake state. CCEP amplitudes decreased by 11.3% to 75.2% (median 31.3%) under anesthesia with65 BIS level. These differences were statistically significant (P0.01, Wilcoxon signed-rank test). With respect to CCEP latencies, there was no significant difference between the awake and anesthetic states.CCEP amplitudes were correlated with depth of anesthesia, whereas CCEP latencies were not affected by anesthesia. The influence of anesthesia should be considered when applying this technique to intraoperative monitoring.

This paper considers one of the challenging tasks during surgical procedure, i.e. depth of anasthesia estimate. The purpose of this paper is to investigate the effect of the analyzed EEG signal fragment duration on the accuracy of anesthesia level estimate using the linear discriminant analysis algorithm and determining the EEG signal length, which yields acceptable accuracy of anesthesia level separation using these parameters.A new method for classifying EEG anesthesia levels is proposed. The possibility of classifying levels of anesthesia is demonstrated by means of sharing the EEG parameters under consideration (SE, BSR, SEF95, RBR). The method can be used in anesthesia monitors that are used to monitor the depth of anesthesia in order to select the appropriate dose of anesthetic drugs during operations, thus avoiding both cases of intraoperative arousal and excessively deep anesthesia.

Background Bispectral index (BIS) monitoring of depth of anesthesia has pioneered the field for more recent monitoring devices like the A-line ARX Index (AAI) or the state (SE) and response entropy (RE) monitoring devices. Following an observational design the present study aimed to simultaneously compare in the same patient recorded BIS, AAI and entropy values. Methods Data from patients (n = 32) undergoing minor gynecological operations were analyzed. For all patients, standardized anesthesia was used. Before induction of anesthesia AEP electrodes, BIS and entropy sensors were simultaneously placed on the forehead and recordings were started at 3 minutes before induction and continued until patient transfer to the postanesthesia care unit. Markers were set at defined landmarks. Results Anesthesia reduced mean BIS, AAI and entropy values. During uneventful, and even more pronounced, during eventful anesthesia BIS/ entropy and BIS/ AAI values showed better correlation than did AAI and entropy values. The prediction probability (Pk) of AAI (0.824 ± 0.036) and RE (0.786 ± 0.040) or SE (0.781 ± 0.040) for preanesthesia awake, postanesthesia awake or anesthesia was comparable and significantly greater than that of BIS (0.705 ± 0.047). However, only 20% of BIS, AAI and entropy values simultaneously categorized the state of the patient as awake, inadequate anesthesia, optimal anesthesia or deep anesthesia. Conclusion The prediction probability (Pk) of entropy and AAI was comparable and better than that of BIS. However, agreement between BIS, AAI and entropy measurements on patient state was poor.

Slow oscillations are a pattern of synchronized network activity generated by the cerebral cortex. They consist of Up and Down states, which are periods of activity interspersed with periods of silence, respectively. However, even when this is a unique dynamic regime of transitions between Up and Down states, this pattern is not constant: there is a range of oscillatory frequencies (0.1–4 Hz), and the duration of Up vs. Down states during the cycles is variable. This opens many questions. Is there a constant relationship between the duration of Up and Down states? How much do they vary across conditions and oscillatory frequencies? Are there different sub regimes within the slow oscillations? To answer these questions, we aimed to explore a concrete aspect of slow oscillations, Up and Down state durations, across three conditions: deep anesthesia, light anesthesia, and slow-wave sleep (SWS), in the same chronically implanted rats. We found that light anesthesia and SWS have rather similar properties, occupying a small area of the Up and Down state duration space. Deeper levels of anesthesia occupy a larger region of this space, revealing that a large variety of Up and Down state durations can emerge within the slow oscillatory regime. In a network model, we investigated the network parameters that can explain the different points within our bifurcation diagram in which slow oscillations are expressed.

During sleep and anesthesia, large groups of neurons throughout the entire cortex activate rhythmically producing wavefronts of activity referred to as slow-wave activity (SWA). In the arousal process, the brain restores its integrative and complex activity. The network mechanisms underlying this global state transition remain however to be elucidated. Here we investigated the network features shaping the SWA under fading anesthesia. Using electrocorticographical recordings of wide cortical areas of the mouse brain, we developed a quantitative measure of the anesthesia level based on slow-wave frequency and complexity. At deep anesthesia, we document a stringent alternation of posterior-anterior-posterior modes of propagation. With fading anesthesia, SWA evolves to produce a plethora of metastable spatiotemporal patterns. A network model of spiking neurons reproduced the data using short-range connectivity, subcortical input and a local activity-dependent adaptation. The emergence from deep anesthesia does not require modifying the connectivity, but small changes in the local excitability of cortical cell assemblies, further supporting the hypothesis of a tight bound between scales in the brain.

Several studies have revealed that vasopressor may be more appropriate for treating intraoperative hypotension and preventing hypervolemia. This study compared the effects of vasopressor infusion and fluid supplementation on intestinal microcirculation during treating intraoperative hypotension. Thirty-two rats were randomly divided into the following four groups: Light Anesthesia group (LA, 0.8–1% isoflurane); Deep Anesthesia group (DA, 1.5–1.8% isoflurane); Fluid DA group (1.5–1.8% isoflurane and fluid supplementation); and Norepinephrine DA group (1.5–1.8% isoflurane and norepinephrine infusion). At 240 min, perfused small vessel density (PSVD) of the mucosa did not differ significantly between the Fluid DA and Norepinephrine DA groups [26.2 (3.2) vs 28.9 (2.5) mm/mm2, P = 0.077], and tissue oxygen saturation of the mucosa was lower in the Fluid DA groups than in the Norepinephrine DA groups [ 48 (7) vs 57 (6) %, P = 0.02]. At 240 min, TSVD and PSVD of the seromuscular layer were higher in the Norepinephrine DA group than in the Fluid DA group. Fluid administration was higher in the Fluid DA group than in the Norepinephrine DA group [66 (25) vs. 9 (5) μL/g, P = 0.001]. Our results showed that norepinephrine can resuscitate intraoperative hypotension related microcirculatory alteration and avoid fluid overload.

Motor activity during general anesthesia (GA) without curarization is often interpreted as reflecting insufficient analgosedation. Here we present the case of an octogenarian scheduled for deep sclerectomy receiving opioid-sparing electroencephalography-(EEG)-guided anesthesia. Periodic Leg Movements (PLM) made their appearance with ongoing surgery while his raw EEG displayed a pattern of deep GA (burst suppression). To the best of our knowledge, this is the first description of actimetry-documented persisting PLM during EEG-monitored GA. Recognizing PLM in the context of GA is of importance for anesthesiologists, as increasing sedation may increase motor activity.

Glomerular filtration rate (GFR) is considered the gold standard to test kidney function. However, the serial blood and/or urine sample collection required for the calculation of the GFR is stressful for the animal and time consuming for the experimenter. Here, we describe a transcutaneous assessment of renal function in conscious animals that does not require plasma or urine sampling and/or deep anesthesia. For the measurement, we use a near-infrared (NIR) device that records the excretion kinetic of the renal marker ABZWCY-HPβCD. ABZWCY-HPβCD is a new hydrophilic, stable, and nontoxic NIR fluorescent agent that can be used as a renal marker as it is filtrated and completely excreted through the kidneys into the urine without reabsorption or secretion and without accumulation in the skin. The data recorded in the device are then analyzed with "GFRmeasure," an open-source, freely downloadable, and user-friendly software.

In this study, we reported a new technique based on laser speckle flowgraphy to record the ocular blood flow in rabbits under deep anesthesia, and proposed parameters to characterize retinal ischemia. We applied the proposed technique to study the correlation of blood flow between the eyes of normal non-anesthetized animals, and to characterize the occlusion of the internal carotid artery (ICA) and external carotid artery (ECA). We established a correlation in blood flow between the eyes of non-anesthetized animals, and derived two new parameters, namely, the laterality index and vascular perfusion estimate (VPE). Our experimental results from 16 eyes (of 13 New Zealand white rabbits) showed a reduction in ocular blood flow with a significant decrease in the VPE after the occlusion of the ECA (p

Purpose. This study aims to compare the effect of the depth of total intravenous anesthesia (TIVA) on intraoperative electrically evoked compound action potential (e-ECAP) thresholds in cochlear implant operations.Methods. Prospectively, a total of 39 patients aged between 1 and 48 years who were scheduled to undergo cochlear implantation surgeries were enrolled in this study. Every patient received both light and deep TIVA during the cochlear implant surgery. The e-ECAP thresholds were obtained during the light and deep TIVA.Results. After comparing the e-ECAP means for each electrode (lead) between the light and deep anesthesia, no significant differences were detected between the light and deep anesthesia.Conclusion. The depth of TIVA may have no significant influence on the e-ECAP thresholds as there was no statistical difference between the light and deep anesthesia.

The electroencephalogram (EEG) can reflect brain activity and contains abundant information of different anesthetic states of the brain. It has been widely used for monitoring depth of anesthesia (DoA). In this study, we propose a method that combines multiple EEG-based features with artificial neural network (ANN) to assess the DoA. Multiple EEG-based features can express the states of the brain more comprehensively during anesthesia. First, four parameters including permutation entropy, 95% spectral edge frequency, BetaRatio and SynchFastSlow were extracted from the EEG signal. Then, the four parameters were set as the inputs to an ANN which used bispectral index (BIS) as the reference output. 16 patient datasets during propofol anesthesia were used to evaluate this method. The results indicated that the accuracies of detecting each state were 86.4% (awake), 73.6% (light anesthesia), 84.4% (general anesthesia), and 14% (deep anesthesia). The correlation coefficient between BIS and the index of this method was 0.892 ( p &lt, 0.001 ). The results showed that the proposed method could well distinguish between awake and other anesthesia states. This method is promising and feasible for a monitoring system to assess the DoA.

Mismatch detection is the process of identification of rare stimuli from a sequence of stimuli. This important cognitive function is usually attributed to the cerebral cortex. To test the human midbrain involvement in sound mismatch detection, we recorded local field potentials in the states of deep anesthesia and clear consciousness from the drainage-electrode implanted in the cerebral aqueduct of an adult patient with an obstructive hydrocephaly who had undergone pineal region tumor removal through anterior interhemispheric transcallosal approach. We found a significant difference in the state of deep anesthesia at 256-364 ms after hearing a rarely presented sounds compared with frequently presented sounds and equally probable sounds. This difference was not found in the same experiment in the state of clear consciousness. The results suggest that human midbrain participates in mismatch detection and can do it even without cognitive activity of the cerebral cortex. Amplitude-frequency analysis of the midbrain records revealed that propofol affects the electrical activity of both human midbrain and cortex but the level of inhibition of the cortex is 6 times higher than the level of inhibition of the midbrain. We suppose that the human cortex is more susceptible to propofol than the human midbrain.

Objective: To investigate the effects of deep anesthesia on blood gas and immune function in patients undergoing laparoscopic radical gastrectomy for gastric cancer. Methods: A total of 84 gastric cancer patients in our hospital were randomly divided into observation group (42 cases) and control group (42 cases). Patients in observation group were treated by deep anesthesia, while the control group was treated with shallow anesthesia. The blood gas was observed and compared before and after CO2 pneumoperitoneum, and the immune function was observed and compared before anesthesia, after operation and 72 h post-operation. Results: The PaCO2 and pH level of patients in the two groups had no significant difference before pneumoperitoneum; Compared with before pneumoperitoneum, no obvious blood gas change was observed in the observation group, the difference had no statistically significant; Blood gas level of control group was significantly higher than that of before pneumoperitoneum , the difference was statistically significant, pH (7.26 依 0.07) was statistically decreased; After pneumoperitoneum, the level of PaCO2 and pH was significantly different in both groups , the difference was statistically significant. Indexes of the patients in the observation and control group of CD3+, CD4+, CD4+/CD8+, NK level had no significant difference before anesthesia, the difference was not statistically significant; The immunology index of CD3+, CD4+, CD4+/ CD8+ and NK cell levels of the postoperative patients in both groups were significantly lower than before anesthesia, and the differences were statistically significant, but each index in the observation group decreased significantly less than that of the control group, the difference was statistically significant; The immunological indexes can be restored to before anesthesia postoperative 72 h with two groups, and had no significant difference. Conclusion: The blood gas analysis index was stable and the immune function was suppressed in patients with deep anesthesia.

The objective of this study was to evaluate menthol and eugenol as anesthetics for early juveniles of curimba, Prochilodus lineatus. Juveniles of 4.0±0.5 g and a total length of 8.8±0.1 cm were exposed to the anesthetics menthol (20, 30, 40, 50, 60, 70, and 80 mg L−1) and eugenol (20, 30, 40, 50, 60, and 70 mg L−1) up to deep anesthesia. The anesthetic effects were evaluated measuring the induction time to deep anesthesia (characterized by loss of equilibrium, absence of swimming, reduction of opercular movements, and responses only to intense tactile stimuli), recovery time, time to appetite return, and mortality rate after 96 h of procedure. The concentrations between 60 to 80 mg of menthol L−1 provided the lowest time of induction. Increased concentrations led to a decrease in recuperation time. The concentrations between 50 to 70 mg of eugenol L−1 provided the lowest induction times; however, recovery time was not affected by eugenol concentrations. The return to appetite was observed 24 h after anesthesia, while the survival after 96 h was >90%. Concentrations of 60 and 50 mg L−1 of menthol and eugenol, respectively, are recommended for effective anesthesia with limited side effects.

EnglishThe goal of this study was to investigate the sedative and anesthetic properties of essential oils (EOs) in map treefrog tadpoles (Hypsiboas geographicus) and to determine the sedation and deep anesthesia induction times as well as the recovery time. The tadpoles were exposed to one of the EOs from three plant species: Aniba rosaeodora (EOAR - 25, 50, 100 or 200µL L-1), Lippia origanoides (EOLO - 13, 25, 50, 100 or 200µL L-1), and Lippia alba (either chemotype citral [EOL-C - 25, 50, 100 or 200µL L-1] or linalool [EOL-L - 50, 75, 100 or 200µL L-1]) (n = 8 per replicate). The tadpoles exposed to 25 and 50µL L-1 EOL-C and EOL-L, respectively, were not anesthetized within 30min (the maximum time of observation), and those exposed to 200µL L-1 EOLO did not recover within 30min. Sedation, deep anesthesia and recovery times showed a concentration-dependent relationship for all EOs tested, with the exception of the recovery with EOLO. The results allowed concluding that all investigated EOs can be used to anesthetize tadpoles of H. geographicus, but the use of EOLO must not exceed 100µL L-1. Key words: amphibians; animal welfare; natural anesthetics portuguesO objetivo deste estudo foi investigar as propriedades sedativas e anestesicas de oleos essenciais (OEs) em girinos da perereca Hypsiboas geographicus e determinar os tempos de inducao a sedacao e anestesia profunda, bem como o de recuperacao. Os girinos foram expostos a um dos OEs de tres especies de plantas: Aniba rosaeodora (OEAR - 25, 50, 100 ou 200µL L-1), Lippia origanoides (OELO - 13, 25, 50, 100 ou 200µL L-1 ) ou Lippia alba quimiotipos citral (OEL-C - 25, 50, 100 ou 200µL L-1) ou linalol (OEL-L - 50, 75, 100 ou 200µL L-1) (n = 8 cada repeticao). Girinos expostos a 25 e 50µL L-1 OEL-C e OEL-L, respectivamente, nao foram anestesiados dentro de 30min (tempo maximo de observacao) e aqueles expostos a 200µL L-1 OELO nao recuperaram dentro de 30min. Os tempos de sedacao, anestesia profunda e recuperacao apesentaram uma relacao concentracao-resposta para todos os OEs testadas, exceto a recuperacao com OELO. Os resultados permitem concluir que todos os OEs investigados podem ser usados para anestesiar os girinos de H. geographicus, mas o uso de OELO nao deve ser superior a 100µL L-1. Palavras-chave: anfibios; bem estar animal; anestesicos naturais

New algorithm for anesthesia depth analysis using EEG signal is presented. The algorithm is intended for the use in anesthesia depth monitors in the course of surgical operations. The suggested algorithm is based upon the combination of the following three approaches: signal randomness analysis with the use of approximate entropy, power spectrum analysis and analysis of specific signal changes that take place at the state of deep anesthesia. The algorithm was tested with the use of real ECG recordings obtained in the course of surgical operations and demonstrated good performance. The software package realizing this algorithm is used in an anesthesia depth monitor prepared to the batch production. Further efforts for the algorithm improving should be directed to the increase of the algorithm robustness to noises.

This study aims to use combined wavelet and neural network model to extract electroencephalogram (EEG) signal features during anesthesia and classify them according to the Depth of Anaesthesia (DOA). EEG signals were selected according to their Bispectral Index (BIS) value during anaesthesia and were processed using Discrete Wavelet Transform (DWT).The dimensionality of the wavelet coefficient vectors were reduced by extracting key features from their distribution. Artificial Neural networks (ANN) were implemented using the extracted features of EEG signals as inputs and then classifying anesthetic depth as awake, light anesthesia, moderate anaesthesia, deep anesthesia and very deep anaesthesia. The proposed model will classify depth of anaesthesia accurately.

Introduction Several studies have attempted to use human dental pulp stem cells (hDPSCs) for pulp-dentin complex regeneration in vitro . However, the safety of such applications should be first evaluated in vivo before their use in clinical trials. The purpose of this study was to investigate the in vivo fate of intrapulpally transplanted hDPSCs. Methods hDPSCs were isolated and cultured from impacted third molars. In vivo experiments were performed using 7-week-old male BALB/c nude mice. Under deep anesthesia, 1 × 10 5 hDPSCs were transplanted in mice via the tail vein for intravenous injection or into the pulp chamber for intrapulpal transplantation. A total of 56 mice, 28 per group, were used. Mice were sacrificed at different time points, and the numbers of hDPSCs in the organs were analyzed quantitatively. In addition, qualitative analysis was performed to detect intrapulpally transplanted hDPSCs. Results Intravenously injected hDPSCs were mostly distributed to the lungs and rarely detected in other organs at all observed time points. The hDPSCs transplanted into the pulp chamber rarely migrated to other organs over time. Conclusions These data indicate a differential distribution of transplanted hDPSCs between the intravenous and intrapulpal route and show the safety of pulpal transplantation of hDPSCs.

The paper considers theoretical problems and results of experiments on recognition of anesthesia stages from electroencephalograms (EEGs) by methods based on analyzing the parameters of approximated entropy. It is shown that a discrete sequence of point entropy estimates can be efficiently used for describing regular and chaotic components of the EEG signal and for identifying a patient's functional conditions during surgical operations. The minimum length of the time interval is determined for which the obtained entropy characteristics of the signal are reliable and stable. The computational resources required for obtaining entropy parameters of the signal are estimated in online EEG analysis. On this basis, restrictions on the signal sampling frequency are introduced and the number of point estimates of the approximated entropy is selected for which the proposed analyzing algorithms can be implemented in medical systems with midlevel computers.

The authors would like to confirm a fluid pathway from the scala tympani to the organ of Corti, and to observe its morphological changes.A staining solution for succinic dehydrogenase was perfused with phenazine methosulfate in the scala tympani of living guinea pigs (n = 5) under deep anesthesia. After fixation, the cochleas were eventually embedded in epon. Sections were observed under a light microscope.Blue-stained tissue is indicative of the pathway taken by the solution. The staining solution entered the organ of Corti through Hensen-Deiters' slit. The slit widened and Hensen's cells were pushed laterally. A new space was formed medial to Hensen's cells. Cortilymphatic hydrops developed.The Hensen-Deiters' slit is a pathway of a certain staining solution from the scala tympani to inside the organ of Corti of the guinea pig. The influx of the fluid pushes Hensen's cells laterally and upward, resulting in a formation of hydrops of the organ of Corti or cortilymphatic hydrops. The hydrops is observed in animals with experimental perilymphatic fistula and with viral labyrinthitis. At the end stage of the hydrops, only the surface of the organ of Corti remains as a thin layer without any cellular elements.

OBJECTIVE Motor evoked potentials (MEPs) are a critical indicator for monitoring motor function during neurological surgery. In this study, the influence of depth of anesthesia on MEP response was assessed. METHODS Twenty-eight patients with brain tumors who underwent awake craniotomy were included in this study. From a state of deep anesthesia until the awake state, MEP amplitude and latency were measured using 5-train electrical bipolar stimulations on the same site of the precentral gyrus each minute during the surgery. The depth of anesthesia was evaluated using the bispectral index (BIS). BIS levels were classified into 7 stages: < 40, and from 40 to 100 in groups of 10 each. MEP amplitude and latency of each stage were compared. The deviation of the MEP measurements, which was defined as a fluctuation from the average in every BIS stage, was also considered. RESULTS A total of 865 MEP waves in 28 cases were evaluated in this study. MEP amplitude was increased and latency was decreased in accordance with the increases in BIS level. The average MEP amplitudes in the > 90 BIS level was approximately 10 times higher than those in the < 40 BIS level. Furthermore, the average MEP latencies in the > 90 BIS level were 1.5–3.1 msec shorter than those in the < 60 BIS level. The deviation of measured MEP amplitudes in the > 90 BIS level was significantly stabilized in comparison with that in the < 60 BIS level. CONCLUSIONS MEP amplitude and latency were closely correlated with depth of anesthesia. In addition, the deviation in MEP amplitude was also correlated with depth of anesthesia, which was smaller during awake surgery (high BIS level) than during deep anesthesia. Therefore, MEP measurement would be more reliable in the awake state than under deep anesthesia.

The present study investigated the effects of toluene inhalation and the restorative effects of melatonin on branching and basal dendritic outgrowth of superficial pyramidal neurons in rat’s frontal, parietal, and occipital cortices. At postnatal day 21 (P21), Sprague-Dawley male rats were randomly assigned to either an air-only group or a toluene group. From P22 to P32 the animals were exposed to either clean air or toluene vapors (5000–6000 ppm) for 10 min/day. This strategy simulated common toluene abuse in humans, which consists of 15–20 rapid inhalations of highly concentrated solvent. Once the inhalation period was over (P32), toluene exposed animals were randomly reassigned to one of following experimental groups: (i) air-control/saline; (ii) toluene/saline; (iii) toluene/melatonin 0.5 mg/kg; (iv) toluene/melatonin 1.0 mg/kg; (v) toluene/melatonin 5.0 mg/kg; and (vi) toluene/melatonin 10 mg/kg. Seven days after the last inhalation (P39), all the animals were sacrificed under deep anesthesia; brains were dissected out and stained according to the Golgi-Cox-Sholl procedure. Layer II/III pyramidal neurons were morphologically analyzed by measuring their basilar dendritic length and the number of branches. The results obtained revealed that (i) toluene inhalation significantly reduced dendritic outgrowth and branching in all cortical areas studied, and (ii) intraperitoneal administration of melatonin (0.5–10 mg/kg) was able to restore the dendritic impairment induced by toluene exposure.

Modern computer-based methods to monitor anesthesia are widespread. They are used in order to avoid awareness, to reduce consumption of anesthetics, to optimize recovery times and to detect prolonged times of deep anesthesia and associated immunsuppression, mortality and morbidity. This review illustrates the evidence with which these goals were achieved until now. Finally, a recommendation for each indication is given. The useage of EEG-monitoring may help to avoid awareness and allows a reduced of consumption of anesthetics. The question if a cumulated time of deep anesthesia is associated with elevated mortality might be of a certain importance in the future.

In this paper, we present a new method to identify anesthetic states based on routinely recorded electroencephalogram (EEG). The identification of anesthesia stages are conducted using fast Fourier transform (FFT) and modified detrended fluctuation analysis (DFA) method. Simulation results demonstrate that this new method can clearly discriminate all five anesthesia states: very deep anesthesia, deep anesthesia, moderate anesthesia, light anesthesia and awake.

O objetivo deste trabalho foi avaliar o eugenol como anestésico para a tilápia-do-nilo. Para a concentração ideal, foram avaliados seis tratamentos (50, 75, 100, 150, 200 e 250 mg L-1), com dez peixes por tratamento, anestesiados individualmente, acompanhados durante a indução e recuperação. A toxicidade foi estimada pela submissão de 210 peixes a 7 concentrações de eugenol (50, 75, 100, 150, 200, 250, 300 mg L-1), durante 600 s e, para a margem de segurança, 120 peixes foram submetidos a 75 mg L-1 durante cinco intervalos de tempo (600, 1.200, 1.800 e 2.400 s). As concentrações eficientes foram 50 e 75 mg L-1. Os valores de toxicidade letal (CL), aos 600 s, foram: CL01, 81,97 mg L-1; CL50, 184,26 mg L-1; e CL99, 286,55 mg L-1; e os tempos de concentrações letais (TCL) foram: TCL01, 566,97 s; TCL50, 1.611,66 s; e TCL99, 2.656,34 s. Concluiu-se que 75 mg L-1 são suficientes para a anestesia profunda de curta duração, com margem de segurança de 484,27 s, e 50 mg L-1 para longos períodos (600 s). A maior concentração terapêutica do eugenol custa R$ 0,065 por litro de água. A eutanásia pode ser realizada com 286,55 mg L-1 durante 600 s. The objective of this work was to evaluate eugenol as anesthetic for Nile tilápia. For the best concentration of the anaesthetic, six treatments (50, 75, 100, 150, 200, and 250 mg L-1) were evaluated, with ten fishes per treatment, anesthetised individually and monitored during the induction and recovery. Toxicity was estimated in 210 fish submitted to seven eugenol concentrations (50, 75, 100, 150, 200, 250, and 300 mg L-1) for 600 s; and for safety margin, 120 fish were submitted to 75 mg L-1 for five time intervals (600, 1,200, 1,800, and 2,400 s). The effective concentrations were 50 and 75 mg L-1. Lethal concentration (LC) values for 600 s were: LC01 81.97 mg L-1, LC50 184.26 mg L-1, and LC99 286.55 mg L-1. Times of lethal concentration (TLC) were TLC01 566.97 s, TLC50 1,611.66 s, and TLC99 2,656.34 s. For fast deep anesthesia, 75 mg L-1 of eugenol is recommended, with a safety margin of 484,27 s; for long period anesthesia (600 s) 50 mg L-1 were recommended. The higher therapeutic concentration costs R$ 0.065 per liter. Eugenol was effective for euthanasia at 286.55 mg L-1 for 600 s.

Depth of anesthesia estimation with the Electroencephalogram (EEG) is a main current challenge in anesthesia studies. This paper proposes an original method founded on combination of permutation entropy and frequency measure to calculate an index, called Brain function index (BFI), to quantify depth of anesthesia. As EEG derived features characterize different aspects of EEG signal, it would be logical to utilize multiple features to evaluate the effect of anesthetic. Such a method implemented in the Saadat brain function assessment module (Saadat Co., Tehran, Iran). The BFI and commercial RE index as employed in the Datex-Ohmeda monitor are applied to EEG signals gathered from 18 patients during sevoflurane anesthesia. The results show that both BFI and RE indices track the changes in EEG especially at deep anesthesia state. However, the BFI index makes better response about the point of loss of consciousness and it can be derived with significantly less computational complexity. Taking into account the high accuracy of this method, an innovative EEG processing device may be extended to help the anesthetists to estimate the depth of anesthesia precisely.

The discharge properties of 51 afferents were studied in the rat soleus muscle spindles. Under deep anesthesia using a pentobarbital sodium solution (30 mg/kg), a laminectomy was performed and the right L4 and L5 dorsal and ventral roots were transected near their entry into the spinal cord. In situ, the minimal ( L min) muscle length [3 ± 0.08 (SE) cm] of the soleus was measured at full ankle extension. Unitary potentials from the L5dorsal root were recorded in response to ramp-and-hold stretches applied at 3 mm (S3) and 4 mm (S4) amplitudes and four stretch velocities (6, 10, 15, and 30 mm/s), sinusoidal stretches performed at four amplitudes (0.12, 0.25, 0.5, and 1 mm) and six stretch frequencies (0.5, 1, 2, 3, 6, and 10 Hz), and vibrations applied at 50-, 100-, and 150-Hz frequencies. These two kinds of stretches were performed at three different muscle lengths ( L min+10%, L min+15%, and L min+20%), whereas vibrations were applied at L min+20% muscle length. Conduction velocity of the fibers was calculated but did not allow to discriminate different fiber types. However, the mean conduction velocity of the first fiber group (43.3 ± 0.8 m/s) was significantly higher than that of the second fiber group (33.9 ± 0.9 m/s). Three parameters allowed to differentiate the responses of primary and secondary endings: the dynamic index (DI), the discharge during the stretch release from the ramp-and-hold stretches, and the linear range and the vibration sensitivity from sinusoidal stretches. The slope histogram of the linear regression based on the DI and the stretch velocity was clearly bimodal. Therefore the responses were separated into two groups. During the stretch release at a velocity of 3 mm/s, the first response group ( n = 26) exhibited a pause, whereas the second ( n = 25) did not. The linear range of the second ending group (0.12–1 mm) was broader than that of the first (0.12–0.25 mm). The first ending group showed a higher sensitivity to high-vibration frequencies of small amplitude than the second. In comparison with the literature, we can assert that the first and the second ending groups corresponded to the primary and secondary endings, respectively. In conclusion, our study showed that in rat soleus muscle spindles, it was possible to immediately classify the discharge of Ia and II fibers by using some parameters measured under ramp-and-hold and sinusoidal stretches.

Objective : It is well known that electroencephalograms (EEGs) show electrical silence in deep anesthesia as well as brain death. This is the first report on intracranial EEG changes in deep anesthesia. Methods : We developed a new direct brain monitoring system capable of recording intracranial EEGs. This study included 13 patients with head trauma or cerebrovascular accident under deep anesthesia. Results : The intracranial EEGs showed different patterns of wave activity in depth compared with the cortical surface. In 3 of the cases, the scalp EEG showed a flat tracing at 2.0–2.5% of isoflurane. In two of the cases, the intracranial EEGs showed electrical silence when the scalp EEG was flat. Decreasing the concentration of isoflurane to 1.5%, the intracranial EEG showed single paroxysmal appearance of ‘revival' theta waves on the electrocorticogram (ECoG) or electroventriculogram (EVG). The intracranial ‘revival' wave was followed by high-voltage burst-waves. In another case, at 2.0–2.5% of isoflurane, the amplitude of the waves was greatest on the EVG. Conclusion : There is wave activity difference in the brain depth, which the scalp EEG is unable to show. Intracranial EEGs are able to show the first signs of revival after a nearly flat tracing in deep anesthesia.