ABSTRACT
Resumen: La anestesiología cuenta con una nueva generación de monitores de la profundidad anestésica como Narcotrend, SedLine y el índice biespectral; con un procesador del electroencefalograma llamado espectrograma o espectrografía. Tras la obtención del electroencefalograma, se procesa para graficar en tres dimensiones: la frecuencia, el tiempo y la potencia en una escala de colores, con lo que se obtiene la matriz de densidad espectral (DSA, por sus siglas en inglés). El objetivo de esta revisión narrativa es ilustrar los efectos de los anestésicos más comunes en el espectrograma y hacer una breve revisión de su huella en el electroencefalograma.
Abstract: Anesthesiology has a new generation of anesthetic depth monitors such as Narcotrend, SedLine and Bispectral Index; with an electroencephalogram processor called a spectrogram or spectrograph. After obtaining the electroencephalogram, it is processed to graph three dimensions: frequency, time, and power on a color scale, obtaining the DSA (density spectral array). The objective of this narrative review is to illustrate the effects of the most common anesthetics on the spectrogram and to briefly review their signature on the electroencephalogram.
ABSTRACT
The effect of general anesthetics (GA) on the developing brain has been a research hotspot in the last two decades. Numerous studies have shown that GA could damage the developing brain and cause long-term cognitive impairment in the preclinical setting, while it remains controversial in the clinical context regarding this topic. In light of the limitations of directly translating the preclinical findings into clinical context, drawbacks of retrospective studies, lack of standard behavioral and mental assessing tools in clinical studies, and other confounding factors, it is difficult to gain an agreement on the issue. To improve the repeatability and persuasion of data in the field of GA-induced developing brain, we tried to integrally analyze the current status and progress of the topic and make it as reference for the related studies in the future.
ABSTRACT
@#With the rapid development of surgery and the expansion of indications for surgical treatment ，the number of non-obstetric operations during pregnancy and infant operations has been increasing. Most of these operations need to be performed under general anesthesia，and the developing brain of fetus and infants are inevitably exposed to general anesthetics. Therefore，in recent years，the neurotoxicity effects of general anesthetics on the developing brain have become the focus and controversy in the medical sciences. Especially in 2016，US Food and Drug Administration（FDA）added black box for warning of general anesthetics commonly used in clinic，which caused confusion among doctors，patients and staffs in the related fields. Therefore，we will elaborate the preclinical and clinical studies of neurotoxicity of general anesthetics in combination with the characteristics of developing brain.
ABSTRACT
General anesthetics are widely used in pregnant women,gravidas and infants.In the basic studies of rodents,mammals and non-human primate,general anesthetics can cause neurotoxicity,neuroapoptosis and damage neurodevelopment on the developing brain.Therefore,To explore protective measures and mechanism of anesthetic neurotoxicity is of great significance for formulating clinical anesthesia plan,guiding clinical obstetrics and pediatric anesthesia.This article reviewed the progress of ameliorating the neurotoxicity of general anaesthetics on developing brain including anesthetic assistants,hormone drugs,plant extracts,nutritional components and others.
ABSTRACT
BACKGROUND: General anesthetics induce neuronal apoptosis in the immature brain. Regional anesthesia using local anesthetics can be an alternative to general anesthesia. Therefore, this study investigated the possible effect of lidocaine on neuronal apoptosis. METHODS: Fifty-one 7-day-old C57BL6 mice were allocated into control (group C), lidocaine (group L), lidocaine plus midazolam (group LM) and isoflurane (group I) groups. Group C received normal saline administration. Groups L and LM were injected with lidocaine (4 mg/kg, subcutaneously) only and the same dose of lidocaine plus midazolam (9 mg/kg, subcutaneously). Group I was exposed to 0.75 vol% isoflurane for 6 h. After 6 h, apoptotic neurodegeneration was assessed using caspase-3 immunostaining and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining. RESULTS: For the entire brain section, neuronal cells exhibiting caspase-3 activation were observed more frequently in group I than in group C (P < 0.001). In the thalamus, apoptosis of group L was more frequent than that of group C (P < 0.001), but less freqent than that of groups LM and I (P = 0.0075 and P < 0.001, respectively). In the cortex, group I experienced more apoptosis than group L and C (all Ps < 0.001). On TUNEL staining, the difference in apoptosis between the lidocaine and control groups was marginal (P = 0.05). CONCLUSIONS: Lidocaine induced minimal apoptosis in the developing brain compared with isoflurane and lidocaine plus midazolam. However, we cannot fully exclude the possible adverse effect of subcutaneously administered lidocaine on the developing brain.
Subject(s)
Animals , Mice , Anesthesia, Conduction , Anesthesia, General , Anesthetics, General , Anesthetics, Local , Apoptosis , Brain , Caspase 3 , DNA Nucleotidylexotransferase , In Situ Nick-End Labeling , Isoflurane , Lidocaine , Midazolam , Neurons , ThalamusABSTRACT
En la anestesia balanceada se asocian medicamentos de diferentes grupos farmacológicos a fin de potenciar los efectos deseados de unos y otros, lo cual se logra con el uso simultáneo de estos a dosis bajas, minimizando los riesgos propios de la anestesia. Existen muchos protocolos evaluados en equinos pero aún quedan otros por valorar. Por lo anterior, el objetivo de este estudio fue evaluar tres protocolos de anestesia balanceada en equinos sanos para determinar las características anestésicas logradas con cada uno. Se utilizaron cuatro equinos para probar los tres protocolos propuestos, dejando un periodo de descanso de 30 días entre uno y otro. Los resultados fueron analizados mediante un Anova y la prueba de Kruskal-Wallis para determinar la existencia de diferencias entre tratamientos. Los protocolos evaluados se comportaron de manera similar; las tres fases anestésicas fueron adecuadas en cuanto a calidad y tiempo; los parámetros fisiológicos no se afectaron considerablemente, y la inconsciencia e inmovilidad alcanzadas fueron suficientes lo que sugiere que son adecuados para la realización de procedimientos quirúrgicos de corta duración en equinos...
In balanced anesthesia, drugs from different pharmacological groups are associated in orderto enhance the desired effects of some and others, which is achieved by their simultaneoususe in low doses, minimizing the risks of anesthesia. There are many protocols evaluatedin horses but there are still others to evaluate. Therefore, the purpose of this study was toevaluate three balanced anesthesia protocols in healthy horses in order to determine theanesthetic properties achieved with each. Four horses were used to test the three proposedprotocols, leaving a resting period of 30 days between one and another. The results wereanalyzed by Anova and Kruskal-Wallis test to determine the existence of differences betweentreatments. The protocols evaluated behaved similarly; the three anesthetic phases were adequatein terms of quality and time; physiological parameters were not significantly affected,and the unconsciousness and immobility achieved were sufficient, which suggests that theyare suitable for short duration surgical procedures in horses...
Na anestesia balanceada se associam medicamentos de diferentes grupos farmacológicoscom o objetivo de potenciar os efeitos desejados de uns e de outros, isso se consegue com ouso simultâneo dos mesmos em doses baixas, minimizando os riscos próprios da anestesia.Existem muitos protocolos avaliados em equinos, mas ainda restam outros por avaliar. Porisso, objetivo deste estudo foi avaliar três protocolos de anestesia balanceada em equinos saudáveispara determinar as características anestésicas conseguidas com cada um. Utilizaramsequatro equinos para testar os três protocolos propostos, deixando um período de descansode 30 dias entre um e outro. Os resultados foram analisados mediante um Anova e o teste deKruskal-Wallis para determinar a existência de diferenças entre tratamentos. Os protocolosavaliados se comportaram de maneira similar; as três fases anestésicas foram adequadas noque diz respeito a qualidade e tempo; os parâmetros fisiológicos não foram afetados consideravelmente,e a inconsciência e imobilidade alcançadas foram suficientes o que sugere quesão adequados para a realização de procedimentos cirúrgicos de curta duração em equinos...
Subject(s)
Animals , Anesthesia , Anesthesiology , Anesthetics, GeneralABSTRACT
Long-term or even permanent neuronal injury can follow administration of general anesthetics.It has been confirmed that some elderly patients may experience a decline in cognitive function after general anesthesia.However,the effects of general anesthetics on the central nervous system have not been determined yet.Here we summarize the effects of general anesthetics on the central nervous system in pediatric patients and immature animals.
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General anesthetics produce a widespread neurodepression in the central nervous system by enhancing inhibitory neurotransmission and reducing excitatory neurotransmission. However, the action mechanisms of general anesthetics are not completely understood. Moreover, the general anesthetic state comprises multiple components (amnesia, unconsciousness, analgesia, and immobility), each of which is mediated by different receptors and neuronal pathways. Recently, neurotransmitter- and voltage-gated ion channels have emerged as the most likely molecular targets for general anesthetics. The gamma-aminobutyric acid type A (GABA(A)) receptors are leading candidates as a primary target of general anesthetics. This review summarizes current knowledge on how anesthetics modify GABA(A) receptor function.
Subject(s)
Analgesia , Anesthesia, General , Anesthetics , Anesthetics, General , Central Nervous System , gamma-Aminobutyric Acid , Ion Channels , Neurons , Receptors, GABA-A , Synaptic Transmission , UnconsciousnessABSTRACT
Voltage-gated sodium channels are large glycoproteins that permit selective sodium ion conduction in excitable cells such as neurons. They generate upstroke of action potential and transmit depolarizing impulses through the neuronal network including pain pathway. They are composed of core forming alpha-subunit and one or more auxiliary beta-subunits. Local anesthetics bind in the inner pore of the sodium channel. They block sodium currents and generation of action potential. Amino acid residues which contribute to the drug binding site have been identified by mutational analysis. Also, blockade of sodium ion currents has been investigated as a possible mechanism of general anesthetics. But it is not sufficient to explain the major mechanism of action of general anesthetics.
Subject(s)
Action Potentials , Anesthesia , Anesthetics, General , Anesthetics, Local , Binding Sites , Glycoproteins , Neurons , Sodium , Sodium ChannelsABSTRACT
Introduction of patch-clamp techniques allowed an increase in resolution of membrane current recordings. However, the technique was limited by apparent need for direct contact of pipette with cell membrane. Thus, this technique was restricted to isolated or cultured cell preparation. Although much has been achieved with such preparations, the studies of synapsis between cultured cells are undefined. Many of these problems were overcome by application of patch-clamp techniques to brain-slices. The use of high-resolution optics allowed visualization of cells to be recorded. It was possible to remove tissue covering cells and record currents in synaptically connected neurons. The brain-slice technique has greatly facilitated the investigation of electrical properties of neurons and the analysis of synaptic transmission between neurons. "Blow and seal"technique, when combined with infrared differential interference contrast video microscopy, permits recording of membrane potential and currents, not only from large cell body of neurons, but also from small processes. The technique offers many advantages, such as the case with which patch-pipette recordings can be made, the possibility of identifying cell type prior to recording and finally, the ability to visualize and record electrical activity from different compartments or from more than one site in the same neuron.
Subject(s)
Anesthetics, General , Cell Membrane , Cells, Cultured , Chromosome Pairing , Membrane Potentials , Membranes , Microscopy, Video , Neurons , Patch-Clamp Techniques , Synaptic TransmissionABSTRACT
Two-pore domain K+ (K2P) channels are recently described. They have properties of background K+ channels, and play a crucial role in setting the resting membrane potential and regulating cell excitability. Mammalian family of K2P channel proteins are encoded by 17 KCNK genes and subdivided into 6 subfamilies on the basis of sequence similarities: TWIK, TREK, TASK, TALK, THIK, and TRESK (TWIK related spinal cord K+ channel). TWIK is weakly inward-rectifying, and TASK (acid sensitive) is a background outward-rectifiers whose activity is inhibited by low pH. TREK and TRAAK (TWIK related arachidonic acid-stimulated K+ channel) are both outward-rectifiers that are activated by polyunsaturated fatty acids, including arachidonic acid. The alkaline-activated K2P channel TALK-1 is primarily expressed in the pancreas. THIK is halothane-inhibited K+ channel. TRESK is a TWIK related spinal cord K+ channel. Many studies with volatile general anesthetics were performed using the patch-clamp technique and they showed the activation of K+ currents and they suggested that the K2P channels might be an another plausible group of targets for general anesthetics. An appreciation of how general anesthetics modulate the activity of K2P channels at the molecular level will be enhanced by future studies using site-directed mutagenesis, high-resolution structural approaches, and molecular dynamics simulations.
Subject(s)
Humans , Anesthetics, General , Arachidonic Acid , Fatty Acids, Unsaturated , Hydrogen-Ion Concentration , Membrane Potentials , Mutagenesis, Site-Directed , Pancreas , Patch-Clamp Techniques , Proteins , Spinal CordABSTRACT
Analgesic effect is the most important pharmacologic action of general anesthetics.The receptor mechanisms of analgesia of general anesthetics are complex,which may be related to GABAA receptor,NMDA receptor,glycine receptor,opioid receptor,nnAChRs and so on.In addition,other non-specificity mechanisms may also be involved.In this paper,the receptor mechanisms of analgesia of general anesthetics are reviewed.
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Molecular cloning of cDNAs coding for ligand-gated ion channel subunits makes it possible to study the pharmacology of recombinant receptors with defined subunit compositions. Many laboratories have used these techniques recently to study actions of agents that produce general anesthesia. Most of the volatile and intravenous anesthetics potentiate the function of GABAA receptor to different extent. Glycine, AMPA, kainate,NMDA, and 5-HT3 recepors are also the targets for many anesthetics. Subunit specific actions of some of the agents suggest that construction and testing of certain chimeric receptor subunits may be useful for defining the amino acid sequences responsible for anesthetic actions.