A systematic review of risk factors for postinduction hypotension in surgical patients undergoing general anesthesia.

OBJECTIVE: Clinical evidence has proved that postinduction hypotension (PIH) is very prevalent in surgical patients undergoing general anesthesia, and commonly develops within 20 min after the induction of general anesthesia. However, the risk factors for PIH are not clear till now, therefore, a systematic review of current evidence was conducted. MATERIALS AND METHODS: PubMed, Embase, Cochrane library, and Web of Science were searched for articles published in English up to June 2021. The following search items were used: postinduction, postintubation, propofol induction, anesthesia induction, general anesthesia induction, hypotension, risk factor, general anesthesia, surgery. The articles were screened using the inclusion and exclusion criteria, and the data from included studies were extracted and analyzed. RESULTS: Twelve studies were included. Seven studies reported the association between age and PIH, and six showed age was a risk factor. Five or three studies reported the association between mean arterial pressure (MAP) and PIH or between systolic blood pressure (SBP) and PIH, but the results were conflicting. Results from two studies regarding gender and PIH were conflicting. Two studies reported that weight was negatively correlated with PIH. Low baseline blood volume, emergency operation, long-term intake of the angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) were risk factors for PIH. One study showed that ASA III-V, propofol induction, and increasing fentanyl dosage were risk factors for PIH. CONCLUSIONS: Aging, ASA III-V, emergency operation, low baseline blood volume, long-term intake of ACEI/ARB, propofol induction, and increasing fentanyl dosage are potential risk factors for PIH, while body weight gain is a protective factor. Based on the current evidence, it is difficult to determine whether baseline blood pressure or gender is associated with the development of PIH.

Effects of acute stress, general anesthetics, tonometry, and temperature on intraocular pressure in rats.

Intraocular pressure (IOP) is important for eye health as abnormal levels can led to ocular tissue damage. IOP is typically estimated by tonometry, which only provides snapshots of pressure history. Tonometry also requires subject cooperation and corneal contact that may influence IOP readings. The aim of this research was to investigate IOP dynamics of conscious animals in response to stressors, common anesthetics, tonometry, and temperature manipulations. An eye of male Brown-Norway rats was implanted with a fluid-filled cannula connected to a wireless telemetry system that records IOP continuously. Stress effects were examined by restricting animal movements. Anesthetic effects were examined by varying isoflurane concentration or injecting a bolus of ketamine. Tonometry effects were examined using applanation and rebound tonometers. Temperature effects were examined by exposing anesthetized and conscious animals to warm or cool surfaces. Telemetry recordings revealed that IOP fluctuates spontaneously by several mmHg, even in idle and anesthetized animals. Environmental disturbances also caused transient IOP fluctuations that were synchronous in recorded animals and could last over a half hour. Animal immobilization produced a rapid sustained elevation of IOP that was blocked by anesthetics, whereas little-to-no IOP change was detected in isoflurane- or ketamine-anesthetized animals if body temperature (BT) was maintained. IOP and BT decreased precipitously when heat support was not provided and were highly correlated during surface temperature manipulations. Surface temperature had no impact on IOP of conscious animals. IOP increased slightly during applanation tonometry but not rebound tonometry. The results show that IOP is dynamically modulated by internal and external factors that can activate rapidly and last long beyond the initiating event. Wireless telemetry indicates that animal interaction induces startle and stress responses that raise IOP. Anesthesia blocks these responses, which allows for better tonometry estimates of resting IOP provided that BT is controlled.

Intraocular pressure and pupil diameter in healthy cats anesthetized with isoflurane and pre-medicated with isolated acepromazine or in combination with tramadol / [Pressão intraocular e diâmetro pupilar em gatos saudáveis anestesiados com isoflurano e pré-medicados com acepromazina isolada ou em combinação com tramadol]

The objective of this study was to determine changes on intraocular pressure (IOP) and pupil diameter (PD) in healthy cats anesthetized with isoflurane, and premedicated with acepromazine alone or in combination with tramadol. Thirty cats were allocated in two groups (n=15/each) and were treated with acepromazine (AG) or acepromazine/tramadol (ATG). PD and IOP were assessed before and following 30 (PM1), and 40 minutes (PM2) of treatments. Anesthesia was induced with propofol, and IOP and DP were recorded (A10) at 10 minute intervals until the end of anesthesia (A40). IOP decreased in AG and ATG, when comparing baseline with PM1. IOP decreased only in AG, in comparisons between baseline and PM2. During anesthesia, IOP did not change within and between groups. Comparisons between baseline with those recorded at PM1 and 2 showed that PD increased in the ATG. During anesthesia, PD decreased significantly in AG and ATG. Both protocols maintained the IOP within the reference range to perform corneal or intraocular surgery in healthy cats but did not sustain pre-anesthetic pupil dilation observed in ATG.(AU)

O objetivo do presente artigo é determinar possíveis alterações na pressão intraocular (PIO) e no diâmetro pupilar (DP) em gatos saudáveis anestesiados com isoflurano e pré-medicados com acepromazina isolada ou em combinação com acepromazina/tramadol. Trinta gatos saudáveis foram distribuídos aleatoriamente em dois grupos (n=15/cada) e tratados com acepromazina (GA) ou acepromazina/tramadol (GAT). DP e PIO foram avaliadas antes (basal) e após 30 (PM1) e 40 minutos (PM2) dos tratamentos. A anestesia foi induzida com propofol, e a PIO e o DP foram registrados (A10) a cada 10 minutos até o final da anestesia com isoflurano (A40). Ao se compararem os valores obtidos no basal com PM1, a PIO diminuiu em GA e GAT; com PM2, a PIO reduziu apenas no GA. Durante a anestesia, a PIO não diferiu dentro e entre os grupos. Comparações entre os valores basais e os registrados em PM1 e em PM2 mostraram que a DP aumentou significativamente no GAT. Durante a anestesia, o DP diminuiu significativamente em GA e GAT. Ambos os protocolos mantêm a PIO dentro dos valores de referência para realizar cirurgias corneanas ou intraoculares em gatos saudáveis, mas não sustentam a dilatação pupilar pré-anestésica observada em GAT.(AU)

Contributions of synaptic and astrocyte physiology to the anaesthetised encephalogram revealed using a computational model.

BACKGROUND: General anaesthesia is known to enhance inhibitory synaptic transmission to produce characteristic effects on the EEG and reduction in brain metabolism secondary to reduced neuronal activity. Evidence suggests that anaesthesia might have a direct effect on synaptic metabolic processes, and this relates to anaesthesia sensitivity. We explored elements of synaptic transmission looking for possible contributions to the anaesthetised EEG and how it may modulate anaesthesia sensitivity. METHODS: We developed a Hodgkin-Huxley-type neural network computer simulation capable of mimicking anaesthetic prolongation of gamma-aminobutyric acid (GABA)ergic inhibitory postsynaptic potentials (IPSPs), and capable of altering postsynaptic ion homeostasis and neurotransmitter recycling. We examined their interactions on simulated electrocorticography (sECoG), and compared these with published anaesthesia EEG spectra. RESULTS: The sECoG spectra from the model were comparable with published normal awake EEG spectra. Prolongation of IPSP duration in the model caused inhibition of high frequencies and saturation of low frequencies with a peak in keeping with current evidence. IPSP prolongation alone was unable to reproduce alpha rhythms or the generalised increase in EEG power found with anaesthesia. Adding inhibition of postsynaptic ion homeostasis to IPSP prolongation helped retain alpha rhythms, increased sECoG power, and antagonised the slow-wave saturation peak in a dose-dependent fashion that appeared dependent on the postsynaptic membrane potential, providing a plausible mechanism for how metabolic changes can modulate anaesthesia sensitivity. CONCLUSIONS: Our model suggests how metabolic processes can modulate anaesthesia and produce non-receptor dependent drug sensitivity.

Radical pairs may play a role in xenon-induced general anesthesia.

Understanding the mechanisms underlying general anesthesia would be a key step towards understanding consciousness. The process of xenon-induced general anesthesia has been shown to involve electron transfer, and the potency of xenon as a general anesthetic exhibits isotopic dependence. We propose that these observations can be explained by a mechanism in which the xenon nuclear spin influences the recombination dynamics of a naturally occurring radical pair of electrons. We develop a simple model inspired by the body of work on the radical-pair mechanism in cryptochrome in the context of avian magnetoreception, and we show that our model can reproduce the observed isotopic dependence of the general anesthetic potency of xenon in mice. Our results are consistent with the idea that radical pairs of electrons with entangled spins could be important for consciousness.

Propofol rather than Isoflurane Accelerates the Interstitial Fluid Drainage in the Deep Rat Brain.

Objective: Different anesthetics have distinct effects on the interstitial fluid (ISF) drainage in the extracellular space (ECS) of the superficial rat brain, while their effects on ISF drainage in the ECS of the deep rat brain still remain unknown. Herein, we attempt to investigate and compare the effects of propofol and isoflurane on ECS structure and ISF drainage in the caudate-putamen (CPu) and thalamus (Tha) of the deep rat brain. Methods: Adult Sprague-Dawley rats were anesthetized with propofol or isoflurane, respectively. Twenty-four anesthetized rats were randomly divided into the propofol-CPu, isoflurane-CPu, propofol-Tha, and isoflurane-Tha groups. Tracer-based magnetic resonance imaging (MRI) and fluorescent-labeled tracer assay were utilized to quantify ISF drainage in the deep brain. Results: The half-life of ISF in the propofol-CPu and propofol-Tha groups was shorter than that in the isoflurane-CPu and isoflurane-Tha groups, respectively. The ECS volume fraction in the propofol-CPu and propofol-Tha groups was much higher than that in the isoflurane-CPu and isoflurane-Tha groups, respectively. However, the ECS tortuosity in the propofol-CPu and propofol-Tha groups was much smaller than that in isoflurane-CPu and isoflurane-Tha groups, respectively. Conclusions: Our results demonstrate that propofol rather than isoflurane accelerates the ISF drainage in the deep rat brain, which provides novel insights into the selective control of ISF drainage and guides selection of anesthetic agents in different clinical settings, and unravels the mechanism of how general anesthetics function.

The relationship between exposure to general anesthetic agents and the risk of developing an impulse control disorder.

Most studies examining the effect of extended exposure to general anesthetic agents (GAAs) have demonstrated that extended exposure induces both structural and functional changes in the central nervous system. These changes are frequently accompanied by neurobehavioral changes that include impulse control disorders that are generally characterized by deficits in behavioral inhibition and executive function. In this review, we will.

Effects of noxious stimulation on the electroencephalogram during general anaesthesia: a narrative review and approach to analgesic titration.

Electroencephalographic (EEG) activity is used to monitor the neurophysiology of the brain, which is a target organ of general anaesthesia. Besides its use in evaluating hypnotic states, neurophysiologic reactions to noxious stimulation can also be observed in the EEG. Recognising and understanding these responses could help optimise intraoperative analgesic management. This review describes three types of changes in the EEG induced by noxious stimulation when the patient is under general anaesthesia: (1) beta arousal, (2) (paradoxical) delta arousal, and (3) alpha dropout. Beta arousal is an increase in EEG power in the beta-frequency band (12-25 Hz) in response to noxious stimulation, especially at lower doses of anaesthesia drugs in the absence of opioids. It is usually indicative of a cortical depolarisation and increased cortical activity. At higher concentrations of anaesthetic drug, and with insufficient opioids, delta arousal (increased power in the delta band [0.5-4 Hz]) and alpha dropout (decreased alpha power [8-12 Hz]) are associated with noxious stimuli. The mechanisms of delta arousal are not well understood, but the midbrain reticular formation seems to play a role. Alpha dropout may indicate a return of thalamocortical communication, from an idling mode to an operational mode. Each of these EEG changes reflect an incomplete modulation of pain signals and can be mitigated by administration of opioid or the use of regional anaesthesia techniques. Future studies should evaluate whether titrating analgesic drugs in response to these EEG signals reduces postoperative pain and influences other postoperative outcomes, including the potential development of chronic pain.

La seguridad de las cosas sencillas / The security of simple things

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Automated Pulse Oximeter Waveform Analysis to Track Changes in Blood Pressure During Anesthesia Induction: A Proof-of-Concept Study.

BACKGROUND: Intraoperative hypotension is associated with postoperative complications and death. Oscillometric brachial cuffs are used to measure arterial pressure (AP) in most surgical patients but may miss acute changes in AP. We hypothesized that pulse oximeter waveform analysis may help to detect changes in systolic AP (SAP) and mean AP (MAP) during anesthesia induction. METHODS: In 40 patients scheduled for an elective surgery necessitating general anesthesia and invasive AP monitoring, we assessed the performance of a pulse oximeter waveform analysis algorithm (optical blood pressure monitoring [oBPM]) to estimate SAP, MAP, and their changes during the induction of general anesthesia. Acute AP changes (>20%) in SAP and MAP assessed by the reference invasive method and by oBPM were compared using 4-quadrant and polar plots. The tracking ability of the algorithm was evaluated on changes occurring over increasingly larger time spans, from 30 seconds up to 5 minutes. The second objective of the study was to assess the ability of the oBPM algorithm to cope with the Association for the Advancement of Medical Instrumentation (AAMI) standards. The accuracy and precision of oBPM in estimating absolute SAP and MAP values compared to the invasive method was evaluated at various instants after algorithm calibration, from 30 seconds to 5 minutes. RESULTS: Rapid changes (occurring over time spans of ≤60 seconds) in SAP and MAP assessed by oBPM were strongly correlated and showed excellent concordance with changes in invasive AP (worst-case Pearson correlation of 0.94 [0.88, 0.97] [95% confidence interval], concordance rate of 100% [100%, 100%], and angular concordance rate at ±30° of 100% [100%, 100%]). The trending ability tended to decrease progressively as the time span over which the changes occurred increased, reaching 0.89 (0.85, 0.91) (Pearson correlation), 97% (95%, 100%) (concordance rate), and 90% (85%, 94%) (angular concordance rate) in the worst case. Regarding accuracy and precision, oBPM-derived SAP values were shown to comply with AAMI criteria up to 2 minutes after calibration, whereas oBPM-derived MAP values were shown to comply with criteria at all times. CONCLUSIONS: Pulse oximeter waveform analysis was useful to track rapid changes in SAP and MAP during anesthesia induction. A good agreement with reference invasive measurements was observed for MAP up to at least 5 minutes after initial calibration. In the future, this method could be used to track changes in AP between intermittent oscillometric measurements and to automatically trigger brachial cuff inflation when a significant change in AP is detected.

General anesthesia in infants: neurobiological and neuropsychological concerns.

General anesthetics are crucial drugs for surgical interventions, which are indicated to induce analgesia, diminish pain, and reduce anxiety in order to facilitate invasive procedures. In pediatric patients, benefits of general anesthetics also include abolishment of motility. Besides their probed benefits on surgery, the recent warning of the Food and Drug Administration (FDA) on the use of general anesthetics in children yielded a controversy on their potential neurotoxic effects. In this review, the main facts of the cerebral development are studied, and the available evidence concerning the use of general anesthesia on the neuropsychological development of children is analyzed. Most of the studies found were uncontrolled retrospective cohorts for which conclusions are difficult to obtain. However, a few group of controlled studies, including the Mayo Anesthesia Safety in Kids study (MASK), have partially supported the FDA warning. Cumulated evidence appears to support the safety use of general anesthetics, but no conclusive data supporting that it may induce massive effects on the cognitive development of exposed children has been reported. Important evidence suggests that specific cognitive functions may result altered under long-term expositions. Such data must be considered for those involved in anesthetic procedures.

La anestesia general es una herramienta imprescindible para el proceso quirúrgico, ya que disminuye el dolor, reduce la ansiedad y genera inconsciencia. Sin ella, las cirugías serían dolorosas, riesgosas y emocionalmente traumáticas. La reciente emisión de una alerta sobre el uso de fármacos anestésicos en niños menores de 3 años por parte de la Food and Drug Administration (FDA) de los Estados Unidos generó controversia en torno a sus posibles efectos negativos. En este artículo se abordan los principales hitos del desarrollo neurobiológico del niño y se revisan las posibles consecuencias neuropsicológicas del uso de anestesia general en esta población. La mayoría de los reportes que abordan este tema son de tipo retrospectivo y arrojan resultados controversiales por sus inherentes dificultades metodológicas. Sin embargo, el estudio prospectivo sobre seguridad del uso de anestesia general en niños de la Clínica Mayo (MASK, Mayo Anesthesia Safety in Kids), junto con otros estudios a gran escala, han confirmado algunos datos obtenidos en los estudios experimentales que dieron sustento a la alerta emitida por la FDA. Así, las evidencias hasta ahora publicadas sugieren que el uso de anestesia general es seguro para el desarrollo cognitivo general del niño, aunque evidencian también alteraciones focalizadas en procesos cognitivos específicos que deben ser consideradas por el médico y la familia ante un procedimiento quirúrgico-anestésico.

Anestesia general en infantes: consideraciones neurobiológicas y neuropsicológicas / General anesthesia in infants: neurobiological and neuropsychological concerns

Resumen La anestesia general es una herramienta imprescindible para el proceso quirúrgico, ya que disminuye el dolor, reduce la ansiedad y genera inconsciencia. Sin ella, las cirugías serían dolorosas, riesgosas y emocionalmente traumáticas. La reciente emisión de una alerta sobre el uso de fármacos anestésicos en niños menores de 3 años por parte de la Food and Drug Administration (FDA) de los Estados Unidos generó controversia en torno a sus posibles efectos negativos. En este artículo se abordan los principales hitos del desarrollo neurobiológico del niño y se revisan las posibles consecuencias neuropsicológicas del uso de anestesia general en esta población. La mayoría de los reportes que abordan este tema son de tipo retrospectivo y arrojan resultados controversiales por sus inherentes dificultades metodológicas. Sin embargo, el estudio prospectivo sobre seguridad del uso de anestesia general en niños de la Clínica Mayo (MASK, Mayo Anesthesia Safety in Kids), junto con otros estudios a gran escala, han confirmado algunos datos obtenidos en los estudios experimentales que dieron sustento a la alerta emitida por la FDA. Así, las evidencias hasta ahora publicadas sugieren que el uso de anestesia general es seguro para el desarrollo cognitivo general del niño, aunque evidencian también alteraciones focalizadas en procesos cognitivos específicos que deben ser consideradas por el médico y la familia ante un procedimiento quirúrgico-anestésico.

Abstract General anesthetics are crucial drugs for surgical interventions, which are indicated to induce analgesia, diminish pain, and reduce anxiety in order to facilitate invasive procedures. In pediatric patients, benefits of general anesthetics also include abolishment of motility. Besides their probed benefits on surgery, the recent warning of the Food and Drug Administration (FDA) on the use of general anesthetics in children yielded a controversy on their potential neurotoxic effects. In this review, the main facts of the cerebral development are studied, and the available evidence concerning the use of general anesthesia on the neuropsychological development of children is analyzed. Most of the studies found were uncontrolled retrospective cohorts for which conclusions are difficult to obtain. However, a few group of controlled studies, including the Mayo Anesthesia Safety in Kids study (MASK), have partially supported the FDA warning. Cumulated evidence appears to support the safety use of general anesthetics, but no conclusive data supporting that it may induce massive effects on the cognitive development of exposed children has been reported. Important evidence suggests that specific cognitive functions may result altered under long-term expositions. Such data must be considered for those involved in anesthetic procedures.

A comparison of respiratory function in pigs anaesthetised by propofol or alfaxalone in combination with dexmedetomidine and ketamine.

BACKGROUND: General anaesthesia in pigs maintained with intravenous drugs such as propofol may cause respiratory depression. Alfaxalone gives less respiratory depression than propofol in some species. The aim of the investigation was to compare respiratory effects of propofol-ketamine-dexmedetomidine and alfaxalone-ketamine-dexmedetomidine in pigs. Sixteen pigs premedicated with ketamine 15 mg/kg and midazolam 1 mg/kg intramuscularly were anaesthetised with propofol or alfaxalone to allow endotracheal intubation, followed by propofol 8 mg/kg/h or alfaxalone 5 mg/kg/h in combination with ketamine 5 mg/kg/h and dexmedetomidine 4 µg/kg/h given as a continuous infusion for 60 min. The pigs breathed spontaneously with an FIO2 of 0.21. Oxygen saturation (SpO2), end-tidal CO2 concentration (PE'CO2), respiratory rate (fR) and inspired tidal volume (VT) were measured, and statistically compared between treatments. If the SpO2 dropped below 80% or if PE'CO2 increased above 10.0 kPa, the pigs were recorded as failing to complete the study, and time to failure was statistically compared between treatments. RESULTS: Alfaxalone treated pigs had significantly higher respiratory rates and lower PE'CO2 than propofol treated pigs, with a fR being 7.3 /min higher (P = 0.01) and PE'CO2 0.8 kPa lower (P = 0.05). SpO2 decreased by 0.6% and fR by 1.0 /min per kg increase in body weight in both treatment groups. Three of eight propofol treated and two of eight alfaxalone treated pigs failed to complete the study, and times to failure were not significantly different between treatments (P = 0.75). CONCLUSIONS: No major differences in respiratory variables were found when comparing treatments. Respiratory supportive measures must be available when using both protocols.

Impact of supraglottic device with assist ventilation under general anesthesia combined with nerve block in uniportal video-assisted thoracoscopic surgery.

BACKGROUND: With the improvement of anesthesia and surgical techniques, supraglottic device with assist ventilation under general anesthesia (GA) combined with nerve block is gradually applied to video-assisted thoracoscopic surgery. However, the safety of assist ventilation has not been fully confirmed, and a large number of samples should be studied in clinical exploration. METHODS: The subjects included 120 patients, undergoing elective thoracoscopic GA, with American Society of Anesthesiologists (ASA) physical status I or II, were randomly divided into 3 groups, 40 cases in each group. Group T: received double-lumen bronchial intubation, Group I: received intercostal nerve block using a supraglottic device, Group P: received paravertebral nerve block using a supraglottic device. Mean arterial pressure, heart rate, saturation of pulse oximetry and surgical field satisfaction, general anesthetic dosage and recovery time were recorded before induction of GA (T0), at the start of the surgical procedure (T1), 15 minutes later (T2), 30 minutes later (T3), and before the end of the surgical procedure (T4). Static and dynamic pain rating (NRS) and Ramsay sedation score were recorded 2 hours after surgery (T5), 12 hours after surgery (T6), 24 hours after surgery (T7), time to get out of bed, hospitalization time and cost, patient satisfaction and adverse reactions. RESULTS: There was no significant difference with the surgical visual field of the 3 groups (P > .05). The MAP, HR and SpO2 of the 3 groups were decreased from T2 to T3 compared with T0(P < .05). Compared with group T: the total dosage of GA was reduced in group I and group P, the recovery time was shorter, the time to get out of bed was earlier (P < .05), the hospitalization time was shortened, the hospitalization cost was lower, and the patient satisfaction was higher (P < .05). The static and dynamic NRS scores were lower from T5 to T7 (P < .05). Ramsay sedation scores were higher (P < .05), and the incidence of adverse reactions was lower (P < .05). Comparison between group I and group P: Dynamic NRS score of group P was lower from T6 to T7 (P < .05). CONCLUSION: Supraglottic device with assist ventilation under general anesthesia combined with nerve block in uniportal video-assisted thoracoscopic surgery is safe and feasible.

Pharmacokinetic and pharmacodynamic considerations of general anesthesia in pediatric subjects.

Introduction: The target concentration strategy uses PKPD information for dose determination. Models have also quantified exposure-response relationships, improved understanding of developmental pharmacokinetics, rationalized dose prescription, provided insight into the importance of covariate information, explained drug interactions and driven decision-making and learning during drug development.Areas covered: The prime PKPD consideration is parameter estimation and quantification of variability. The main sources of variability in children are age (maturation) and weight (size). Model use is mostly confined to pharmacokinetics, partly because anesthesia effect models in the young are imprecise. Exploration of PK and PD covariates and their variability hold potential to better individualize treatment.Expert opinion: The ability to model drugs using computer-based technology is hindered because covariate data required to individualize treatment using these programs remain lacking. Target concentration intervention strategies remain incomplete because covariate information that might better predict individualization of dose is absent. Pharmacogenomics appear a valuable area for investigation for pharmacodynamics and pharmacodynamics. Effect measures in the very young are imprecise. Assessment of the analgesic component of anesthesia is crude. While neuromuscular monitoring is satisfactory, depth of anaesthesia EEG interpretation is inadequate. Closed loop anesthesia is possible with better understanding of EEG changes.

Distinct effects of general anesthetics on lung metastasis mediated by IL-6/JAK/STAT3 pathway in mouse models.

Metastasis can occur following surgical resection of solid tumors and metastasis is the main cause of cancer death. The role of anesthetics used during surgery in cancer metastasis and the underlying mechanism remains largely unknown. Here we show that surgical dissection of primary tumors in mice under anesthesia with sevoflurane leads to significantly more lung metastasis than with propofol in both syngeneic murine 4T1 and xenograft human MDA-MB-231 breast cancer models. Sevoflurane increases the level of serum IL-6, which activates STAT3 and the infiltration of CD11b+ myeloid cells into the lung. Interruption of IL-6/JAK/STAT3 pathway by a JAK inhibitor AZD1480 reverses the pro-metastatic effect of sevoflurane and the associated increase of both activated STAT3 and infiltrated CD11b+ cells in 4T1 model. Our study provides the preclinical evidence informing the distinct effects of anesthetics on metastasis of breast cancers through change of cytokines and the tumor microenvironment.

The effect of perioperative anesthetics for prevention of postoperative delirium on general anesthesia: A network meta-analysis.

STUDY OBJECTIVE: Postoperative delirium (POD) is a common neurological system disorder in surgical patients. Anesthesia providers have a wide choice of sedative agents involving different mechanisms in clinical practice, and the incidence of POD varies regarding which sedative agent administered. This network meta-analysis aimed to comprehensively analyze the safety and efficacy of each choice for patients. DESIGN: A network meta-analysis. SETTING: Vanderbilt University Medical Center. MEASUREMENTS: We searched PubMed, EMBASE, Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) through the end of September 2018 with the registration number CRD42018110585. The randomized controlled trials were identified and extracted by two reviewers independently. Commonly used sedative agents such as placebo, sevoflurane, desflurane, isoflurane, dexmedetomidine, propofol, midazolam, and ketamine were assessed in this network meta-analysis and the primary outcome was the incidence of POD. The data were synthesized by network meta-analysis. Pair-wise meta-analyses were conducted using the random-effects model. Each intervention was ranked according to its corresponding surface under the cumulative ranking curve (SUCRA) values. The GRADE framework was undertaken to evaluate the risk of bias. MAIN RESULTS: We identified 39 RCTs and 5991 patients in this meta-analysis. Dexmedetomidine was found to be the most effective option in reducing POD, compared to midazolam, propofol, desflurane, and sevoflurane. The results revealed that dexmedetomidine was associated with a lower incidence of POD, whereas midazolam was associated with a significantly higher number of patients with delirium. Midazolam and propofol were also associated with a higher incidence of perioperative hypotension and bradycardia. CONCLUSION: Our study provided meta-analytic evidence and suggested dexmedetomidine could be considered as the most effective sedative agent to reduce POD. However, clinical practitioners still need to weigh the pros and cons before choosing a sedative agent for individual patient.

Anestesia para reparación antenatal de mielomeningocele: Presentación de un caso / Anesthesia for myelomenigocele antenatal repair: Case report

INTRODUCTION: The advance in the methods of prenatal diagnosis and surgical techniques have allowed the development of fetal surgery, achieving identification and early treatment of anomalies invalidating extrauterine life. Myelomeningocele (MMC) is the most frequent neural tube defect and its intrauterine correction has demonstrated benefits. OBJECTIVE: To publicize the anesthetic management of a prenatal correction of MMC performed in a public hospital in Chile. CASE REPORT: 31-year-old woman, pregnancy of 25 weeks of gestational age, fetus carrying MMC lumbosacral, who underwent open correction. Procedure performed with incidents under general anesthesia with remifentanil and sevoflorane MAC in 2 and tocolytic prophylaxis. At 48 hours post operative, he presented an acute pulmonary edema compatible (EPA), which was successfully resolved with depletive therapy for 24 hours in the Intensive Care Unit, without the need for mechanical ventilation or use of vasoactive drugs. Discharged one week later in good condition, with interruption of pregnancy by elective caesarean section at 37 weeks, with a newborn without stigmas of neurological sequelae. CONCLUSIONS: The mother-fetus binomial is a challenge for the anesthetist. In intrauterine surgery the need for knowledge about the pharmacology of tocolytics, placental uterine physiology and the complications of the procedure are added.

INTRODUCCIÓN: El avance en los métodos de diagnóstico prenatal y las técnicas quirúrgicas han permitido el desarrollo de la cirugía fetal, logrando identificación y tratamiento precoz de anomalías invalidantes para la vida extrauterina. El mielomeningocele (MMC) es el defecto del tubo neural más frecuente y su corrección intrauterina tiene beneficios demostrados. OBJETIVO: Dar a conocer el manejo anestésico de una corrección prenatal de MMC realizada en un hospital público de Chile. CASO CLÍNICO: Mujer de 31 años, embarazo de 25 semanas de edad gestacional, feto portador de MMC lumbosacro, que se sometió a una corrección por vía abierta. Procedimiento realizado con incidentes bajo anestesia general con remifentanilo y sevoflorano MAC en 2 y profilaxis tocolítica. A las 48 horas postoperatorias presentó cuadro compatible con edema pulmonar agudo (EPA), que se resolvió exitosamente con terapia depletiva por 24 horas en Unidad de Cuidados Intensivos, sin necesidad de ventilación mecánica ni uso de drogas vasoactivas. Dada de alta una semana después en buenas condiciones. El embarazo se interrumpió por cesárea electiva a las 37 semanas, con un recién nacido sin estigmas de secuela neurológica. CONCLUSIONES: El binomio madre-feto es un reto para el anestesista. En cirugía intraútero se suma la necesidad de conocimientos sobre la farmacología de los tocolíticos, fisiología útero placentaria y las complicaciones propias del procedimiento.

Paro cardiorrespiratorio intraoperatorio en un paciente con síndrome de Brugada / Intraoperative cardiac arrest in a patient with Brugada síndrome

A 61-year-old female patient with history of hipertension is scheduled to undergo a minor ginecological procedure (endoscopic endometrial polipus resection) with general anesthesia. She received standard monitorization, induction with midazolam, propofol and fentanyl. Ventilated with laringeal mask. Anesthesia was maintained with sevoflurane, nitrous oxide and oxygen. During surgical procedure, the patient received atropine and ephedrine associated with two episodes of bradycardia without hemodinamic disturbances. The surgery ended without problems. During the weaking up process she presented characteristical waves of ventricular fibrillation, recuperating sinusal rhythm secondary to defibrillation with 360 J. There was no clear cause for cardiac arrest at that moment so patient was translated to the ICU for observation, monitoring and study. Postoperative EKG presented an ascending ST segment in V to V derivations without hemodynamic alterations associated. The possible diagnosis of Brugada's Syndrome was proposed. The patient received an implantable defibrillator. The mechanisms and anesthetic implications are discussed and reviewed.

Paciente de 61 años, hipertensa, fue sometida a un procedimiento endoscópico menor (histeroscopía) bajo anestesia general balanceada. Recibió monitorización estándar, inducción con midazolam, propofol y fentanilo. Se ventiló con máscara laríngea y la mantención anestésica fue con sevoflurano asociado a NO en O. En dos oportunidades recibió atropina y efedrina para el manejo de bradicardias sin compromiso hemodinámico. Se completó el procedimiento ginecológico sin complicaciones. Durante el despertar anestésico, presentó una fibrilación ventricular que cedió con desfibrilación. Se estabilizó y trasladó a UCI donde se estudió las posibles etiologías. Se obtiene ECG postoperatorio con elevación del segmento ST en derivaciones Va V sin alteraciones hemodinámicas asociadas, postulándose un síndrome de Brugada. Se le instaló desfibrilador implantable. Se revisa y discuten los diversos mecanismos e implicancias anestésicas asociadas.

Masas cardíacas, utilidad de la ecocardiografía transesofágica durante el intraperioperatorio / Intracardiac tumors: utility of transesophageal echocardiography during the periodic intraoperative

We present our experience in cardiac tumor resection surgery in adult patients: 30 subjects with sternotomy approach with later diagnosis of myxomas (12), fibroelastomas (7), sarcomas (4), cardiac methastasis of a breast cancer and cardiac invasion of renal tumor (6), and 3 with videothroacoscopic approach with diagnosis of atrial myxoma (2) and intraventricular sarcoma (1). We highlight the usefulness of TEE as an essential monitor in this subtype of cardiac surgery in allowing location confirmation and completion of resection. Likewise as anesthesiologists and active participants of the surgical team, we were able to document absence of residual heart defects, lesions or perforations or dysfunction of heart valves. Evaluation of preexisting anatomy and function and post Cardiopulmonary Bypass ventricular function and circulation were important in early diagnosis of complications.

Presentamos nuestra experiencia en resección de tumores cardíacos en pacientes adultos: 30 casos con resecciones tumorales por esternotomía: 12 mixomas, 7 fibroeslastomas, 4 sarcomas, 6 tumores renales con invasión cardíaca y 1 metástasis cardíaca de cáncer de mama. En 3 pacientes las resecciones tumorales fueron por videotoracoscopía (2 mixomas y un sarcoma intraventricular). La cirugía por video supone un nuevo desafío para el anestesiólogo. Destacamos la utilidad de la ecocardiografía transesofágica como monitor, hoy imprescindible en cirugía cardíaca. Éste nos permitió confirmar la localización del tumor y su completa resección. Así mismo, como anestesiólogos y formando parte activa en el equipo quirúrgico, pudimos documentar la ausencia de defectos residuales, perforaciones o incompetencia de las válvulas cardíacas; evaluar la función ventricular y la volemia postcirculación extracorpórea, obtener información no conocida previamente y realizar así un diagnóstico precoz de complicaciones.