Impact of various anesthetic regimens on motor-evoked potentials in infants undergoing spinal surgery: A case series.

Motor-evoked potential (MEP) monitoring is commonly used in children. MEP monitoring in infants is difficult due to smaller signals requiring higher stimulation voltages. There is limited information on the effect of different anesthetics on MEP monitoring in this age group. This case series describes the effect of different anesthetic regimens on MEP monitoring in infants. Patients <1 year of age who underwent spinal surgery with MEP monitoring between February 2022 and July 2023 at a single tertiary care children hospital were reviewed. The motor-evoked potential amplitudes were classified into 4 levels based on the voltage in the upper and lower limbs (none, responded, acceptable, sufficient). "Acceptable" or "sufficient" levels were defined as successful monitoring. A total of 19 infants were identified, involving 3 anesthesia regimens: 4/19 (21.1%) cases were anesthetized with propofol/remifentanil total intravenous anesthesia (TIVA), 3/19 (15.8%) with propofol/remifentanil/low-dose sevoflurane and another 12/19 (63.2%) cases who initially received propofol/remifentanil/sevoflurane and were converted to propofol/remifentanil anesthesia intraoperatively. The 4 cases with propofol/remifentanil showed 20/32 (62.5%) successful monitoring points. In contrast, 6/24 (25%) successful points were achieved with propofol/remifentanil intravenous anesthesia/0.5 age-adjusted minimum alveolar concentration sevoflurane. In 12 cases converted from propofol/remifentanil/low-dose inhalational anesthetics to TIVA alone, successful MEP monitoring points increased from 46/96 (47.9%) to 81/96 (84.4%). Adding low-dose inhalation anesthetic to propofol-based TIVA suppresses MEP amplitudes in infants. The optimal anesthetic regimen for infants requires further investigation.

Influencing Factors of Delirium during Recovery in Urological Postoperative Patients Undergoing Sevoflurane Anaesthesia.

OBJECTIVE: To analyse the incidence and influencing factors of delirium during recovery in urological postoperative patients undergoing sevoflurane anaesthesia. METHODS: The clinical data of patients undergoing sevoflurane anaesthesia in the urology surgery department in our hospital from January 2022 to December 2022 were retrospectively analysed. The incidence of delirium during the recovery period was recorded by using the Chinese version of the Confusion Assessment Method (CAM) for Severity of Delirium after surgery, and the patients were divided into occurrence and non-occurrence groups. Whether delirium occurred during recovery was determined through univariate analysis. In binary logistic regression analysis, the occurrence of emergence delirium was the dependent variable, and the variables with statistical differences in the univariate analysis were the independent variables. The influencing factors of emergence delirium in post-urological surgery patients who underwent sevoflurane anaesthesia were determined. RESULTS: Delirium during recovery occurred in 10 of 100 patients (10.00%). Odds ratio (OR) of age (OR = 1.445, p = 0.022), history of diabetes (OR = 1.798, p = 0.010), operation time (OR = 1.670, p = 0.008), American Society of Anesthesiologists (ASA) classification (OR = 1.740, p = 0.006) and sevoflurane inhalation concentration (OR = 1.890, p = 0.001) are the influencing factors of postoperative delirium in urologic patients undergoing sevoflurane anaesthesia. CONCLUSIONS: Age, history of diabetes, operation time, ASA classification and sevoflurane inhalation concentration are the influencing factors.

Similarity and dissimilarity in alterations of the gene expression profile associated with inhalational anesthesia between sevoflurane and desflurane.

Although sevoflurane is one of the most commonly used inhalational anesthetic agents, the popularity of desflurane is increasing to a level similar to that of sevoflurane. Inhalational anesthesia generally activates and represses the expression of genes related to xenobiotic metabolism and immune response, respectively. However, there has been no comprehensive comparison of the effects of sevoflurane and desflurane on the expression of these genes. Thus, we used a next-generation sequencing method to compare alterations in the global gene expression profiles in the livers of rats subjected to inhalational anesthesia by sevoflurane or desflurane. Our bioinformatics analyses revealed that sevoflurane and, to a greater extent, desflurane significantly activated genes related to xenobiotic metabolism. Our analyses also revealed that both anesthetic agents, especially sevoflurane, downregulated many genes related to immune response.

Involvement of Fgf2-mediated tau protein phosphorylation in cognitive deficits induced by sevoflurane in aged rats.

OBJECTIVE: Anesthetics have been linked to cognitive alterations, particularly in the elderly. The current research delineates how Fibroblast Growth Factor 2 (Fgf2) modulates tau protein phosphorylation, contributing to cognitive impairments in aged rats upon sevoflurane administration. METHODS: Rats aged 3, 12, and 18 months were subjected to a 2.5% sevoflurane exposure to form a neurotoxicity model. Cognitive performance was gauged, and the GEO database was employed to identify differentially expressed genes (DEGs) in the 18-month-old cohort post sevoflurane exposure. Bioinformatics tools, inclusive of STRING and GeneCards, facilitated detailed analysis. Experimental validations, both in vivo and in vitro, examined Fgf2's effect on tau phosphorylation. RESULTS: Sevoflurane notably altered cognitive behavior in older rats. Out of 128 DEGs discerned, Fgf2 stood out as instrumental in regulating tau protein phosphorylation. Sevoflurane exposure spiked Fgf2 expression in cortical neurons, intensifying tau phosphorylation via the PI3K/AKT/Gsk3b trajectory. Diminishing Fgf2 expression correspondingly curtailed tau phosphorylation, neurofibrillary tangles, and enhanced cognitive capacities in aged rats. CONCLUSION: Sevoflurane elicits a surge in Fgf2 expression in aging rats, directing tau protein phosphorylation through the PI3K/AKT/Gsk3b route, instigating cognitive aberrations.

Minimal alveolar concentration of sevoflurane in combination with remimazolam in adults during laryngeal mask insertion: an up-down sequential allocation study.

BACKGROUND: Remimazolam is a novel ultrashort-acting intravenous benzodiazepine sedative-hypnotic. The combination of remimazolam and sevoflurane does not increase respiratory sensitivity, produce bronchospasm, or cause other adverse conditions. We aimed to observe the effects of different remimazolam doses on the minimum alveolar concentration (MAC) of sevoflurane at end-expiration during laryngeal mask insertion and evaluate the effect of sex on the efficacy of the combination of remimazolam on the suppression of laryngeal mask insertion in adult patients. METHODS: We included 240 patients undergoing laparoscopic surgery under general anesthesia with elective placement of a laryngeal mask (120 males and 120 females). The patients were randomly divided into four groups according to sex: a control group (randomization for female patients, RF0; randomization for male patients, RM0) and three remimazolam groups (RF1, RM1 / RM2, RF2 / RM3, RF3), with 30 patients in each group. Induction was established by vital capacity rapid inhalation induction (VCRII), using 8% sevoflurane and 100% oxygen (6 L/min) in all patients. The (RF1, RM1), (RM2, RF2), and (RM3, RF3) groups were continuously injected with remimazolam at doses of 1, 1.5, and 2.0 mg/kg/h, respectively, while the (RM0, RF0) group was injected with an equal volume of normal saline. The end-expiratory concentration of sevoflurane was adjusted to a preset value after the patient's eyelash reflex disappeared. After the end-expiratory concentration of sevoflurane was kept stable for at least 15 min, the laryngeal mask was placed, and the patient's physical response to the mask placement was observed immediately and within 30 s of placement. The MAC of sevoflurane was measured using the up-and-down sequential method of Dixon. RESULTS: The calculated MAC of end-expiratory sevoflurane during laryngeal mask insertion in adult females was (2.94 ± 0.18)%, (2.69 ± 0.16)%, (2.32 ± 0.16)% and (1.83 ± 0.15)% in groups RF0, RF1, RF2 and RF3; (2.98 ± 0.18)%, (2.80 ± 0.19)%, (2.54 ± 0.15)% and (2.15 ± 0.15)% in male groups RM0, RM1, RM2 and RM3, respectively. The MAC values were significantly lower in the (RF1-RF3, RM1-RM3) group when compared to the (RF0, RM0) group. There was no significant difference between (RF0, RF1) and (RM0, RM1), but the MAC value of the RF2-RF3 group was significantly lower than that of the RM2-RM3 group. CONCLUSIONS: Remimazolam can effectively reduce end-expiratory sevoflurane MAC values during laryngeal mask placement in adults. When remimazolam was measured above 1.5 mg/kg/h, the effect of inhibiting laryngeal mask implantation in female patients was stronger than that in male patients. Remimazolam at a dose of 1-2 mg/kg/h combined with sevoflurane induction can be safely and effectively used in these patients.

Inhaled anesthesia associated with reduced mortality in patients with stage III breast cancer: A population-based study.

BACKGROUND: Patients diagnosed with stage III breast cancer often undergo surgery, radiation therapy, and chemotherapy as part of their treatment. The choice of anesthesia technique during surgery has been a subject of interest due to its potential association with immune changes and prognosis. In this study, we aimed to compare the mortality rates between stage III breast cancer patients undergoing surgery with propofol-based intravenous general anesthesia and those receiving inhaled anesthetics. METHODS: Using data from Taiwan's National Health Insurance Research Database and Taiwan Cancer Registry, we identified a cohort of 10,896 stage III breast cancer patients. Among them, 1,506 received propofol-based intravenous anesthetic maintenance, while 9,390 received inhaled anesthetic maintenance. To ensure comparability between the two groups, we performed propensity-score matching. RESULTS: Our findings revealed a significantly lower mortality rate in patients who received inhaled anesthetics compared to those who received propofol-based intravenous anesthesia. Sensitivity analysis further confirmed the robustness of our results. CONCLUSIONS: This study suggests that inhaled anesthesia technique is associated with a lower mortality rate in clinical stage III breast cancer. Further research is needed to validate and expand upon these results.

Reducing the carbon footprint of operating rooms through education on the effects of inhalation anesthetics on global warming: A retrospective study.

Environmental concerns, especially global warming, have prompted efforts to reduce greenhouse gas emissions. Healthcare systems, including anesthesia practices, contribute to these emissions. Inhalation anesthetics have a significant environmental impact, with desflurane being the most concerning because of its high global warming potential. This study aimed to educate anesthesiologists on the environmental impact of inhalation anesthetics and assess changes in awareness and practice patterns, specifically reducing desflurane use. This study included data from patients who underwent surgery under general anesthesia 1 month before and after education on the effects of inhalation anesthetics on global warming. The primary endpoint was a change in inhalational anesthetic use. Secondary endpoints included changes in carbon dioxide equivalent (CO2e) emissions, driving equivalent, and medical costs. After the education, desflurane use decreased by 50%, whereas sevoflurane use increased by 50%. This shift resulted in a reduction in the overall amount of inhalational anesthetics used. The total CO2e and driving-equivalent values decreased significantly. The cost per anesthesia case decreased, albeit to a lesser extent than expected. Education on the environmental impact of inhalation anesthetics has successfully altered anesthesiologists' practice patterns, leading to reduced desflurane usage. This change has resulted in decreased CO2e emissions and has had a positive effect on mitigating global warming. However, further research is required to assess the long-term impact of such education and the variability in practice patterns across different institutions.

The role of astrocytic γ-aminobutyric acid in the action of inhalational anesthetics.

BACKGROUND: Inhalational anesthetics target the inhibitory extrasynaptic γ-aminobutyric acid type A (GABAA) receptors. Both neuronal and glial GABA mediate tonic inhibition of the extrasynaptic GABAA receptors. However, the role of glial GABA during inhalational anesthesia remains unclear. This study aimed to evaluate whether astrocytic GABA contributes to the action of different inhalational anesthetics. METHODS: Gene knockout of monoamine oxidase B (MAOB) was used to reduce astrocytic GABA levels in mice. The hypnotic and immobilizing effects of isoflurane, sevoflurane, and desflurane were assessed by evaluating the loss of righting reflex (LORR) and tail-pinch withdrawal response (LTWR) in MAOB knockout and wild-type mice. Minimum alveolar concentration (MAC) for LORR, time to LORR, MAC for LTWR and time to LTWR of isoflurane, sevoflurane, and desflurane were assessed. RESULTS: Time to LORR and time to LTWR with isoflurane were significantly longer in MAOB knockout mice than in wild-type mice (P < 0.001 and P = 0.032, respectively). Time to LORR with 0.8 MAC of sevoflurane was significantly longer in MAOB knockout mice than in wild-type mice (P < 0.001), but not with 1.0 MAC of sevoflurane (P=0.217). MAC for LTWR was significantly higher in MAOB knockout mice exposed to sevoflurane (P < 0.001). With desflurane, MAOB knockout mice had a significantly higher MAC for LORR (P = 0.003) and higher MAC for LTWR (P < 0.001) than wild-type mice. CONCLUSIONS: MAOB knockout mice showed reduced sensitivity to the hypnotic and immobilizing effects of isoflurane, sevoflurane, and desflurane. Behavioral tests revealed that the hypnotic and immobilizing effects of inhalational anesthetics would be mediated by astrocytic GABA.

Evaluation of Quality of Recovery With Quality of Recovery-15 Score After Closed-Loop Anesthesia Delivery System-Guided Propofol Versus Desflurane General Anesthesia in Patients Undergoing Transabdominal Robotic Surgery: A Randomized Controlled Study.

BACKGROUND: Robotic technique of surgery allows surgeons to perform complex procedures in difficult-to-access areas of the abdominal/pelvic cavity (eg, radical prostatectomy and radical hysterectomy) with improved access and precision approach. At the same time, automated techniques efficiently deliver propofol total intravenous anesthesia (TIVA) with lower anesthetic consumption. As both above are likely to bring benefit to the patients, it is imperative to explore their effect on postanesthesia recovery. Quality of Recovery-15 (QoR-15) is a comprehensive patient-reported measure of the quality of postanesthesia recovery and assesses compendious patients' experiences (physical and mental well-being). This randomized study assessed the effect of automated propofol TIVA versus inhaled desflurane anesthesia on postoperative quality of recovery using the QoR-15 questionnaire in patients undergoing elective robotic surgery. METHODS: One hundred twenty patients undergoing robotic abdominal surgery under general anesthesia (GA) were randomly allocated to receive propofol TIVA administered by closed-loop anesthesia delivery system (CLADS) (CLADS group) or desflurane GA (desflurane group). Postoperative QoR-15 score on postoperative day 1 (POD-1) and postoperative day 2 (POD-2) (primary outcome variables), individual QoR-15 item scores (15 nos.), intraoperative hemodynamics (heart rate, mean blood pressure), anesthesia depth consistency, anesthesia delivery system performance, early recovery from anesthesia (time-to-eye-opening, and time to tracheal extubation), and postoperative adverse events (sedation, postoperative nausea and vomiting [PONV], pain, intraoperative awareness recall) (secondary outcome variables) were analyzed. RESULTS: On POD-1, the CLADS group scored significantly higher than the desflurane group in terms of "overall" QoR-15 score (QoR-15 score: 114.5 ± 13 vs 102.1 ± 20.4; P = .001) and 3 individual QoR-15 "items" scores ("feeling rested" 7.5 ± 1.9 vs 6.4 ± 2.2, P = .007; "good sleep" 7.8 ± 1.9 vs 6.6 ± 2.7, P = .027; and "feeling comfortable and in control" 8.1 ± 1.7 vs 6.9 ± 2.4, P = .006). On the POD-2, the CLADS group significantly outscored the desflurane group with respect to the "overall" QoR-15 score (126.0 ± 13.6 vs 116.3 ± 20.3; P = .011) and on "5" individual QoR-15 items ("feeling rested" 8.1 ± 1.4 vs 7.0 ± 2.0, P = .003; "able to return to work or usual home activities" 6.0 ± 2.2 vs 4.6 ± 2.6, P = .008; "feeling comfortable and in control" 8.6 ± 1.2 vs 7.7 ± 1.9, P = .004; "feeling of general well-being" 7.8 ± 1.6 vs 6.9 ± 2.0, P = .042; and "severe pain" 9.0 ± 1.9 vs 8.1 ± 2.5, P = .042). CONCLUSIONS: Automated propofol TIVA administered by CLADS is superior to desflurane inhalation GA with respect to early postoperative recovery as comprehensively assessed on the QoR-15 scoring system. The effect of combined automated precision anesthesia and surgery (robotics) techniques on postoperative recovery may be explored further.

Comparison of three scoring criteria to assess recovery from general anesthesia in the postanesthesia care unit in the indian population.

Background: Different discharge criteria are available for shifting patients out from postanesthesia care room following surgery. This study was done to compare the three-scoring system namely traditional time-based criteria, Fast track criteria and modified Aldrete score, in Indian population patients who recover after general anesthesia in postanesthesia care unit (PACU). Materials and Methods: Three hundred and seventy-five patients scheduled for general anesthesia were included in this study. Induction of anesthesia was done with intravenous (IV) propofol and maintained with sevoflurane inhalation with oxygen and nitrous oxide. Reversal of residual neuromuscular blockade was done with IV neostigmine and glycopyrrolate. Patients were shifted to PACU following tracheal extubation and recovery was assessed using the traditional time-based criteria, fast track criteria, and modified Aldrete score. Results: As per modified Aldrete score, mean time of shift out is 19 min with median of 15 min and standard deviation of 21.7 min. As per fast-track score, mean time of shift out is 187 min with median of 30 min and standard deviation of 243.7 min. As per the time-based criteria, mean time of shift out is 222 min with median of 240 min and standard deviation of 136.8 min. While using modified Aldrete score, majority of patients had a shorter stay in PACU and faster time to shift out as compared to fast-track criteria and traditional time-based criteria. Conclusion: Modified Aldrete score when compared to fast-track scoring and time-based criteria shows early recovery and reduces the length of stay in PACU.

Résumé Contexte: Différents critères de sortie sont disponibles pour faire sortir les patients de la salle de soins post-anesthésie après une intervention chirurgicale. Cette étude a été réalisée pour comparer le système de notation à trois, à savoir les critères traditionnels basés sur le temps, les critères accélérés et le score Aldrete modifié, en Inde. Population de patients qui se rétablissent après une anesthésie générale en unité de soins post-anesthésiques (USPA). Matériels et méthodes: Trois cent et soixante-quinze patients devant subir une anesthésie générale ont été inclus dans cette étude. L'induction de l'anesthésie a été réalisée par voie intraveineuse (IV) propofol et maintenu avec inhalation de sévoflurane avec de l'oxygène et du protoxyde d'azote. L'inversion du bloc neuromusculaire résiduel a été réalisée avec néostigmine IV et glycopyrrolate. Les patients ont été transférés vers une USPA après l'extubation trachéale et la récupération a été évaluée à l'aide du critères traditionnels basés sur le temps, critères accélérés et score d'Aldrete modifié. Résultats: Selon le score d'Aldrete modifié, temps moyen de sortie est de 19 min avec une médiane de 15 min et un écart type de 21,7 min. Selon le score accéléré, le temps moyen de sortie est de 187 minutes avec une médiane de 30 min et écart type de 243,7 min. Selon les critères temporels, le temps moyen de changement de poste est de 222 minutes avec une médiane de 240 minutes et écart type de 136,8 min. En utilisant le score d'Aldrete modifié, la majorité des patients ont eu un séjour plus court en USPA et un temps de changement plus rapide. Par rapport aux critères accélérés et aux critères traditionnels basés sur le temps. Conclusion: Score d'Aldrete modifié par rapport au traitement accéléré la notation et les critères basés sur le temps montrent une récupération précoce et réduisent la durée du séjour en USPA. Mots-clés: Critères accélérés, score d'Aldrete modifié, unité de soins post-anesthésie, critères de sortie post-anesthésie, sortie basée sur le temps.

Acute Intraoperative Tympanic Membrane Rupture in Patient Anesthetized With Desflurane Without Nitrous Oxide: A Case Report.

We report a case of acute intraoperative tympanic membrane (TM) rupture in a patient anesthetized with desflurane without N2O. The patient was undergoing endoscopic retrograde cholangiopancreatography (ERCP) to treat ascending cholangitis. TM rupture is known to occur with N2O but has not been reported in the literature with the use of inhaled volatile anesthetics without N2O. We suspect that several factors contributed to this complication, including prone positioning, a remote history of ear trauma, and the selection of desflurane as the maintenance anesthetic as opposed to a vapor with a higher blood-gas partition coefficient.

Single exposure to anesthesia/surgery in neonatal mice induces cognitive impairment in young adult mice.

BACKGROUND: The effects of a solitary neonatal exposure to anesthesia plus surgery (anesthesia/surgery) on cognitive function and the underlying mechanism in developing brains remains largely undetermined. We, therefore, set out to investigate the impact of single exposure to anesthesia/surgery in neonatal mice. METHODS: Six-day-old male and female mice received abdominal surgery under 3% sevoflurane plus 50% oxygen for 2 h. The new object recognition (NOR) and Morris water maze (MWM) were used to evaluate cognitive function in young adult mice. Western blot, ELISA and RT-PCR were used to measure levels of NR2B and IL-6 in medial prefrontal cortex and IL-6 in blood of the mice. We employed NR2B siRNA and IL-6 antibody in the interaction studies. RESULTS: The anesthesia/surgery decreased the ratio of novel time to novel plus familiar time in NOR and the number of platform crossings, but not escape latency, in MWM compared to sham condition. The mice in anesthesia/surgery group had increased NR2B expression in medial prefrontal cortex, and IL-6 amounts in blood and medial prefrontal cortex. Local injection of NR2B siRNA in medial prefrontal cortex alleviated the anesthesia/surgery-induced cognitive impairment. IL-6 antibody mitigated the anesthesia/surgery-induced upregulation of NR2B and cognitive impairment in young adult mice. CONCLUSIONS: These results suggest that a single neonatal exposure to anesthesia/surgery causes impairment of memory, but not learning, in young adult mice through IL-6-regulated increases in NR2B concentrations in medial prefrontal cortex, highlighting the need for further research on the underlying mechanisms of anesthesia/surgery's impact on cognitive function in developing brains.

Guidelines for inhaled sedation in the ICU.

INTRODUCTION AND OBJECTIVES: Sedation is used in intensive care units (ICU) to improve comfort and tolerance during mechanical ventilation, invasive interventions, and nursing care. In recent years, the use of inhalation anaesthetics for this purpose has increased. Our objective was to obtain and summarise the best evidence on inhaled sedation in adult patients in the ICU, and use this to help physicians choose the most appropriate approach in terms of the impact of sedation on clinical outcomes and the risk-benefit of the chosen strategy. METHODOLOGY: Given the overall lack of literature and scientific evidence on various aspects of inhaled sedation in the ICU, we decided to use a Delphi method to achieve consensus among a group of 17 expert panellists. The processes was conducted over a 12-month period between 2022 and 2023, and followed the recommendations of the CREDES guidelines. RESULTS: The results of the Delphi survey form the basis of these 39 recommendations - 23 with a strong consensus and 15 with a weak consensus. CONCLUSION: The use of inhaled sedation in the ICU is a reliable and appropriate option in a wide variety of clinical scenarios. However, there are numerous aspects of the technique that require further study.

Consistency analysis of consciousness index and bispectral index in monitoring the depth of sevoflurane anesthesia in laparoscopic surgery.

Background: The Index of Consciousness (IoC) is a new monitoring index of anesthesia depth reflecting the state of consciousness of the brain independently developed by China. The research on monitoring the depth of anesthesia mainly focuses on propofol, and bispectral index (BIS) is a sensitive and accurate objective index to evaluate the state of consciousness at home and abroad. This study mainly analyzed the effect of IoC on monitoring the depth of sevoflurane anesthesia and the consistency and accuracy with BIS when monitoring sevoflurane maintenance anesthesia. Objective: To investigate the monitoring value of the Index of Consciousness (IoC) for the depth of sevoflurane anesthesia in laparoscopic surgery. Methods: The study population consisted of 108 patients who experienced elective whole-body anesthesia procedures within the timeframe of April 2020 to June 2023 at our hospital. Throughout the anesthesia process, which encompassed induction and maintenance using inhaled sevoflurane, all patients were diligently monitored for both the Bispectral Index (BIS) and the Index of Consciousness (IoC). We conducted an analysis to assess the correlation between IoC and BIS throughout the anesthesia induction process and from the maintenance phase to the regaining of consciousness. To evaluate the predictive accuracy of IoC and BIS for the onset of unconsciousness during induction and the return of consciousness during emergence, we employed receiver operating characteristic (ROC) curve analysis. Results: The mean difference between BIS and IoC, spanning from the pre-anesthesia induction phase to the completion of propofol induction, was 1.3 (95% Limits of Agreement [-53.4 to 56.0]). Similarly, during the interval from the initiation of sevoflurane inhalation to the point of consciousness restoration, the average difference between BIS and IoC was 0.3 (95% LOA [-10.8 to 11.4]). No statistically significant disparities were observed in the data acquired from the two measurement methodologies during both the anesthesia induction process and the journey from maintenance to the regaining of consciousness (P > 0.05). The outcomes of the ROC curve analysis disclosed that the areas under the curve (AUC) for prognosticating the occurrence of loss of consciousness were 0.967 (95% CI [0.935-0.999]) for BIS and 0.959 (95% CI [0.924-0.993]) for IoC, with optimal threshold values set at 81 (sensitivity: 88.10%, specificity: 92.16%) and 77 (sensitivity: 79.55%, specificity: 95.45%) correspondingly. For the prediction of recovery of consciousness, the AUCs were 0.995 (95% CI [0.987-1.000]) for BIS and 0.963 (95% CI [0.916-1.000]) for IoC, each associated with optimal cutoff values of 76 (sensitivity: 92.86%, specificity: 100.00%) and 72 (sensitivity: 86.36%, specificity: 100.00%) respectively. Conclusion: The monitoring of sevoflurane anesthesia maintenance using IoC demonstrates a level of comparability to BIS, and its alignment with BIS during the maintenance phase of sevoflurane anesthesia is robust. IoC displays promising potential for effectively monitoring the depth of anesthesia.

Post-Anesthesia Cognitive Dysfunction in Mice Is Associated with an Age-Related Increase in Neuronal Intracellular [Ca2+]-Neuroprotective Effect of Reducing Intracellular [Ca2+]: In Vivo and In Vitro Studies.

Background: Postoperative cognitive dysfunction (POCD) is a common disorder after general anesthesia in elderly patients, the precise mechanisms of which remain unclear. Methods: We investigated the effect of isoflurane with or without dantrolene pretreatment on intracellular calcium concentration ([Ca2+]i), reactive oxygen species (ROS) production, cellular lactate dehydrogenase (LDH) leak, calpain activity, and cognitive function using the Morris water maze test of young (3 months), middle-aged (12-13 months), and aged (24-25 months) C57BL6/J mice. Results: Aged cortical and hippocampal neurons showed chronically elevated [Ca2+]i compared to young neurons. Furthermore, aged hippocampal neurons exhibited higher ROS production, increased LDH leak, and elevated calpain activity. Exposure to isoflurane exacerbated these markers in aged neurons, contributing to increased cognitive deficits in aged mice. Dantrolene pretreatment reduced [Ca2+]i for all age groups and prevented or significantly mitigated the effects of isoflurane on [Ca2+]i, ROS production, LDH leak, and calpain activity in aged neurons. Dantrolene also normalized or improved age-associated cognitive deficits and mitigated the cognitive deficits caused by isoflurane. Conclusions: These findings suggest that isoflurane-induced cytotoxicity and cognitive decline in aging are linked to disruptions in neuronal intracellular processes, highlighting the reduction of [Ca2+]i as a potential therapeutic intervention.

Dysregulation of iron homeostasis and ferroptosis in sevoflurane and isoflurane associated perioperative neurocognitive disorders.

In recent years, sevoflurane and isoflurane are the most popular anesthetics in general anesthesia for their safe, rapid onset, and well tolerant. Nevertheless, many studies reported their neurotoxicity among pediatric and aged populations. This effect is usually manifested as cognitive impairment such as perioperative neurocognitive disorders. The wide application of sevoflurane and isoflurane during general anesthesia makes their safety a major health concern. Evidence indicates that iron dyshomeostasis and ferroptosis may establish a role in neurotoxicity of sevoflurane and isoflurane. However, the mechanisms of sevoflurane- and isoflurane-induced neuronal injury were not fully understood, which poses a barrier to the treatment of its neurotoxicity. We, therefore, reviewed the current knowledge on mechanisms of iron dyshomeostasis and ferroptosis and aimed to promote a better understanding of their roles in sevoflurane- and isoflurane-induced neurotoxicity.