Age-dependent coupling characteristics of bilateral frontal EEG during desflurane anesthesia.

OBJECTIVES: The purpose of this study is to investigate the age dependence of bilateral frontal electroencephalogram coupling characteristics, and find potential age-independent depth of anesthesia monitoring indicators for the elderlies. Approach: We recorded bilateral forehead EEG data from 41 patients (ranged in 19-82 years old), and separated into three age groups: 18-40 years (n = 12); 40-65 years (n = 14), > 65 years (n = 15). All these patients underwent desflurane maintained general anesthesia. We analyzed the age-related EEG spectra, phase amplitude coupling (PAC), coherence and phase lag index (PLI) of EEG data in the states of awake, general anesthesia (GA), and recovery. Main results: The frontal alpha power shows age dependence in the state of GA maintained by desflurane. Modulation index (MI) in slow oscillation-alpha and delta-alpha bands showed age dependence and state dependence in varying degrees, the PAC pattern also became less pronounced with increasing age. In the awake state, the coherence in delta, theta and alpha frequency bands were all significantly higher in the > 65 years age group than in the 18-40 years age group (p < 0.05 for three frequency bands). The coherence in alpha-band was significantly enhanced in all age groups in GA (p < 0.01) and then decreased in recovery state. Notably, the PLI in the alpha band was able to significantly distinguish the three states of awake, GA and recovery (p < 0.01) and the results of PLI in delta and theta frequency bands had similar changes to those of coherence. Significance: We found the EEG coupling and synchronization between bilateral forehead are age-dependent. The PAC, coherence and PLI portray this age-dependence. The PLI and coherence based on bilateral frontal EEG functional connectivity measures and PAC based on frontal single-channel are closely associated with anesthesia-induced unconsciousness. .

Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study.

BACKGROUND: Postoperative delirium (POD) is more prevalent among elderly patients with type 2 diabetes mellitus (T2DM). Insulin resistance (IR) can be assessed using the triglyceride-glucose (TyG) index, a novel biomarker. This study aims to investigate the predictive potential of the TyG index for POD in elderly patients with T2DM. MATERIALS AND METHODS: Elderly patients (≥ 65) with T2DM who underwent non-neurosurgery and non-cardiac surgery were enrolled. Univariate and multivariate logistic regression analyses were conducted to assess the association between the TyG index and POD. Additionally, subgroup analyses were performed to compare the sex-specific differences in the predictive ability of the TyG index for POD. RESULTS: A total of 4566 patients were included in this retrospective cohort. The receiver operating characteristic (ROC) curve analysis determined the optimal cut-off value for the TyG index to be 8.678. In the univariate model, a TyG index > 8.678 exhibited an odds ratio (OR) of 1.668 (95% CI: 1.210-2.324, P = 0.002) for predicting POD. In the multivariate regression models, the ORs were 1.590 (95% CI: 1.133-2.252, P < 0.008), 1.661 (95% CI: 1.199-2.325, P < 0.003), and 1.603 (95% CI: 1.137-2.283, P = 0.008) for different models. Subgroup analyses demonstrated that the predictive ability of the TyG index was more pronounced in females compared to males. CONCLUSION: The TyG index shows promise as a novel biomarker for predicting the occurrence of POD in elderly surgical patients with T2DM.

[Retracted] Dexmedetomidine improves early postoperative neurocognitive disorder in elderly male patients undergoing thoracoscopic lobectomy.

[This retracts the article DOI: 10.3892/etm.2020.9113.].

Prelimbic cortical pyramidal neurons to ventral tegmental area projections promotes arousal from sevoflurane anesthesia.

AIMS: General anesthesia has been used in surgical procedures for approximately 180 years, yet the precise mechanism of anesthetic drugs remains elusive. There is significant anatomical connectivity between the ventral tegmental area (VTA) and the prelimbic cortex (PrL). Projections from VTA dopaminergic neurons (VTADA ) to the PrL play a role in the transition from sevoflurane anesthesia to arousal. It is still uncertain whether the prelimbic cortex pyramidal neuron (PrLPyr ) and its projections to VTA (PrLPyr -VTA) are involved in anesthesia-arousal regulation. METHODS: We employed chemogenetics and optogenetics to selectively manipulate neuronal activity in the PrLPyr -VTA pathway. Electroencephalography spectra and burst-suppression ratios (BSR) were used to assess the depth of anesthesia. Furthermore, the loss or recovery of the righting reflex was monitored to indicate the induction or emergence time of general anesthesia. To elucidate the receptor mechanisms in the PrLPyr -VTA projection's impact on anesthesia and arousal, we microinjected NMDA receptor antagonists (MK-801) or AMPA receptor antagonists (NBQX) into the VTA. RESULTS: Our findings show that chemogenetic or optogenetic activation of PrLPyr neurons prolonged anesthesia induction and promoted emergence. Additionally, chemogenetic activation of the PrLPyr -VTA neural pathway delayed anesthesia induction and promoted anesthesia emergence. Likewise, optogenetic activation of the PrLPyr -VTA projections extended the induction time and facilitated emergence from sevoflurane anesthesia. Moreover, antagonizing NMDA receptors in the VTA attenuates the delayed anesthesia induction and promotes emergence caused by activating the PrLPyr -VTA projections. CONCLUSION: This study demonstrates that PrLPyr neurons and their projections to the VTA are involved in facilitating emergence from sevoflurane anesthesia, with the PrLPyr -VTA pathway exerting its effects through the activation of NMDA receptors within the VTA.

Gut microbiota and cognitive performance: A bidirectional two-sample Mendelian randomization.

PURPOSE: Previous studies have suggested a potential association between gut microbiota and neurological and psychiatric disorders. However, the causal relationship between gut microbiota and cognitive performance remains uncertain. METHODS: A two-sample Mendelian randomization (MR) study used SNPs linked to gut microbiota (n = 18,340) and cognitive performance (n = 257,841) from recent GWAS data. Inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode were employed. Heterogeneity was assessed via Cochran's Q test for IVW. Results were shown with funnel plots. Outliers were detected through leave-one-out method. MR-PRESSO and MR-Egger intercept tests were conducted to address horizontal pleiotropy influence. LIMITATIONS: Limited to European populations, generic level, and potential confounding factors. RESULTS: IVW analysis revealed detrimental effects on cognitive perfmance associated with the presence of genus Blautia (P = 0.013, 0.966[0.940-0.993]), Catenibacterium (P = 0.035, 0.977[0.956-0.998]), Oxalobacter (P = 0.043, 0.979[0.960-0.999]). Roseburia (P < 0.001, 0.935[0.906-0.965]), in particular, remained strongly negatively associated with cognitive performance after Bonferroni correction. Conversely, families including Bacteroidaceae (P = 0.043, 1.040[1.001-1.081]), Rikenellaceae (P = 0.047, 1.026[1.000-1.053]), along with genera including Paraprevotella (P = 0.044, 1.020[1.001-1.039]), Ruminococcus torques group (P = 0.016, 1.062[1.011-1.115]), Bacteroides (P = 0.043, 1.040[1.001-1.081]), Dialister (P = 0.027, 1.039[1.004-1.074]), Paraprevotella (P = 0.044, 1.020[1.001-1.039]) and Ruminococcaceae UCG003 (P = 0.007, 1.040[1.011-1.070]) had a protective effect on cognitive performance. CONCLUSIONS: Our results suggest that interventions targeting specific gut microbiota may offer a promising avenue for improving cognitive function in diseased populations. The practical application of these findings has the potential to enhance cognitive performance, thereby improving overall quality of life.

Protection of Ndrg2 deficiency on renal ischemia-reperfusion injury via activating PINK1/Parkin-mediated mitophagy.

BACKGROUND: Renal ischemia-reperfusion (R-I/R) injury is the most prevalent cause of acute kidney injury, with high mortality and poor prognosis. However, the underlying pathological mechanisms are not yet fully understood. Therefore, this study aimed to investigate the role of N-myc downstream-regulated gene 2 (Ndrg2) in R-I/R injury. METHODS: We examined the expression of Ndrg2 in the kidney under normal physiological conditions and after R-I/R injury by immunofluorescence staining, real-time polymerase chain reaction, and western blotting. We then detected R-I/R injury in Ndrg2-deficient (Ndrg2-/-) mice and wild type (Ndrg2+/+) littermates in vivo, and detected oxygen and glucose deprivation and reperfusion injury (OGD-R) in HK-2 cells. We further conducted transcriptomic sequencing to investigate the role of Ndrg2 in R-I/R injury and detected levels of oxidative stress and mitochondrial damage by dihydroethidium staining, biochemical assays, and western blot. Finally, we measured the levels of mitophagy in Ndrg2+/+ and Ndrg2-/- mice after R-I/R injury or HK-2 cells in OGD-R injury. RESULTS: We found that Ndrg2 was primarily expressed in renal proximal tubules and significantly decreased its expression 24 h after R-I/R injury. Ndrg2-/- mice exhibited significantly attenuated R-I/R injury compared to Ndrg2+/+ mice. Transcriptomics profiling showed that Ndrg2 deficiency induced perturbations of multiple signaling pathways, downregulated inflammatory responses and oxidative stress, and increased autophagy following R-I/R injury. Further studies revealed that Ndrg2 deficiency reduced oxidative stress and mitochondrial damage. Notably, Ndrg2 deficiency significantly activated phosphatase and tensin homologue on chromosome ten-induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy. The downregulation of NDRG2 expression significantly increased cell viability after OGD-R injury, increased the expression of heme oxygenase-1, decreased the expression of nicotinamide adenine dinucleotide phosphate oxidase 4, and increased the expression of the PINK1/Parkin pathway. CONCLUSION: Ndrg2 deficiency might become a therapy target for R-I/R injury by decreasing oxidative stress, maintaining mitochondrial homeostasis, and activating PINK1/Parkin-mediated mitophagy.

The relationship between trajectories of renal oxygen saturation and acute kidney injury: a prospective cohort study with a secondary analysis.

BACKGROUND: Acute kidney injury (AKI) is a major postoperative consequence, affecting prognosis of older patients. Effective prediction or intervention to predict or prevent the incidence of AKI is currently unavailable. AIMS: Dynamic changes of renal tissue oxygen saturation (RSO2) during surgery process are understudied and we intended to explore the distinct trajectories and associations with postoperative AKI. METHODS: This was a secondary analysis including data for older patients who underwent open hepatectomy surgery with informed consent. Latent class mixed models (LCMM) method was conducted to generate trajectories of intraoperative renal tissue RSO2 through different time points. The primary outcome was postoperative 7-day AKI. The univariate and multivariate regression analysis were performed to identify the relationship between distinct trajectories of renal tissue RSO2 and the risk of AKI. Meanwhile, the prediction efficacy of renal tissue RSO2 at different time points was compared to find potential intervention timing. RESULTS: Postoperative AKI occurred in 14 (15.2%) of 92 patients. There are two distinct renal tissue RSO2 trajectories, with 44.6% generating "high-downwards" trajectory and 55.4% generating "consistently-high" trajectory. Patients with "high-downwards" trajectory had significantly higher risk of postoperative AKI than another group (Unadjusted OR [Odds Ratio] = 3.790, 95% CI [Confidence Interval]: 1.091-13.164, p = 0.036; Adjusted OR = 3.973, 95% CI 1.020-15.478, p = 0.047, respectively). Predictive performance was 71.4% sensitivity and 60.3% specificity for "high-downwards" trajectory of renal tissue RSO2 to identify AKI. Furthermore, the renal tissue RSO2 exhibited the lowest level and the best results in terms of the sensitivity during the hepatic occlusion period, may be considered as a "time of concern". CONCLUSIONS: Older patients undergoing hepatectomy may show high-downwards trajectory of renal tissue RSO2, indicating a higher risk of AKI, and the lowest level was identified during the hepatic occlusion period. These findings may help to provide potential candidates for future early recognition of deterioration of kidney function and guide interventions.

Sevoflurane exerts antidepressant-like effects via the BDNF-TrkB pathway.

Depression has emerged as the predominant psychiatric affliction affecting individuals. Prior research has substantiated the antidepressant properties exhibited by numerous anesthetics. Sevoflurane, a widely utilized inhalant anesthetic in clinical practice, remains relatively uncharted in terms of its specific antidepressant effects. In this study, we used open field test, forced swimming test and novelty-suppressed feeding test to investigate the anxiety and depression-like behaviors in C57BL/6 mice following the inhalation of sevoflurane. We then used western blotting to scrutinized the expression levels of proteins associated with the brain-derived neurotrophic factor (BDNF)-tryosine receptor kinase B (TrkB) pathway in the hippocampus and prefrontal cortex. To further investigate whether sevoflurane exerts antidepressant-like effects via the BDNF-TrkB pathway, we downregulated TrkB expression by administering siRNA into the lateral ventricle. We found that the inhalation of 2.5 % sevoflurane exerted a significant antidepressant-like effect, accompanied by an elevation in p-TrkB expression levels in the hippocampus and prefrontal cortex. Intriguingly, this antidepressant-like effect was abrogated following the downregulation of TrkB expression through the microinjection of siRNA into the lateral ventricle. In conclusion, this study provides evidence supporting the notion that sevoflurane exerts its antidepressant-like effect via the BDNF-TrkB signaling pathway.

Prediction models for postoperative delirium in elderly patients with machine-learning algorithms and SHapley Additive exPlanations.

Postoperative delirium (POD) is a common and severe complication in elderly patients with hip fractures. Identifying high-risk patients with POD can help improve the outcome of patients with hip fractures. We conducted a retrospective study on elderly patients (≥65 years of age) who underwent orthopedic surgery with hip fracture between January 2014 and August 2019. Conventional logistic regression and five machine-learning algorithms were used to construct prediction models of POD. A nomogram for POD prediction was built with the logistic regression method. The area under the receiver operating characteristic curve (AUC-ROC), accuracy, sensitivity, and precision were calculated to evaluate different models. Feature importance of individuals was interpreted using Shapley Additive Explanations (SHAP). About 797 patients were enrolled in the study, with the incidence of POD at 9.28% (74/797). The age, renal insufficiency, chronic obstructive pulmonary disease (COPD), use of antipsychotics, lactate dehydrogenase (LDH), and C-reactive protein are used to build a nomogram for POD with an AUC of 0.71. The AUCs of five machine-learning models are 0.81 (Random Forest), 0.80 (GBM), 0.68 (AdaBoost), 0.77 (XGBoost), and 0.70 (SVM). The sensitivities of the six models range from 68.8% (logistic regression and SVM) to 91.9% (Random Forest). The precisions of the six machine-learning models range from 18.3% (logistic regression) to 67.8% (SVM). Six prediction models of POD in patients with hip fractures were constructed using logistic regression and five machine-learning algorithms. The application of machine-learning algorithms could provide convenient POD risk stratification to benefit elderly hip fracture patients.

Association of sleep quality on the night of operative day with postoperative delirium in elderly patients: A prospective cohort study.

BACKGROUND: Sleep disturbances in the peri-operative period have been associated with adverse outcomes, including postoperative delirium (POD). However, research on sleep quality during the immediate postoperative period is limited. OBJECTIVES: This study aimed to investigate the association between sleep quality on the night of the operative day assessed using the Sleep Quality Numeric Rating Scale (SQ-NRS), and the incidence of POD in a large cohort of surgical patients. DESIGN: A prospective cohort study. SETTING: A tertiary hospital in China. PATIENTS: This study enrolled patients aged 65 years or older undergoing elective surgery under general anaesthesia. The participants were categorised into the sleep disturbance and no sleep disturbance groups according to their operative night SQ-NRS. MAIN OUTCOME MEASURES: The primary outcome was delirium incidence, whereas the secondary outcomes included acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively. RESULTS: In total, 3072 patients were included in the analysis of this study. Among them, 791 (25.72%) experienced sleep disturbances on the night of operative day. Patients in the sleep disturbance group had a significantly higher risk of developing POD (adjusted OR 1.43, 95% CI 1.11 to 1.82, P  = 0.005). Subgroup analysis revealed that age 65-75 years; male sex; ASA III and IV; haemoglobin more than 12 g l -1 ; intra-operative hypotension; surgical duration more than 120 min; and education 9 years or less were significantly associated with POD. No interaction was observed between the subgroups. No significant differences were observed in the secondary outcomes, such as acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively. CONCLUSIONS: The poor subjective sleep quality on the night of operative day was independently associated with increased POD risk, especially in certain subpopulations. Optimising peri-operative sleep may reduce POD. Further research should investigate potential mechanisms and causal relationships. TRIAL REGISTRY: chictr.org.cn: ChiCTR1900028545.

Public Knowledge and Awareness of Anesthesiology and Anesthesiologists in China: A Cross-Sectional National Survey of 1 Million Participants.

BACKGROUND: In the past 20 years, anesthesiology has become one of the most advanced specialties and has undergone rapid development. However, public awareness regarding anesthesiology and anesthesiologists is limited, especially in developing countries. It is important for anesthesiologists to make the public aware of their role during surgery. Therefore, a nationwide survey was set up to investigate public awareness of anesthesiology and anesthesiologists in China. METHOD: A cross-sectional nationwide survey was performed from June 2018 to June 2019 in 34 provinces, municipalities, and autonomous regions across China and an overseas region. The questionnaires of the survey were divided into 2 main parts: general items and research items. General items included the demographic characteristics of the participants; research items consisted of 10 questions about the public's awareness of anesthesiologists and anesthesiology. Data quality control was undertaken by the investigation committee throughout the survey process. RESULTS: The nationwide survey enrolled 1,001,279 participants (male, 40.7%). We found that most of the participants regarded anesthesiologists as doctors. However, public knowledge of anesthesiologists' work and duties during surgery was quite low, with correct response rate ranging from 16.5% to 52.9%, and anesthesiologist responsibilities were often mistakenly attributed to surgeons or nurses. It is disappointing that more than half of participants still thought that, once the patient fell asleep after receiving anesthetics, the anesthesiologist could leave the operating room. Finally, the correct response rate was positively correlated with the economic levels of the regions. CONCLUSIONS: Public awareness regarding anesthesiology and anesthesiologists in China remains inadequate. Due to the biases and characteristics of the participants, the actual situation of the general Chinese public is likely even worse than reflected here. Therefore, extensive measures should be undertaken to improve public knowledge of anesthesiology and anesthesiologists.

Risk factors prediction of 6-month mortality after noncardiac surgery of older patients in China: a multicentre retrospective cohort study.

BACKGROUND: Identifying the risk factors associated with perioperative mortality is crucial, particularly in older patients. Predicting 6-month mortality risk in older patients based on large datasets can assist patients and surgeons in perioperative clinical decision-making. This study aimed to develop a risk prediction model of mortality within 6 months after noncardiac surgery using the clinical data from 11 894 older patients in China. MATERIALS AND METHODS: A multicentre, retrospective cohort study was conducted in 20 tertiary hospitals. The authors retrospectively included 11 894 patients (aged ≥65 years) who underwent noncardiac surgery between April 2020 and April 2022. The least absolute shrinkage and selection operator model based on linear regression was used to analyse and select risk factors, and various machine learning methods were used to build predictive models of 6-month mortality. RESULTS: The authors predicted 12 preoperative risk factors associated with 6-month mortality in older patients after noncardiac surgery. Including laboratory-associated risk factors such as mononuclear cell ratio and total blood cholesterol level, etc. Also including medical history associated risk factors such as stroke, history of chronic diseases, etc. By using a random forest model, the authors constructed a predictive model with a satisfactory accuracy (area under the receiver operating characteristic curve=0.97). CONCLUSION: The authors identified 12 preoperative risk factors associated with 6-month mortality in noncardiac surgery older patients. These preoperative risk factors may provide evidence for a comprehensive preoperative anaesthesia assessment as well as necessary information for clinical decision-making by anaesthesiologists.

Preoperative prognostic nutritional index predicts postoperative delirium in aged patients after surgery: A matched cohort study.

OBJECTIVE: Prognostic nutritional index (PNI) is an indicator to evaluate the nutritional immune status of patients. This study aimed to assess whether preoperative PNI could predict the occurrence of postoperative POD in aged patients undergoing non-neurosurgery and non-cardiac surgery. METHOD: The aged patients undergoing non-neurosurgery and non-cardiac surgery between January 2014 and August 2019 were included in the retrospective cohort study. The correlation between POD and PNI was investigated by univariate and multivariable logistic regression analysis, propensity score matching (PSM), inverse probability of treatment weighting (IPTW), and subgroup analysis. RESULTS: In the cohort (n = 29,814), the cutoff value of PNI was 46.01 determined by the receiver operating characteristic (ROC) curve. In univariate and three multivariable regression analysis, the ORs of PNI ≤ 46.01 was 2.573(95% CI:2.261-2.929, P < 0.001),1.802 (95% CI:1.567-2.071, P < 0.001),1.463(95% CI:1.246-1.718, P < 0.001),1.370(95% CI:1.165-1.611, P < 0.001). In the PSM model and IPTW model, the ORs of PNI ≤ 46.01 were 1.424(95% CI:1.172-1.734, P < 0.001) and 1.356(95% CI:1.223-1.505, P < 0.001). CONCLUSION: The PNI was found to have a predictive value for POD in patients undergoing non-neurosurgery and non-cardiac surgery. Improving preoperative nutritional status may be beneficial in preventing POD for aged patients.

Association between intraoperative mean arterial pressure variability and postoperative delirium after hip fracture surgery: a retrospective cohort study.

BACKGROUND: Postoperative delirium (POD) is a common complication in elderly patients after hip fracture surgery. Our study was to investigate whether intraoperative mean arterial pressure variability (MAPV) was associated with POD in elderly patients after hip fracture surgery. METHODS: In this retrospective cohort study, patients aged 65 years and older undergoing hip fracture surgery were included. The correlation between MAPV and POD was investigated using univariate and multivariate logistic regression. Covariate-related confounding effects were eliminated with propensity score matching (PSM) analysis. Then, a subgroup analysis was conducted to further examine the associations between MAPV and POD. RESULTS: Nine hundred sixty-three patients with a median age of 80 years (IQR: 73-84) were enrolled. POD occurred in 115/963 (11.9%) patients within 7 days after surgery. According to multivariate regression analysis, MAPV > 2.17 was associated with an increased risk of POD (OR: 2.379, 95% CI: 1.496-3.771, P < 0.001). All covariates between the two groups were well balanced after PSM adjustment. A significant correlation between MAPV and POD was found in the PSM analysis (OR: 2.851, 95% CI: 1.710-4.746, P < 0.001). CONCLUSIONS: An increased intraoperative MAPV may be a predictor for POD.

Postoperative pain-related outcomes and perioperative pain management in China: a population-based study.

Background: Postoperative pain poses a significant challenge to the healthcare system and patient satisfaction and is associated with chronic pain and long-term narcotic use. However, systemic assessment of the quality of postoperative pain management in China remains unavailable. Methods: In this cross-sectional study, we analyzed data collected from a nationwide registry, China Acute Postoperative Pain Study (CAPOPS), between September 2019 and August 2021. Patients aged 18 years or above were required to complete a self-reported pain outcome questionnaire on the first postoperative day (POD1). Perioperative pain management and pain-related outcomes, including the severity of pain, adverse events caused by pain or pain management, and perception of care and satisfaction with pain management were analyzed. Findings: A total of 26,193 adult patients were enrolled. There were 48.7% of patients who had moderate-to-severe pain on the first day after surgery, and pain severity was associated with poor recovery and patient satisfaction. The systemic opioid use was 68% on the first day after surgery, and 89% of them were used with intravenous patient-controlled analgesia, while the rate of postoperative nerve blocks was low. Interpretation: Currently, almost half of patients still suffer from moderate-to-severe pain after surgery in China. The relatively high rate of systemic opioid use and low rate of nerve blocks used after surgery suggests that more effort is needed to improve the management of acute postoperative pain in China. Funding: National Key Research and Development Program of China (No. 2018YFC2001905).

Individualised positive end-expiratory pressure titrated intra-operatively by electrical impedance tomography optimises pulmonary mechanics and reduces postoperative atelectasis: A randomised controlled trial.

BACKGROUND: A protective intra-operative lung ventilation strategy has been widely recommended for laparoscopic surgery. However, there is no consensus regarding the optimal level of positive end-expiratory pressure (PEEP) and its effects during pneumoperitoneum. Electrical impedance tomography (EIT) has recently been introduced as a bedside tool to monitor lung ventilation in real-time. OBJECTIVE: We hypothesised that individually titrated EIT-PEEP adjusted to the surgical intervention would improve respiratory mechanics during and after surgery. DESIGN: Randomised controlled trial. SETTING: First Medical Centre of Chinese PLA General Hospital, Beijing. PATIENTS: Seventy-five patients undergoing robotic-assisted laparoscopic hepatobiliary and pancreatic surgery under general anaesthesia. INTERVENTIONS: Patients were randomly assigned 2 : 1 to individualised EIT-titrated PEEP (PEEPEIT; n = 50) or traditional PEEP 5 cmH2O (PEEP5 cmH2O; n = 25). The PEEPEIT group received individually titrated EIT-PEEP during pneumoperitoneum. The PEEP5 cmH2O group received PEEP of 5 cmH2O during pneumoperitoneum. MAIN OUTCOME MEASURES: The primary outcome was respiratory system compliance during laparoscopic surgery. Secondary outcomes were individualised PEEP levels, oxygenation, respiratory and haemodynamic status, and occurrence of postoperative pulmonary complications (PPCs) within 7 days. RESULTS: Compared with PEEP5 cmH2O, patients who received PEEPEIT had higher respiratory system compliance (mean values during surgery of 44.3 ±â€Š11.3 vs. 31.9 ±â€Š6.6, ml cmH2O-1; P < 0.001), lower driving pressure (11.5 ±â€Š2.1 vs. 14.0 ±â€Š2.4 cmH2O; P < 0.001), better oxygenation (mean PaO2/FiO2 427.5 ±â€Š28.6 vs. 366.8 ±â€Š36.4; P = 0.003), and less postoperative atelectasis (19.4 ±â€Š1.6 vs. 46.3 ±â€Š14.8 g of lung tissue mass; P = 0.003). Haemodynamic values did not differ significantly between the groups. No adverse effects were observed during surgery. CONCLUSION: Individualised PEEP by EIT may improve intra-operative pulmonary mechanics and oxygenation without impairing haemodynamic stability, and decrease postoperative atelectasis. TRIAL REGISTRATION: Chinese Clinical Trial Registry (www.chictr.org.cn) identifier: ChiCTR2100045166.

Ventrolateral periaqueductal gray GABAergic neurons promote arousal of sevoflurane anesthesia through cortico-midbrain circuit.

The mechanism of general anesthesia remains elusive. The ventrolateral periaqueductal gray (vlPAG) in the midbrain regulates sleep and awake states. However, the role of vlPAG and its circuits in anesthesia is unclear. We utilized opto/chemogenetics, righting reflex, and electroencephalographic recording to assess consciousness changes. We employed fiber photometry to measure the activity of neurons and neurotransmitters. As a result, photometry recording showed that the activity of GABA neurons in vlPAG decreased during sevoflurane anesthesia and was reactivated after anesthesia. Activating GABAergic neurons in vlPAG promoted arousal during anesthesia, while inhibiting them delayed this process. Furthermore, medial prefrontal cortex (mPFC) to vlPAG pyramidal neurons projections and vlPAG to ventral tegmental area (VTA) GABAergic projections played a prominent role in the anesthesia-awake transition. GABA neurotransmitter activity of VTA synchronized with mPFC-vlPAG pyramidal neuron projections. Therefore, the cortico-midbrain circuits centered on vlPAG GABAergic neurons exert an arousal-promoting effect during sevoflurane anesthesia.

Application of dexmedetomidine for lung injury in elderly patients undergoing one-lung ventilation.

Introduction: This study aimed to evaluate the effects of dexmedetomidine (DEX) on lung injury, the oxygenation index and perioperative pulmonary complications in elderly patients who underwent thoracotomy with one-lung ventilation (OLV). Material and methods: A total of 120 elderly patients with lung cancer were included in the present study. According to the random number table method, these patients were randomly divided into two groups: group D and group C. Patients in group D were intravenously pumped with 0.5 µg/kg/h of DEX before anesthesia. The infusion was completed within 15 min, and anesthesia was induced by venous injection. Patients in group C were pumped with equal volumes of normal saline. Results: At T2 and T3, compared with group C, group D had a significant decrease in cardiac index, mean arterial pressure and central venous pressure (p < 0.05). At T2, T3 and T4, compared with group C, group D had a significant increase in pH and PaO2 (p < 0.05). At T2, T3 and T4, compared with group C, group D had a significant decrease in Qs/Qt (p < 0.05). At T6, compared with group C, group D had a significant decrease in the supernatant of bronchoalveolar lavage fluid of tumor necrosis factor-α and interleukin 6 (p < 0.05). At T5, compared with group C, group D had a significant decrease in Visual Analogue Scale score (p < 0.05), and a significant increase in Ramsay Sedation Scale score (p < 0.05), and the number of respiratory and cardiovascular events also decreased (p < 0.05). Conclusions: In elderly patients, dexmedetomidine can reduce Qs/Qt and increase PaO2 during OLV in surgery. It can reduce lung injury. Moreover, DEX reduced respiratory and cardiovascular complications in the perioperative period.

Mental health changes in elderly patients undergoing non-cardiac surgery during the COVID-19 pandemic in China.

BACKGROUND: The COVID-19 pandemic has a heavy impact on the mental health of elderly surgical patients worldwide. In particular, the elderly patients faced considerable psychological stress due to various environmental and medical factors during the outbreak. This study aims to examine changes in mental health trends among non-cardiac surgical patients aged 65 and above in China during the COVID-19 pandemic. METHODS: This multi-center, convenient sampling, longitudinal observational study was conducted from April 1, 2020 to April 30, 2022. Primary outcome was the prevalence of postoperative depression. Secondary outcome was the prevalence of postoperative anxiety. Follow-up was conducted separately at 7 days and 30 days after surgery. Depression symptoms were assessed using the Patient Health Questionnaire 9 (PHQ-9) scale. Anxiety symptoms were assessed using Generalized Anxiety Disorder-7 (GAD-7) scale, with scores of ≥5 defining positive depression or anxiety symptoms. Multivariate logistic regression analysis was used to investigate risk factors of mental health status in more elderly patients undergoing non-cardiac surgery. RESULTS: A total of 4639 patients were included, of whom 2279 (46.0 %) were male, 752 (15.2 %) were over the age of 75, and 4346 (93.7 %) were married. The monthly prevalence trends demonstrated that compared to the outbreak period, a significant reduction in the prevalence of depression and anxiety symptoms in elderly patients who underwent surgery during the post-pandemic period. In post-pandemic period, a statistically significant decrease in the prevalence of all severity depression and anxiety patients was noted at the 7-day follow-up, but no significant decrease was observed for severe depression and anxiety in the 30-day follow-up. In COVID-19 low-risk area, a significant overall decrease in prevalence of mental health was observed during the post-pandemic period compared to the outbreak period, including 7-day depression, 7-day anxiety, 30-day depression, and 30-day anxiety (all with P < 0.001). Female and patients with ≥2 comorbidities appeared to be more susceptible to postoperative depression and anxiety during the pandemic. LIMITATION: The absence of data from the early days of the COVID-19 outbreak. CONCLUSIONS: This study analyzed the prevalence of depression and anxiety in elderly non-cardiac patients during and after the COVID-19 pandemic, focusing on dimensions such as severity, risk-areas, gender, and comorbidity. Our findings revealed a significant decrease in the prevalence of depression and anxiety in elderly surgery patients during the post-pandemic period.