Intraoperative electroencephalogram features related to frailty in older patients: an exploratory prospective observational study.

Frailty is an independent risk factor for the increased incidence of postoperative delirium (POD). To date, the effect of frailty on intraoperative electroencephalogram (EEG) changes remains unexplored. The present study, an exploratory analysis of a prospective cohort study, aimed to investigate the differences in EEG characteristics between frail and robust patients. This prospective observational study was conducted between December 2020 and November 2021. The preoperative frailty status was assessed using the FRAIL scale. The patients' baseline (before anesthesia) and intraoperative EEG data were collected using a brain function monitor. Finally, 20 robust and 26 frail older patients scheduled for elective spinal surgery or transurethral prostatectomy under propofol-based general anesthesia were included in the final analysis. Baseline and intraoperative EEG spectrogram and power spectra were compared between the frail and robust groups. No differences were observed in baseline EEG between the frail and robust groups. When the intraoperative EEG spectral parameters were compared, the alpha peak frequency (10.56 ± 0.49 vs. 10.14 ± 0.36 Hz, P = 0.002) and alpha peak, delta, theta, alpha, and beta powers were lower in the frail group. After adjusting for age, Charlson Comorbidity Index (CCI), and mini-mental state examination (MMSE) score, the FRAIL score was still negatively associated with total, delta, theta, alpha, and beta powers. Frail patients had reduced EEG (0-30 Hz) power after the induction of propofol-based general anesthesia. After adjusting for age, CCI, and MMSE score, frail patients still showed evidence of reduced δ, θ, α, and ß power.

Autophagy impairment is involved in midazolam-induced lipid droplet accumulation and consequent phagocytosis decrease in BV2 cells.

An increasing number of experimental and clinical observation suggest that the use of anaesthetics is closely associated with postoperative central nervous system (CNS) complications, such as delirium and cognitive dysfunction. Brain energy rescue is an emerging therapeutic strategy for central nervous system disease (CNSDs). However, the effect of anaesthetics on nerve cell energy utilisation, especially microglia, and its potential effects on cell function still unclear. Elucidating the effects of anaesthetics on lipid droplets, which are specific lipid storage organs, and phagocytosis of microglia is crucial to discover a new therapeutic concept for postoperative CNS complications. Here, we studied the effects of the commonly used anaesthetic midazolam on lipid droplets and phagocytosis in immortalised microglial BV2 cells. Lipid droplets were assessed by flow cytometry and triglyceride quantification. The phagocytosis of BV2 cells was evaluated by detecting their phagocytosis by latex beads. Additionally, the autophagy of BV2 cells was evaluated by western blot and observation under microscopy. Our results showed that midazolam caused lipid droplet accumulation and reduced phagocytosis in BV2 cells, and inhibition of lipid droplet accumulation partially restored phagocytosis. Furthermore, midazolam blocks autophagic degradation by increasing phosphorylated TFEB in BV2 cells, inhibition of midazolam-increased phosphorylated TFEB might contribute to the improvement of autophagic flux by rapamycin. Moreover, promoting autophagy reverse the lipid droplet accumulation and phagocytosis decrease. This study suggests autophagy is a target for attenuating lipid droplet accumulation, normal degradation of lipid droplets is important for maintaining microglia phagocytosis and attenuating the side effects of midazolam on the CNS.

Contribution of intraoperative electroencephalogram suppression to frailty-associated postoperative delirium: mediation analysis of a prospective surgical cohort.

BACKGROUND: Frailty is a risk factor for postoperative delirium (POD), and has led to preoperative interventions that have reduced, but not eliminated, the risk. We hypothesised that EEG suppression, another risk factor for POD, mediates some of the frailty risk for POD. METHODS: A prospective cohort study enrolled patients aged 65 yr or older, scheduled for noncardiac surgery under total intravenous anaesthesia. Frailty was assessed using the FRAIL scale. Cumulative duration of EEG suppression, defined as an amplitude between -5 and 5 µV for >0.5 s during anaesthesia, was measured. POD was diagnosed by either confusion assessment method (CAM), CAM-ICU, or medical records. The severity of POD was assessed using the Delirium Rating Scale - Revised-98 (DRS). Mediation analysis was used to estimate the relationships between frailty, EEG suppression, and severity of POD. RESULTS: Among 252 enrolled patients, 51 were robust, 129 were prefrail, and 72 were frail. Patients classified as frail had higher duration of EEG suppression than either the robust (19 vs 0.57 s, P<0.001) or prefrail groups (19 vs 3.22 s, P<0.001). Peak delirium score was higher in the frail group than either the robust (17 vs 15, P<0.001) or prefrail groups (17 vs 16, P=0.007). EEG suppression time mediated 24.2% of the frailty-DRS scores association. CONCLUSION: EEG suppression time mediated a statistically significant portion of the frailty-POD association in older noncardiac surgery patients. Trials directed at reducing EEG suppression time could result in intraoperative interventions to reduce POD in frail patients. CLINICAL TRIAL REGISTRATION: ChiCTR2000041092 (Chinese Clinical Trial Registry).

Long-term exposure to copper induces mitochondria-mediated apoptosis in mouse hearts.

Copper is a trace element necessary for the normal functioning of organisms, but excessive copper contents may be toxic to the heart. The goal of this study was to investigate the role of excessive copper accumulation in mitochondrial damage and cell apoptosis inhibition. In vivo, the heart copper concentration and cardiac troponin I (c-TnI) and N-terminal forebrain natriuretic peptide (NT-pro-BNP) levels increased in the copper-laden model group compared to those of the control group. Histopathological and ultrastructural observations revealed that the myocardial collagen volume fraction (CVF), perivascular collagen area (PVCA) and cardiomyocyte cross-sectional area (CSA) were markedly elevated in the copper-laden model group compared with the control group. Furthermore, transmission electron microscopy (TEM) showed that the mitochondrial double-layer membrane was incomplete in the copper-laden model groups. Furthermore, cytochrome C (Cyt-C) expression was downregulated in mitochondria but upregulated in the cytoplasm in response to copper accumulation. In addition, Bcl-2 expression decreased, while Bax and cleaved caspase-3 levels increased. These results indicate that copper accumulation in cardiomyocyte mitochondria induces mitochondrial injury, and Cyt-C exposure and induces apoptosis, further resulting in heart damage.

The association between perioperative pupillary parameters and postoperative acute pain: A pilot cross-sectional study.

OBJECTIVE: We aim to explore the capacity of perioperative pupillary variables to predict acute pain in the post-anesthesia care unit (PACU). METHODS: Patients scheduled to undergo thoracic or abdominal surgery under general anesthesia between April 2021 and June 2021 were enrolled. We measured the pupil diameter, pupillary light reflex (PLR), and pupillary reflex dilatation 5 min before anesthesia induction (T1), 5 min after intubation (T2), at the end of anesthesia (T3), immediately before extubation (T4), and 5 min after extubation (T5). We assessed the early postoperative pain intensity in the PACU using Numeric Rating Scales (NRS) at recovery, 5 min after recovery, and 10 min after recovery. Logistic regression models were used to evaluate the association between perioperative pupillary variables and postoperative pain intensity. RESULTS: Fifty-one patients were enrolled, 50 of whom were included in the final analysis. A total of 13 patients (26%) needed remedial analgesia in the PACU. Pupil parameters at T1, T2, T3, and T5 were not associated with NRS in the PACU. Multiple logistic regression models and receiver operating characteristic (ROC) curves indicated that only latency of PLR at T4 can predict postoperative acute pain. The ROC analysis showed that the cutoff value for latency of PLR at T4 was 0.29 s to discriminate between no pain and pain, and the area under the curve was 0.778 (95% CI 0.634-0.922, p = 0.002) with sensitivity 50.0% and specificity 91.7%. CONCLUSION: The latency of PLR immediately before extubation may be a useful predictor for postoperative acute pain in the PACU.

Opioid-sparing effect of modified intercostal nerve block during single-port thoracoscopic lobectomy: Retraction: A randomised controlled trial.

BACKGROUND: Peripheral local anaesthetic blockade has an important role in multimodal postoperative analgesia after video-assisted thoracic surgery. Intercostal nerve block has an opioid-sparing effect after thoracoscopic surgery, but there is little information about an intra-operative opioid-sparing effect. OBJECTIVE: This prospective randomised trial was designed to evaluate the feasibility of a modified intercostal nerve block and its potential opioid-sparing effect during single-port thoracoscopic lobectomy. DESIGN: This was a randomised controlled study. SETTING: The First Affiliated Hospital of Anhui Medical University, Hefei, China, from January 2020 to April 2020. PATIENTS: Fifty patients scheduled for single-port thoracoscopic lobectomy were enrolled. INTERVENTION: Patients were randomised to receive the intercostal nerve block using 10 ml 0.35% ropivacaine (group MINB) or conventional general anaesthesia (group CGA). Following a bolus of 0.5 to 1.0 µg kg-1 remifentanil, it was then infused at 0.2 to 0.5 µg kg-1 min-1 during surgery to keep mean arterial pressure or heart rate values around 20% below baseline values. MAIN OUTCOME MEASURES: The primary outcome was intra-operative remifentanil consumption. RESULTS: Median [IQR] remifentanil consumption was reduced in the MINB group [0 µg (0 to 0 µg)] compared with the CGA group [1650.0 µg (870.0 to 1892.5 µg)]. The median difference was 1650.0 µg (95%CI 1200.0 to 1770.0 µg; P = 0.00). The total number of analgesic demands during the first 24 and 48 h in the MINB group was significantly less than in the CGA group (difference = 1; 95% CI 1 to 3; P = 0.00 and difference = 4; 95% CI 3 to 5; P = 0.00; respectively). The difference in time to first demand for analgesia was significant [difference = 728 min (95% CI 344 to 1381 min), P = 0.00] and also in the number of patients requiring additional tramadol (P = 0.03). CONCLUSION: We have shown intra-operative opioid-sparing with a modified intercostal nerve block during single-port thoracoscopic lobectomy, with opioid-sparing extending 48 h after surgery. However, the opioid-sparing effect was not associated with a reduction in opioid side effects. TRIAL REGISTRATION: http://www.chictr.org.cn, ChiCTR2000029337.

Propofol decreases the excitability of cholinergic neurons in mouse basal forebrain via GABAA receptors.

Propofol is an intravenous anesthetic that can active γ-aminobutyric acid A (GABAA) receptors and generate sedative-hypnotic effects. Propofol has been widely applied clinically to achieve sedation comparable to sleep in humans. The basal forebrain (BF) is a brain region that plays an important role in sleep-wake regulation. Previous studies suggest that propofol affects the sleep-wake circuit via the BF; however, the mechanism remains elusive. In the current study we investigated the effects of propofol on the inherent properties of cholinergic neurons and their ability to convert excitatory inputs into spikes in mouse BF slices using whole-cell patch clamp recordings. Bath application of propofol (10 µM) significantly elevated the threshold potentials (Vts), decreased the number of spikes in response to a depolarizing current injection, and augmented the inter-spike intervals (ISIs), energy barrier (Vts-Vrs), and absolute refractory periods (ARPs). These effects were eliminated by co-application of a GABAA receptor antagonist picrotoxin (50 µM). Altogether, our results reveal that propofol decreases the excitability of cholinergic neurons in mouse BF via GABAA receptors.

Persistency of Enlarged Autolysosomes Underscores Nanoparticle-Induced Autophagy in Hepatocytes.

The diverse biological effects of nanomaterials form the basis for their applications in biomedicine but also cause safety issues. Induction of autophagy is a cellular response after nanoparticles exposure. It may be beneficial in some circumstances, yet autophagy-mediated toxicity raises an alarming concern. Previously, it has been reported that upconversion nanoparticles (UCNs) elicit liver damage, with autophagy contributing most of this toxicity. However, the detailed mechanism is unclear. This study reveals persistent presence of enlarged autolysosomes in hepatocytes after exposure to UCNs and SiO2 nanoparticles both in vitro and in vivo. This phenomenon is due to anomaly in the autophagy termination process named autophagic lysosome reformation (ALR). Phosphatidylinositol 4-phosphate (PI(4)P) relocates onto autolysosome membrane, which is a key event of ALR. PI(4)P is then converted into phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 ) by phosphatidylinositol-4-phosphate 5-kinase. Clathrin is subsequently recruited by PI(4,5)P2 and leads to tubule budding of ALR. Yet it is observed that PI(4)P cannot be converted in nanoparticle-treated hepatocytes cells. Exogenous supplement of PI(4,5)P2 suppresses the enlarged autolysosomes in vitro. Abolishment of these enlarged autolysosomes by autophagy inhibitor relieves the hepatotoxicity of UCNs in vivo. The results provide evidence for disrupted ALR in nanoparticle-treated hepatocytes, suggesting that the termination of nanoparticle-induced autophagy is of equal importance as the initiation.

Perioperative risk factors and cumulative duration of "triple-low" state associated with worse 30-day mortality of cardiac valvular surgery.

ABSRACT: Hospital stay and mortality in high-risk patients after noncardiac surgery has been associated with a triple low anesthesia. However, the association between anesthesia-related factors and perioperative outcome after cardiac surgery remains unclear.We tested the effect of a novel triple low state: low mean arterial pressure (MAP) <65 mmHg and low bispectral index (BIS) <45 during a low target effect-site concentration (Ce) <1.5 µg ml-1 of propofol anesthesia on postoperative duration of hospitalization and 30-day mortality in cardiac valvular patients. In this prospective observational study, univariable and multivariable logistic regression analyses were used to determine whether perioperative factors, in particular, cumulative duration of triple low state were independently associated with duration of hospitalization and 30-day mortality among patients who underwent elective valvular replacement. 489 patients were included in the final analysis. After adjusting for related covariates, cumulative duration of the triple-low state was not associated with prolonged hospitalization (multivariable odds ratio: 1.007; 95 % confidence interval 0.997-1.017; P = 0.564), but was a significant predictor of 30-day mortality (multivariable odds ratio: 1.016; 95 % confidence interval 1.002-1.031; P = 0.030). Compared to a triple-low duration of <15 min, a duration >60 min increased the 30-day mortality rate by 8 times. After adjusting for patient- and procedure-related characteristics, the cumulative duration of a triple-low state (intraoperative low MAP, low BIS, and low Ce) was associated with poorer 30-day mortality, but not with prolonged duration of hospital stay.The mortality risk was even greater when a cumulative time >60 min.

Opioid receptor A118G polymorphism does not affect the consumption of sufentanil and ropivacaine by patient-controlled epidural analgesia after cesarean section.

BACKGROUND: Previous reports have suggested that polymorphism of the opioid receptor A118G affects the efficacy of opioid analgesia. The aim of this study was to investigate whether such polymorphism contributed to variability in epidural mixture (sufentanil plus ropivacaine) requirements through patient-controlled epidural analgesia (PCEA) after cesarean section. METHODS: One hundred eighty consenting women undergoing elective cesarean delivery were enrolled in the study. Patients received sufentanil and ropivacaine for pain control after surgery. Sufentanil (50 mcg) diluted with 0.2% ropivacaine in a total volume of 100 mL was administered by PCEA with a background infusion rate of 2 mL/h and a pump program set to deliver 0.5-mL boluses with a lockout time of 15 minutes. The analgesic effect and adverse effects were measured with rating scales. The total consumption of the epidural mixture in the first 24 hours postoperatively was recorded. Blood samples were genotyped to classify patients into 3 groups according to A118G polymorphism. RESULTS: Of 161 patients included in the analysis, 63 were homozygous (AA), 81 were heterozygous (AG), and 17 were homozygous (GG) for the A118G polymorphism. No difference was observed among groups in the consumption of the epidural mixture within the first 24 hours postoperatively (P = 0.3). Satisfaction with analgesia, pain scores, and adverse effects were similar among the groups. CONCLUSIONS: The analgesic requirements of patients receiving sufentanil and ropivacaine through PCEA after caesarean section were not associated with A118G polymorphism.

Involvement of GSK3ß/ß-catenin signaling in the impairment effect of ketamine on spatial memory consolidation in rats.

The cellular mechanisms underlying amnesia produced by the analgesic ketamine are not clear. The current study examined the effects of ketamine on memory consolidation in rats trained in a Morris water maze task, and further tested whether the glycogen synthase kinase (GSK)3ß/ß-catenin signaling pathway was involved in mediating the effects of posttraining ketamine on retention. Adult male Sprague-Dawley rats were injected with ketamine (0, 25, 50, or 100mg/kg) immediately after an eight-trial water maze training session. A probe trial was carried out 24 h later to examine the effects of ketamine on memory. Rats hippocampi were subjected to western blot assays to measure levels of native versus phosphorylated (p) GSK3ß and ß-catenin protein. Memory performance was significantly impaired in rats injected with ketamine (100 mg/kg) after training. Western blots showed that p-GSK-3ß(Ser9) levels were reduced and p-ß-catenin(Ser33/37/Thr41) levels were elevated in ketamine treated rats during consolidation. These posttraining changes in hippocampal p-GSK-3ß and p-ß-catenin were blocked by injection of 100mg/kg ketamine immediately after training, indicating that the 100mg/kg dose of ketamine altered activation of GSK3ß/ß-catenin signaling pathway in the hippocampus. Acute injection of the GSK3ß specific inhibitor SB216763 (1 ng/0.5 µl/side) into area CA1 of the hippocampus after water maze training prevented ketamine-induced impairment of memory and blocked ketamine-induced effects on the GSK3ß/ß-catenin signaling pathway in the hippocampus. Our results suggest that an anesthetic dose of ketamine injected immediately after Morris water maze training impaired memory consolidation and support the hypothesis that GSK3ß/ß-catenin signaling may play a role in ketamine-induced retrograde amnesia.

Peroxisome proliferator-activated receptor-α activation protects against endoplasmic reticulum stress-induced HepG2 cell apoptosis.

Live ischemia-reperfusion injury is associated with endoplasmic reticulum (ER) stress-induced apoptosis. Activation of peroxisome proliferator-activated receptor-α (PPARα) may inhibit hepatocyte apoptosis induced by oxidative stress and protect against liver injury. This study aimed to investigate the effects of PPARα activation, through a specific agonist, on ER stress-induced apoptosis in human liver hepatocellular carcinoma (HepG2) cells. HepG2 cells were challenged with H2O2 and treated with WY14643, a selective PPARα agonist, in the presence or absence of the PPARα antagonist of MK886. Cell viable assay (MTT) and immunostaining were used to evaluate cell viability. The level of apoptotic cell death was quantified through Annexin V/PI staining. Alanine aminotransferase, asparatate aminotransferase, and malondialdehyde levels were measured to determine the presence of cellular injury and oxidative stress. RT-PCR and Western blot analysis were used to detect mRNA and protein expression of PPARα, BiP, and CHOP. Immunofluorescence was utilized to determine the intracellular localization of CHOP. H2O2 and MK886 both reduced the viability of HepG2 cells, increased oxidative stress and apoptosis, up-regulated the BiP and CHOP expression, and induced CHOP translocation from the cytoplasm to the nucleus. Compared with cells treated with H2O2 alone, pre-administration of WY14643 increased cell viability, attenuated apoptosis, improved cell function, down-regulated BiP and CHOP expression and inhibited CHOP translocation. The effects of WY14643 were completely abolished using the MK886 antagonist. PPARα activation protects against H2O2-induced HepG2 cell apoptosis. The underlying mechanisms may be associated with its activation to suppress excessive ER stress.

Effect of intraoperative dexmedetomidine on recovery of gastrointestinal function after caesarean section undergoing spinal and epidural anesthesia: A randomized, double blind, placebo-controlled clinical trial.

OBJECTIVE: Gastrointestinal dysfunction after cesarean section negatively affects postoperative recovery. Dexmedetomidine has been shown to improve postoperative gastrointestinal function in patients undergoing lumbar spinal fusion surgery and laparoscopic gastrectomy, but its role in cesarean section has not been fully elucidated. The study aimed to investigate the effect of dexmedetomidine on gastrointestinal function after cesarean section. STUDY DESIGN: 220 pregnant women who underwent elective cesarean section were randomized into group D and group S. Group D patients received a loading dose of 0.5 µg/kg of dexmedetomidine for 10 mins followed by a maintenance dose of 0.5 µg/kg/h intravenously immediately after the umbilical cord was cut intraoperatively, whereas the other group (group S) received an equivalent quantity of normal saline as loading and maintenance dose IV by infusion pump. The primary outcome was time to first flatus after surgery (hours). Secondary outcomes included time to first feces and first bowel sounds (hours), incidence rates of postoperative gastrointestinal complications, and the length of postoperative hospital stay (days). RESULTS: Modified intention-to-treat analysis showed that patients in Group D had a significantly shorter time to first flatus (21 [16 to 28.25] vs. 25 [18 to 32.25] h; P = 0.014), time to first feces (45.5 [35.75 to 55.25] vs. 53 [40 to 60] h; P = 0.019), and time to first bowel sounds (P = 0.010), a lower incidence of abdominal distension (21[20.6 %] vs. 36[34.3 %], P = 0.027), shorter length of postoperative hospital stay (P = 0.010) compared to patients in Group S. CONCLUSION: Intraoperative dexmedetomidine infusion reduces the time to first flatus, the incidence of abdominal distension, and shortens the length of hospital stay, promoting gastrointestinal function after cesarean section.

In vivo imaging reveals a synchronized correlation among neurotransmitter dynamics during propofol and sevoflurane anesthesia.

General anesthesia is widely applied in clinical practice. However, the precise mechanism of loss of consciousness induced by general anesthetics remains unknown. Here, we measured the dynamics of five neurotransmitters, including γ-aminobutyric acid, glutamate, norepinephrine, acetylcholine, and dopamine, in the medial prefrontal cortex and primary visual cortex of C57BL/6 mice through in vivo fiber photometry and genetically encoded neurotransmitter sensors under anesthesia to reveal the mechanism of general anesthesia from a neurotransmitter perspective. Results revealed that the concentrations of γ-aminobutyric acid, glutamate, norepinephrine, and acetylcholine increased in the cortex during propofol-induced loss of consciousness. Dopamine levels did not change following the hypnotic dose of propofol but increased significantly following surgical doses of propofol anesthesia. Notably, the concentrations of the five neurotransmitters generally decreased during sevoflurane-induced loss of consciousness. Furthermore, the neurotransmitter dynamic networks were not synchronized in the non-anesthesia groups but were highly synchronized in the anesthetic groups. These findings suggest that neurotransmitter dynamic network synchronization may cause anesthetic-induced loss of consciousness.

Clinical application of a connection device consisting of a bag valve mask and nebulizer in first aid: Two case reports.

In clinical practice, several emergencies may threaten the life of patients, and these emergencies can be unpredictable and challenging. During the coronavirus disease 2019 pandemic, in January 2023, a patient developed respiratory distress caused by coronavirus, but was unable to access respiratory support due to shortages of medical resources, intensive care unit beds and ventilators. The medical staff quickly created a portable high-flow atomized oxygen therapy apparatus consisting of a simple breathing bag connected to a nebulizer to provide breathing support. In addition, the Ambulatory Surgery Center, The First Affiliated Hospital of Anhui Medical University (Hefei, China) witnessed a case of severe laryngeal spasm after tracheal extubation during the recovery period from general anesthesia. Due to the lack of an anesthesia machine nebulizer, the aforementioned device was used to provide oxygen under pressure and initiate treatment to quickly relieve the symptoms of laryngeal obstruction. The present case report describes how the medical staff quickly applied emergency airway management skills and knowledge to create a portable high-flow atomized oxygen therapy apparatus in a resource-poor setting to save the lives of two patients.

EEG-derived pain threshold index-guided versus standard care during propofol-remifentanil anesthesia: A randomized controlled trial.

Purpose: The pain threshold index (PTI), a novel index of nociception based on spontaneous EEG wavelet analysis, has been reported to provide reliable accuracy for predicting postoperative pain and hemodynamic reactivity. The present study is aimed to investigate whether PTI-guided analgesia reduces the pain intensity and rate of remedial analgesia in the post-anesthesia care unit (PACU). Methods: A total of 122 females undergoing elective gynecologic surgeries had been randomized to receive either PTI-guided analgesia (PTI group) or standard clinical care (control group). Remifentanil administration in the PTI group was guided by PTI to maintain the value between 40 and 65, while that in the control group was guided by hemodynamic changes. The primary outcome was remedial analgesia rate in the PACU. The postoperative pain scores, intraoperative remifentanil requirements, opioid-related adverse events and perioperative serum stress hormone concentrations between the two groups were also compared. Findings: It was found that 23 of 58 patients (40%) in the control group and 8 of 58 patients (14%) in the PTI group needed remedial analgesia. The relative risk of receiving remedial analgesia was 2.88 (95% CI, 1.40-5.89, P = 0.002) in the control group. Sufentanil consumption in the PACU (µg) was lower in the PTI group (P = 0.002) than in the control group. Remifentanil and propofol consumption, opioid-related adverse events between these two groups were comparable. Implications: PTI-guided analgesia during gynaecologic operations resulted in 25.87% less remedial analgesia. However, studies with different PTI thresholds and larger, more diverse populations should be conducted to further demonstrate the clinical effectiveness of PTI.

The influence of anesthesia and surgery on fear extinction.

Accumulating evidence has demonstrated significant clinical post-traumatic stress disorder (PTSD) symptoms after anesthesia or surgery. Fear extinction dysfunction is a notable feature of PTSD. Although anesthetics and surgery profoundly affect memory processes, their designated effects on fear extinction have not been dissertated. Previous studies have suggested that innate immune system activation disrupts fear extinction, and surgery has been shown to increase the inflammatory response. Thus, in the current study, we examined the effects of propofol, sevoflurane, dexmedetomidine and surgery on fear extinction in adolescent mice, and further tested whether dexmedetomidine could reverse the injury effect of surgery on fear extinction through its anti-inflammatory effects. Our results showed that propofol (200 mg/kg) impaired the acquisition and recall of cued fear extinction, and surgery disrupted cued fear extinction acquisition/recall and consolidation. In contrast to cued fear extinction, contextual fear extinction was not affected by propofol or surgery. Moreover, dexmedetomidine prevented surgery-induced impairment of cued extinction acquisition and recall but not consolidation. Finally, TNF-α and IL-6 levels in the ventromedial prefrontal cortex were not necessary for the dexmedetomidine treatment effect of surgery-induced fear extinction dysfunction. The study results showed that propofol and surgery selective impaired the cued fear extinction stage in adolescent mice, and dexmedetomidine may unleash a protective effect in preventing postoperative PTSD.

Preoperative Status of Gut Microbiota Predicts Postoperative Delirium in Patients With Gastric Cancer.

Introduction: Post-operative delirium (POD) is a serious complication which occurs after surgery, especially in the elderly undergoing abdominal surgery. Increasing evidence has revealed an association between the gut microbiota and psychological disorders involving the "brain-gut" axis. However, the association between the pathogenesis of POD after abdominal surgery in aging and composition of the gut microbiota remains unclear. Methods: Forty patients (≥65 years old) who underwent abdominal surgery were included in the study. Twenty patients had POD, whereas 20 patients did not. POD was diagnosed and assessed using the confusion assessment method (CAM) during the postoperative period. Total DNA fractions were extracted from all fecal samples of patients. 16S rRNA sequencing was performed to determine the composition of the gut microbiota. The quality of the samples was determined by calculating the α- and ß-diversities. Results: The α- and ß-diversities indicated that the samples were eligible for detection and comparison. We observed multiple differentially abundant bacteria in patients with and without POD. Generally, Proteobacteria, Enterbacteriaceae, Escherichia shigella, Klebsiella, Ruminococcus, Roseburia, Blautia, Holdemanella, Anaerostipes, Burkholderiaceae, Peptococcus, Lactobacillus, and Dorea were abundant in the POD cohort, whereas Streptococcus equinus and Blautia hominis were abundant in the control cohort. The results of receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of Escherichia shigella was 0.75. Phenotype prediction showed that the gut microbiota may influence POD by altering the tolerance to oxidative stress. Conclusion: There were significant associations between the pathogenesis of POD and composition of the gut microbiota. Escherichia shigella are promising diagnostic bacterial species for predicting POD onset after abdominal surgery in elderly people. Clinical Trial Registration: http://www.chictr.org.cn/index.aspx, Chinese Clinical Trial Registry ChiCTR200030131.

Xin-Ji-Er-Kang Alleviates Isoproterenol-Induced Myocardial Hypertrophy in Mice through the Nrf2/HO-1 Signaling Pathway.

Xin-Ji-Er-Kang (XJEK) inhibited cardiovascular remodeling in hypertensive mice in our previous studies. We hypothesized that XJEK may prevent isoproterenol (ISO)-induced myocardial hypertrophy (MH) in mice by ameliorating oxidative stress (OS) through a mechanism that may be related to the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1(HO-1) pathways. Forty SPF male Kunming mice were randomized into 5 groups (n = 8 mice per group): control group, MH group, MH + different doses of XJEK (7.5 g/kg/day and 10 g/kg/day), and MH + metoprolol (60 mg/kg/day). On the eighth day after drug treatment, electrocardiogram (ECG) and echocardiography were performed, the mice were sacrificed, and blood and heart tissues were collected for further analysis. XJEK administration markedly ameliorated cardiovascular remodeling (CR), as manifested by a decreased HW/BW ratio and CSA and less collagen deposition after MH. XJEK administration also improved MH, as evidenced by decreased atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and ß-myosin heavy chain (ß-MHC) levels. XJEK also suppressed the decreased superoxide dismutase (SOD) and catalase (CAT) activities and increased malondialdehyde (MDA) levels in serum of mice with MH. XJEK-induced oxidative stress may be related to potentiating Nrf2 nuclear translocation and HO-1 expression compared with the MH groups. XJEK ameliorates MH by activating the Nrf2/HO-1 signaling pathway, suggesting that XJEK is a potential treatment for MH.

The Impact of Morning Surgery or Afternoon Surgery on Postoperative Sleep Quality and Melatonin Levels of Elderly Patients: A Prospective, Randomized Study.

Objective: Postoperative sleep disturbance after surgery is not conducive to the recovery of patients. The purpose of this study was to determine the influence of the timing of surgery (morning vs afternoon) on the postoperative sleep quality of elderly patients and to analyze the relationship between the timing of surgery and the change in the melatonin level. Methods: Sixty patients who received hip surgery were randomly assigned to the Morning Group (Group M) or the Afternoon Group (Group A). The sleep quality was assessed by the Richards-Campbell Sleep Questionnaire. Before and after surgery, the nocturnal urine was collected over a 12-h period, and the 6-sulfatoxymelatonin concentration was measured. Also, the incidence of postoperative delirium (POD) was observed. Results: On the first and second nights after surgery, the sleep quality scores of the patients in Group A were greater than those in Group M, and there was no difference in the sleep quality scores between the two groups on the third night after surgery (P=0.000, P=0.002, P>0.05, respectively). In addition, the urine 6-sulphatoxymelatonin concentration was found to be greater in Group A than in Group M on the first night of surgery (P=0.00). Both the postoperative sleep quality scores and urine 6-sulphatoxymelatonin concentration were significantly less than those before surgery (P=0.00, P=0.00). Conclusion: The postoperative sleep quality scores and melatonin levels of elderly patients who received hip surgery under general anesthesia were significantly less than those of the patients before surgery. Furthermore, the short-term sleep quality of the patients who received surgery in the afternoon was better than that of the patients who received surgery in the morning. This difference may be related to the short-term change of the melatonin level after surgery.