General anesthetic agents induce neurotoxicity through oligodendrocytes in the developing brain.

General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells. Oligodendrocytes perform essential roles in the central nervous system, including myelin sheath formation, axonal metabolism, and neuroplasticity regulation. They are particularly vulnerable to the effects of general anesthetic agents resulting in impaired proliferation, differentiation, and apoptosis. Neurologists are increasingly interested in the effects of general anesthetic agents on oligodendrocytes. These agents not only act on the surface receptors of oligodendrocytes to elicit neuroinflammation through modulation of signaling pathways, but also disrupt metabolic processes and alter the expression of genes involved in oligodendrocyte development and function. In this review, we summarize the effects of general anesthetic agents on oligodendrocytes. We anticipate that future research will continue to explore these effects and develop strategies to decrease the incidence of adverse reactions associated with the use of general anesthetic agents.

Predictive role of glycocalyx components and MMP-9 in cardiopulmonary bypass patients for ICU stay.

Background: Shedding of glycocalyx is relevant to worse prognosis in surgical patients, and elevated levels of serum matrix metalloproteinase-9 (MMP-9) are associated with this phenomenon. This study aimed to investigate the dynamic alterations of serum glycocalyx components and MMP-9 during cardiopulmonary bypass (CPB), and evaluate their predictive capacities for prolonged intensive care unit (ICU) stay, as well as their correlation with coagulation dysfunction. Methods: This retrospective study analyzed serum levels of syndecan-1, heparan sulfate (HS), and MMP-9 at different time points during CPB, and assessed their association with prolonged ICU stay and coagulation dysfunction. Results: Syndecan-1, HS, and MMP-9 exhibited divergent changes during CPB. Serum levels of syndecan-1 (AUC = 78.0 %) and MMP-9 (AUC = 78.4 %) were validated as reliable predictors for prolonged ICU stay, surpassing the predictive value of creatinine (AUC = 70.0 %). Syndecan-1 (rho = 0.566, P < 0.01 at T1 and rho = 0.526, P < 0.01 at T2) and HS (rho = 0.403, P < 0.05 at T4) exhibited correlations with activated partial thromboplastin time (APTT) ratio beyond the normal range. Conclusions: Our findings advocate the potential efficacy of serum glycocalyx components and MMP-9 as early predictive indicators for extended ICU stay following cardiac surgery with CPB. Additionally, we observed a correlation between glycocalyx disruption during CPB and coagulation dysfunction. Further studies with expansive cohorts are warranted to consolidate our findings and explore the predictive potential of other glycocalyx components.

A novel nomogram for predicting the prolonged length of stay in post-anesthesia care unit after elective operation.

BACKGROUND: Prolonged length of stay in post-anesthesia care unit (PLOS in PACU) is a combination of risk factors and complications that can compromise quality of care and operating room efficiency. Our study aimed to develop a nomogram to predict PLOS in PACU of patients undergoing elective surgery. METHODS: Data from 24017 patients were collected. Least absolute shrinkage and selection operator (LASSO) was used to screen variables. A logistic regression model was built on variables determined by a combined method of forward selection and backward elimination. Nomogram was designed with the model. The nomogram performance was evaluated with the area under the receiver operating characteristic curve (AUC) for discrimination, calibration plot for consistency between predictions and actuality, and decision curve analysis (DCA) for clinical application value. RESULTS: A nomogram was established based on the selected ten variables, including age, BMI < 21 kg/m2, American society of Anesthesiologists Physical Status (ASA), surgery type, chill, delirium, pain, naloxone, operation duration and blood transfusion. The C-index value was 0.773 [95% confidence interval (CI) = 0.765 - 0.781] in the development set and 0.757 (95% CI = 0.744-0.770) in the validation set. The AUC was > 0.75 for the prediction of PLOS in PACU. The calibration curves revealed high consistencies between the predicted and actual probability. The DCA showed that if the threshold probability is over 10% , using the models to predict PLOS in PACU and implement intervention adds more benefit. CONCLUSIONS: This study presented a nomogram to facilitate individualized prediction of PLOS in PACU for patients undergoing elective surgery.

Effect of General Anesthetic Agents on Microglia.

The effects of general anesthetic agents (GAAs) on microglia and their potential neurotoxicity have attracted the attention of neuroscientists. Microglia play important roles in the inflammatory process and in neuromodulation of the central nervous system. Microglia-mediated neuroinflammation is a key mechanism of neurocognitive dysfunction during the perioperative period. Microglial activation by GAAs induces anti-inflammatory and pro-inflammatory effects in microglia, suggesting that GAAs play a dual role in the mechanism of postoperative cognitive dysfunction. Understanding of the mechanisms by which GAAs regulate microglia may help to reduce the incidence of postoperative adverse effects. Here, we review the actions of GAAs on microglia and the consequent changes in microglial function. We summarize clinical and animal studies associating microglia with general anesthesia and describe how GAAs interact with neurons via microglia to further explore the mechanisms of action of GAAs in the nervous system.

Major complications of caudal block: A prospective survey of 973 cases in adult anorectal surgery.

Background: We conducted a prospective study of surgical inpatients at a teaching hospital to assess the incidence and potential risk factors for major complications of caudal anesthesia in anorectal surgery. Methods: A total of 973 patients undergoing anorectal surgery under caudal block were included in this prospective, observer-blinded trial after providing consent. Demographic information, detailed perioperative information, anesthesia-related complications and postoperative follow-up information were recorded. Meanwhile, the incidence and risk factors for major caudal anesthesia-related complications were analyzed. Results: A total of 973 patients underwent caudal block. The effective rate was 95.38 % (928 cases). However, there were still 38 (3.91 %) cases with insufficient block and 7 (0.72 %) cases with no block. The major anesthesia-related complications were local anesthetic systemic toxicity (9, 0.92 %), cauda equine syndrome (1, 0.10 %), transient neurological symptoms (3, 0.31 %) and localized pain at the caudal insertion site (30, 3.08 %). The identified risk factor for local anesthetic systemic toxicity was multiple attempts locating the caudal space (OR = 5.30; 1.21-23.29). The identified risk factor for localized pain at the caudal insertion site was multiple attempts locating the caudal space (OR = 10.57; 4.89-22.86). Conclusion: The main complications of caudal block in adult patients are transient neurological symptoms, cauda equine syndrome, serious local anesthetic systemic toxicity and localized pain at the caudal insertion site. Overall, the incidence of complications is low and symptoms are mild. Caudal block is still a safe and reliable method for anesthesia in adult anorectal surgery.

Doxycycline can reduce glycocalyx shedding by inhibiting matrix metalloproteinases in patients undergoing cardiopulmonary bypass: A randomized controlled trial.

BACKGROUND: Cardiopulmonary bypass (CPB) leads to shedding of the glycocalyx of endothelial cells, resulting in a series of complications such as tissue edema and coagulatory and microcirculatory dysfunctions. Matrix metalloproteinases (MMPs) can cause glycocalyx shedding in a variety of pathological processes, but their role in the process of CPB is still unclear. We hypothesized that the MMPs inhibitor doxycycline would reduce glycocalyx shedding by inhibiting MMPs during CPB. METHODS: Thirty-six patients were randomized to receive either 100 mg oral doxycycline (an MMPs inhibitor) or a matching placebo pill twice a day for three days before CPB. The primary outcome was the concentration of plasma syndecan-1. Secondary outcomes included heparan sulphate, MMP-2, MMP-9, ratio of urinary albumin to creatinine, and short-term clinical outcomes. In order to further prove that MMPs in plasma caused the glycocalyx shedding, human umbilical vein endothelial cells were cultured with plasma obtained from cardiac surgery patients before or after CPB (with or without MMPs inhibitor GM6001). The change in glycocalyx content was detected by immunofluorescence. RESULTS: CPB resulted in an increase of MMPs and shedding of the glycocalyx. Plasma syndecan-1 was higher in the control group than in the doxycycline group (median difference:15.04 µg/L; 95% CI: 9.14-20.94 µg/L; P < 0.001). Similar to syndecan-1, plasma heparan sulphate, MMP-2, and MMP-9 concentrations in the doxycycline group were significantly lower than those in the control group during CPB. Doxycycline was also correlated with a reduction in the ratio of urinary albumin to creatinine and improved the short-term clinical outcomes of patients. Endothelial cells cultured with plasma from patients after CPB showed significant shedding of syndecan-1 and heparan sulphate (post-CPB group vs pre-CPB group, P < 0.001). GM6001 was shown to reduce shedding of syndecan-1 and heparan sulphate by inhibiting MMPs (post-CPB + GM6001 group vs post-CPB group, P < 0.001). CONCLUSION: Doxycycline can reduce glycocalyx shedding by inhibiting MMPs during CPB.

Progresses and Prospects of Neuroprotective Agents-Loaded Nanoparticles and Biomimetic Material in Ischemic Stroke.

Ischemic stroke remains the leading cause of death and disability, while the main mechanisms of dominant neurological damage in stroke contain excitotoxicity, oxidative stress, and inflammation. The clinical application of many neuroprotective agents is limited mainly due to their inability to cross the blood-brain barrier (BBB), short half-life and low bioavailability. These disadvantages can be better eliminated/reduced by nanoparticle as the carrier of these drugs. This review expounded the currently hot researched nanomedicines from the perspective of the mechanism of ischemic stroke. In addition, this review describes the bionic nanomedicine delivery strategies containing cells, cell membrane vesicles and exosomes that can effectively avoid the risk of clearance by the reticuloendothelial system. The potential challenges and application prospect for clinical translation of these delivery platforms were also discussed.

The Structure and Function of the Glycocalyx and Its Connection With Blood-Brain Barrier.

The vascular endothelial glycocalyx is a dense, bush-like structure that is synthesized and secreted by endothelial cells and evenly distributed on the surface of vascular endothelial cells. The blood-brain barrier (BBB) is mainly composed of pericytes endothelial cells, glycocalyx, basement membranes, and astrocytes. The glycocalyx in the BBB plays an indispensable role in many important physiological functions, including vascular permeability, inflammation, blood coagulation, and the synthesis of nitric oxide. Damage to the fragile glycocalyx can lead to increased permeability of the BBB, tissue edema, glial cell activation, up-regulation of inflammatory chemokines expression, and ultimately brain tissue damage, leading to increased mortality. This article reviews the important role that glycocalyx plays in the physiological function of the BBB. The review may provide some basis for the research direction of neurological diseases and a theoretical basis for the diagnosis and treatment of neurological diseases.

Cerebral infarction After Laparoscopic Right Lung Wedge or Segment Resection: A Report of Four Cases.

Several cases have been reported of patients who experienced cerebral infarction following thoracoscope left lobectomy. Compared with right lung surgery, the pulmonary veins stump after left lobe surgery were longer and thrombosis was more likely. Besides, cases of cerebral infarction after right lung surgery are rarely reported. Left lobectomy is therefore considered as the main risk factor for postoperative cerebral infarction. However, here we report four cases of cerebral infarction after thoracoscopic wedge or segment resection of right lobe, which cause less damage to the pulmonary vein compared with lobectomy. Magnetic resonance imaging and computed tomography scan reveal intracranial vascular obstruction and cerebral infarction. The case 1 had a poor prognosis because doctors lacked experience treating such complications. In the case 2, the sequela of cerebral infarction was obvious due to the large cerebral infarction area. Benefiting from timely treatment, the rest recovered better.

Protective effect of sevoflurane on vascular endothelial glycocalyx in patients undergoing heart valve surgery: A randomised controlled trial.

BACKGROUND: The glycocalyx plays an important physiological role and may be damaged during cardiopulmonary bypass. Sevoflurane can protect the glycocalyx; however, its relevance in a clinical setting is unknown. OBJECTIVE: Glycocalyx degradation during cardiopulmonary bypass in patients was investigated. On the basis of the available experimental data, we hypothesised that sevoflurane-based anaesthesia would confer additional protection against cardiopulmonary bypass-induced glycocalyx damage. DESIGN: Randomised controlled study. SETTING: Clinical study at The First Affiliated Hospital of Wenzhou Medical University between June 2018 and March 2019. PATIENTS: Fifty-one patients. INTERVENTIONS: After intubation and mechanical ventilation, patients undergoing elective heart valve surgery were maintained under general anaesthesia with either propofol or sevoflurane during surgery. MAIN OUTCOME MEASURES: Glycocalyx markers (such as syndecan-1, heparan sulphate and hyaluronan), sheddases responsible for the degradation of the endothelial glycocalyx (such as matrix metalloproteinase-9 and cathepsin-B), urine albumin-to-creatinine ratio and levels of lactic acid and myocardial enzymes were all measured. Postoperative mechanical ventilation time and length of stay in the cardiac care unit and hospital were also measured. Morbidity and mortality after 30 days and 1 year were evaluated. RESULTS: The vascular endothelial glycocalyx was damaged during cardiopulmonary bypass. The glycocalyx damage in the sevoflurane group was less extensive than that in the propofol group. The urine albumin-to-creatinine ratio increased in both groups but was lower in the sevoflurane group. Enzymes including matrix metalloproteinase-9 and cathepsin-B were positively correlated with glycocalyx marker concentrations. After operation, the sevoflurane group showed lower levels of lactic acid and myocardial enzyme, as well as shorter duration of postoperative mechanical ventilation than the propofol group. CONCLUSION: Sevoflurane can decrease glycocalyx degradation in patients undergoing heart valve surgery under cardiopulmonary bypass. TRIAL REGISTRATION: Chinese Clinical Trial Registry, chictr.org.cn, identifier: ChiCTR1800016367.

The Prognostic Value of Preoperative Geriatric Nutritional Risk Index in Patients with Pancreatic Ductal Adenocarcinoma.

PURPOSE: Patients with malignancy are more likely to develop nutritional problems. The Geriatric Nutritional Risk Index (GNRI) is a new prognostic index for evaluating nutritional status. The objective of this study was to assess if preoperative GNRI could be a prognostic factor for patients with pancreatic ductal adenocarcinoma (PDAC) who underwent radical surgery. PATIENTS AND METHODS: This study included 282 consecutive patients with incident pancreatic ductal adenocarcinoma who were treated with radical surgery. The Cox regression analysis was performed to calculate the overall survival (OS) and assess the prognostic factors. A nomogram was developed based on the results of the multivariate analysis, and the predictive accuracy of the nomogram was assessed. RESULTS: Among the 282 patients, there are 117 males and 165 females. The patients had a mean age of 58.7 ±13.5 years, with the median follow-up time of 72.9 months (interquartile range, 0.7 to 115.2 months). They were classified into abnormal (GNRI ≤ 98) and normal (GNRI > 98) GNRI groups, respectively. Multivariate Cox analysis showed that age (HR = 1.023), drinking history (HR = 1.453), tumor grade (HR = 1.633), TNM stage (HR = 1.921), and GNRI (HR = 1.757) were significantly associated with OS. Based on the above variables, the nomogram was established. The concordance index (C-index) and time-dependent receiver operating characteristics curve (tdROC) showed the nomogram was superior to TNM grade and tumor grade in predicting the OS of patients with PDAC. CONCLUSION: GNRI could be a useful prognostic indicator in patients with PDAC who received surgery. Based on the GNRI and the other clinical indicators, we developed a nomogram model that can provide an accurate estimation of OS in patients with PDAC after radical surgery.

Correlation between acute degradation of the endothelial glycocalyx and microcirculation dysfunction during cardiopulmonary bypass in cardiac surgery.

OBJECTIVE: The association between the shedding of the endothelial glycocalyx (EG) and the pathogenesis of microcirculatory perfusion disturbances has been discussed in experimental studies. This discussion, however, has limited relevance in a clinical setting. We investigated EG shedding in patients undergoing cardiopulmonary bypass (CPB) and its association with alterations in microvascular perfusion. METHODS: The plasma levels of syndecan-1, heparan sulfate, and hyaluronan were used as markers of glycocalyx degradation. Microcirculatory parameters included perfused vessel density (PVD) and De Backer Scores. Sidestream dark field imaging (SDF) was applied to visualize sublingual microcirculation during the preoperative resting state (T0), after sternum splitting, after aortic clamping, 5 min before aortal declamping, 1 h after CPB (T4), 4 h after CPB, 24 h after CPB (T6), and 48 h after CPB. RESULTS: Thirty patients undergoing cardiac surgery were recruited. The plasma levels of glycocalyx degradation markers increased after CPB. This increase indicated severe glycocalyx shedding at T4 relative to that at T0. By T6, the plasma levels of glycocalyx degradation markers had decreased to baseline levels in a stepwise manner. PVD and the De Backer Scores decreased at T4 and recovered at T6. Glycocalyx marker concentrations were correlated with microvascular alterations during cardiac surgery. CONCLUSIONS: Glycocalyx components are closely related to microcirculation perfusion disorders. Damage to the glycocalyx during surgery with CPB may play a key role in microcirculation perfusion dysfunction.