Risk factors for postoperative acute ischemic stroke in advanced-aged patients with previous stroke undergoing noncardiac surgery: a retrospective cohort study.

BACKGROUND: The current study aimed to investigate the incidence and risk factors for postoperative acute ischemic stroke (PAIS) in advanced-aged patients (≥ 75 years) with previous ischemic stroke undergoing noncardiac surgery. METHODS: In this single-center retrospective cohort study, all advanced-aged patients underwent noncardiac surgery from 1 January, 2019, to 30 April, 2022. Data were extracted from hospital electronic medical records. Multivariable logistic regression analysis was performed to determine predictors of PAIS. Multivariable linear or logistic regression analysis was performed to determine predictors of outcomes due to PAIS. RESULTS: Twenty-four patients (6.0%) of the 400 patients developed PAIS. Carotid endarterectomy (CEA), length of surgery and preoperative Modified Rankin scale (mRS) ≥ 3 were significant predictors of PAIS. CEA was associated with increased risk of PAIS (OR 4.14; 95%CI, 1.43-11.99). Each additional minute in length of surgery had slightly increased the risk of PAIS (OR, 1.01; 95%CI, 1.00-1.01). Compared with reference (mRS < 3), mRS ≥ 3 increased odds of PAIS (OR, 4.09;95%CI, 1.12-14.93). Surgery type and length of surgery were found to be significant predictors of in-hospital expense (P < 0.001) and hospital stays (P < 0.05). CONCLUSIONS: CEA, length of surgery and preoperative mRS ≥ 3 may increase the development of PAIS in advanced-aged patients (≥ 75 years) with previous stroke undergoing noncardiac surgery. PAIS increased in-hospital mortality and prolonged hospital stay.

The median effective dose (ED50) of cis-Atracurium for laryngeal mask airway insertion during general Anaesthesia for patients undergoing urinary surgery.

BACKGROUND: In clinical practice, the laryngeal mask airway is an easy-to-use supraglottic airway device. However, the cis-atracurium dosage for laryngeal mask insertion has not been standardised. We aimed to determine the optimal dose of cis-atracurium using a sequential method for successful laryngeal mask insertion. METHODS: The cohort study protocol is registered at clinicaltrial.gov (NCT-03668262). Twenty-three patients undergoing elective urinary surgery were sequentially administered cis-atracurium doses as follows: 150, 100, 70, 50, 30, and 20 µg·kg- 1. The main outcome involved the determination of the response to laryngeal mask airway insertion: ≥16 points and < 16 points indicated "satisfactory" and "unsatisfactory" responses, respectively. The median effective dose was estimated using the mean of the seven crossovers from "satisfactory" and "unsatisfactory" responses. The primary outcome involved the determination of the median effective dose (ED50) of cis-atracurium for laryngeal mask airway insertion. RESULTS: The median effective dose of cis-atracurium was 26.5 µg·kg- 1 (95% CI 23.6-29.8) using the sequential method. Heart rate was decreased in the 50 µg·kg- 1 group compared to that in the 30 µg·kg- 1 group at timepoints T7, T8, and T10 (P = 0.0482, P = 0.0460, and P = 0.0236, respectively), but no difference was observed in the 20 µg·kg- 1 group. Systolic blood pressure was decreased in the 50 µg·kg- 1 group compared to that in the 20 µg·kg- 1 group at timepoints T2, T3, and T4 (P = 0.0159, P = 0.0233, and P = 0.0428, respectively). The train-of-four value was significantly lower in the 50 µg·kg- 1 group than in the 30 µg·kg- 1 group at timepoint T3 (P = 0.0326). CONCLUSIONS: The ED50 of cis-atracurium was 26.5 µg·kg- 1 for laryngeal mask airway insertion. TRIAL REGISTRATION: Clinicaltrial.gov Registry, NCT03668262, Registered on 11 September 2018.

CFD-PBM Simulation of Sauter Mean Diameter in a Stirred Sieve-Plate Extraction Column.

A computational fluid dynamics-population balance model (CFD-PBM)-coupled simulation method was established to simulate the Sauter mean diameter (d32) in a stirred sieve-plate extraction column with Ansys Fluent 19.2. The droplet breakage and coalescence were considered, and the kernel functions were loaded into Fluent as a user-defined function (UDF). The simulated d32 by different kernels was compared with the experimental values, and the results showed that the modified model considering the dispersed phase viscosity has better simulation accuracy and good applicability. In addition, the effects of different operating conditions on d32 were investigated. When the stirring speed is increased, d32 decreases. As the dispersed phase flow rate increases, d32 increases, while the change in the continuous phase flow rate does not have a significant impact on d32.

Pre-incisional Preventive Precise Multimodal Analgesia May Enhance the Rehabilitation Process of Acute Postoperative Pain Following Total Laparoscopic Hysterectomy: A Randomized Controlled Trial.

BACKGROUND: There has been limited research regarding the effect of preventive precise multimodal analgesia (PPMA) on the duration of acute postoperative pain after total laparoscopic hysterectomy (TLH). This randomized controlled trial aimed to evaluate how PPMA affects pain rehabilitation. OBJECTIVES: Our primary objective was to reduce the duration of acute postoperative pain after TLH, including incisional and visceral pain. STUDY DESIGN: A double blind randomized controlled clinical trial. SETTING: Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China. METHODS: Seventy patients undergoing TLH were randomized to Group PPMA or Group Control (Group C) in a 1:1 ratio. Patients in Group PPMA were given PPMA through the pre-incisional administration of parecoxib sodium 40 mg (parecoxib is not approved for use in the US) and oxycodone 0.1 mg/kg as well as local anesthetic infiltration at the incision sites. In Group C, similar doses of parecoxib sodium and oxycodone were injected during uterine removal, and a local anesthetic infiltration procedure was performed immediately before skin closure. The index of consciousness 2 was utilized to titrate the remifentanil dosage in all patients to ensure sufficient analgesia. RESULTS: Compared with the Control, PPMA shortened the durations of incisional and visceral pain at rest (median, interquartile range [IQR]: 0, 0.0- 2.5) vs 2.0, 0.0-48.0 hours, P = 0.045; 24.0, 6.0-24.0 vs 48.0, 24.0-48.0 hours, P < 0.001; and during coughing 1.0, 0.0-3.0 vs 24.0, 0.3-48.0 hours, P = 0.001; 24.0, 24.0-48.0] vs 48.0, 48.0-72.0] hours, P < 0.001). The Visual Analog Scale (VAS) scores for incisional pain within 24 hours and visceral pain within 48 hours in Group PPMA were lower than those in Group C (P < 0.05). PPMA evidently decreased the VAS scores for incisional pain during coughing at 48 hours (P < 0.05). Pre-incisional PPMA significantly reduced postoperative opioid consumption (median, IQR: 3.0 [0.0-3.0] vs 3.0 [0.8-6.0] mg, P = 0.041) and the incidence of postoperative nausea and vomiting (25.0% vs 50.0%, P = 0.039). Postoperative recovery and hospital stay were similar between the 2 groups. LIMITATIONS: This research had some limitations, including that it was a single-center research with a limited sample size. Our study cohort did not represent the overall patient population in the People's Republic of China; therefore, the external validity of our findings remains limited. Furthermore, the prevalence of chronic pain was not tracked. CONCLUSION: Pre-incisional PPMA may enhance the rehabilitation process of acute postoperative pain after TLH.

Air activation of charcoal monoliths for capacitive energy storage.

Charcoal monoliths derived from waste wood were activated with air for the application of electrochemical capacitor electrodes and an insight was given into the activation mechanism. The mild air activation is effective and pollution-free compared to the common chemical activation using KOH etc. for the preparation of crack-free carbon monoliths. The activation process was controlled by altering the activation temperature and time, and their effects on the nanostructure of charcoal monoliths were studied. As the activation temperature or time increased, air eroded the defective surface of charcoal layer-by-layer, with the oxygen atoms being introduced by chemisorption and oxidation reactions and removed by dehydration and decomposition reactions. Meanwhile, micro-pores were produced. The electrode activated at 300 °C for 1 h, with a specific surface area of 567 m2 g-1 and a high micro-porosity of 86%, exhibited a specific capacitance of 203 F g-1 and 35.5 F cm-3. Moreover, it presented a higher total capacitance of 3.6 F cm-2 than most reported pellet electrodes. These findings give a reasonable picture of the air activation process and are instructive to prepare activated carbon monoliths under an oxidizing environment.

Processed Multiparameter Electroencephalogram-Guided General Anesthesia Management Can Reduce Postoperative Delirium Following Carotid Endarterectomy: A Randomized Clinical Trial.

Background: Patients undergoing carotid endarterectomy (CEA) for severe carotid stenosis are vulnerable to postoperative delirium, a complication frequently associated with poor outcome. This study investigated the impact of processed electroencephalogram (EEG)-guided anesthesia management on the incidence of postoperative delirium in patients undergoing CEA. Methods: This single-center, prospective, randomized clinical trial on 255 patients receiving CEA under general anesthesia compared the outcomes of patient state index (PSI) monitoring [SEDLine Brain Function Monitor (Masimo, Inc, Irvine, CA)] (standard group, n = 128) with PSI combined with density spectral array(DSA) -guided monitoring (intervention group, n = 127) to reduce the risk of intraoperative EEG burst suppression. All patients were monitored by continuous transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to avoid perioperative cerebral hypoperfusion or hyperperfusion. According to the surgical process, EEG suppression time was calculated separately for three stages: S1 (from anesthesia induction to carotid artery clamping), S2 (from clamping to declamping), and S3 (from declamping to the end of surgery). The primary outcome was incidence of postoperative delirium according to the Confusion Assessment Method algorithm during the first 3 days post-surgery, and secondary outcomes were other neurologic complications and length of hospital stay. Results: There were no episodes of cerebral hypoperfusion or hyperperfusion according to TCD and NIRS monitoring in either group during surgery. The incidence of postoperative delirium within 3 days post-surgery was significantly lower in the intervention group than the standard group (7.87 vs. 28.91%, P < 0.01). In the intervention group, the total EEG suppression time and the EEG suppression time during S2 and S3 were shorter (Total, 0 "0" vs. 0 "1.17" min, P = 0.04; S2, 0 "0" vs. 0 "0.1" min, P < 0.01; S3, 0 "0" vs. 0 "0" min, P = 0.02). There were no group differences in incidence of neurologic complications and length of postoperative hospital stay. Conclusion: Processed electroencephalogram-guided general anesthesia management, consisting of PSI combined with DSA monitoring, can significantly reduce the risk of postoperative delirium in patients undergoing CEA. Patients, especially those exhibiting hemodynamic fluctuations or receiving surgical procedures that disrupt cerebral perfusion, may benefit from the monitoring of multiple EEG parameters during surgery. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03622515.

Low-Dose Dexmedetomidine Accelerates Gastrointestinal Function Recovery in Patients Undergoing Lumbar Spinal Fusion.

Background: Dexmedetomidine possesses sedative, sympatholytic, and opioid-sparing properties, but its impact on postoperative gastrointestinal function is controversial. Methods: This single-center, prospective, randomized study compared low-dose dexmedetomidine and placebo on gastrointestinal function recovery and inflammation after posterior lumbar spinal fusion. Sixty-six patients were randomized into two groups and received normal saline (control group) or dexmedetomidine (DEX group) during posterior lumbar fusion. Blood was taken at five timepoints to measure lipopolysaccharides, tumor necrosis factor-α, and C-reactive protein. The primary outcome was duration to first flatus. The secondary outcomes were inflammatory mediators and determination of correlations between perioperative factors and duration to first flatus. Results: Patients in DEX group showed significantly lower duration to first flatus (15.37 [13.35-17.38] vs 19.58 [17.31-21.86] h; p = 0.006) and overall sufentanil consumption (67.19 [63.78-70.62] vs 74.67 [69.96-79.30] µg; p = 0.011) than controls. Lipopolysaccharides, tumor necrosis factor-α, and C-reactive protein did not differ between the groups at any timepoint (all p > 0.05). Multiple linear regression modeling assessed the ability of independent variables to predict variance in duration to first flatus (adjusted R2 = 0.379, p = 0.000). In the model, age (ß = 0.243, p = 0.003), gender (ß = -3.718, p = 0.011), BMI (ß = -0.913, p = 0.001), operative segments (ß = -4.079, p = 0.028), and overall sufentanil consumption (ß = 0.426, p = 0.000) contributed significantly. Conclusions: Thus, low-dose dexmedetomidine accelerates gastrointestinal function recovery after lumbar spinal fusion. The effect may be partially produced by opioid-sparing effects rather than inhibition of inflammation. Clinical Trial Registration: www.chictr.org.cn, identifier ChiCTR1800018127.

MicroRNA expression in the hippocampal CA1 region under deep hypothermic circulatory arrest.

Using deep hypothermic circulatory arrest, thoracic aorta diseases and complex heart diseases can be subjected to corrective procedures. However, mechanisms underlying brain protection during deep hypothermic circulatory arrest are unclear. After piglet models underwent 60 minutes of deep hypothermic circulatory arrest at 14°C, expression of microRNAs (miRNAs) was analyzed in the hippocampus by microarray. Subsequently, TargetScan 6.2, RNA22 v2.0, miRWalk 2.0, and miRanda were used to predict potential targets, and gene ontology enrichment analysis was carried out to identify functional pathways involved. Quantitative reverse transcription-polymerase chain reaction was conducted to verify miRNA changes. Deep hypothermic circulatory arrest altered the expression of 35 miRNAs. Twenty-two miRNAs were significantly downregulated and thirteen miRNAs were significantly upregulated in the hippocampus after deep hypothermic circulatory arrest. Six out of eight targets among the differentially expressed miRNAs were enriched for neuronal projection (cyclin dependent kinase, CDK16 and SLC1A2), central nervous system development (FOXO3, TYRO3, and SLC1A2), ion transmembrane transporter activity (ATP2B2 and SLC1A2), and interleukin-6 receptor binding (IL6R) - these are the key functional pathways involved in cerebral protection during deep hypothermic circulatory arrest. Quantitative reverse transcription-polymerase chain reaction confirmed the results of microarray analysis. Our experimental results illustrate a new role for transcriptional regulation in deep hypothermic circulatory arrest, and provide significant insight for the development of miRNAs to treat brain injuries. All procedures were approved by the Animal Care Committee of Xuanwu Hospital, Capital Medical University, China on March 1, 2017 (approval No. XW-INI-AD2017-0112).

Effects of h-BN addition on microstructures and mechanical properties of ß-CaSiO3 bioceramics.

The main purpose of this study consists in investigating the effects of h-BN addition on the sinterability of ß-CaSiO3 (ß-CS) bioceramics. ß-CS bioceramics with different contents of h-BN were prepared at the sintering temperature ranging from 800°C to 1100°C. The results showed that h-BN can be successfully used as sintering additive by being oxidized to form low melting point B2O3 related glassy phase and enhanced the flexural strength by the formation of rod-like ß-CS grains. ß-CS bioceramics with 1wt% h-BN sintered at 1000°C revealed flexural strength and fracture toughness of 182.2MPa and 2.4MPam(1/2) respectively, which were much higher than that of pure ß-CS bioceramics (30.2MPa, 0.53MPam(1/2)) fabricated in the same processing condition.

Effects of silica sol on the microstructure and mechanical properties of CaSiO3 bioceramics.

CaSiO3 ceramics were fabricated with silica sol addition by pressureless sintering. The effects of silica sol on phase composition, microstructure and mechanical properties of CaSiO3 ceramics were investigated. The silica sol additive was found to be effective in speeding up pore elimination, improving the grain growth, decreasing the sintering temperature and shortening the sintering time. When the amount of SiO2 was 5wt%, a flexural strength of 186.2MPa was achieved with an open porosity of 3.9%. The main crystal phase was ß-CaSiO3 below sintering temperature of 1150°C.

The improved mechanical properties of ß-CaSiO3 bioceramics with Si3N4 addition.

The motivation of this study is to investigate the effect of Si3N4 addition on the sinterability of ß-CaSiO3 ceramics. ß-CaSiO3 ceramics with different content of Si3N4 were prepared at the sintering temperature ranging from 1000°C to 1150°C. The results showed that Si3N4 can be successfully used as sintering additive by being oxidized to form SiO2. The ß-CaSiO3 ceramics with 3wt% Si3N4 sintered at 1100°C revealed flexural strength, hardness and fracture toughness of 157.2MPa, 4.4GPa and 2.3MPam(1/2) respectively, which was much higher than that of pure ß-CaSiO3 ceramics (41.1MPa, 1.0GPa, 1.1MPam(1/2)). XRD analysis and SEM observation indicated that the main phase maintained to be ß-phase after sintering.