Effect of remifentanil on post-operative analgesic consumption in patients undergoing shoulder arthroplasty after interscalene brachial plexus block: a randomized controlled trial

Purpose Remifentanil is useful in balanced anesthesia; however, there is concern regarding opioid-induced hyperalgesia. The effect of remifentanil on rebound pain, characterized by hyperalgesia after peripheral nerve block has rarely been studied. This study evaluated whether intraoperative remifentanil infusion may increase postoperative analgesic requirement in patients receiving preoperative interscalene brachial plexus block (IBP). Methods Sixty-eight patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly allocated to remifentanil (R) or control (C) group. Preoperative IBP with 0.5% ropivacaine 15 mL was performed in all patients. Intraoperative remifentanil was administered only in the R group. Postoperative pain was controlled using intravenous patient-controlled analgesia (IV-PCA) and rescue analgesics. The primary outcome was the dosage of fentanyl-nefopam IV-PCA infused over 24 h postoperatively. The secondary outcomes included the numeric rating scale (NRS) score recorded at 4-h intervals over 24 h, amount of rescue analgesics and total postoperative analgesics used over 24 h, occurrence of intraoperative hypotension, postoperative nausea and vomiting (PONV) and delirium. Results The dosage of fentanyl-nefopam IV-PCA was significantly less in C group than R group for postoperative 24 h. Fentanyl 101 [63-158] (median [interquartile range]) mu g was used in the C group, while fentanyl 161 [103-285] mu g was used in the R group (median difference 64 mu g, 95% CI 10-121 mu g, P = 0.02). Nefopam 8.1 [5.0-12.6] mg was used in the C group, while nefopam 12.9 [8.2-22.8] mg was used in the R group (median difference 5.1 mg, 95% CI 0.8-9.7 mg, P = 0.02). The total analgesic consumption: the sum of PCA consumption and administered rescue analgesic dose, converted to morphine milligram equivalents, was higher in the R group than C group (median difference 10.9 mg, 95% CI 3.0-19.0 mg, P = 0.01). The average NRS score, the incidence of PONV and delirium, were similar in both groups. The incidence of intraoperative hypotension was higher in R group than C group (47.1% vs. 20.6%, P = 0.005). Conclusions Remifentanil administration during arthroscopic shoulder surgery in patients undergoing preoperative IBP increased postoperative analgesic consumption.N

Si Nanocrystal-Embedded SiOxnanofoils: Two-Dimensional Nanotechnology-Enabled High Performance Li Storage Materials

Silicon (Si) based materials are highly desirable to replace currently used graphite anode for lithium ion batteries. Nevertheless, its usage is still a big challenge due to poor battery performance and scale-up issue. In addition, two-dimensional (2D) architectures, which remain unresolved so far, would give them more interesting and unexpected properties. Herein, we report a facile, cost-effective, and scalable approach to synthesize Si nanocrystals embedded 2D SiO x nanofoils for next-generation lithium ion batteries through a solution-evaporation-induced interfacial sol-gel reaction of hydrogen silsesquioxane (HSiO 1.5 , HSQ). The unique nature of the thus-prepared centimeter scale 2D nanofoil with a large surface area enables ultrafast Li + insertion and extraction, with a reversible capacity of more than 650 mAh g -1 , even at a high current density of 50 C (50 A g -1 ). Moreover, the 2D nanostructured Si/SiO x nanofoils show excellent cycling performance up to 200 cycles and maintain their initial dimensional stability. This superior performance stems from the peculiar nanoarchitecture of 2D Si/SiO x nanofoils, which provides short diffusion paths for lithium ions and abundant free space to effectively accommodate the huge volume changes of Si during cycling

Two-dimensional SiOx as a high performance Li storage material prepared by solution evaporation induced interfacial sol-gel reaction

Si based anode materials for lithium-ion batteries have gained much attention due to its high theoretical capacity (3,580 mAhg-1). However, Si anode materials have critical limit for their commercial use because of their poor cycle performance associated with severe volume changes during cycling. In this work, we synthesized a two-dimensional(2D) SiOx material by solution evaporation induced interfacial sol-gel reaction. This synthesis method is simple, cost-effective and scalable. The resulting 2D SiOx material showed stable cycle performance with reversible capacity of about 650 mAhg-1 even at a high current density of 50 C (50 A g-1). More detailed analysis of two-dimensional SiOx materials will be discussed in this presentation

High-Performance Si/SiO_<i>x</i> Nanosphere Anode Material by Multipurpose Interfacial Engineering with Black TiO_2–<i>x</i>

Silicon oxides (SiO_<i>x</i>) have attracted recent attention for their great potential as promising anode materials for lithium ion batteries as a result of their high energy density and excellent cycle performance. Despite these advantages, the commercial use of these materials is still impeded by low initial Coulombic efficiency and high production cost associated with a complicated synthesis process. Here, we demonstrate that Si/SiO_<i>x</i> nanosphere anode materials show much improved performance enabled by electroconductive black TiO_2–<i>x</i> coating in terms of reversible capacity, Coulombic efficiency, and thermal reliability. The resulting anode material exhibits a high reversible capacity of 1200 mAh g^–1 with an excellent cycle performance of up to 100 cycles. The introduction of a TiO_2–<i>x</i> layer induces further reduction of the Si species in the SiO_<i>x</i> matrix phase, thereby increasing the reversible capacity and initial Coulombic efficiency. Besides the improved electrochemical performance, the TiO_2–<i>x</i> coating layer plays a key role in improving the thermal reliability of the Si/SiO_<i>x</i> nanosphere anode material at the same time. We believe that this multipurpose interfacial engineering approach provides another route toward high-performance Si-based anode materials on a commercial scale