Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists

The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.     

Diffusion-weighted magnetic resonance imaging in rat kidney using two-dimensional navigated,interleaved echo-planar imaging at 7.0 T

The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague–Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T₂-weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T₂-weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.     

重组人表皮生长因子凝胶联合CO2点阵激光治疗增生性瘢痕的效果观察

目的观察重组人表皮生长因子凝胶联合CO₂点阵激光治疗烧伤及创伤后增生性瘢痕的临床效果。 方法选择2020年12月至2021年10月安徽医科大学第一附属医院烧伤与创面修复外科收治的20例增生性瘢痕患者，按照随机数字表法将患者分为联合治疗组及单纯激光治疗组，每组10例。术前均对2组患者术区进行拍照存像、消毒、擦干，局部均匀涂抹5%复方利多卡因乳膏后以无菌薄膜封闭保护60 min，擦去乳膏后再次消毒术区。术中使用CO₂点阵激光治疗仪对患者瘢痕部位进行扫描，根据患者增生性瘢痕厚度选定合适的机器参数，维持机器频率300 Hz及密度5%，在20～30 J调整能量参数的大小，时间间隔1 s，保证点阵矩形完全覆盖增生瘢痕，允许2次激光形成的热损伤矩阵之间存在25%面积的重叠。术后即刻冷敷创面60 min，冷敷结束至术后1周，单纯激光治疗组不外用任何药物，联合治疗组术区加用重组人表皮生长因子凝胶外用，3次/d。术后3 d治疗部位不碰水，若出现感染情况，可以加用抗生素软膏，点状损伤创面外痂皮未掉落完全时禁止擦洗创面，禁止直接剥除痂皮，禁止术区涂抹化妆品等，避免接受阳光直射。于第1次激光治疗后2个月进行第2次激光治疗，以2次CO₂点阵激光治疗为1个疗程，1个疗程治疗后间隔2个月待术区稳定后行疗效判断，计算2组患者治疗的总有效率；根据温哥华瘢痕量表(VSS)与患者与观察者瘢痕评估量表(POSAS)对患者治疗前、第1次激光治疗后2个月、第2次激光治疗后2个月瘢痕的各项指标进行评分。数据比较采用重复测量方差分析和χ²检验。 结果(1)治疗1个疗程后2个月，单纯激光治疗组与联合治疗组患者治疗的总有效率分别为80%(8/10)、90%(9/10)，2组间比较差异无统计学意义(χ²＝2.40，P＝0.49)。(2)对2组VSS评分的各项指标进行比较，其中疼痛、瘙痒、柔软度及厚度评分的组内及组间各时相点比较，差异均无统计学意义(P>0.05)。治疗前、第1次激光治疗后2个月及第2次激光治疗后2个月，单纯激光治疗组VSS评分中色泽评分分别为(1.9±0.7)、(1.9±0.1)、(1.8±1.0)分，联合治疗组分别为(2.9±0.7)、(2.8±0.6)、(1.9±0.7)分，2组在不同时相点组内比较，差异有统计学意义(F＝ 26.143，P<0.05)；2组组间不同时相点比较，差异有统计学意义(F＝6.753，P＝0.018)。治疗前、第1次激光治疗后2个月及第2次激光治疗后2个月，单纯激光治疗组VSS评分中血管分布评分分别为(1.8±1.0)、(1.7±0.7)、(1.5±1.0)分，联合治疗组分别为(2.6±0.5)、(2.5±0.5)、(1.7±0.8)分，2组在不同时相点组内比较，差异有统计学意义(F＝17.603，P<0.05)，2组组间不同时相点比较，差异无统计学意义(F＝ 2.538，P＝0.129)。(3)对2组POSAS评分的各项指标进行比较，其中厚度、粗糙度、柔软度和表面积评分的组内及组间各时相点比较，差异均无统计学意义(P>0.05)。治疗前、第1次激光治疗后2个月及第2次激光治疗后2个月，单纯激光治疗组POSAS评分中色泽评分分别为(4.9±2.6)、(4.1±0.8)、(3.5±2.0)分，联合治疗组分别为(7.6±1.1)、(6.8±1.4)、(5.4±1.8)分，2组在不同时相点组内比较，差异有统计学意义(F＝ 26.509，P<0.05)，2组组间不同时相点比较，差异有统计学意义(F＝ 8.973，P＝0.008)。治疗前、第1次激光治疗后2个月及第2次激光治疗后2个月，单纯激光治疗组POSAS评分中血管分布评分分别为(4.4±2.1)、(3.9±0.9)、(3.5±1.6)分，联合治疗组分别为(6.3±1.1)、(5.7±2.0)、(4.5±1.6)分，2组在不同时相点组内比较，差异有统计学意义(F＝ 20.118，P<0.05)，2组组间不同时相点比较，差异有统计学意义(F＝ 5.744，P＝0.028)。 结论重组人表皮生长因子凝胶联合CO₂点阵激光及单独使用CO₂点阵激光治疗增生性瘢痕均效果明确，但联合使用重组人表皮生长因子凝胶能有效促进创面愈合、改善瘢痕组织血管分布和减少局部色素沉着。     

High Order Finite Difference Hermite WENO Fixed-Point Fast Sweeping Method for Static Hamilton-Jacobi Equations

In this paper, we combine the nonlinear HWENO reconstruction in [43] and the fixed-point iteration with Gauss-Seidel fast sweeping strategy, to solve the static Hamilton-Jacobi equations in a novel HWENO framework recently developed in [22]. The proposed HWENO frameworks enjoys several advantages. First, compared with the traditional HWENO framework, the proposed methods do not need to introduce additional auxiliary equations to update the derivatives of the unknown function $\phi$. They are now computed from the current value of $\phi$ and the previous spatial derivatives of $\phi$. This approach saves the computational storage and CPU time, which greatly improves the computational efficiency of the traditional HWENO scheme. In addition, compared with the traditional WENO method, reconstruction stencil of the HWENO methods becomes more compact, their boundary treatment is simpler, and the numerical errors are smaller on the same mesh. Second, the fixed-point fast sweeping method is used to update the numerical approximation. It is an explicit method and does not involve the inverse operation of nonlinear Hamiltonian, therefore any Hamilton-Jacobi equations with complex Hamiltonian can be solved easily. It also resolves some known issues, including that the iterative number is very sensitive to the parameter $ε$ used in the nonlinear weights, as observed in previous studies. Finally, to further reduce the computational cost, a hybrid strategy is also presented. Extensive numerical experiments are performed on two-dimensional problems, which demonstrate the good performance of the proposed fixed-point fast sweeping HWENO methods.     

Rules are made to be broken

Techniques in Coloproctology -     

血液肿瘤患者化疗后肛周感染危险因素病例对照研究

目的 探讨血液肿瘤患者接受化疗后发生肛周感染的危险因素。方法 采用回顾性病例对照研究的方法,对四川省某三级甲等医院血液内科2020年12月—2021年5月收治的进行化疗的348例血液肿瘤住院患者相关资料（人口学特征、疾病特征、医疗及护理病例记录、实验室检查结果）予以回顾性分析,根据出院诊断发生肛周感染的病例作为病例组,其余病例作为对照组,统计血液肿瘤患者接受化疗后肛周感染的发生率,采用单因素分析和二元Logistic回归分析肛周感染的危险因素。结果 348例血液肿瘤化疗患者,发生肛周感染35例,感染率为10.1%;Logistic回归分析显示,年龄<60岁（OR=8.776,P=0.039）、痔疮史（OR=7.733,P<0.001）、肛周感染史（OR=14.981,P<0.001）、腹泻（OR=3.893,P=0.019）及白细胞计数<1×10⁹/L（OR=6.851,P=0.002）是血液肿瘤患者接受化疗后发生肛周感染的独立危险因素。结论 血液肿瘤患者接受化疗后肛周感染的发生率较高,年龄<60岁、痔疮史、肛周感染史、腹泻、白细胞计数<1×10⁹/L导致血液肿瘤化疗患者肛周感染率增加,在护理化疗期的血液肿瘤患者过程中,应该结合肛周感染的危险因素,采取针对性干预措施,降低肛周感染发生率。