Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Design and Analysis of Mechanical Servo Press

隨著電子產業的蓬勃發展，為因應電子產品少量多樣以及生命週期短的特性，使傳統的沖壓技術朝伺服式沖床發展。本文利用尺寸合成方式設計省力連桿機構，使沖頭位於能力發生點時，透過特殊連桿角度與架構，放大伺服馬達輸入扭力，以降低伺服馬達扭力需求，並利用機構動態模擬分析軟體RecurDyn分析機械式伺服沖床的運動特性，探討運動狀態下桿件質量在運動過程中產生的慣性效應、間隙造成的碰撞效應、軸承摩擦與潤滑液黏滯造成的阻力效應，對各桿件間作用力與馬達所需扭力造成的影響。由分析結果可發現，透過連桿機構的優化，與原始設計相比，在能力發生點受額定負荷，可降低馬達所需扭力約40%，使用RecurDyn進行動態模擬，結果顯示馬達所需扭力可降低約36%，大幅將低伺服馬達能力需求。In recently, electronic industry has been developed quickly. The developmental trends of press machine forward to servo press to react to the characteristics of electronic products, small volume with large variety and short life cycle. In this thesis, dimensional synthesis methodology was used to design the linkage under the requirement of maximum output torque with minimum input power from servo motor. Also motion characteristics of this mechanical servo press was analyzed by the multi body simulation software, RecurDyn, to study the influences of the inertia effect of linkage mass, the contact effect of clearance, the resistance effect of friction and lubrication viscosity of bearings on the action and reaction forces between each linkages and required torque of motor. From the analysis result, the required motor torque of the optimized linkage mechanism can be reduced by 40% approximately compared the original design. The simulation result also indicates the required motor torque can be reduced about 36%. These results show that the requirement of servo motor can be reduce substantially by optimizing linkage mechanism.摘要 I Abstract II 目錄 III 圖目錄 V 表目錄 IX 第一章 緒論 1 1.1 研究動機與目的 1 1.2 文獻回顧 2 1.3 本文架構 3 第二章 沖床介紹 5 2.1 沖床概述 5 2.2 機械式沖床 9 2.3 機械式伺服沖床 12 第三章 研究方法 15 3.1 連桿機構靜力學分析 15 3.2 連桿機構運動學分析 19 3.3 連桿機構優化設計 26 3.4 連桿機構動力學分析 29 3.4.1電腦輔助分析軟體簡介 29 3.4.2 模型建立 31 3.4.3 邊界條件設定 32 3.4.3.1 滑動軸承 32 3.4.3.2 間隙設定 32 3.4.3.3 摩擦設定 36 3.4.4 力量條件設定 44 3.4.5 運動條件設定 44 第四章 結果與討論 46 4.1 連桿機構優化 46 4.2 實驗與模擬比較 48 4.3 連桿機構動運動特性 50 4.3.1 沖頭的位移、速度、加速度 50 4.3.2 啟動時間 52 4.3.3 馬達所需扭力 53 4.3.4 各桿件間作用力 54 4.3.5 摩擦係數對沖床機構之影響 59 4.3.6 間隙值對對沖床機構之影響 66 4.4 有限元素分析 73 第五章 結論與展望 76 5.1 結論 76 5.2 展望 77 參考文獻 7