Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

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

Runoff potentiality of a watershed through SCS and functional data analysis technique

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling

Influences of thermal stability, and lubrication performance of biodegradable oil as an engine oil for improving the efficiency of heavy duty diesel engine

Nowadays, the development of biodegradable products is important in improving energy efficiency and green environment, particularly in energy conservation and rotation of machinery systems. In the case of sliding components, lubrication system and lubricant quality plays an important role for energy efficiency as it is directly involved with frictional force and components wear characteristics. The conventional mineral oil-based lubricant is used for machinery lubrications; however, it is nonbiodegradable and is an environmental pollutant. This investigation attempts to develop biolubricant acquired from various vegetable oils to replace mineral oil-based lubricants. This study evaluates the physicochemical properties, thermal stability, and lubricating and tribological characteristics of olive oil and its comparative analysis with commercial lube oil. A four-ball tribotester was used to measure the friction and wear properties of the sample according to the ASTM 4172 method. Olive oil has an excellent oxidation stability due to the presence of high percentages of oleic acid in fatty acid composition. Olive oil showed higher viscosity index and kinematic viscosity than other vegetable oils; hence, it is better for boundary lubrication. Thermogravimetric analysis showed that olive oil persists thermally steady up to 390 °C. Olive oil showed a lower coefficient of friction, wear scar diameter, and worn scar surface area than commercial lube oil. Therefore, due to the better lubricating performance, olive oil has high potential for use as an engine lubricating oil for improving efficiency of heavy-duty engines in the automotive applications

Perceptions of students in different phases of medical education of the educational environment: Universiti Sultan Zainal Abidin

Nor Iza A Rahman, Aniza Abd Aziz, Zainal Zulkifli, Muhammad Arshad Haj, Farah Hanani Binti Mohd Nasir, Sharvina Pergalathan, Muhammad Ismail Hamidi, Salwani Ismail, Nordin Bin Simbak, Mainul Haque Faculty of Medicine, Universiti Sultan Zainal Abidin, Kuala Terengganu, Terengganu, Malaysia Background: The Dundee Ready Education Environment Measure (DREEM) was planned and designed to quantify the educational environment precisely for medical schools and health-related professional schools. DREEM is now considered a valid and reliable tool, which is globally accepted for measuring the medical educational environment. The educational environment encountered by students has an impact on satisfaction with the course of study, perceived sense of well-being, aspirations, and academic achievement. In addition to being measurable, the educational environment can also be changed, thus enhancing the quality of medical education and the environment, and the medical education process. The objective of this study was to assess the educational environment of the Universiti Sultan Zainal Abidin (UniSZA) undergraduate medical program from the students&rsquo; perspective. The study expected to explore UniSZA medical students&rsquo; overall perceptions, perceptions of learning, teachers, atmosphere, academic self-perception, and social self-perception using the DREEM questionnaire. Methods: A cross-sectional survey was conducted to study the perceptions of the students toward the educational environment of UniSZA as a new medical school, using the DREEM questionnaire. All medical students of UniSZA from Years I&ndash;V enrolled in the Bachelor of Medicine and Bachelor of Surgery programs were the target population (n=270). Therefore, the universal sampling technique was used. The data were analyzed using the SPSS 20 software. This study obtained ethical clearance from the Faculty of Medicine and Health Sciences, UniSZA. Results: A total of 195 out of 270 students responded. Respondents included 31% males and 69% females. The overall DREEM scores were significantly higher (P&lt;0.001) for females than males. Conclusion: The medical students at UniSZA showed a positive perception of their educational environment. The new medical faculty, established for only a few years, has achieved an above-average, conducive educational environment for students. Most of the students showed a positive perception for the entire five domains tested in the DREEM survey. Females were consistently satisfied with UniSZA&rsquo;s educational environment, and self-perception was high, as compared to male undergraduates. Keywords: perceptions, medical students, educational environment, DREEM, UniSZA&nbsp