Outcomes of Layered versus Mass Closure in Transverse Incision during Emergency Laparotomy in Children

Background: The value of laparotomy closure technique may be measured by the incidence of early and late wound complications. The best laparotomy closure technique should be less time consuming, easy and cost-effective, while preventing both early and late complications. Objective: To compare the outcomes of layered versus mass closure in transverse incision during emergency laparotomy in children. Methods: This prospective comparative study was conducted at Department of Pediatric Surgery, Dhaka Medical College Hospital (DMCH), Dhaka, Bangladesh from July 2016 to June 2018. A total of 60 pediatric age cases that underwent laparotomy were included in this study. Cases were randomly allocated into two groups;30 patients were in Group A (Layered closure) and 30 patients were in Group B (Mass closure). The outcome variables were time required for wound closure, wound infection, wound dehiscence and incisional hernia. Data were analyzed and compared by statistical tests. Results: The mean age of Group A and Group B patients were 31.08 ± 30.25 months and 34.70 ± 42.73 months respectively (p = 0.706). The ratio between male and female subject was 1.1:1 in Group A and 3.3:1 in Group B. The common diseases of the study patients who underwent laparotomy were intussusceptions, intestinal obstruction due to bands and adhesion, perforated appendix and perforation of small intestine due to blunt trauma respectively. Mean wound closure time was significantly less in mass closure group [28.20 ± 2.17 minutes in layered closure group and 18.80 ± 1.67 minutes in mass closure group, (p ≤ 0.001)]. Wound infection rate, incidence of superficial wound dehiscence, and incisional hernia were relatively less in mass closure group, however, the differences were not statistically significant (p = 0.053, p = 0.095 and p = 0.301 respectively). There was no complete wound dehiscence in Group A, but that was in 1 (3.3%) patient in Group B (p = 0.313). Conclusion: Mass closure technique is comparatively better than layered closure technique.

Chemical composition, mass closure and sources of atmospheric PM_(10) from industrial sites in Shenzhen, China

Concentrations of atmospheric PM10 and chemical components （including twenty-one elements, nine ions, organic carbon （OC） and elemental carbon （EC）） were measured at five sites in a heavily industrial region of Shenzhen, China in 2005. Results showed that PM10 concentrations exhibited the highest values at 264 μg/m3 at the site near a harbor with the influence of harbor activities. Sulfur exhibited the highest concentrations （from 2419 to 3995 ng/m3） of all the studied elements, which may be related to the influence of coal used as fuel in this area for industrial plants. This was verified by the high mass percentages of SO42-, which accounted for 34.3%-39.7% of the total ions. NO3-/SO42- ratios varied from 0.64-0.71, which implies coal combustion was predominant compared with vehicle emission. The anion/cation ratios range was close to 0.95, indicating anion deficiency in this region. The harbor site showed the highest OC and EC concentrations, with the influence of emission from vessels. Secondary organic carbon accounted for about 22.6%-38.7% of OC, with the highest percentage occurring at the site adjacent to a coal-fired power plant and wood plant. The mass closure model performed well in this heavily industrial region, with significant correlation obtained between chemically determined and gravimetrically measured PM10 mass. The main constituents of PM10 were found to be organic materials （30.9%-69.5%）, followed by secondary inorganic aerosol （7.9%-25.0%）, crustal materials （6.7%-13.8%）, elemental carbon （3.5%-10.8%）, sea salt （2.4%-6.2%） and trace elements （2.0%-4.9%） in this heavily industrialized region. Principal component analysis indicated that the main sources for particulate matter in this industrial region were crustal materials and coal/wood combustion, oil combustion, secondary aerosols, industrial processes and vehicle emission.

Chemical Composition of PM_(2.5) at an Urban Site of Chengdu in Southwestern China

PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The annual average of PM2.5 was 165 btg m a, which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic car- bon contributed 32.0%, and trace elements contributed 13.8~0. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of dif- ferent anthropogenic and natural sources. Weakly acidic to neutral particles were found for PMz5. Major sources of PM2.u identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate： sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering.