<strong>Background:</strong> 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 cons...<strong>Background:</strong> 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. <strong>Objective:</strong> To compare the outcomes of layered versus mass closure in transverse incision during emergency laparotomy in children. <strong>Methods: </strong>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. <strong>Results: </strong>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). <strong>Conclusion: </strong>Mass closure technique is comparatively better than layered closure technique.展开更多
Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibili...Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibility effect came from the reduced pressure-strain term due to reduced pressure fluctuations. Although better understanding of the compressible turbulence is generally achieved with the increased DNS and experimental research effort, there are still some discrepancies among these recent findings. Analysis of the DNS and experimental data suggests that some of the discrepancies are apparent if the compressible effect is related to the turbulent Mach number, Mt. From the comparison of two classes of compressible flow, homogenous shear flow and inhomogeneous shear flow （mixing layer）, we found that the effect of compressibility on both classes of shear flow can be characterized in three categories corresponding to three regions of turbulent Mach numbers： the low-Mr, the moderate-Mr and high-Mr regions. In these three regions the effect of compressibility on the growth rate of the turbulent mixing layer thickness is rather different. A simple approach to the reduced pressure-strain effect may not necessarily reduce the mixing-layer growth rate, and may even cause an increase in the growth rate. The present work develops a new second-moment model for the compressible turbulence through the introduction of some blending functions of Mt to account for the compressibility effects on the flow. The model has been successfully applied to the compressible mixing layers.展开更多
文摘<strong>Background:</strong> 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. <strong>Objective:</strong> To compare the outcomes of layered versus mass closure in transverse incision during emergency laparotomy in children. <strong>Methods: </strong>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. <strong>Results: </strong>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). <strong>Conclusion: </strong>Mass closure technique is comparatively better than layered closure technique.
基金the National Natural Science Foundation of China (10232020,90505005)
文摘Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibility effect came from the reduced pressure-strain term due to reduced pressure fluctuations. Although better understanding of the compressible turbulence is generally achieved with the increased DNS and experimental research effort, there are still some discrepancies among these recent findings. Analysis of the DNS and experimental data suggests that some of the discrepancies are apparent if the compressible effect is related to the turbulent Mach number, Mt. From the comparison of two classes of compressible flow, homogenous shear flow and inhomogeneous shear flow （mixing layer）, we found that the effect of compressibility on both classes of shear flow can be characterized in three categories corresponding to three regions of turbulent Mach numbers： the low-Mr, the moderate-Mr and high-Mr regions. In these three regions the effect of compressibility on the growth rate of the turbulent mixing layer thickness is rather different. A simple approach to the reduced pressure-strain effect may not necessarily reduce the mixing-layer growth rate, and may even cause an increase in the growth rate. The present work develops a new second-moment model for the compressible turbulence through the introduction of some blending functions of Mt to account for the compressibility effects on the flow. The model has been successfully applied to the compressible mixing layers.
