The significant impact of age on the clinical outcomes of laparoscopic appendectomy : results from the Polish Laparoscopic Appendectomy multicenter large cohort study

Acute appendicitis (AA) is the most common surgical emergency and can occur at any age. Nearly all of the studies comparing outcomes of appendectomy between younger and older patients set cut-off point at 65 years. In this multicenter observational study, we aimed to compare laparoscopic appendectomy for AA in various groups of patients with particular interest in the elderly and very elderly in comparison to younger adults. Our multicenter observational study of 18 surgical units assessed the outcomes of 4618 laparoscopic appendectomies for AA. Patients were divided in 4 groups according to their age: Group 1- 8 days. Logistic regression models comparing perioperative results of each of the 3 oldest groups compared with the youngest one showed significant differences in odds ratios of symptoms lasting >48hours, presence of complicated appendicitis, perioperative morbidity, conversion rate, prolonged LOS (>8 days). The findings of this study confirm that the outcomes of laparoscopic approach to AA in different age groups are not the same regarding outcomes and the clinical picture. Older patients are at high risk both in the preoperative, intraoperative, and postoperative period. The differences are visible already at the age of 40 years old. Since delayed diagnosis and postponed surgery result in the development of complicated appendicitis, more effort should be placed in improving treatment patterns for the elderly and their clinical outcome

Risk factors for serious morbidity, prolonged length of stay and hospital readmission after laparoscopic appendectomy : results from Pol-LA (Polish Laparoscopic Appendectomy) multicenter large cohort study

Laparoscopic appendectomy (LA) for treatment of acute appendicitis has gained acceptance with its considerable benefits over open appendectomy. LA, however, can involve some adverse outcomes: morbidity, prolonged length of hospital stay (LOS) and hospital readmission. Identification of predictive factors may help to identify and tailor treatment for patients with higher risk of these adverse events. Our aim was to identify risk factors for serious morbidity, prolonged LOS and hospital readmission after LA. A database compiled information of patients admitted for acute appendicitis from eighteen Polish and German surgical centers. It included factors related to the patient characteristics, peri- and postoperative period. Univariate and multivariate logistic regression models were used to identify risk factors for serious perioperative complications, prolonged LOS, and hospital readmissions in acute appendicitis cases. 4618 laparoscopic appendectomy patients were included. First, although several risk factors for serious perioperative complications (C-D III-V) were found in the univariate analysis, in the multivariate model only the presence of intraoperative adverse events (OR 4.09, 95% CI 1.32-12.65, p = 0.014) and complicated appendicitis (OR 3.63, 95% CI 1.74-7.61, p = 0.001) was statistically significant. Second, prolonged LOS was associated with the presence of complicated appendicitis (OR 2.8, 95%CI: 1.53-5.12, p = 0.001), postoperative morbidity (OR 5.01, 95% CI: 2.33-10.75, p < 0.001), conversions (OR 6.48, 95% CI: 3.48-12.08, p < 0.001) and reinterventions after primary procedure (OR 8.79, 95% CI: 3.2-24.14, p < 0.001) in the multivariate model. Third, although several risk factors for hospital readmissions were found in univariate analysis, in the multivariate model only the presence of postoperative complications (OR 10.33, 95% CI: 4.27-25.00), reintervention after primary procedure (OR 5.62, 95% CI: 2.17-14.54), and LA performed by resident (OR 1.96, 95%CI: 1.03-3.70) remained significant. Laparoscopic appendectomy is a safe procedure associated with low rates of complications, prolonged LOS, and readmissions. Risk factors for these adverse events include complicated appendicitis, postoperative morbidity, conversion, and re-intervention after the primary procedure. Any occurrence of these factors during treatment should alert the healthcare team to identify the patients that require more customized treatment to minimize the risk for adverse outcomes

Friction and Lubrication of Large Tilting-Pad Thrust Bearings

Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper

Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine

In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand, the availability of experimental field data on bearing operation is limited, for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have conducted in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data

Przedsiębiorcy społeczni – co odróżnia ich od osób angażujących się w przedsięwzięcia biznesowe?

Social entrepreneurs, very often operate with highly limited resources, not to say with virtually nothing. They possess motivation, but apart from financial or technical resources very often they also need complex set of skills, especially those connected with leadership. Social entrepreneurship is similar to business entrepreneurship in many way, however there are some differences. Both similarities and differences can be find in theoretical papers, however there is a limited number of research which prove them. A research conducted in 2014 among 76 respondents, engaged in business and social activities, proved that to some extent social and business entrepreneurs have some common features, however some of them are unique for each of this entrepreneurship type.Przedsiębiorcy społeczni bardzo często działają wykorzystując dostępne im bardzo ograniczone zasoby lub praktycznie nie mając zasobów w ogóle. Posiadają motywację, ale poza finansowymi czy technicznymi zasobami potrzebują często również złożonego zestawu kompetencji, szczególnie tych, które wiążą się z przywództwem. Przedsiębiorcy społeczni w wielu aspektach wykazują podobieństwo do przedsiębiorców operujących w otoczeniu biznesowym, jednak istnieją też miedzy nimi pewne różnice. Zarówno podobieństwa, jak i różnice między tymi dwoma grupami przedsiębiorców można odnaleźć w artykułach teoretycznych, natomiast niewielka liczba badań dowodzi ich istnienia. Badanie przeprowadzone w 2014 roku w grupie 76 respondentów zaangażowanych w działalność społeczną i biznesową wykazało, że do pewnego stopnia przedsiębiorcy społeczni oraz przedsiębiorcy zaangażowani w działalność nastawioną na zysk wykazują podobne charakterystyki, choć każdy z tych dwóch typów przedsiębiorców cechuje się także właściwościami unikatowymi dla siebie