How do surgeons decide? Conduit choice in coronary artery bypass graft surgery in the UK

OBJECTIVES Conduits used in coronary artery bypass grafting may have significant impact on outcomes, but evidence is mixed and there is large variation in practice. This study provides insights into the opinions of the UK surgeons on conduit use and their decision-making processes. METHODS A questionnaire was created using the Ottawa Decision Support Framework to elicit the importance that surgeons placed on bilateral internal mammary artery grafting, skeletonization, total arterial revascularization and sequential anastomoses on a scale of 1–10. Scores ≥8 were deemed ‘important’ and ≤3 ‘not important’. Surgeons were asked to specify changes to practice in frail patients or emergencies. Additional questions included conduit type used, factors affecting decision-making and vein harvesting methods. Questionnaires were administered in person with data analysed centrally. RESULTS Ninety-seven consultant cardiac surgeons from 25 centres responded. Thirty-two percent surgeons routinely used radial arteries and 36% used right internal mammary artery. High-quality evidence contributed most to decision-making receiving a total of 328/960 points, with consultant experience being the second (255/960 points). There was a bimodal distribution of perceived importance of bilateral internal mammary artery use, with 29 (30%) ‘important’ and ‘not important’ scores each. 23% of surgeons found total arterial revascularization important. Most surgeons (64%) preferred pedicled mammary arteries. Twenty-six percent of surgeons considered sequential grafting to be important. CONCLUSIONS Low uptake of total arterial revascularization and bilateral internal mammary artery among the UK consultants may be due to the lack of high-quality evidence demonstrating a significant benefit. It is also possible that reluctance to use certain conduits may stem from low levels of exposure to conduits or inadequate training, particularly given the importance of consultant experience on decision-making

The trade-off between singing and mass gain in a daytime-singing bird, the European robin

The functions of bird song are well described, but empirical studies examining the costs of singing are scarce. Two potential costs are a metabolic cost of singing, and lost feeding opportunities, but such energetic costs will only be biologically important if they have a significant effect on the bird's body reserves. Overnight loss of reserves has previously been found to increase with increasing song rates in nocturnally singing common nightingales Luscinia megarhynchos. However, it is not clear how such costs compare with those incurred by daytime-singing birds, which may forfeit foraging opportunities when they sing. In this paper we investigated the effect of variation in song rate on the body reserves of a typical daytimesinging bird, the European robin Erithacus rubecula, singing at different rates in three different circumstances: (i) Natural variation in song rate of free-living robins. (ii) Manipulations of the song rate of free-living robins using playbacks of conspecific song. (iii) Manipulations of the song rate of aviary-housed robins using playbacks of conspecific song. In all three parts of our study, birds gained less mass when they sang more. Our analyses suggested that this might have been due primarily to a reduction in food intake rate, rather than to the metabolic cost of the singing itself or a concurrent increase in locomotor costs. These results together demonstrate that the costs of singing, as measured by their overall net effects on body reserves, can have a significant impact on the energetic state of daytime-singing birds

State of the Art on the Search for Sustainability and Quality of Life in Cities

The concept of sustainability appears simple but is difficult to define. It can be at once an idea, a lifestyle, a production mode, or a way of “consuming”. As John Huckle writes, “…Like liberty, justice and democracy, sustainability has no single and agreed meaning. It takes on different meaning within different political ideologies and programmes underpinned by different kind of knowledge, values and philosophy” (Huchle 1996