Stroke volume variation may be used as a continuous preload variable and in combination with the continuously measured cardiac output, defining on-line the most important characteristics of cardiac function, allowing for optimal fluid management.

Preoperative administration of statins is associated with the reduced risk of postoperative delirium after cardiac surgery with cardiopulmonary bypass.

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This study did not show a significant effect of OT team hierarchical structure on trainee's ability to challenge authority; however, the results are concerning. The challenges were suboptimal in quality and there was an alarming high rate of blood checking and administration in both groups. This may reflect lack of training in appropriately and effectively challenging authority within the formal curriculum with implications for patient safety.

Receptor specificity of the substance P-related peptides neurokinin A and neurokinin B was studied in the isolated guinea pig ileum. Substance P and the recently discovered neurokinins elicit contraction of the ileum both directly through action on a muscle cell receptor and indirectly through stimulation of a neuronal receptor, leading to release of acetylcholine, which causes muscle contraction via muscarinic receptors. Two specific assay procedures for the function of the neuronal receptor were developed. The muscular receptor was inactivated either by desensitization with the selective agonist substance P methyl ester or by receptor blockade with the selective antagonist [Arg6, D-Trp7,9, MePhe8Jsubstance P-(461) hexapeptide. Both procedures revealed that the neuronal receptor is clearly distinct from the muscular receptor, since it exhibits different agonist specificity and is insensitive to antagonists of the muscular receptor.Neurokinin B was found to be the most potent agonist (ECse = 1 nM) for the neuronal receptor. Furthermore, [D-Ala2, Metslenkephalinamlde inhibited in a naloxone-sensitive manner the effect of neurokinin B mediated via the neuronal receptor. These results suggest that the different mammalian tachykinins can play specific physiological roles by virtue of their distinct receptor specificities.The tachykinins are a family of biologically active peptides

Multidisciplinary care teams exist throughout healthcare systems. In the operating room (OR), effective communication between teams is essential, especially during crisis situations where patient safety can be in acute danger. An oftenneglected skillset in educational curriculums is challenging authority. This narrative synthesis aims to explore the literature on challenging authority in the OR environment. A systematic search of Medline, EBM reviews and PsycINFO was conducted using terms related to challenging authority, speaking up, communication, patient safety, gradients and hierarchy. The initial search identified 4822 publications, out of which 31 studies were included. The data synthesis of the included studies was grouped into three distinct categories following a meta-aggregative approach: discussion and review articles, observational or qualitative studies, and studies identifying the role of specific barriers or investigating the effect of educational interventions. Themes emerging from expert beliefs, what reality tells us and what we test are consistent. Hierarchy, organisational culture and education are the most frequently observed and tested themes. Simulation research has been successful in eliciting and confirming the role of specific barriers to speaking up. Barriers and enablers are largely modifiable within institutions however, education regarding the importance of speaking up will need to accompany these modifications for any significant changes to occur. Editor's key pointsThe authors examined the literature on speaking up in the operating theatre environment using narrative synthesis. They demonstrate emerging themes from the literature consistent with our intuitive understanding e hierarchy gradients, organisational culture, and education are the most frequently observed factors affecting ability to challenge authority. Barriers and enablers to speaking up are largely modifiable. Promoting speaking up within health teams requires organisations to cultivate a culture of open, safe communication, accompanied by education regarding the importance of speaking up.

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Purpose To determine if there is an association between perioperative administration of beta-blockers and postoperative delirium in patients undergoing vascular surgery. Methods After Institutional Review Board approval, data were retrospectively collected on patients who underwent vascular surgery in an academic hospital during the period January 2006 to January 2007. Patients with preoperative altered level of consciousness, carotid endarterectomy, or discharge within 24 h of surgery were excluded from the study. Identification of delirium was based on evaluation of the level of consciousness with the NEECHAM Confusion Scale and/or a chart-based instrument for delirium. Multivariable logistic regression analysis was used to identify independent perioperative predictors of postoperative delirium. Beta-blockers were tested for a potential effect. Conclusions Preoperative administration of beta-blockers is associated with an increased risk of postoperative delirium after vascular surgery. Conversely, preoperative statin administration is associated with a lower risk of postoperative delirium. A randomized prospective controlled trial is required to validate these findings. RésuméObjectif De´terminer s'il existe un lien entre l'administration pe´riope´ratoire de beˆta-bloquants et le delirium postope´ratoire chez les patients subissant une chirurgie vasculaire.