Anaesthesia
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Dexamethasone is often administered to surgical patients for anti-emetic prophylaxis. This study examined the early (up to 24 h) in-vivo effects of dexamethasone (8 mg) to demonstrate the magnitude and temporal nature of changes on circulating peripheral blood mononuclear cell gene expression and activation in 10 healthy male volunteers. Blood samples were drawn at baseline, 2 h, 4 h and 24 h. ⋯ Reductions in classical (p = 0.0009) and intermediate monocytes (p = 0.0178) and dendritic cells (p = 0.0012) were followed by increases in the level of these populations at 24 h compared with pre-dexamethasone (classical monocytes p = 0.0073, intermediate monocytes p = 0.0271, dendritic cells p = 0.0142). There was a profound reduction in the mean fluorescence intensity of the maturation marker, human histocompatibility leucocyte antigen, at 24 h in all monocyte subsets (p = 0.0002 for classical and non-classical monocytes, p = 0.0001 for intermediate monocytes) and dendritic cells (p = 0.0001). This study confirms rapid transient effects of 8 mg dexamethasone on innate immune cells with the potential to alter the inflammatory response to surgery and provides support for the hypothesis that intra-operative administration may be both immunosuppressive and immune-activating in the immediate peri-operative period.
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Arm-crank ergometry may be useful in patients unable to pedal, for instance due to peripheral arterial disease. Twenty participants with small abdominal aortic aneurysm undertook two serial arm-crank tests and then a pedal test, four of whom had indeterminate anaerobic thresholds, precluding analysis. ⋯ The correlation coefficients (95%CI) for peak oxygen consumption and anaerobic threshold were 0.88 (0.62-1.0) and 0.70 (0.32-1.0). There were no significant differences in serial arm-crank tests, with intracluster correlations (95%CI) of 0.87 (0.86-0.88) and 0.65 (0.61-0.69) for peak oxygen consumption and anaerobic threshold, respectively.
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Human factors are the individual, team, environmental and organisational aspects of the anaesthetic environment that affect performance and decision-making of anaesthesia teams. This study aimed to identify which human factors were enablers and/or barriers to anaesthesia teams during airway management challenges. Sixteen interviews were conducted with experienced anaesthetists and anaesthetic nurses using an in-depth interview technique (the Critical Decision Method) to identify human factors enablers and/or barriers during successful management of a significant airway challenge. ⋯ Five overarching barriers were also identified: time and resource limitations; teamwork and communication; equipment location and storage; experience and learning; insufficient back-up planning; and equipment preparation. This study showed that a variety of human factors issues affect the handling of airway challenges, ranging from individual and team to organisational and environmental aspects. Recommendations for the design of airway management decision support tools that relate to equipment standardisation, decision support complexity, inclusive mutual learning and teamwork are discussed.
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Spirometric monitoring provides precise measurement and delivery of tidal volumes within a narrow range, which is essential for lung-protective strategies that aim to reduce morbidity and mortality in mechanically-ventilated patients. Conventional anaesthesia ventilators include inbuilt spirometry to monitor inspiratory and expiratory tidal volumes. The GE Aisys CS2 anaesthesia ventilator allows additional near-patient spirometry via a sensor interposed between the proximal end of the tracheal tube and the respiratory tubing. ⋯ In conclusion, the present in-vitro study shows that measurements with near-patient spirometry are more accurate and less variable than with inbuilt spirometry. Differences between measurement methods were most significant in the smallest patients. We therefore recommend near-patient spirometry, especially for neonatal and paediatric patients.