1,355,643 research outputs found
Three years of Extreme Physiology & Medicine
No full text© 2015 Grocott and Montgomery. This article is distributed under the terms of the Creative Commons Attribution 4.0 Interna‑
tional License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in
any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Com‑
mons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecom‑
mons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
Survival after postoperative morbidity: a longitudinal observational cohort study.
No full textBACKGROUND: Previous studies have suggested that there may be long-term harm associated with postoperative complications. Uncertainty exists however, because of the need for risk adjustment and inconsistent definitions of postoperative morbidity. METHODS: We did a longitudinal observational cohort study of patients undergoing major surgery. Case-mix adjustment was applied and morbidity was recorded using a validated outcome measure. Cox proportional hazards modelling using time-dependent covariates was used to measure the independent relationship between prolonged postoperative morbidity and longer term survival. RESULTS: Data were analysed for 1362 patients. The median length of stay was 9 days and the median follow-up time was 6.5 yr. Independent of perioperative risk, postoperative neurological morbidity (prevalence 2.9%) was associated with a relative hazard for long-term mortality of 2.00 [P=0.001; 95% confidence interval (CI) 1.32-3.04]. Prolonged postoperative morbidity (prevalence 15.6%) conferred a relative hazard for death in the first 12 months after surgery of 3.51 (P<0.001; 95% CI 2.28-5.42) and for the next 2 yr of 2.44 (P<0.001; 95% CI 1.62-3.65), returning to baseline thereafter. CONCLUSIONS: Prolonged morbidity after surgery is associated with a risk of premature death for a longer duration than perhaps is commonly thought; however, this risk falls with time. We suggest that prolonged postoperative morbidity measured in this way may be a valid indicator of the quality of surgical healthcare. Our findings reinforce the importance of research and quality improvement initiatives aimed at reducing the duration and severity of postoperative complications
Solving methodological challenges using a theory-driven evaluation in the study of complex patient care
No full textThis article draws on two research designs, which were used in a study of the palliative management of malignant wounds, to demonstrate the inherent challenges in producing generalizable knowledge from a complex subject. The designs included quasi-experimentation and a form of theory-driven evaluation. The focus of the study was the performance of dressings to reduce the impact of the wounds on daily life. The convention for evaluating the outcomes of interventions is a controlled study design. This approach is considered the valid way of producing evidence that is generalizable. An experimental design was therefore adopted to conduct a series of n = 1 quasi-experiments on wound dressing performance with qualitative methods to explore individual experiences. Problems with the methods, in particular the failure to capture complex inter-relationships between clinical problems and patient experiences, forced the researcher to abandon the experimental design. An alternative approach to measurement was adopted to maintain the study focus, the TELER® system of treatment evaluation, which includes indicators of patient-centred outcomes of care. The philosophical position of the study was reviewed. Consensus emerged as an unalterable, major influence on the design and paradigmatic assumptions of the study. A 'system of reasoning' was adopted to overcome the inherent relativist position of knowledge derived from this approach. The system abstracts general issues from case study data to construct theoretical explanations that may be consistent with, or challenge, current knowledge. This article is based on the evolution of one particular study. However, it makes a more general contribution to evaluation research by explaining the rationale for a form of theory-driven evaluation that uses evidence, reason and theory to develop generalizable explanations from complex, individual case study data. The methodology is proposed for other complex situations where specific and rigorous evidence, capable of generalization is needed
A methodology for evaluating wound care technologies in the context of treatment and care
No full textBackground: the question of whether particular methodologies can generate knowledge of a sufficiently rigorous and relevant standard to guide patients’ interventions is regularly debated. This debate tends to be polarised between those who advocate the randomised controlled trial (RCT) as the ultimate scientific methodology and those who find RCTs wanting in terms of the information derived and their limited generalisability beyond the immediate trial population. This paper argues for a suite of methodologies that can evaluate wound care interventions; it also details a novel methodology for use in complex chronic and palliative wound care.Aim: to outline a methodology that can evaluate the clinical performance of wound care products in the context of complex treatment and care.Methods: the methodology is informed by the UK Medical Research Council framework for the design of complex evaluations, and is an N-of-1 design.Results: a novel methodology for evaluating the effectiveness of wound care technologies in complex chronic wound care and palliative wound care has been proposed.Conclusion: the methodology requires validation in prospective studies. The purpose of this paper is to open a constructive debate.Conflict of interest: non
Saline or Hartmann's solution: is it still a controversy?
No full textAnaesthetists and other clinicians have long debated the relative merits of using Hartmann’s (or lactated Ringer’s) solution instead of normal saline during operations. Until recently there have only been case reports that have highlighted the possibility of a ‘dilutional acidosis’ occurring when saline was used to replace massive blood loss
Towards a synthesis of substorm electrodynamics : HF radar and auroral observations
No full textAt 08:35 UT on 21 November 2004, the onset of an interval of substorm activity was captured in the southern hemisphere by the Far UltraViolet (FUV) instrument on board the IMAGE spacecraft. This was accompanied by the onset of Pi2 activity and subsequent magnetic bays, evident in ground magnetic data from both hemispheres. Further intensifications were then observed in both the auroral and ground magnetic data over the following ~3 h. During this interval the fields-of-view of the two southern hemisphere Tasman International Geospace Enviroment Radars (TIGER) moved through the evening sector towards midnight. Whilst initially low, the amount of backscatter from TIGER increased considerably during the early stages of the expansion phase such that by ~09:20 UT an enhanced dusk flow cell was clearly evident. During the expansion phase the equatorward portion of this flow cell developed into a narrow high-speed flow channel, indicative of the auroral and sub-auroral flows identified in previous studies (e.g. Freeman et al., 1992; Parkinson et al., 2003). At the same time, higher latitude transient flow features were observed and as the interval progressed the flow reversal region and Harang discontinuity became very well defined. Overall, this study has enabled the spatial and temporal development of many different elements of the substorm process to be resolved and placed within a simple conceptual framework of magnetospheric convection. Specifically, the detailed observations of ionospheric flows have illustrated the complex interplay between substorm electric fields and associated auroral dynamics. They have helped define the distinct nature of different substorm current systems such as the traditional substorm current wedge and the more equatorward currents associated with polarisation electric fields. Additionally, they have revealed a radar signature of nightside reconnection which provides the promise of quantifying nightside reconnection in a way which has already proved extremely successful in studies of the dayside magnetosphere
Soft rock: the power shifts in Madrid and London could help Gibraltar
No full textGibraltar's border with Spain, and its economic dependence on financial services, mean it has a lot to lose from a hard Brexit. Chris Grocott (University of Leicester) looks at the implications of a new Spanish government and the departures of Boris Johnson and David Davis
Pre-oxygenation before extubation. Comment on: Oxygen therapy and anaesthesia: too much of a good thing?
No full text- …
