High altitude respiratory physiology and patho- physiology

At high altitude, reduced atmospheric pressure causes the partial pressure of oxygen to decrease – creating an environment of hypobaric hypoxia which presents a unique set of challenges for the respiratory system. Pulmonary physiological responses such as the hypoxic ventilatory drive are essential for successful acclimatisation, whilst others such as hypoxic pulmonary vasoconstriction may be implicated in the development of altitude illnesses. Pulmonary conditions are some of the most common (e.g. high altitude cough) and also the most serious illnesses seen at altitude (e.g high altitude pulmonary oedema, HAPE). Minimising the chance of developing HAPE through planning an appropriate ascent profile should be strongly encouraged as HAPE can rapidly be fatal if left untreated. Whilst pharmacological agents such as nifedipine can help with the management of HAPE, rapid descent remains the single-most important treatment option once symptomatic. Given the increasing popularity of travelling to altitude, an awareness of how hypobaric hypoxia affects chronic respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD) is also becoming increasingly important for respiratory physician

An analysis of magnetic reconnection events and their associated auroral enhancements

An analysis of simultaneous reconnection events in the near-Earth magnetotail and enhancements in the aurora is undertaken. Exploiting magnetospheric data from the Geotail, Cluster, and Double Star missions, along with auroral images from the IMAGE and Polar missions, the relationship between a reconnection signature and its auroral counterpart is explored. In this study of 59 suitable reconnection events, we find that 43 demonstrate a clear coincidence of reconnection and auroral enhancement. The magnetic local time (MLT) locations of these 43 reconnection events are generally located within ±1 h MLT of the associated auroral enhancement. A positive correlation coefficient of 0.8 between the two MLT locations is found. The enhancements are localized and short-lived (τ≤10 min) and are as likely to occur during the substorm process as in isolation of a substorm. No significant dependence of the reconnection or auroral enhancement location on the dusk-dawn components of the solar wind velocity (Vy), IMF (By) or local By or Vy, as measured by the reconnection-detecting spacecraft, is found

Early identification of wound infection: understanding wound odour

Malodorous wounds can be distressing for patients and their families, negatively impacting on quality-of-life outcomes. For health professionals malodorous wounds can also cause distress manifesting in feelings of disgust when faced with a wound emitting an unpleasant or repulsive odour. There has been investigation into the management of controlling odour particularly in relation to fungating wounds. However, there is limited research that explores techniques for early identification and recognition of wound odours that may be indicative of infection. Electronic nose technology has received some attention, but to date has not been integrated into either diagnostics of infection in wounds or education of health professionals to prepare them for the realities of clinical practice

Oxygen management during cardiopulmonary bypass : a single-center, 8-year retrospective cohort study

OBJECTIVE : To characterize the institutional oxygen management practices during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery, including any potential changes during an 8-year study period. DESIGN : A retrospective cohort study. SETTING : A tertiary care cardiac surgical program. PARTICIPANTS : Patients who underwent cardiac surgery involving CPB, with or without hypothermic circulatory arrest (HCA), between January 1, 2010, and December 31, 2017. MEASUREMENTS AND MAIN RESULTS : In addition to baseline patient characteristics, the authors recorded the partial pressures of arterial oxygen (Pa o 2 ), fraction of inspired oxygen, and mixed venous oxygen saturation during CPB of 696 randomly selected patients during an 8-year study period. The overall mean Pa o 2 was 255 ± 48 mmHg, without any significant change during the 8-year study period (p = 0 . 30). The mean Pa o 2 of HCA patients was significantly higher than in patients without HCA (327 ± 93 mmHg v 252 ± 45 mmHg, respectively; p < 0 . 001). CONCLUSIONS : The current approach to oxygen management during CPB at the authors’ institution is within the range of hyperoxemic levels, and these practices have not changed over time. The impact of these practices on patients’ outcomes is not fully understood, and additional studies are needed to establish firm evidence to guide optimal oxygen management practice during CPB.The University of Manitoba Department of Anesthesiology, Perioperative and Pain Medicinehttps://www.elsevier.com/locate/jbusres2022-01-01hj2021Anaesthesiolog

Characteristics of medium-scale travelling ionospheric disturbances observed near the Antarctic Peninsula by HF radar

We present a survey of medium-scale traveling ionospheric disturbances (MSTIDs) observed by a Super Dual Auroral Radar Network HF radar located in the Falkland Islands between May 2010 and April 2011. The radar has a field of view that overlooks the Antarctic Peninsula, a known hot spot of gravity wave activity. We present observations of radar ground-backscatter data, in which the signatures of MSTIDs are manifested as structured enhancements in echo power. Observed periods were in the range 30–80 min, corresponding to frequencies of 0.2–0.6 mHz. Wavelengths were generally in the range 200–800 km and phase speeds in the range 100–300 m s−1. These values are within the ranges typically associated with medium-scale gravity waves. We find a primary population of northward (equatorward) propagating MSTIDs, which demonstrate an association with enhanced solar wind-magnetosphere coupling and a smaller, westward propagating population, that could be associated with atmospheric gravity waves excited by winds over the Andean and Antarctic Peninsula mountains or by the high winds of the Antarctic Polar Vortex

Dynamic effects of restoring footpoint symmetry on closed magnetic field lines

Here we present an event where simultaneous global imaging of the aurora from both hemispheres reveals a large longitudinal shift of the nightside aurora of about 3 h, being the largest relative shift reported on from conjugate auroral imaging. This is interpreted as evidence of closed field lines having very asymmetric footpoints associated with the persistent positive y component of the interplanetary magnetic field before and during the event. At the same time, the Super Dual Auroral Radar Network observes the ionospheric nightside convection throat region in both hemispheres. The radar data indicate faster convection toward the dayside in the dusk cell in the Southern Hemisphere compared to its conjugate region. We interpret this as a signature of a process acting to restore symmetry of the displaced closed magnetic field lines resulting in flux tubes moving faster along the banana cell than the conjugate orange cell. The event is analyzed with emphasis on Birkeland currents (BC) associated with this restoring process, as recently described by Tenfjord et al. (2015). Using data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) during the same conditions as the presented event, the large-scale BC pattern associated with the event is presented. It shows the expected influence of the process of restoring symmetry on BCs. We therefore suggest that these observations should be recognized as being a result of the dynamic effects of restoring footpoint symmetry on closed field lines in the nightside

Exercise rehabilitation following intensive care unit discharge for recovery from critical illness:executive summary of a Cochrane Collaboration systematic review

Skeletal muscle wasting and weakness are major complications of critical illness and underlie the profound physical and func-\ud tional impairments experienced by survivors after discharge from the intensive care unit (ICU). Exercise-based rehabilitation\ud has been shown to be bene\ud fi\ud cial when delivered during ICU admission. This review aimed to determine the effectiveness of\ud exercise rehabilitation initiated after ICU discharge on primary outcomes of functional exercise capacity and health-related\ud quality of life. We sought randomized controlled trials, quasi-randomized controlled trials, and controlled clinical trials compar-\ud ing an exercise intervention commenced after ICU discharge vs. any other intervention or a control or\ud ‘\ud usual care\ud ’\ud programme\ud in adult survivors of critical illness. Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval Sys-\ud tem Online (MEDLINE), Excerpta Medica Database, and Cumulative Index to Nursing and Allied Health Literature databases\ud were searched up to February 2015. Dual, independent screening of results, data extraction, and quality appraisal were per-\ud formed. We included six trials involving 483 patients. Overall quality of evidence for both outcomes was very low. All studies\ud evaluated functional exercise capacity, with three reporting positive effects in favour of the intervention. Only two studies\ud evaluated health-related quality of life and neither reported differences between intervention and control groups. Meta-\ud analyses of data were precluded due to variation in study design, types of interventions, and selection and reporting of out-\ud come measurements. We were unable to determine an overall effect on functional exercise capacity or health-related quality\ud of life of interventions initiated after ICU discharge for survivors of critical illness. Findings from ongoing studies are awaited.\ud Future studies need to address methodological aspects of study design and conduct to enhance rigour, quality, and synthesis

Researching the lived experiences of cancer patients with malignant fungating wounds

Background: Researching the experiences of terminally ill patients with disfiguring wounds is likely to be a challenge anywhere, and this investigation came face-to-face with different attitudes on the part of both patients and nurses and doctors in England (the South-East) and Italy (Tuscany). Aim: To highlight the complexity of researching sensitive subjects and the difficulties encountered from the perspective of the researcher(s). Methods: Fourteen patients were interviewed. In England access was relatively straightforward, with nurses linked to the hospice doing most of the recruitment. Access was more difficult in Italy, with some doctors expressing opposition. Discussion: How ethical is it to treat dying patients as subjects for research? How does research of this kind vary from one culture to another? Conclusions: Interviewees can find it therapeutic to talk about their experiences to a sympathetic listener—although the listening does pose a considerable strain on the researcher

Anarchy in the UK('s most famous fortress): comradeship and cupidity in Gibraltar and neighbouring Spain, 1890-1902

This article is the first to investigate the growth of anarchist ideology and tactics in Gibraltar and the surrounding Spanish region, the Campo de Gibraltar, in the period 1890-1902. We draw upon hitherto unused material from both The National Archives in London and the Gibraltar Government Archives. By doing so, we demonstrate that during this period Gibraltarian and Spanish workers came together, not only to defend and advance their interests by direct action, such as strikes and attacks on employers, but also to advance educational and social causes too. Indeed, by 1898-9 the appeal of this movement was so strong that an attempt by the British Social Democratic Federation to establish a more constitutionalist approach to industrial relations failed. By 1902, the power of anarchist movements and tactics concerned employers in Gibraltar so greatly that they engineered a lock-out – styled a general strike by local workers – and successfully smashed the organising power of the local movement. Meanwhile, on the Spanish side of the frontier a massacre engineered by the local Spanish authorities resulted in the deaths of a number of activists and a hiatus in the movement that would last until the Great War of 1914-18