Numerical program for analysis of three-dimensional supersonic exhaust flow fields (CHAR 3D)

Choice of reference plane orientation depends on specific nozzle geometry, with different configurations requiring different reference plane systems. In addition, for given configuration several reference systems may be used in different regions of flow field, so each system is locally aligned with flow

Hypoxia after stroke: a review of experimental and clinical evidence

Background Hypoxia is a common occurrence following stroke and associated with poor clinical and functional outcomes. Normal oxygen physiology is a finely controlled mechanism from the oxygenation of haemoglobin in the pulmonary capillaries to its dissociation and delivery in the tissues. In no organ is this process more important than the brain, which has a number of vascular adaptions to be able to cope with a certain threshold of hypoxia, beyond which further disruption of oxygen delivery potentially leads to devastating consequences. Hypoxia following stroke is common and is often attributed to pneumonia, aspiration and respiratory muscle dysfunction, with sleep apnoea syndromes, pulmonary embolism and cardiac failure being less common but important treatable causes. As well as treating the underlying cause, oxygen therapy is a vital element to correcting hypoxia, but excessive use can itself cause molecular and clinical harm. As cerebral vascular occlusion completely obliterates oxygen delivery to its target tissue, the use of supplemental oxygen, even when not hypoxic, would seem a reasonable solution to try and correct this deficit, but to date randomised clinical trials have not shown benefit. Conclusion Whilst evidence for the use of supplemental oxygen therapy is currently lacking, it is vital to rapidly identify and treat all causes of hypoxia in the acute stroke patient, as a failure to will lead to poorer clinical outcomes. The full results of a large randomised trial looking at the use of supplemental oxygen therapy are currently pending

Management of Acute Stroke in the Older Person.

The majority of people who suffer a stroke are older adults. The last two decades have brought major progress in the diagnosis and management of stroke, which has led to significant reductions in mortality, long-term disability, and the need for institutional care. However, acute, interventional and preventative treatments have mostly been trialled in younger age groups. In this article we will provide an overview of the evidence for acute stroke treatments in relation to age, discuss special considerations in the older person, and contemplate patient choice, quality of life, and end-of-life-decisions

The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4

Determinants and outcomes of stroke following percutaneous coronary intervention by indication

Background and Purpose—Stroke after percutaneous coronary intervention (PCI) is a serious complication, but its determinants and outcomes after PCI in different clinical settings are poorly documented. Methods—The British Cardiovascular Intervention Society (BCIS) database was used to study 560 439 patients who underwent PCI in England and Wales between 2006 and 2013. We examined procedural-type specific determinants of ischemic and hemorrhagic stroke and the likelihood of subsequent 30-day mortality and in-hospital major adverse cardiovascular events (a composite of in-hospital mortality, myocardial infarction or reinfarction, and repeat revascularization). Results—A total of 705 stroke cases were recorded (80% ischemic). Stroke after an elective PCI or PCI for acute coronary syndrome indications was associated with a higher risk of adverse outcomes compared with those without stroke; 30-day mortality and major adverse cardiovascular events outcomes in fully adjusted model were odds ratios 37.90 (21.43–67.05) and 21.05 (13.25–33.44) for elective and 5.00 (3.96–6.31) and 6.25 (5.03–7.77) for acute coronary syndrome, respectively. Comparison of odds of these outcomes between these 2 settings showed no differences; corresponding odds ratios were 1.24 (0.64–2.43) and 0.63 (0.35–1.15), respectively. Conclusions—Hemorrhagic and ischemic stroke complications are uncommon, but serious complications can occur after PCI and are independently associated with worse mortality and major adverse cardiovascular events outcomes in both the elective and acute coronary syndrome setting irrespective of stroke type. Our study provides a better understanding of the risk factors and prognosis of stroke after PCI by procedure type, allowing physicians to provide more informed advice around stroke risk after PCI and counsel patients and their families around outcomes if such neurological complications occur

Routine low-dose continuous or nocturnal oxygen for people with acute stroke: three-arm Stroke Oxygen Supplementation RCT.

BACKGROUND: Stroke is a major cause of death and disability worldwide. Hypoxia is common after stroke and is associated with worse outcomes. Oxygen supplementation could prevent hypoxia and secondary brain damage. OBJECTIVES: (1) To assess whether or not routine low-dose oxygen supplementation in patients with acute stroke improves outcome compared with no oxygen; and (2) to assess whether or not oxygen given at night only, when oxygen saturation is most likely to be low, is more effective than continuous supplementation. DESIGN: Multicentre, prospective, randomised, open, blinded-end point trial. SETTING: Secondary care hospitals with acute stroke wards. PARTICIPANTS: Adult stroke patients within 24 hours of hospital admission and 48 hours of stroke onset, without definite indications for or contraindications to oxygen or a life-threatening condition other than stroke. INTERVENTIONS: Allocated by web-based minimised randomisation to: (1) continuous oxygen: oxygen via nasal cannula continuously (day and night) for 72 hours after randomisation at a flow rate of 3 l/minute if baseline oxygen saturation was ≤ 93% or 2 l/minute if > 93%; (2) nocturnal oxygen: oxygen via nasal cannula overnight (21:00-07:00) for three consecutive nights. The flow rate was the same as the continuous oxygen group; and (3) control: no routine oxygen supplementation unless required for reasons other than stroke. MAIN OUTCOME MEASURES: Primary outcome: disability assessed by the modified Rankin Scale (mRS) at 3 months by postal questionnaire (participant aware, assessor blinded). Secondary outcomes at 7 days: neurological improvement, National Institutes of Health Stroke Scale (NIHSS), mortality, and the highest and lowest oxygen saturations within the first 72 hours. Secondary outcomes at 3, 6, and 12 months: mortality, independence, current living arrangements, Barthel Index, quality of life (European Quality of Life-5 Dimensions, three levels) and Nottingham Extended Activities of Daily Living scale by postal questionnaire. RESULTS: In total, 8003 patients were recruited between 24 April 2008 and 17 June 2013 from 136 hospitals in the UK [continuous,n = 2668; nocturnal,n = 2667; control,n = 2668; mean age 72 years (standard deviation 13 years); 4398 (55%) males]. All prognostic factors and baseline characteristics were well matched across the groups. Eighty-two per cent had ischaemic strokes. At baseline the median Glasgow Coma Scale score was 15 (interquartile range 15-15) and the mean and median NIHSS scores were 7 and 5 (range 0-34), respectively. The mean oxygen saturation at randomisation was 96.6% in the continuous and nocturnal oxygen groups and 96.7% in the control group. Primary outcome: oxygen supplementation did not reduce disability in either the continuous or the nocturnal oxygen groups. The unadjusted odds ratio for a better outcome (lower mRS) was 0.97 [95% confidence interval (CI) 0.89 to 1.05;p = 0.5] for the combined oxygen groups (both continuous and nocturnal together) (n = 5152) versus the control (n = 2567) and 1.03 (95% CI 0.93 to 1.13;p = 0.6) for continuous versus nocturnal oxygen. Secondary outcomes: oxygen supplementation significantly increased oxygen saturation, but did not affect any of the other secondary outcomes. LIMITATIONS: Severely hypoxic patients were not included. CONCLUSIONS: Routine low-dose oxygen supplementation in stroke patients who are not severely hypoxic is safe, but does not improve outcome after stroke. FUTURE WORK: To investigate the causes of hypoxia and develop methods of prevention. TRIAL REGISTRATION: Current Controlled Trials ISRCTN52416964 and European Union Drug Regulating Authorities Clinical Trials (EudraCT) number 2006-003479-11. FUNDING DETAILS: This project was funded by the National Institute for Health Research (NIHR) Research for Patient Benefit and Health Technology Assessment programmes and will be published in full inHealth Technology Assessment; Vol. 22, No. 14. See the NIHR Journals Library website for further project information

Shared Bacterial and Viral Respiratory Agents in Bighorn Sheep (Ovis canadensis), Domestic Sheep (Ovis aries), and Goats (Capra hircus) in Montana

Transmission of infectious agents from livestock reservoirs has been hypothesized to cause respiratory disease outbreaks in bighorn sheep (Ovis canadensis), and land management policies intended to limit this transmission have proven controversial. This cross-sectional study compares the infectious agents present in multiple populations of bighorn sheep near to and distant from their interface with domestic sheep (O. aries) and domestic goat (Capra hircus) and provides critical baseline information needed for interpretations of cross-species transmission risks. Bighorn sheep and livestock shared exposure to Pasteurellaceae, viral, and endoparasite agents. In contrast, although the impact is uncertain, Mycoplasma sp. was isolated from livestock but not bighorn sheep. These results may be the result of historic cross-species transmission of agents that has resulted in a mosaic of endemic and exotic agents. Future work using longitudinal and multiple population comparisons is needed to rigorously establish the risk of outbreaks from cross-species transmission of infectious agents

Mechanical thrombectomy: can it be safely delivered out of hours in the UK?

BACKGROUND: Mechanical thrombectomy was approved by NICE as a treatment for stroke in 2016. However, most of the evidence is from studies conducted during working hours. Only few centres in the UK perform thrombectomies out-of-hours. The Royal Stoke University Hospital (RSUH) has offered thrombectomies over 24 h (24/7) since 2010. The aim of this service review is to compare the outcomes for patients treated in regular working hours to those treated outside normal working hours within this unit. METHODS: This retrospective service analysis includes all patients treated with mechanical thrombectomy at RSUH since the start of the service in January 2010 to June 2019. Data on key demographics, timings, procedural complications, and long-term outcomes including death and disability at 90 days were collected. In-hours was defined as the time between 8:00-17:00 h, Monday to Friday; out-of-hours was defined as any time outside this period. RESULTS: In total, 516 mechanical thrombectomies were performed in this time period; data were available on 501 of these. Successful recanalization (TICI 2b/3) was achieved in 86% of patients. By 90 days 96 (19%) had died and 234 (47%) were functionally independent (modified Rankin Scale score ≤ 2). 211 (42%) of the procedures were performed in-hours and 290 (58%) out-of-hours. Door-to-CT and door-to-groin times were significantly longer out-of-hours than in-hours, but thrombectomy duration was significantly shorter. There were no significant differences in complications and short- and long-term outcomes. CONCLUSION: Mechanical thrombectomy was delivered safely and effectively 24/7 in this UK hospital, with no difference in clinical outcomes