Kenneth Keown, MD, was a forward-thinking anesthesiologist who developed techniques to allow the safe practice of cardiac anesthesia and opened the door for the future development of more complex intracardiac surgical procedures. His early successful protocols for cardiac anesthesiology and his wide-reaching education of others on these methods earned him the designation of "the grand old man of anesthesia for inside-the-heart surgery" at a young age. His contributions also extended to groundbreaking research in hypothermia, lidocaine uses as an antiarrhythmic, and advocacy for anesthesiology as a specialty.
View Article and Find Full Text PDFBackground: The intimal hyperplasia (IH) and vascular remodelling that follows endovascular injury, for instance after post-angioplasty re-stenosis, results in downstream ischaemia and progressive end organ damage. Interferon gamma (IFNγ) is known to play a critical role in this process. In mouse models we have previously shown that fibrocytes expressing tissue factor (TF) are recruited early to the site of injury.
View Article and Find Full Text PDFBackground & Aims: Continuous risk-stratification of candidates and urgency-based prioritization have been utilized for liver transplantation (LT) in patients with non-hepatocellular carcinoma (HCC) in the United States. Instead, for patients with HCC, a dichotomous criterion with exception points is still used. This study evaluated the utility of the hazard associated with LT for HCC (HALT-HCC), an oncological continuous risk score, to stratify waitlist dropout and post-LT outcomes.
View Article and Find Full Text PDFThe obesity epidemic has significant implications for all aspects of healthcare. The physiological changes of obesity affect every area of perioperative medicine. In this article, we discuss several anesthetic concerns regarding obesity.
View Article and Find Full Text PDFPseudosound caused by turbulent pressure fluctuations in fluid flow past a hydrophone, referred to as flow noise, can mask propagating sounds of interest. Flow shields can mitigate flow noise by reducing non-acoustic pressure fluctuations sensed by a hydrophone. We evaluate the performance of three hydrophone flow shields (two nylon fabrics and an oil-filled enclosure) in a tidal channel with peak current speed of 1.
View Article and Find Full Text PDFHuman induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have the potential to remuscularize infarcted hearts but their arrhythmogenicity remains an obstacle to safe transplantation. Myofibroblasts are the predominant cell-type in the infarcted myocardium but their impact on transplanted hiPSC-CMs remains poorly defined. Here, we investigate the effect of myofibroblasts on hiPSC-CMs electrophysiology and Ca handling using optical mapping of advanced human cell coculture systems mimicking cell-cell interaction modalities.
View Article and Find Full Text PDFVascular disease forms the basis of most cardiovascular diseases (CVDs), which remain the primary cause of mortality and morbidity worldwide. Efficacious surgical and pharmacological interventions to prevent and treat vascular disease are urgently needed. In part, the shortage of translational models limits the understanding of the cellular and molecular processes involved in vascular disease.
View Article and Find Full Text PDFIn recent years, 911 call volumes have increased, and emergency medical services (EMS) are routinely stretched beyond capacity. To better match resources with patient needs, some EMS systems have integrated clinician roles into the emergency medical communications centre (MCC). Our objective was to explore the nature and scope of clinical roles in emergency MCCs.
View Article and Find Full Text PDFIntroduction: Discharging older adults with frailty home from the emergency department (ED) poses unique challenges due to multiple interacting physical and social problems. Paramedic supportive discharge services help overcome these challenges by adding in-home assessment and/or interventions. Our objective is to describe existing paramedic programmes designed to support discharge from the ED or hospital to avoid unnecessary hospital admissions.
View Article and Find Full Text PDFFemoral artery (FA) endothelial function is a promising biomarker of lower extremity vascular health for peripheral artery disease (PAD) prevention and treatment; however, the impact of age on FA endothelial function has not been reported in healthy adults. Therefore, we evaluated the reproducibility and acceptability of flow-mediated dilation (FMD) in the FA and brachial artery (BA) (n = 20) and performed cross-sectional FA- and BA-FMD measurements in healthy non-smokers aged 22−76 years (n = 50). FMD protocols demonstrated similar good reproducibility.
View Article and Find Full Text PDFTone mapping functions are applied to images to compress the dynamic range of an image, to make image details more conspicuous, and most importantly, to produce a pleasing reproduction. Contrast Limited Histogram Equalization () is one of the simplest and most widely deployed tone mapping algorithms. works by iteratively refining an input histogram (to meet certain conditions) until convergence, then the cumulative histogram of the result is used to define the tone map that is used to enhance the image.
View Article and Find Full Text PDFObjectives: In many emergency medical services (EMS) systems, a direct medical oversight physician is available to paramedics for mandatory and/or elective consultations. At the time of this study, a clinical support desk (CSD) was being implemented within the medical communications center of a provincial EMS system in addition to the physician resource. The CSD was initially staffed with a registered nurse or an advanced care paramedic.
View Article and Find Full Text PDFBackground: Abdominal wall hernia (AWH) affects mental health and mental health questions are frequently included within Patient-Reported Outcome Measures (PROMS) for this patient population. However, these questions have not been informed by the subjective lived experiences of mental health in AWH patients. This study is the first to qualitatively examine how AWH affects patients' mental health.
View Article and Find Full Text PDFBackground: Routine chemical venous thromboembolism (VTE) prophylaxis for liver surgery remains controversial, and often delayed post-operatively due to perceived bleeding risk. This study asked whether patients undergoing hepatectomy for colorectal metastases (CRM) were at risk from VTE pre-operatively, and the impact of hepatectomy on that risk.
Methods: Single-centre prospective observational cohort study of patients undergoing open hepatectomy for CRM, comparing pre-, peri- and post-operative haemostatic variables.
Background: Tissue factor (TF) generates proteases that can signal through PAR-1 and PAR-2. We have previously demonstrated PAR-1 signalling primes innate myeloid cells to be exquisitely sensitive to interferon-gamma (IFNγ). In this work we explored how TF mediated PAR-2 signalling modulated responsiveness to IFNγ and investigated the interplay between PAR-1/-2 signalling on macrophages.
View Article and Find Full Text PDF: diabetes and age are major risk factors for the development of lower extremity peripheral artery disease (PAD). Cocoa flavanol (CF) consumption is associated with lower risk for PAD and improves brachial artery (BA) endothelial function. : to assess if femoral artery (FA) endothelial function and dermal microcirculation are impaired in individuals with type 2 diabetes mellitus (T2DM) and evaluate the acute effect of CF consumption on FA endothelial function.
View Article and Find Full Text PDFIntroduction Advanced airway management by paramedics is potentially life-saving, but carries a significant risk to patient safety and can be associated with poor clinical outcome if performed incorrectly. Previously, our team had found that an intensive education intervention demonstrated an improvement in paramedic performance on a written exam and increased confidence in airway skills. This study measured intubation success and the number of attempts per patient before and after intensive paramedic airway management education intervention.
View Article and Find Full Text PDFRoutine interventions such as balloon angioplasty, result in vascular activation and remodeling, often requiring re-intervention. models and small animal experiments have enabled the discovery of important mechanisms involved in this process, however the clinical translation is often underwhelming. There is a critical need for an model representative of the human vascular physiology and encompassing the complexity of the vascular wall and the physical forces regulating its function.
View Article and Find Full Text PDFAngiogenesis, the formation of new capillaries from existing ones, is a fundamental process in regenerative medicine and tissue engineering. While it is known to be affected by circadian rhythms , its peripheral regulation within the vasculature and the role it performs in regulating the interplay between vascular cells have not yet been investigated. Peripheral clocks within the vasculature have been described in the endothelium and in smooth muscle cells.
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