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Expert physiological and pharmacological care by anaesthetists is required in all stroke endovascular thrombectomy cases. RCTs show clinical benefits in recanalisation rates and functional recovery after endovascular thrombectomy with general anaesthesia compared with sedation. Many stroke centres will require wholesale reorganisation of stroke pathways to ensure anaesthesia services are available for all cases. Anaesthetists have an integral role in improving clinical outcomes in large vessel occlusion stroke. [ABSTRACT FROM AUTHOR]

Risk calculators and prediction models are available to assist clinicians and patients with peri-operative decision making to optimise outcomes. In a vascular surgical setting, the majority of these models is based on open AAA repair outcomes, and in general their clinical use is limited. The objective of this study was to develop and validate a simple and accurate vascular surgical risk prediction model. A national administrative database was accessed to collect information on all adult patients undergoing vascular surgery between 1 July 2011 and 30 June 2016 in New Zealand. The primary outcomes were mortality at 30 days, one year, and two years. Previously established covariables including American Society of Anaesthesiologists (ASA) physical status score, sex, surgical urgency, cancer status and ethnicity were tested, and other covariables such as smoking status, presence of renal failure, diabetes, anatomical site of operation, structure operated, and type of procedures (open or endovascular) were explored. LASSO regression was used to select variables for inclusion in the model. A total of 21 597 cases formed the final risk prediction models, with covariables including ASA score, gender, surgical urgency, cancer status, presence of renal failure, diabetes, anatomical site, structure operated, and endovascular procedure. The area under the receiver operating curve (AUROC) for 30 day, one year, and two year mortality using L-min model was 0.869, 0.833, and 0.824, respectively, demonstrating very good discrimination. Calibration with the validation dataset was also excellent, with slopes of 0.971, 1.129, and 1.011, respectively, and McFadden's pseudo-R2 statistics of 0.250, 0.227, and 0.227, respectively. A simple and accurate multivariable risk calculator for vascular surgical patients was developed and validated using the New Zealand national dataset, with excellent discrimination and calibration for 30 day, one year, and two year mortality. [ABSTRACT FROM AUTHOR]

Abstract: Comparisons of model behaviors are an efficient way of understanding the differences amongst various models and thus providing guidance to model users for selecting suitable models for their own purposes. This study focuses on a comparison of the most commonly used fire spread algorithms used in scenario fire regime models. This paper provides an overview of fire regime modeling and describes a simulation model, Ecological Disturbance Model, as a simulation shell for such a comparison using the Fort A La Corne forest area in central Saskatchewan, Canada, as the study area. Simulation results suggested that for a fire scenario modeling approach, various fire spread algorithms such as DISPATCH, percolation, and cellular automata (CA) may not result in significant differences between user-defined and simulated fire frequencies; however, significant differences in simulated forest dynamics could result when using different fire spread algorithms. The simulation results from DISPATCH and CA are more similar than those from the percolation algorithm; however, the latter appeared to be a better representative of observed fire spread processes due to its underlying assumption of fire spread mechanisms. Simulation results also suggested that the fire spread algorithms that replicate four or eight direction fire spread in percolation and CA will not make a significant difference in simulated fire regimes or forest dynamics. It is thus recommend that using simulation shells as a tool to take alternative assumptions or models into account to narrow down the uncertainty parameters and avoid the paradoxes in the modeling of natural resource management. [Copyright &y& Elsevier]

Abstract: Evaluation and implementation of the forest policy of emulating natural fire patterns in harvest planning require a good understanding of both natural and human influenced fire regimes. The SEM-LAND model (Spatially Explicit Model for LANdscape Dynamics) was employed to simulate both natural and current fire regimes in central Saskatchewan. The model used the indexes and relationships summarized in the Canadian Forest Fire Weather Index System and the Canadian Forest Fire Behavior Prediction System to simulate the interactions among fire events, landscape structures, topography, and weather conditions. The impact of fire suppression operations on fire spread simulated the following three stages: fire ignition, initial attack, and fire escape. Our results suggest that fire suppression could lead to longer fire cycles, smaller mean fire sizes, more fire numbers per year, and increased mean forest age (time-since-fire). The relationship between mean forest age and annual area burned was estimated from the results of this model experiment. This relationship can be used to determine the ideal fire management target of annual allowable area burned from expected future forest conditions. We conclude that the SEM-LAND model was capable of simulating fire regimes in Saskatchewan. [Copyright &y& Elsevier]

Postoperative delirium (POD) is the most common serious postoperative complication in older adults. It has uncertain aetiology, limited preventative strategies, and poor long-term outcomes. This updated systematic review and meta-analysis aimed to estimate the effect of processed electroencephalography (pEEG)-guided general anaesthesia during surgery on POD incidence. We performed a systematic review and meta-analysis by searching OVID MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) electronic databases. Studies of adult patients having general anaesthesia for any surgery where pEEG was used and POD was an outcome measure were included. Full-text reports of RCTs published from database inception until August 28, 2021, were included. Trials were excluded if sedation rather than general anaesthesia was administered, or the setting was intensive care. The primary outcome was POD assessed by validated tools. The study was prospectively registered with PROSPERO. Nine studies, which included 4648 eligible subjects, were identified. The incidence of POD in the pEEG-guided general anaesthesia or lighter pEEG target group was 19.0% (440/2310) compared with 23.3% (545/2338) in the usual care or deeper pEEG target group (pooled odds ratio=0.78; 95% confidence interval, 0.60–1.00; P =0.054). Significant heterogeneity was detected (I 2=53%). Our primary analysis demonstrated a highly sensitive result with a pooled analysis of trials in which the intervention group adhered to manufacturer's recommended guidelines, showing reduced incidence of POD with pEEG guidance. High clinical heterogeneity limits inferences from this and any future meta-analyses. CRD42020199404 (PROSPERO). [ABSTRACT FROM AUTHOR]

Labour and delivery units often become contested workplaces with tensions between obstetrics, nursing, and midwifery practices. These tensions can impede communication and raise concerns about provider wellness and patient safety. Remedying such tensions requires inquiry into the drivers of recurrent problems in interprofessional practice. We engaged in change-oriented inquiry informed by institutional ethnography (IE) within an academic hospital in Toronto, Canada (2017–2019). Clinicians identified critical incident analysis reports used to document recurrent issues for transfers of care (TOC) and consultations between professionals. We then mapped the everyday/everynight work of midwives, nurses, and obstetricians by observing (75 h) and interviewing them (n = 15). We also traced work processes to local (forms and hospital policies) and external (national policies and evidence-based guidelines) texts. Our IE-informed analysis made visible the otherwise hidden links between the everyday work of practitioners and its social organization. Three intrapartum work processes involving midwives consulting with obstetricians were identified: induction of labour with TOC back to midwife once labour was "active", consultation without TOC, and TOC for various indications. Three points of disjuncture complicated these processes: (i) a local "3 consult rule", linked to medico-legal governance and remuneration structures; (ii) subjective interpretations of the "4-cm dilation rule", a policy meant to standardize practice; and (iii) regulations delaying the timing of consultations. The Electronic Fetal Monitoring system served as a powerful text, materializing issues of professional scope and autonomy for midwives, and medicolegal accountability for obstetricians. Our study extends extant evidence that medicine-driven governance of midwifery practices can perpetuate interprofessional challenges. While practitioners spoke of the three disjunctures as 'laws', most also viewed them as ostensibly modifiable. Interprofessional tensions may be addressed by considering how social organization, materialized in texts detailing medico-legal liability and remuneration, can constrain possible practices through regulatory protocols, local ruling policies, and cultural expectations (e.g., documentation practices). • Medicine-driven governance of midwifery practices can perpetuate challenges. • Electronic Fetal Monitoring acts as a text that materializes professional conflicts. • Intersections of health and law underlie the observed social organization of work. • Making disjunctures explicit can stimulate collaborative change. [ABSTRACT FROM AUTHOR]

A computational fluid dynamics (CFD) tool, CFX-TASCflow, with a drag force sub-model for woodchip particles was used to explore the optimization of woodchip co-firing of a Canadian utility boiler, after it was first validated by comparing the model results with field operation data when firing Colombia coal. The CFD model predicted both a small increase in NO emissions and a significant increase in unburned carbon in fly ash for the originally proposed co-firing configuration, with 85% of the unburned carbon originating from the woodchips. Improvement strategies were examined, including intensifying the swirl inside the furnace to improve oxygen availability for woodchip combustion, lowering the woodchip injection level to increase residence time, and reducing woodchip particle size to shorten burnout time. The model results revealed the importance of intensified swirl on the burnout of large woodchip particles and the sensitivity of NO emissions to the air distribution in the combustion zone. Also, the model predicted an increase in large unburned woodchip particles falling into the bottom hopper when lowering woodchip injection level, although there was an overall improvement in predicted woodchip burnout. An improvement in woodchip burnout was also observed with reduced woodchip particle size. Based on these results, a co-firing strategy is suggested that is predicted to give reasonable burnout and NOx emissions at a minimum retrofitting cost. [ABSTRACT FROM AUTHOR]

A single subanaesthetic dose of ketamine rapidly alleviates the symptoms of major depressive disorder (MDD). However, few studies have investigated the acute effects of ketamine on the BOLD pharmacological magnetic resonance imaging (phMRI) response and EEG spectra. In a randomised, double-blind, active placebo-controlled crossover trial, resting-state simultaneous EEG/fMRI was collected during infusion of ketamine or active placebo (remifentanil) in 30 participants with MDD. Montgomery-Asberg depression rating scale scores showed a significant antidepressant effect of ketamine compared to placebo (69% response rate). phMRI analyses showed BOLD signal increases in the anterior cingulate and medial prefrontal cortices and sensitivity of the decrease in subgenual anterior cingulate cortex (sgACC) BOLD signal to noise correction. EEG spectral analysis showed increased theta, high beta, low and high gamma power, and decreased delta, alpha, and low beta power with differing time-courses. Low beta and high gamma power time courses explained significant variance in the BOLD signal. Interestingly, the variance explained by high gamma power was significantly associated with non-response to ketamine, but significant associations were not found for other neurophysiological markers when noise correction was implemented. The results suggest that the decrease in sgACC BOLD signal is potentially noise and unrelated to ketamine's antidepressant effect, highlighting the importance of noise correction and multiple temporal regressors for phMRI analyses. The lack of effects significantly associated with antidepressant response suggests the phMRI methodology employed was unable to detect such effects, the effect sizes are relatively small, or that other processes, e.g. neural plasticity, underlie ketamine's antidepressant effect. • Assessment of ketamine phMRI with physiological noise and motion correction. • Ketamine increases BOLD signal in the ACC and mPFC. • Multiple temporal time courses of ketamine-induced activity identified. • Decrease in sgACC BOLD signal is not associated with antidepressant response. • Effect in sgACC is potentially noise. [ABSTRACT FROM AUTHOR]