Theoretical models are presented of the effects of space, facilities and group size on the behaviour of chickens at high stocking densities, with relevance for all animals. The appropriateness of each model is supported by published data, although such data are scant for some important variables. Freedom of movement is analysed by taking the area of a hen as 475 cm2 and finding the number of free bird spaces left at different space allowances. This provides support for current recommendations of a maximum of seven laying hens per m2 on deep litter, but suggests that a maximum for broilers of 34 kg/m2 unacceptably restricts freedom of movement. In cages, freedom of movement increases with space allowance per hen, and, for a given space allowance, with cage and group size. Nesting behaviour is analysed for synchrony, which decreases with group size. Perching and feeding are often synchronous and the space needed for these is determined by body width. Recommendations are derived for hens in furnished cages. The main part of the cage should be as large as possible; an absolute minimum of 600 cm2 per bird is suggested, but 675 cm2 per bird is probably the minimum practical. Perch and feeder space should be provided at 14 cm or more per bird, with a possible derogation for light hybrids to 12 cm. The number of nest spaces needed varies with the number of birds, with nest spaces being 300 cm2 each. These recommendations sum to a minimum of 800 cm2 per bird for groups of eight or more, 850 cm2 for groups of four to seven, and 900 cm2 for groups of three or fewer, plus litter area. Crowding is primarily caused by limited space allowance, but for a given space allowance it is worse in small enclosures and groups.

Flagellar dyneins are the molecular motors responsible for producing the propagating bending motions of cilia and flagella. They are located within a densely packed and highly organised super-macromolecular cytoskeletal structure known as the axoneme. Using the mesoscale simulation technique Fluctuating Finite Element Analysis (FFEA), which represents proteins as viscoelastic continuum objects subject to explicit thermal noise, we have quantified the constraints on the range of molecular conformations that can be explored by dynein-c within the crowded architecture of the axoneme. We subsequently assess the influence of crowding on the 3D exploration of microtubule-binding sites, and specifically on the axial step length. Our calculations combine experimental information on the shape, flexibility and environment of dynein-c from three distinct sources; negative stain electron microscopy, cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET). Our FFEA simulations show that the super-macromolecular organisation of multiple protein complexes into higher-order structures can have a significant influence on the effective flexibility of the individual molecular components, and may, therefore, play an important role in the physical mechanisms underlying their biological function.

Introduction: Emergency Department (ED) crowding is an intensifying crisis. While input, throughput, and output factors all contribute to crowding, throughput factors are the most dependent on ED staff and process. Diagnostic testing is a fundamental ED process that has not been systematically evaluated. We present a systematic review of interventions designed to reduce ED length of stay (LOS) by optimizing laboratory or imaging turnaround time, or by introducing point-of-care testing (POCT). Methods: We conducted systematic database searches in Medline, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials without filters or language restrictions, of all interventions on diagnostic technology that affected ED throughput (PROSPERO:CRD42019125651). Studies were screened by two independent reviewers. Study quality was assessed using the Cochrane ROB-2 tools for randomized controlled trials (RCTs), and the National Heart, Lung, and Blood Institute tool for all other study designs. Results: 18 studies met inclusion criteria (Cohen's kappa = 0.69). Study results were not pooled due to high statistical heterogeneity as assessed by chi-squared and I-squared statistics. 12 POCT intervention studies reported LOS changes ranging from -114 to + 8 minutes (-26.8% to + 3.8%), although three were non-significant findings. Four studies that initiated POCT or lab-ordering at triage reported LOS reductions ranging from 22 to 174 minutes, but only one of these, at 29 minutes (16%), was statistically significant. One study of improved laboratory troponin processing reported a LOS reduction of 43 minutes (12.3%). Another, which allowed triage nurses to order ankle x-rays using the Ottawa ankle rules, reported a non-significant LOS reduction of 28 minutes for patients with ankle injuries. LOS improvements reflected the population of patients who underwent the testing modality, rather than overall ED LOS. Seven studies had low risk of bias, 11 studies had some risk of bias, and no studies had high risk of bias (Cohen's kappa = 0.58). Conclusion: Eleven of 18 diagnostic testing studies reported LOS reductions. POCT was the most common intervention type, and usually reduced EDLOS within relevant patient subsets, while triage-initiated testing generally did not. To aid widespread adoption, future research should focus on interrupted time series or RCT designs, and more comprehensive descriptions of the contextual factors affecting implementation of these interventions.

Introduction: Emergency Department (ED) crowding is the primary threat to emergency care quality. Input and outflow factors are important factors, but EDs must optimize throughput efficiency by improving internal processes from triage to disposition, and triage is the first throughput phase. Triage throughput interventions exclude strategies that direct patients away from the ED (these modify input rather than throughput). Previous research has described physicians in triage, team triage, telemedical triage, and nurse practitioner (NP) or physician assistant (PA) led triage, but their impact has never been systematically evaluated. Methods: We conducted systematic database searches in Medline, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials without the use of filters or language restrictions of all triage interventions that effected ED throughput (PROSPERO:CRD42019125651). Two independent reviewers screened studies. Study quality was assessed using the Cochrane Risk of Bias tool (version 2) for randomized controlled trials, and the National Heart, Lung, and Blood Institute quality assessment tool for other designs. Results: 18 studies met inclusion criteria (Cohen's k = 0.69). Study results were not pooled due to high statistical heterogeneity as assessed by chi-squared and I-squared statistics. Studies were grouped into physician led, NP or PA led, and team triage interventions. Six physician in triage interventions reported LOS changes between -82 and + 18 minutes. Five NP/PA led triage interventions resulted in LOS changes of -106 to + 19 minutes. Five team triage interventions reported LOS reductions of 4 to 34 minutes. One telemedicine triage study reported a non-significant 8 minute increase in LOS. Six physician at triage interventions yielded significant LWBS rate improvement (relative risk {RR}= 0.29-0.82). Team triage interventions generated LWBS rate changes ranging from meaningful improvement (RR = 0.58) to substantial deterioration (RR = 1.68). Five studies have low risk of bias, 11 studies have some risk of bias, and 2 studies have high risk of bias (Cohen's kappa = 0.58). Conclusion: Fourteen of 18 triage interventions reduced EDLOS and/or LWBS rate. Physician, NP and PA led triage were the most effective triage interventions. To aid widespread adoption, future research should focus on interrupted time series or RCT designs, and more comprehensive descriptions of the contextual factors affecting implementation of these interventions.

Introduction: Emergency Department (ED) crowding is an international health system issue that is worsening. Further, ED crowding and “hallway medicine” has been identified as one of the most significant healthcare challenges currently facing Canadians. One contributor is preventable transfers from long-term care facilities (LTCFs) to Emergency Departments (EDs). In Canada, there were 63,752 LTCF patient transfers to the ED in 2014, with 24% (15,202) of them due to potentially preventable conditions. Each preventable transfer exposes patients to transport and hospital-related complications, and costs the healthcare system thousands of dollars. There have been many proposed and studied interventions aimed at alleviating the issue, but few attempts to assess and evaluate different interventions across institutions in a systematic manner. Methods: A scoping review of the literature using three electronic databases was conducted. A scoping review methodology was used due to the range of interventions and the heterogeneity in study design and outcome. Inclusion criteria included: studies on interventions designed to reduce transfers from LTCFs, studies that reported key outcomes such as number of ED transfers, and studies with a control or comparison group. Articles were screened by two independent reviewers (Cohen's k = 0.68), and study quality was assessed using the National Heart, Lung, Blood Institute quality assessment tools. Results: Findings were organized into five intervention types (telemedicine, outreach teams, interdisciplinary teams, integrated approaches, and other), and both a tabular and narrative synthesis was completed. Eleven studies had a good quality assessment rating, 13 studies had a fair rating, and two studies had a poor rating. Twenty out of the 26 studies reported statistically significant reductions in ED transfer rate, ranging from 10-70%. Interdisciplinary healthcare teams staffed within LTCFs were the most effective interventions. Conclusion: There are several promising interventions that have successfully reduced the number of preventable transfers from LTCFs to EDs, in a variety of health system settings. Further analysis of the relative resource requirements of each intervention, and practices that can enable successful implementation are needed to inform healthcare policy and administrative decision making. Widespread implementation of these interventions has the potential to considerably reduce ED crowding.

Introduction: Crowding is associated with poor patient outcomes in emergency departments (ED). Measures of crowding are often complex and resource-intensive to score and use in real-time. We evaluated single easily obtained variables to establish the presence of crowding compared to more complex crowding scores. Methods: Serial observations of patient flow were recorded in a tertiary Canadian ED. Single variables were evaluated including total number of patients in the ED (census), in beds, in the waiting room, in the treatment area waiting to be assessed, and total inpatient admissions. These were compared with Crowding scores (NEDOCS, EDWIN, ICMED, three regional hospital modifications of NEDOCS) as predictors of crowding. Predictive validity was compared to the reference standard of physician perception of crowding, using receiver operator curve analysis. Results: 144 of 169 potential events were recorded over 2 weeks. Crowding was present in 63.9% of the events. ED census (total number of patients in the ED) was strongly correlated with crowding (AUC = 0.82 with 95% CI = 0.76 - 0.89) and its performance was similar to that of NEDOCS (AUC = 0.80 with 95% CI = 0.76 - 0.90) and a more complex local modification of NEDOCS, the S-SAT (AUC = 0.83, 95% CI = 0.74 - 0.89). Conclusion: The single indicator, ED census was as predictive for the presence of crowding as more complex crowding scores. A two-stage approach to crowding intervention is proposed that first identifies crowding with a real-time ED census statistic followed by investigation of precipitating and modifiable factors. Real time signalling may permit more standardized and effective approaches to manage ED flow.

Introduction: Delay of hospital admission until completion of assessment by consultants is a major contributor to emergency department (ED) crowding. We measured emergency physicians’ (EP) ability to predict patient admission, and estimated potential time saved if EPs could request a bed at the time of consultation. Methods: This is a prospective cohort study in a tertiary care center over 4 months using a convenience sample of ED patients requiring consultation. We consecutively recruited patients from purposefully selected shifts to balance day of the week and time of day. We excluded patients younger than 18 years or those likely to be admitted (traumas, strokes, STEMI codes, and CTAS1). We asked EPs to predict patient disposition (admission or alternate disposition) just before consultation. We defined admission as: admission to any service, admission within 48 hours of ED discharge, patients held overnight without bed request, or if bed request was delayed by 12 or more hours, and alternate disposition as any other disposition. We present EP prediction test characteristics using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with 95% confidence intervals (CI). The potential time saved was calculated from consultation to bed request for admitted patients. Results: Characteristics for the 454 included patients were: mean age 60.1 years, 48.4% male, 46.9% evening presentation, 69.4% were admitted (most commonly by Internal Medicine 26.9%), and median consult to bed request time was 3.5 hours (interquartile range 2.0 – 5.3 hours). Overall EP prediction sensitivity, specificity, PPV and NPV were 90.5% (95%CI 86.7-93.5), 84.2% (95%CI 77.0-89.8), 92.8% (95%CI 89.8-95.0) and 79.6% (95%CI 73.4-84.7) respectively. In other words, EPs correctly predicted 92.8% of patient admissions. The PPV for Internal Medicine was 95.7% (95%CI 89.7-98.4) and ranged from 78.9% (95%CI 53.9-93.0) for Psychiatry to 100% (95%CI 78.1-100) for Family Medicine. A total of 1113.5 hours of ED stretcher time (37.1 hours per shift) could have been saved if EPs initiated a concurrent bed request at time of consultation. Conclusion: EPs correctly predicted 92.8% of patient admissions across a broad field of disciplines. We estimate 1113.5 hours of ED stretcher time could have been saved over the study period if EPs triggered an inpatient bed request at the time of consultation, rather than waiting for the consultants’ disposition decision.

Introduction: Access block (AB) is the most important indicator of Emergency Department (ED) crowding, but the impact of AB on consultation time has not been described. Our objectives were to determine if ED AB affects inpatient service consultation time, and operational and patient outcomes. Methods: We conducted a health records review of all ED patients referred and admitted at a university-affiliated tertiary care hospital over 60-days. A computational algorithm determined hourly ED AB at the time of consultation request, and observational cohorts were determined based on ED AB high (>35% ED bed capacity occupied by admitted patients) or low (<35%). The outcomes included total consultation time (TCT), ED physician initial assessment (PIA) time, ED length of stay (LOS), transfer time to inpatient bed (TTB), hospital LOS, return to ED (RTED) within 30 days, and 30-day mortality. Results: We included 2,871 patients (48% male; M = 63 years, IQR 45–78), and the low AB cohort were higher acuity (N = 1,692; 50.4% CTAS 1–2) than the high AB cohort (N = 1,179; 47.1% CTAS 1–2). Median TCT was not significantly different (low = 209min, high = 212min; p = 0.09), and there was no difference in consults completed within the 3-hour institutional time target (low = 41.1%, high = 40.9%; p = 0.89). Median ED PIA time was not significantly different (low = 66min, high = 68min; p = 0.08), however, patients seen within the funding-associated provincial ED PIA time target was significantly less during high AB (high = 82.2%, low = 89.2%; p < 0.001). Median ED LOS was significantly longer during high AB (high = 12.1hr, low = 11.1hr; p = 0.009), but median hospital LOS was not different (high = 109.5hr, low = 112.4hr; p = 0.44). Median TTB was significantly longer during high AB (high = 8.0hr, low = 5.9hr; p = 0.0004). There was no difference in RTED visits (high = 12.4%, low = 10.6%; p = 0.15) or 30-day mortality (high = 8.4%, low = 9.2%; p = 0.51). Conclusion: In conclusion, consultation time is not affected by AB. However, boarding admitted patients in the ED impairs our ability to meet funding-associated performance metrics. Reducing boarding time should be an ED and hospital-wide priority, as it negatively impacts funding and delays patient care.

Human stampedes are a major cause of mortality in mass gatherings, but they have received limited scientific attention. While the number of publications has increased, there is no recent review of new study results. This study compiles and reviews available literature on stampedes, their prevention, preparedness, and response.

A search for peer-reviewed and grey literature in PubMed (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA), Google Scholar (Google Inc.; Mountain View, California USA), Web of Science (Thomson Reuters; New York, New York USA), the World Health Organization Library Database (WHOLIS; World Health Organization; Geneva, Switzerland), and ReliefWeb (UN Office for the Coordination of Humanitarian Affairs; Geneva, Switzerland) was conducted, and papers were selected according to pre-defined eligibility criteria. Included items were read and results were compiled and summarized. A total of 64 publications were included, of which, 34 were published between 2013-2016. The most studied events were Germany’s Love Parade stampede in 2010 (Duisburg, Germany; n = 6) and the United Kingdom (UK) Hillsborough Stadium stampede in 1989 (Sheffield, England; n = 4). Conflicting definitions of human stampedes were found. The common belief that they result from an irrational and panicking crowd has progressively been replaced by studies suggesting that successive systemic failures are main underlying causes. There is a lack of systematic reporting, making news reports often the only source available. Prevention measures are mainly related to crowd management and venue design, but their effectiveness has not been studied. Drills are recommended in the preparedness phase to improve coordination and communication. Delay in decisions, poor triage, or loss of medical records are common problems in the response, which may worsen the outcome.

Stampedes are complex phenomenon that remain incompletely understood, hampering formulation of evidence-based strategies for their prevention and management. Documentation comes mostly from high-profile events and findings are difficult to extrapolate to other settings. More research from different disciplines is warranted to address these gaps in order to prevent and mitigate future events. A start would be to decide on a common definition of stampedes.

Moitinho de AlmeidaM, von SchreebJ. Human Stampedes: An Updated Review of Current Literature. Prehosp Disaster Med. 2019;34(1):82–88.