Search

Ludii is a general game system being developed as part of the ERC-funded Digital Ludeme Project (DLP). While its primary aim is to model, play, and analyse the full range of traditional strategy games, Ludii also has the potential to support a wide range of AI research topics and competitions. This paper describes some of the future competitions and challenges that we intend to run using the Ludii system, highlighting some of its most important aspects that can potentially lead to many algorithm improvements and new avenues of research. We compare and contrast our proposed competition motivations, goals and frameworks against those of existing general game playing competitions, addressing the strengths and weaknesses of each platform., Accepted at the IEEE Conference on Games (CoG) 2019

The Digital Ludeme Project (DLP) aims to reconstruct and analyse over 1000 traditional strategy games using modern techniques. One of the key aspects of this project is the development of Ludii, a general game system that will be able to model and play the complete range of games required by this project. Such an undertaking will create a wide range of possibilities for new AI challenges. In this paper we describe many of the features of Ludii that can be used. This includes designing and modifying games using the Ludii game description language, creating agents capable of playing these games, and several advantages the system has over prior general game software., Accepted at the IEEE Conference on Games (CoG) 2019 (Demo paper)

In recent years, state-of-the-art game-playing agents often involve policies that are trained in self-playing processes where Monte Carlo tree search (MCTS) algorithms and trained policies iteratively improve each other. The strongest results have been obtained when policies are trained to mimic the search behaviour of MCTS by minimising a cross-entropy loss. Because MCTS, by design, includes an element of exploration, policies trained in this manner are also likely to exhibit a similar extent of exploration. In this paper, we are interested in learning policies for a project with future goals including the extraction of interpretable strategies, rather than state-of-the-art game-playing performance. For these goals, we argue that such an extent of exploration is undesirable, and we propose a novel objective function for training policies that are not exploratory. We derive a policy gradient expression for maximising this objective function, which can be estimated using MCTS value estimates, rather than MCTS visit counts. We empirically evaluate various properties of resulting policies, in a variety of board games., Comment: Accepted at the IEEE Conference on Games (CoG) 2019

This paper proposes using a linear function approximator, rather than a deep neural network (DNN), to bias a Monte Carlo tree search (MCTS) player for general games. This is unlikely to match the potential raw playing strength of DNNs, but has advantages in terms of generality, interpretability and resources (time and hardware) required for training. Features describing local patterns are used as inputs. The features are formulated in such a way that they are easily interpretable and applicable to a wide range of general games, and might encode simple local strategies. We gradually create new features during the same self-play training process used to learn feature weights. We evaluate the playing strength of an MCTS player biased by learnt features against a standard upper confidence bounds for trees (UCT) player in multiple different board games, and demonstrate significantly improved playing strength in the majority of them after a small number of self-play training games., Comment: Accepted at IEEE CEC 2019, Special Session on Games. Copyright of final version held by IEEE

ObjectivesInadequate acute pain management can reduce the quality of life, cause unnecessary suffering and can often lead to the development of chronic pain. Using group-based trajectory modelling, we previously identified six distinct pain intensity trajectories for the first 14-day postemergency department (ED) discharge; two linear ones with moderate or severe pain during follow-up (~40% of the patients) and four cubic polynomial order trajectories with mild or no pain at the end of the 14 days (low final pain trajectories). We assessed if previously described acute pain intensity trajectories over 14 days after ED discharge are predictive of chronic pain 3 months later.DesignProspective cohort study.SettingTertiary care trauma centre academic hospital.ParticipantsThis study included 18 years and older ED patients who consulted for acute (≤2 weeks) pain conditions that were discharged with an opioid prescription. Patients completed a 14-day diary in which they listed their daily pain intensity (0–10 numeric rating scale).OutcomesThree months after ED visit, participants were questioned by phone about their current pain intensity (0–10 numeric rating scale). Chronic pain was defined as patients with current pain intensity ≥4 at 3 months.ResultsA total of 305 participants remained in the study at 3 months, 49% were women and a mean age of 55±15 years. Twelve per cent (11.9; 95% CI 8.2 to 15.4) of patients had chronic pain at the 3-month follow-up. Controlling for age, sex and pain condition, patients with moderate or severe pain trajectories and those with only a severe pain trajectory were respectively 5.1 (95% CI 2.2 to 11.8) and 8.2 (95% CI 3.4 to 20.0) times more likely to develop chronic pain 3 months later compared with patients in the low final pain trajectories.ConclusionSpecific acute pain trajectories following an ED visit are closely related to the development of chronic pain 3 months later.Trial registration numberNCT02799004; Results.

Background Studies evaluating long-term prescription opioid use are retrospective and based on filled opioid prescriptions from governmental databases. These studies cannot evaluate if opioids were really consumed and are unable to differentiate if they were used for a new pain or chronic pain or were misused. The aim of this study was to assess opioid use rate and reasons for consuming 3 months after being discharged from the emergency department (ED) with an opioid prescription. Methods This is a prospective cohort study conducted in the ED of a tertiary care urban center with a convenience sample of discharged patients ≥ 18 years who consulted for an acute pain condition (≤2 weeks). Three months post-ED visit, participants were interviewed by phone on their past 2-week opioid consumption and their reasons for consuming: a) for pain related to the initial ED visit, b) for a new unrelated pain, or c) for another reason. Results Of the 524 participants questioned at 3 months (mean ± SD age = 51 ± 16 years, 47% women), 47 patients (9%, 95% confidence interval [CI] = 7%-12%) reported consuming opioids in the previous 2 weeks. Among those, 34 (72%) reported using opioids for their initial pain, nine (19%) for a new unrelated pain and four (9%) for another reason (0.8%, 95% CI = 0.3%-2.0%, of the whole cohort). Patients who used opioids during the 2 weeks after the ED visit were 3.8 (95% CI = 1.2-12.7) times more likely to consume opioids at 3 months. Conclusion Opioid use at the 3-month follow-up in ED patients discharged with an opioid prescription for an acute pain condition is not necessarily associated with opioid misuse; 91% of those patients consumed opioids to treat pain. Of the whole cohort, less than 1% reported using opioids for reasons other than pain. The rate of long-term opioid use reported by prescription-filling database studies should not be viewed as a proxy for incidence of opioid misuse.

Introduction: Les patients ayant un retour de circulation spontanée (RCS) durant la phase préhospitalière de leur réanimation suite à un arrêt cardiaque extrahospitalier (ACEH) ont un meilleur taux de survie que ceux n'en ayant pas. La durée des efforts de réanimation avant l'initiation d'un transport ne varie généralement pas en fonction du rythme initial observé. Cette étude vise à comparer la durée des manœuvres de réanimation nécessaire afin de générer la majorité des RCS préhospitaliers et des RCS préhospitaliers menant à une survie en fonction du rythme initial. Methods: La présente étude de cohorte a été réalisée à partir des bases de données collectées de la Corporation d'Urgences-santé dans la région de Montréal entre 2010 et 2015. Les patients avec un ACEH d'origine médicale ont été inclus. Les patients dont l'ACEH était témoigné par les paramédics ont été exclus, tout comme ceux dont le rythme initial était inconnu. Nous avons comparé entre les groupes (rythme défibrillable [RD], activité électrique sans pouls [AESP] et asystolie) les taux de RCS préhospitalier et le temps nécessaires pour obtenir une majorité des RCS préhospitaliers et des RCS préhospitaliers menant à une survie. Results: Un total de 6002 patients (3851 hommes et 2151 femmes) d'un âge moyen de 52 ans ( ±10) ont été inclus dans l’étude, parmi lesquels 563 (9%) ont survécu jusqu’à leur congé hospitalier et 1310 (22%) ont obtenu un RCS préhospitalier. Un total de 1545 (26%) patients avaient un RD, 1654 (28%) une AESP et 2803 (47%) une asystolie. Les patients avec un RD ont obtenu plus fréquemment un RCS préhospitalier et un RCS préhospitalier menant à une survie que les patients avec une AESP qui eux même avaient un meilleur pronostic que ceux avec une asystolie initial (777 patients [55%] vs 385 [23%] vs 148 [5%], p < 0,001; 431 [28%] vs 85 [5%] vs 7 [0,2%], p < 0,001, respectivement). Les RCS survenaient également plus rapidement lorsque le rythme initial était un RD (13 minutes [ ±12] vs 18 [ ±13] vs 25 [ ±12], p < 0,001). Cependant, une période de réanimation plus longue était nécessaire afin d'obtenir 95% des RCS préhospitaliers menant à une survie pour les patients avec un RD (26 minutes vs 21 minutes vs 21 minutes). Conclusion: Les patients avec un rythme initial défibrillable suite à leur ACEH sont à meilleur pronostic. Il serait envisageable de transporter plus rapidement vers l'hôpital les patients avec une AESP ou une asystolie que ceux avec un rythme défibrillable si l'arrêt des manœuvres n'est pas envisagé.

Introduction: Les patients dont l'arrêt cardiaque extrahospitalier (ACEH) n'a pas été témoigné sont généralement exclus des protocoles de réanimation par circulation extracorporelle puisque le délai avant l'initiation de leur réanimation est inconnu. Il a été proposé que la présence d'un rythme initial défibrillable (RD) est fortement suggestif une très courte période avant l'initiation des manœuvres de réanimation. La présente étude vise à décrire l'association entre la durée avant l'initiation de la réanimation et la présence d'un RD chez des patients souffrant d'un ACEH. Methods: Cette étude de cohorte a été réalisée à partir des bases de données collectées de la Corporation d'Urgences-santé dans la région de Montréal entre 2010 et 2015. Les patients dont l'arrêt était témoigné, mais dont les témoins n'ont pas entamé de manœuvres de réanimation, ont été inclus. Nous avons également inclus les patients dont l'arrêt était témoigné par les paramédics comme groupe contrôle (durée avant l'initiation de la réanimation = 0 minute). Les patients avec un retour de circulation spontanée avant l'arrivée des services préhospitaliers ont été exclus, tout comme ceux dont le rythme initial était inconnu. Nous avons décrit l’évolution de la proportion de chacun des rythmes et construit une régression logistique multivariée ajustant pour les variables sociodémographiques et cliniques pertinentes. Results: Un total de 1751 patients (1173 hommes et 578 femmes) d'un âge moyen de 69 ans (±16) ont été inclus dans l'analyse principale, parmi lesquels 603 (34%) avaient un RD. Un total de 663 autres patients ont vu leur ACEH témoigné directement par les paramédics. Un plus court délai avant l'initiation des manœuvres est associé à la présence d'un RD (rapport de cotes ajusté = 0,97 [intervalle de confiance à 95% 0,94-0,99], p = 0,016). Cependant, cette relation n'est pas linéaire et la proportion de RD ne diminue pas avant notablement jusqu’à ce que 15 minutes s’écoulent avant le début de la réanimation (0 min = 35%, 1-5 min = 37%, 5-10 min = 35%, 10-15 min = 34%, +de 15 min = 16%). Conclusion: Bien que la proportion de patients avec un RD diminue lorsque le délai augmente avant l'initiation des manœuvres, cette relation ne semble pas linéaire. La baisse principale de la proportion de patients avec RD semble se produire suite à la quinzième minute de délai avant le début de la réanimation.

Introduction: The objective of the study was to evaluate the acute pain intensity evolution in ED discharged patients using Group-based trajectory modeling (GBTM). This method identified patient groups with similar profiles of change over time without assuming the existence of a particular pattern or number of groups. Methods: This was a prospective cohort study of ED patients aged ≥18 years with an acute pain condition (≤ 2 weeks) and discharged with an opioid prescription. Patients completed a 14-day diary assessing daily pain intensity level (0-10 numeric rating scale) and pain medication use. Results: Among the 372 included patients, six distinct post-ED pain intensity trajectories were identified: two started with severe levels of pain, one remained with severe pain intensity (12.6% of the sample) and the other ended with moderate pain intensity level (26.3%). Two other trajectories had severe initial pain, one decreased to mild pain (21.7%) and the other to no-pain (13.8%). Another trajectory had moderate initial pain which decreased to a mild level (15.9%) and the last one started with mild pain intensity and had no pain at the end of the 14-day (9.7%). The pain trajectory patterns were significantly associated with age, type of painful conditions, pain intensity at ED discharge, and with opioid consumption. Conclusion: Acute pain resolution following an ED visit seems to progress through six different trajectory patterns that are more informative than simple linear models and could be useful to adapt acute pain management in future research.

ObjectivesThis study aimed to ascertain the association between self-reported pain intensity and vital signs in both emergency department (ED) patients and a subgroup of patients with diagnosed conditions known to produce significant pain.MethodsWe performed a retrospective analysis of real-time, archived data from an electronic medical record system at an urban teaching hospital and regional community hospital. We included consecutive ED patients ≥16 years old who had a self-reported pain intensity ≥1 as measured during triage, from March 2005 to December 2012. The primary outcome was vital signs for self-reported pain intensity levels (mild, moderate, severe) on an 11-point verbal numerical scale. Changes in pain intensity levels were also compared to variations in vital signs. Both analyses were repeated on a subgroup of patients with diagnosed conditions recognized to produce significant pain: fracture, dislocation, or renal colic.ResultsWe included 153,567 patients (mean age of 48.4±19.3 years; 55.5% women) triaged with pain (median intensity of 7/10±3). Of these, 8.9% of patients had diagnosed conditions recognized to produce significant pain. From the total sample, the difference between mild and severe pain categories was 2.7 beats/minutes (95% CI: 2.4−3.0) for heart rate and 0.13 mm Hg (95% CI: -0.26−0.52) for systolic blood pressure. These differences generated small effect sizes and were not clinically significant. Results were similar for patients who experienced changes in pain categories and for those conditions recognized to produce significant pain.ConclusionHealth care professionals cannot use vital signs to estimate or substantiate self-reported pain intensity levels or changes over time.

Opioids are an important avenue for the treatment of pain among individuals presenting to the emergency department. Unfortunately, opioid administration can lead to several complications including nausea/vomiting, oxygen desaturation and hypotension. The authors aimed to determine the incidence of such adverse events among 31,742 patients who were treated with opioids in the emergency department of a single large tertiary care hospital in Montreal, Quebec., BACKGROUND: The efficacy of opioids for acute pain relief in the emergency department (ED) is well recognized, but treatment with opioids is associated with adverse events ranging from minor discomforts to life-threatening events. OBJECTIVE: To assess the impact of age, sex and route of administration on the incidence of adverse events due to opioid administration in the ED. METHODS: Real-time archived data were analyzed retrospectively in a tertiary care urban hospital. All consecutive patients (≥16 years of age) who were assigned to an ED bed and received an opioid between March 2008 and December 2012 were included. Adverse events were defined as: nausea/vomiting (minor); systolic blood pressure (SBP) subcutaneous > oral). CONCLUSIONS: The incidence of adverse events associated with opioid administration in the ED is generally low and is associated with age, sex and route of administration.

Symmetry detection is a promising approach for reducing the search tree of games. In General Game Playing (GGP), where any game is compactly represented by a set of rules in the Game Description Language (GDL), the state-of-the-art methods for symmetry detection rely on a rule graph associated with the GDL description of the game. Though such rule-based symmetry detection methods can be applied to various tree search algorithms, they cover only a limited number of symmetries which are apparent in the GDL description. In this paper, we develop an alternative approach to symmetry detection in stochastic games that exploits constraint programming techniques. The minimax optimization problem in a GDL game is cast as a stochastic constraint satisfaction problem (SCSP), which can be viewed as a sequence of one-stage SCSPs. Minimax symmetries are inferred according to themicrostructure complement of these one-stage constraint networks. Based on a theoretical analysis of this approach, we experimentally show on various games that the recent stochastic constraint solver MAC-UCB, coupled with constraint-based symmetry detection, significantly outperforms the standard Monte Carlo Tree Search algorithms, coupled with rule-based symmetry detection. This constraint-driven approach is also validated by the excellent results obtained by our player during the last GGP competition.

Introduction: Parmi les patients souffrant d'un arrêt cardiaque extrahospitalier (ACEH), ceux ayant un retour de circulation spontanée (RCS) durant la phase préhospitalière de leur réanimation ont un meilleur taux de survie. Il est plausible que les patients ayant un RCS plus précocement durant leur réanimation préhospitalière aient de meilleur taux de survie que les patients ayant un RCS plus tardif. Cette étude visait à décrire l'association entre la survie et la durée de la réanimation par les paramédics avant le RCS préhospitalier. Methods: La présente étude de cohorte a été réalisée à partir des bases de données collectées de la Corporation d'Urgences-santé dans la région de Montréal entre 2010 et 2015. Tous les patients adultes avec un RCS préhospitalier suite à un ACEH d'origine médicale ont été inclus. Les patients ayant eu un arrêt devant les paramédics ont été exclus, tout comme ceux avec un RCS avant l'arrivée des services préhospitaliers. L'association entre la survie et le temps de réanimation avant le RCS a été évaluée à l'aide d'une régression logistique multivariée ajustant pour les variables sociodémographiques et cliniques pertinentes (âge, sexe, rythme initial, heure de l'appel initial, arrêt témoigné, manœuvre par témoin, présence de premiers répondants ou de paramédics de soins avancés, délai avant l'arrivée des intervenants préhospitaliers). Results: Un total de 1194 patients (818 hommes et 376 femmes) d'un âge moyen de 64 ans ( ±17) ont été inclus dans l’étude, parmi lesquels 433 (36%) ont survécu jusqu’à leur congé hospitalier. Le délai moyen avant leur RCS était de 17 minutes ( ±12). Nous avons observé une association indépendante entre la survie au congé hospitalier et le délai avant le RCS préhospitalier (rapport de cotes ajusté = 0,91 [intervalle de confiance à 95% 0,89-0,92], p < 0,001). Plus de 50% des survivants avaient obtenu un RCS moins de 9 minutes après l'initiation des manœuvres de réanimation par les intervenants préhospitaliers, et plus de 95% avant 26 minutes. Aucun (0%) des 17 patients ayant eu un RCS plus de 56 minutes après l'initiation de la réanimation préhospitalière n'a survécu. Conclusion: Un RCS précoce semble être un facteur de bon pronostic parmi les patients souffrant d'un ACEH. La majorité des patients avec un RCS préhospitalier allant survivre à leur hospitalisation ont obtenus leur RCS dans les 9 minutes suivant l'initiation des manœuvres de réanimation.

Introduction: Opioid side effects are common when treating chronic pain. However, the rate of opioid side effects for acute pain has rarely been examined, particularly in the post emergency department (ED) setting. The objective of this study was to evaluate the short-term incidence of opioid induced side effects (constipation, nausea/vomiting, dizziness, and drowsiness) in patients discharged from the ED with an opioid prescription. Methods: This was a prospective cohort study of patients aged ≥18 years that visited the ED for an acute pain condition (≤ 2 weeks) and were discharged with an opioid prescription. Patients completed a 14-day diary assessing daily pain medication use and side effects. Results: Mean age of the 386 patients included was 55 ± 16 years; 50% were women. During the 2-week follow-up, 80% of patients consumed at least one dose of opioids. Among the patients who used opioids, 38% (95%CI: 33-48) reported constipation, 27% (95%CI:22-32) nausea/vomiting, 30% (95%CI:25-35) dizziness, 51% (95%CI:45-57) drowsiness, and 77% (95%CI:72-82) reported any side effects. Adjusting for age, sex, and pain condition, patients who used opioids were more likely to report any side effect (OR 7.5, 95%CI:4.3-13.3) and constipation (OR 7.5, 95%CI:3.1-17.9). A significant dose response effect was observed for constipation but not for the other side effects. Nausea/vomiting (OR 2.0, 95%CI:1.1-3.6) and dizziness (OR 1.9, 95%CI:1.1-3.4) were associated with oxycodone compared to morphine. Conclusion: Similar to chronic pain, opioid side effects are highly prevalent during short-term treatment for acute pain. Physicians should be aware and inform patients about those side effects.

Introduction: Studies suggest that acute pain evolution after an emergency department (ED) visit has been associated with the development of chronic pain. Using group-based trajectory modeling (GBTM), we aimed to evaluate if ED discharged patients with similar pain intensity profiles of change over 14 days are associated with chronic pain at 3 months. Methods: This is a prospective cohort study of patients aged 18 years or older who visited the ED for an acute pain condition (≤2 weeks) and were discharged with an opioid prescription. Patients completed a 14-day diary in which they listed their daily pain intensity level (0-10 numeric rating scale). Three months post-ED visit, participants were interviewed by phone to report their pain intensity related to the initial pain. Results: A total of 305 patients were retained at 3 months (mean age ± SD: 55 ± 15 years, 49% women). Using GBTM, six distinct pain intensity trajectories were identified during the first 14 days of the acute pain period; two linear one with moderate or severe pain during the follow-up (representing almost 40% of the patients) and four cubic polynomial order trajectories, with mild or no-pain at the end of the 14 days (low final pain). Twelve percent (11.9; ±95%CI: 8.2-15.4) of the patients had chronic pain at 3 months. Controlling for age, sex and types of pain condition, patients with trajectories of moderate or severe pain and those with only severe pain were 5.1 (95%CI: 2.2-11.8) and 8.2 (95%CI: 3.4-20.0) times more likely to develop chronic pain at 3 months, respectively, compared to the low final pain group. Conclusion: Trajectories could be useful to early identification of patients at risk of chronic pain.

Introduction: Different tools have been developed to complement medical training, and improve student learning. Although social media has been described as an innovative educational strategy, evidence for its use is scarce in emergency medicine (EM). The primary outcome of this study was to evaluate whether brief teaching points (tweets) sent to medical students (MS) via a Twitter feed, would yield better exam score at the end of an emergency medicine (EM) rotation. Methods: Participants included in this prospective cohort study were MS completing an EM rotation at our tertiary care academic center. The control group was recruited from December 2016 to November 2017 and the experimental group from November 2017 to November 2018. The MS in the experimental group were invited to follow a Twitter feed. A total of 32 EM-related tweets based on learning objectives were sent out throughout the 4 week rotation. At the end of the rotation, MS of both cohorts took an exam and completed a survey of assiduity and appreciation. Exam scores were compared using t-tests. Results: A total of 80 MS were recruited for the study, 38 in the experimental cohort. Average exam scores were similar in both cohorts (control = 63 ± 9% vs experimental = 64 ± 8% for a mean difference of -2% [95%CI -6 to 2], p = 0.37). Of the experimental group, only 7 (18%) of the participants reported viewing more than 50% of the tweets. There was no difference between mean exam scores of this sub-group and that of the control cohort (66 ± 10% for a mean difference of 4% [95%CI -4 to 11], p = 0.33). The majority (n = 20, 53%) of the MS in the experimental cohort did not read any tweets. When compared to the rest of the experimental cohort MS who reported viewing ≥50% of the tweets found the Twitter feed to be a useful educational tool. Indeed, on a 3 item Likert scale used to evaluate different aspects of appreciation, they found the Twitter feed to be beneficial to their rotation (86% vs 13%, p < 0.001) as well as helpful in patient management (71% vs 16%, p = 0.001). These same MS would have liked more tweets (100% vs 19%, p < 0.001) and would like to use Twitter in other rotations (100% vs 32%, p = 0.005). Conclusion: In this study, there was no difference in the exam scores between MS having access to regular EM-focused educational tweets in comparison to those who did not. Results also found a lower than expected assiduity of MS to the educational Twitter feed, although those who used it significantly found it useful.

Introduction: La réanimation par circulation extracorporelle (R-CEC) permet potentiellement d'améliorer la survie de patients souffrant d'un arrêt cardiaque extrahospitalier (ACEH) réfractaire aux traitements habituels. Cette technique, se pratiquant généralement en centre hospitalier (CH), doit être réalisée le plus précocement possible. Un transport vers le CH en temps opportun est donc nécessaire. Cette étude vise à décrire la durée nécessaire des manœuvres de réanimation préhospitalières afin d'optimiser le moment du départ vers le CH dans le but d'obtenir un maximum de retour de circulation spontanée (RCS) préhospitalier. Methods: La présente étude de cohorte a été réalisée à partir des bases de données collectées de la Corporation d'Urgences-santé dans la région de Montréal entre 2010 et 2015. Les patients éligibles à une R-CEC selon les critères locaux ont été inclus (Results: Un total de 236 patients (207 hommes et 29 femmes) d'un âge moyen de 52 ans (±10) ont été inclus dans l’étude, parmi lesquels 93 (39%) ont survécu jusqu’à leur congé hospitalier et 136 (58%) ont obtenu un RCS préhospitalier. Le délai moyen avant leur RCS était de 13 minutes (±10). Plus de 50% des survivants avaient eu un RCS moins de 8 minutes après l'initiation des manœuvres de réanimation par les intervenants préhospitaliers, et plus de 90% avant 24 minutes. Plus de 50% de tous les RCS survenaient dans les 10 premières minutes de réanimation et plus de 90% dans les 31 premières minutes. La courbe ROC montrait visuellement que le délai avant le RCS maximisant la sensibilité et la spécificité pour prédire la survie chez ces patients était à 22 minutes (Sensibilité = 90%, spécificité = 78%; aire sous la courbe = 0,89 [intervalle de confiance à 95% 0,84-0,93]). Conclusion: Le départ vers le CH pourrait être considéré pour ces patients entre 8 et 24 minutes après l'initiation des manœuvres. Une période de réanimation de 22 minutes semble être le meilleur compromis à cet égard.

Recent advances were made in the field of point-of-care ultrasound (POCUS). Thoracic and lung ultrasound have become a rapid and accurate method of diagnosis of hypoxic diseases. The purpose of this article is to review the recent literature on POCUS, emphasizing on its use in the operating room.Many international critical care societies published guidelines on the use of ultrasound in the installation of central venous access. More recently, evidenced-based guidelines on the use of POC lung ultrasound were published. Lung ultrasound has shown its superiority over conventional chest radiography in the diagnosis of many disorders of significant importance in anesthesiology, particularly the pneumothorax.POC thoracic and lung ultrasound is used in many critical medicine fields. The aim of this review is to describe the basic lung ultrasound technique and the knowledge required in order to diagnose and treat the hypoxic patient. Emphasis is on disorder such as pleural effusion, alveolar interstitial disease, as well as pneumothorax, which is of particular importance in the field of anesthesiology.

The challenge of General Game Playing (GGP) is to devise game playing programs that take as input the rules of any strategic game, described in the Game Description Language (GDL), and that effectively play without human intervention. The aim of this paper is to address the GGP challenge by casting GDL games (potentially with chance events) into the Stochastic Constraint Satisfaction Problem (SCSP). The stochastic constraint network of a game is decomposed into a sequence of µSCSPs (also know as one-stage SCSP), each associated with a game round. Winning strategies are searched by coupling the MAC (Maintaining Arc Consistency) algorithm, used to solve each µSCSP in turn, together with the UCB (Upper Confidence Bound) policy for approximating the values of those strategies obtained by the last µSCSP in the sequence. Extensive experiments conducted on various GDL games with different deliberation times per round, demonstrate that the MAC-UCB algorithm significantly outperforms the state-of-the-art UCT (Upper Confidence bounds for Trees) algorithm.

Introduction: A 2008 survey found that 1.9% of the entire US population was using prescription pain medication non-medically and that 56% obtained them from a friend or relatives. Diversion of pain medication may occur when a portion of the prescription is unused for pain relief after an ED visit. We hypothesized that at least 10 pills (~40%) of an opioid prescription 2 weeks after an ED visit, will not be consumed and become available for potential misuse. Objective: Determine the quantity of unused opioids pills for common acute pain diagnoses, 2 weeks after an ED visit for acute pain. Methods: Prospective observational cohort study of consecutive ED patients from a tertiary academic urban hospital with 60,000 ED visits annually. Inclusion criteria: aged ≥18 years, acute pain conditions present ≤2 weeks, pain intensity at triage of ≥4 (on a 0-10 numeric rating scale; NRS), and discharged with a new opioid prescription. ED physicians identified (24/7) eligible patients. They recorded the pain complaint/location, the final diagnosis, the quantity and type of prescribed pain medication. Discharged patients completed paper or electronic 14-day diary (REDCap database) to document their pain medication consumption. As a mitigation strategy, they were also contacted by phone at 2 weeks for the same information. A paired t-test was used to test the difference between the amounts of opioids prescribed and consumed. Results: 350 patients were recruited. Mean age 50 (SD ±16) and 54.2% were men. Painful diagnosis: fracture (18.2%), acute back pain (15.3%), renal colic (15.3%), Sprain (excluding back/neck pain) (6.9%), Contusion (6.4%), acute neck pain (5.8%), abdominal pain (4.9%), and other (27.2%). Opioids prescribed: oxycodone (47%), morphine (37%) and hydromorphone (16%). Means quantity of opioid pills prescribed: 24 (IC95%: 23-26). Filled opioid prescription: 92%. Means quantity of opioid pills consumed: 8 (IC95%: 7-9). Means quantity of unused opioids pills: 16. Opioid pills available for misuse in our cohort: 5,600 pills. Conclusion: After an ED visit for acute pain a significant portion of opioids prescribed is unused and available for misuse. A large pragmatic study should be done to confirm that an opioid prescription strategy based on our results will limit unused opioid pills while maintaining pain relief.

ObjectivesPrescription opioid diversion is a significant contributor to the opioid misuse epidemic. We examined the quantity of opioids consumed by emergency department (ED) discharged patients after treatment for an acute pain condition (musculoskeletal, fracture, renal colic, abdominal pain and other), and the percentage of unused opioids available for potential misuse.DesignProspective cohort study.SettingTertiary care trauma centre academic hospital.ParticipantsA convenience sample of patients ≥18 years who visited the ED for an acute pain condition (≤2 weeks) and were discharged with an opioid prescription. Patients completed a 14-day paper diary of daily pain medication use. To reduce lost to follow-up, participants also responded to standardised phone interview questions about their previous 14-day pain medication use.OutcomesQuantity of morphine 5 mg tablets (or equivalent) prescribed, consumed and unused during a 14-day follow-up. Quantity of opioids to adequately supply 80% of patients for 2 weeks and 95% of patients for the first 3 days was also calculated.ResultsResults for 627 patients were analysed (mean age ±SD: 51±16 years, 48% women). Patients consumed a median of seven tablets of morphine 5 mg (32% of the total prescribed opioids). The quantity of opioids to adequately supply 80% of patients for 2 weeks was 20 tablets of morphine 5 mg for musculoskeletal pain, 30 for fracture, 15 for renal colic or abdominal pain and 20 for other pain conditions. The quantity to adequately supply 95% of patients for the first 3 days was 15 tablets of morphine 5 mg.ConclusionsPatients discharged from the ED with an acute pain condition consumed a median of fewer than 10 tablets of morphine 5 mg (or equivalent). ED physicians should consider prescribing a smaller quantity of opioids and asking the pharmacist to dispense them in portions to minimise unused opioids.Trial registration numberNCT02799004; Results.

Introduction: Les patients souffrant dun arrêt cardiaque extra hospitalier (ACEH) sont fréquemment traités à laide de soins avancés en réanimation cardiovasculaire (SARC). Dans ce contexte, des bicarbonates de sodium sont parfois administrés à des patients en arrêt cardiaque réfractaire chez qui une acidose métabolique importante, une hyperkaliémie ou une intoxication est suspectée. Puisquil ny a que peu dévidences quant à cet usage, lobjectif de la présente étude est dévaluer lassociation entre le traitement à laide de bicarbonate de sodium (une dose ou plus) et le devenir (retour de circulation spontané et survie au congé) chez les patients souffrant dun ACEH. Methods: La présente étude de cohorte a été réalisée à partir des bases de données de la Corporation dUrgences-santé dans la région de Montréal entre 2010 et 2015. Les patients adultes ayant souffert dun ACEH dorigine médicale traités en préhospitalier par des paramédics de soins avancés prodiguant des SARC ont été inclus. Les associations dintérêt ont été évaluées initialement à laide de régressions logistiques univariées, puis à laide de régressions logistiques multivariées ajustant pour les variables sociodémographiques et cliniques pertinentes. Results: Un total de 1973 patients (1349 hommes et 683 femmes) dun âge moyen de 66 ans (±17) ont été inclus dans cette étude, parmi lesquels 77 (3,8%) ont reçu une dose de bicarbonate, 763 (37,5%) ont retrouvés un pouls en préhospitalier et 222 (10,9%) ont survécu jusquà leur congé de lhôpital. Sans ajustement, il y avait une association négative entre le traitement à laide de bicarbonates et le retour de circulation spontané (rapport de cotes [RC]=0,46 [intervalle de confiance {IC} 95% 0,27-0,79], p=0,005) et la survie au congé (RC=0,21 [IC 95% 0,05-0,86], p=0,030). Cependant, ces associations nétaient plus significatives suite à lajustement pour les autres covariables (RC ajusté=0,63 [IC 95% 0,34-1,18], p=0,15 et RC ajusté=1,69 [95% IC 0,29-10,01], p=0,56). Conclusion: Il ny a pas dassociation indépendante entre le traitement à laide de bicarbonates et le devenir chez les patients souffrant dun ACEH. Dans ce contexte, il serait adéquat de réaliser un essai clinique afin de trancher définitivement sur cette question.

Introduction: Patients suffering from out-of-hospital cardiac arrest (OHCA) with an initial shockable rhythm (ventricular tachycardia or ventricular fibrillation) have higher odds of survival than those suffering from non-shockable rhythm (asystole or pulseless electrical activity). Because of that prognostic significance, patients with an initial non-shockable rhythm are often not considered for advanced resuscitation therapies such as extracorporeal resuscitation. However, the prognostic significance of the conversion to a shockable rhythm from an initially non-shockable rhythm remains uncertain. This study aimed to determine the degree of association between the conversion (or not) of a non-shockable rhythm to a shockable rhythm and resuscitation outcomes in patients with OHCA. It was hypothesized that such a conversion would be associated with a higher survival to discharge. Methods: The present study used a registry of adult OHCA between 2010 and 2015 in Montreal, Canada. Adult patients with non-traumatic OHCA and an initial non-shockable rhythm were included. The primary outcome measure was survival to hospital discharge, and the secondary outcome measure was prehospital return of spontaneous circulation (ROSC). The associations of interest were evaluated with univariate logistic regressions and multivariate models controlling for demographic and clinical variables (e.g. age, gender, type of initial non-shockable rhythm, witnessed arrest, bystander cardiopulmonary resuscitation). Assuming a survival rate of 3% and 25% of the variability explained by the control variables, including more than 4580 patients would allow to detect an absolute difference of 4% in survival between both groups with a power of more than 90%. Results: A total of 4893 patients (2869 men and 2024 women) with a mean age of 70 years (standard deviation 17) were included, of whom 450 (9.2%) experienced a conversion to a shockable rhythm during the course of their prehospital resuscitation. Among all patients, 146 patients (3.0%) survived to discharge and 633 (12.9%) experienced prehospital ROSC. In the univariate models, there was no association between the conversion to a shockable rhythm and survival (odds ratio [OR] 1.14 [95% confidence interval {CI} 0.66-1.95]), but a significant assocation was observed with ROSC (OR 2.00 [95% CI 1.57-2.55], pConclusion: There is no clinically significant association between the conversion to a shockable rhythm and resuscitation outcomes in patients suffering from OHCA. The initial rhythm remains a much better outcome predictor than subsequent rhythms and should be preferred when evaluating the eligibility for advanced resuscitation procedures.

Introduction: Most studies evaluating prescription opioid dependence or misuse are retrospective and are based on prescription filling rates from pharmaceutical databases. These studies cannot evaluate if opioids are really consumed nor differentiate if used for a new pain, chronic pain, or for misuse/dependence. The aim of this study was to assess the opioid consumption in emergency department (ED) patients three months after discharge with an opioid prescription. Methods: This prospective cohort study was conducted in the ED of a tertiary care centre with a convenience sample of patients aged 18 years and older, recruited 24/7, who consulted and were discharged for an acute pain condition ( 2 weeks). We excluded patients who: did not speak French or English, were using opioid medication prior to their ED visit, with an ED stay > 48 hours, or suffering from cancer or chronic pain. Three months post-ED visit, participants were contacted by phone for a structured interview on their past two-week opioid use, their reasons for consuming them, and also answered the Rapid Opioid Dependence Screen (RODS) questionnaire. Results: In the 524 participants interviewed at three months (mean age ± SD: 51±16 years, 47% women), 44 (8.4%) patients consumed opioids in the previous two weeks. Among those, 72% consumed opioids for their initial pain, 19% for a new unrelated pain, and 9% for another reason. In this entire cohort, only five patients (1%) tested positive to opioid dependence from the RODS test. The low dependence incidence could be affected by a social desirability bias. Conclusion: This study suggests that opioid use at 3-month, for patients initially treated for acute pain, is associated with opioid dependency in 1% or possible misuse in only 9%. Additional prospective studies using multiple methods to measure opioids consumption, misuse, and dependence are needed.

ObjectivesWe sought to determine the incidence, nature, and predisposing factors of atrioventricular block (AVB) associated with closure of atrial septal defects (ASDs) using the Amplatzer septal occluder (ASO).BackgroundIn our institution, 162 patients underwent ASD closure using ASO between December 1997 and December 2001. This includes small children with large defects.MethodsElectrocardiographic tracings during ASO implantation and at follow-up visits were reviewed. Anatomic characteristics and device size were assessed as potential risk factors for AVB.ResultsTen patients (6.2%) presented with new-onset (n = 9) or aggravation of preexisting (n = 1) AVB. Atrioventricular block occurred during the procedure (n = 3) or was first noted one day to one week later (n = 7). Patients had first-degree (n = 4), second-degree Wenckebach (n = 4), or third-degree (n = 2) AVB, with no symptoms or hemodynamic compromise. First-degree AVB persisted in two patients at 12 and 33 months of follow-up, whereas most recovered normal AV conduction within one (n = 7) or six months (n = 1). A larger shunt (Qp/Qs ratio 2.8 ± 0.9 vs. 2.1 ± 0.8, p < 0.01) and device size (24 ± 5 vs. 19 ± 6 mm, p < 0.01) were the only determinant factors for AVB. A device size ≥19 mm was used in 90% (9 of 10) of patients who developed AVB, as compared with 49% of those without AVB (p < 0.02).ConclusionsClosure of ASDs using the large ASO can be associated with the development of AV block and mandate a closer follow-up. In our series, however, all AVBs resolved or improved spontaneously, with no recurrence at mid-term follow-up.

Introduction: Extracorporeal cardiopulmonary resuscitation (E-CPR) has been used successfully to increase survival in patients suffering from out-of-hospital cardiac arrest (OHCA). However, few OHCA patients can benefit from E-CPR since this procedure is only performed in dedicated centers. Prehospital triage systems have helped decrease mortality from other acute conditions, by directly transporting patients to dedicated centers, often bypassing primary care centers. Our study aimed to quantify the possible impact of a prehospital triage system on the proportion of E-CPR eligible patients transported to E-CPR centers. Methods: We used a registry of adult OHCA collected between 2010 and 2015 from the city of Montréal, Canada. Included patients were adults with non-traumatic witnessed OHCA refractory to 15 minutes of resuscitation. Using this cohort, we created 3 scenarios in which potential E-CPR candidates could be redirected to E-CPR centers. We used strict eligibility criteria in our first pair (e.g. age Results: A total of 3136 patients (2054 men and 982 women) with a mean age of 69 years (standard deviation 15) were included. In each simulation, prehospital redirection would have significantly increased the proportion of patients transported to an E-CPR center (pair 1: 1.3% vs 3.8%, pConclusion: In an urban setting, a prehospital triage system could triple the number of patients with refractory OHCA who would have an access to E-CPR. This implies that centers with E-CPR capability should prepare themselves accordingly for such a system to effectively improve survival following OHCA.

Introduction: Patients suffering from out-of-hospital cardiac arrest (OHCA) are frequently transported to the closest hospital after return of spontaneous circulation (ROSC). Percutaneous coronary intervention (PCI) is often indicated as a diagnostic and therapeutic procedure following OHCA. This study aimed to determine the association between the type of destination hospital (PCI-capable or not) and survival to discharge for patients with OHCA and prehospital ROSC. We hypothesized that being transported to a PCI-capable hospital would be associated with a higher survival to discharge. Methods: The present study used a registry of adult OHCA between 2010 and 2015 in Montréal, Canada. We included adult patients with non-traumatic OHCA and prehospital ROSC. The association of interest was evaluated with a multivariate logistic regression model to control for demographic and clinical variables (age, gender, time of day, initial rhythm, witnessed arrest, bystander CPR, presence of first responders or advanced care paramedics, prehospital supraglottic airway placement, delay before paramedics’ arrival). Assuming a survival rate of 40% and 75% of the variability explained by other factors included in the model, more than 1200 patients needed to be included to detect an absolute difference of 10% in survival between both groups with a power of more than 90%. Results: A total of 1691 patients (1140 men and 551 women) with a mean age of 64 years (standard deviation 17) were included, of which 1071 (63%) were transported to a PCI-capable hospital. Among all patients, 704 patients (42%) survived to hospital discharge. We observed a significant independent association between survival to discharge and being transported to a PCI-capable hospital (adjusted odds ratio [AOR] 1.46 [95% confidence interval 1.09-1.96]) after controlling for confounding variables. Having an initial shockable rhythm and presence of first responders also increased survival to discharge (AORs 3.67 [95% confidence interval 2.75-4.88] and 1.53 [95% confidence interval 1.12-2.09], respectively). Conclusion: Patients experiencing ROSC after OHCA could benefit from a direct transport to a PCI-capable hospital. This benefit might also be related to unmeasured interventions other than PCI these hospitals can provide (e.g. high-level intensive care or cardiovascular surgery).

The field of lung ultrasound (US) in critical care is in rapid expansion. Lung sliding (LS) identification has been used in emergency medicine (EM) to diagnose pneumothorax as well as to evaluate the adequacy of endotracheal intubation. Presence of the Lung Pulse artefact (back and forth pleural motion induced by the heartbeat) as well as the underlying heart may affect correct identification of LS in the left hemithorax, but this has never been studied. Our main objective was to evaluate the rate of correct identification (accuracy) of the presence or absence of LS in the right and left hemithorax.

The shock index (SI) is an easy-to-use clinical tool that rapidly identifies patients at risk of haemodynamic decompensation. Previous studies focused primarily on patients suffering from pneumonia, pulmonary embolism, ruptured ectopic pregnancy and traumatic haemorrhagic shock. Modified SIs have also been studied. Could the SI be accurate in patients suffering from gastrointestinal (GI) haemorrhage? The aim of this study was to compare the performance of the SI with various modified SIs and conventional vital signs in predicting 30-day mortality in a population of patients with a GI haemorrhage.

In our busy emergency departments the identification of patients at risk of rapid hemodynamic decompensation is crucial. The shock index (SI) (pulse/systolic blood pressure) is a non-invasive clinical sign associated with more complications if higher than 0.7. The effect of β-blockers (BB) and calcium channel blockers (CCB) on the SI has not yet been described. Most studies excluded these patients, owing to the medications' effect on the cardiac pulse. Considering that BB and CCB are commonly prescribed, we studied their effect on the SI's predictability on 30-day mortality in a urosepsis population.

Rapid confirmation of the adequacy of endotracheal intubation is critical in the field of emergency medicine (EM). Methods confirming endotracheal tube (ET) position should have accuracy near 100%. Studies confirming ET position using lung sliding (LS) identification were done by physicians with extensive ultrasound (US) training using sometimes lengthy examination. These conditions are not easily reproduced in the emergency department. Our primary objective was to compare the accuracy of EM physicians with different levels of academic and US training to correctly identify presence or absence of LS on random short sequences of lung US. Our secondary objective was to determine if results were better when participants had the choice to abstain themselves in uncertain cases.

Background Point-of-care ultrasound (POCUS) can be used to provide rapid answers to specific and potentially life-threatening clinical questions, and to improve the safety of procedures. The rate of POCUS access and use in Canada is unclear. The objective of this study was to examine access to POCUS and potential barriers/facilitators to its use among rural physicians in Quebec. Methods This descriptive cross-sectional study used an online survey. The 30-item questionnaire is an adapted and translated version of a questionnaire used in a prior survey conducted in rural Ontario, Canada. The questionnaire was pre-tested for clarity and relevance. The survey was sent to non-locum physicians working either full- or part-time in rural emergency departments (EDs) (n = 206). All EDs were located in rural and small towns and provided 24/7 medical coverage with acute care hospitalization beds. Results In total, 108 surveys were completed (participation rate = 52.4 %). Of the individuals who completed surveys, ninety-three percent were family physicians, and seven percent had Canadian College of Family Physicians – Emergency Medicine (CCFP-EM) certification. The median number of years of practice was seven. A bedside ultrasound device was available in 95 % of rural EDs; 75.9 % of physicians reported using POCUS on a regular basis. The most common indications for POCUS use were to rule out abdominal aortic aneurysm (70.4 %) and to evaluate presence of free fluid in trauma and intrauterine pregnancy (60 %). The most common reason (73 %) for not using POCUS was limited access to POCUS training programs. Over 40 % of POCUS users received training in POCUS during medical school or residency. Sixty-four percent received training from the Canadian Emergency Ultrasound Society, 13 % received training from the Canadian Association of Emergency Physicians, and 23 % were trained in another course. Finally, 95 % of respondents reported that POCUS skills are essential for rural ED practice. Conclusions POCUS use in rural EDs in the province of Quebec appears to be relatively widespread. Access to training programs is a barrier to greater use.

This systematic review done in March and updated in November 2014 has been conducted in accordance with the STARD, PRISMA and STROBE recommendations. Retrospective and prospective studies with a comparison group published in English were kept.