Background In 2016, based on recommendations of the American Association of Blood Banks (AABB), Choosing Wisely Canada released transfusion guidelines for patients with Iron Deficiency Anemia. The goal of the present study was to examine the number of transfusions given in Calgary emergency departments (EDs) before and after the release of these guidelines. Methods We analyzed 11,786 anemia encounters from January 2014 to December 2019. A transfusion was considered potentially avoidable if the patient's hemoglobin was > 70 g/L and if the patient was hemodynamically stable. We used time-series analyses to examine change in rate of total and potentially avoidable transfusions quarterly over the total and pre and post intervention periods. Results In total, 1409/11,786 (12.0%) of the encounters received transfusions; 80.0% (1127/1409) were indicated while 19.9% (281/1409) were potentially avoidable. In the pre-intervention period, the rate of potentially avoidable transfusions was 21.5% (133/618) and in the post-intervention period, the rate of potentially avoidable transfusions was 18.7% (148/791). The rate of potentially avoidable transfusions decreased quarterly at a rate of 0.3% which did not reach statistical significance (p = 0.06). Discussion Our data suggest that the number of potentially avoidable transfusions has not decreased since the release of Choosing Wisely Canada guidelines and local educational initiatives. This may be due to the fact that there is a pre-existing down trend in the number of transfusions provided. Keywords Knowledge translation • Clinical practice guidelines • Quality improvement RésuméContexte En 2016, sur la base des recommandations de l'AABB (Association américaine des banques de sang) Choisir avec soin Canada a publié des directives sur la pratique transfusionnelle pour les patients atteints d'anémie ferriprive. Le but de la présente étude était d'examiner le nombre de transfusions administrées dans les services d'urgence (SU) de Calgary avant et après la publication de ces directives. Méthodes Nous avons analysé 11 786 cas d'anémie entre janvier 2014 et décembre 2019. Une transfusion était jugée comme potentiellement évitable si l'hémoglobine du patient était > 70 g/L et si le patient était stable sur le plan hémodynamique. Nous avons utilisé des analyses de séries chronologiques pour examiner trimestriellement le changement du taux de transfusions totales et potentiellement évitables au cours de l'ensemble des périodes, y compris avant et après l'intervention.

Background: Burst suppression (BS) is an electroencephalography (EEG) pattern in which there are isoelectric periods interspersed with bursts of cortical activity. Targeting BS through anaesthetic administration is used as a tool in the neuro-intensive care unit but its relationship with cerebral blood flow (CBF) and cerebral autoregulation (CA) is unclear. We performed a systematic scoping review investigating the effect of BS on CBF and CA in animals and humans.Methods: We searched MEDLINE, BIOSIS, EMBASE, SCOPUS and Cochrane library from inception to August 2022. The data that were collected included study population, methods to induce and measure BS, and the effect on CBF and CA.Results: Overall, there were 66 studies that were included in the final results, 41 of which examined animals, 24 of which examined humans, and 1 of which examined both. In almost all the studies, BS was induced using an anaesthetic. In most of the animal and human studies, BS was associated with a decrease in CBF and cerebral metabolism, even if the mean arterial pressure remained constant. The effect on CA during periods of stress (hypercapnia, hypothermia, etc.) was variable.Discussion: BS is associated with a reduction in cerebral metabolic demand and CBF, which may explain its usefulness in patients with brain injury. More evidence is needed to elucidate the connection between BS and CA.

This chapter will review updates in the various imaging modalities used to diagnose acute ischemic stroke (AIS), how these are used to select patients for intervention, and the different interventions used for management of AIS. The backbone of the AIS diagnostic algorithm remains the computed tomography scan (CT) given its speed of use and sensitivity. CT-angiography (CTA) is crucial in diagnosing large-vessel occlusions (LVOs) and multiphase CTA and CT-perfusion (CTP) can demonstrate the number of collaterals in the area and remaining salvageable tissue. MRI can be used to select patients presenting in an unknown time window for thrombolysis. The primary goal of AIS management is to rescue the ischemic penumbra and the approach to treating AIS has gone from a time-based to tissue-based approach. While tPA is still the agent of choice for thrombolysis in patients with AIS, tenecteplase (TNK) may be just as effective and more efficient to use. Endovascular thrombectomy (EVT) has shown considerable efficacy for alleviating LVOs and using CTP, patients can be selected for hours after symptom-onset if viable tissue remains. It remains unclear if an “EVT-alone” strategy is superior to “tPA + EVT” strategy but this may be dependent on clot, patient, and geographical characteristics.

Background: Vasovagal syncope (VVS) occurs due to cerebral hypoperfusion from a fall in blood pressure, with accompanying bradycardia in most cases. Seizure and/or asystole may accompany VVS, though their prediction within the VVS cohort remains elusive.Objective: To further characterize VVS and to find predictive features of “complex” VVS (defined as VVS associated with seizures and/or asystole).Methods: We reviewed medical records of all patients who were referred for orthostatic intolerance and had a definite VVS during the head-up tilt table testing (HUTT). The following variables were recorded: cardiovascular indices during HUTT, autonomic testing results, and semiology of asystole and/or seizure when present. Simple frequency and correlation analysis were performed using the ANOVA.Results: A total of 78 independent VVS were recorded in 60 patients of which 24% were not preceded by presyncope. Vasodepressor (45%) and mixed (38%) VVS were the most prevalent types. Eighteen (23%) were complex VVS; five had an associated seizure (SySz), nine were accompanied by asystole (SyAs), and four had both (SySzAs). Males were significantly more likely to have complex VVS. Mean asystole duration was somewhat longer in the SyAsSz group. The severity of bradycardia significantly correlated with complex VVS and was a predictor of SySz. Autonomic abnormalities were frequent but did not distinguish the two VVS subgroups. Seizures had multiple distinguishing features from those typically associated with epileptic seizures.Conclusions: The underlying pathophysiologic mechanisms of complex VVS remain unclear, but the severity of cerebral hypoperfusion due to bradycardia likely plays a key role in seizure generation.

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