Statistically significant differences versus convincing evidence of real treatment effects: an analysis of the false positive risk for single-centre trials in anaesthesia.

BACKGROUND: The American Statistical Association has highlighted problems with null hypothesis significance testing and outlined alternative approaches that may 'supplement or even replace P-values'. One alternative is to report the false positive risk (FPR), which quantifies the chance the null hypothesis is true when the result is statistically significant. METHODS: We reviewed single-centre, randomised trials in 10 anaesthesia journals over 6 yr where differences in a primary binary outcome were statistically significant. We calculated a Bayes factor by two methods (Gunel, Kass). From the Bayes factor we calculated the FPR for different prior beliefs for a real treatment effect. Prior beliefs were quantified by assigning pretest probabilities to the null and alternative hypotheses. RESULTS: For equal pretest probabilities of 0.5, the median (inter-quartile range [IQR]) FPR was 6% (1-22%) by the Gunel method and 6% (1-19%) by the Kass method. One in five trials had an FPR ≥20%. For trials reporting P-values 0.01-0.05, the median (IQR) FPR was 25% (16-30%) by the Gunel method and 20% (16-25%) by the Kass method. More than 90% of trials reporting P-values 0.01-0.05 required a pretest probability >0.5 to achieve an FPR of 5%. The median (IQR) difference in the FPR calculated by the two methods was 0% (0-2%). CONCLUSIONS: Our findings suggest that a substantial proportion of single-centre trials in anaesthesia reporting statistically significant differences provide limited evidence of real treatment effects, or, alternatively, required an implausibly high prior belief in a real treatment effect. CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42023350783).

Minimum false-positive risk of primary outcomes and impact of reducing nominal P-value threshold from 0.05 to 0.005 in anaesthesiology randomised clinical trials: a cross-sectional study.

BACKGROUND: Reproducibility of research is poor; this may be because many articles report statistically significant findings that are false positives. Two potential solutions are to lower the P-value for statistical significance testing from 0.05 to 0.005 and to report the minimum false-positive risk (minFPR). This study determined these metrics for randomised controlled trials (RCTs) in general anaesthesiology journals. METHODS: We identified superiority RCTs published between January 1, 2019 and March 15, 2021 from seven leading anaesthesia journals. P-values for primary outcomes were collected, and minFPRs for these outcomes were calculated using a formula assuming a 50% prior probability of an intervention being effective (minFPR50). The primary outcomes were the percentage of RCTs maintaining statistical significance at P<0.005 and minFPR50. RESULTS: We included 318 RCTs. P-values below 0.05 were reported in 205/318 (64%) of RCTs. Of these 205 RCTs, 119/205 (58%) maintained statistical significance at the P<0.005 threshold. The mean (standard deviation) minFPR50 was 22% (20). At P=0.005, the minFPR50 was approximately 5%. CONCLUSIONS: These proposed metrics aimed at mitigating reproducibility concerns would call a significant portion of the anaesthesiology literature into question. We found a minFPR of 22% and determined that 42% of primary outcomes would not maintain statistical significance if the P-value threshold changed from 0.05 to 0.005. These findings could partially explain the lack of reproducibility of research findings.

Minimum protamine dose required to neutralize heparin in cardiac surgery: a single-centre, prospective, observational cohort study.

PURPOSE: Excess protamine contributes to coagulopathy following cardiopulmonary bypass (CPB) and may increase blood loss and transfusion requirements. The primary aim of this study was to find the least amount of protamine necessary to neutralize residual heparin following CPB using the gold standard assays of anti-IIa and anti-Xa activity. Secondary objectives were to evaluate whether the post-CPB activated clotting time could be used as a surrogate marker for quantifying heparin neutralization. METHODS: Twenty-eight consecutive patients undergoing elective cardiac surgery were enrolled. Protamine administration was standardized through an infusion pump at 25 mg·min-1. Blood samples were withdrawn prior to and following administration of 150, 200, 250, and 300 mg protamine and analyzed for activated clotting time and anti-IIa and -Xa activity. RESULTS: Following a mean (standard deviation) cumulative heparin dose of 67,700 (19,400) units and a CPB duration of 113 (71) min, protamine requirements varied widely. Eight out of 25 (32%) patients showed complete neutralization of anti-IIa and -Xa activity at the first sampling point (150 mg protamine; protamine:heparin ratio, 0.3 [0.1]). A protamine:heparin ratio of 0.5 (0.2) was sufficient for heparin neutralization in > 90% of patients. After CPB, a low to mid-range activated clotting time correlated well with anti-IIa and -Xa activity. CONCLUSIONS: The protamine:heparin ratio required to neutralize residual unfractionated heparin (UFH) following CPB is variable. A protamine:heparin ratio of 0.3 was sufficient to neutralize UFH in some patients, while a ratio of 0.5 is sufficient to neutralize both residual anti-IIa and -Xa activity in most patients. Larger studies are necessary to confirm these findings and evaluate their clinical implications. STUDY REGISTRATION: ClinicalTrials.gov (NCT03787641); registered 26 December 2018.

RéSUMé: OBJECTIF: L'excès de protamine contribue à la coagulopathie après la circulation extracorporelle (CEC) et peut augmenter les pertes de sang et les besoins transfusionnels. L'objectif principal de cette étude était de déterminer la quantité minimale de protamine nécessaire pour neutraliser l'héparine résiduelle post-CEC en utilisant les tests de référence de l'activité anti-IIa et anti-Xa. Les objectifs secondaires consistaient à évaluer si le temps de coagulation activé post-CEC pouvait être utilisé comme marqueur de substitution pour quantifier la neutralisation de l'héparine. MéTHODE: Vingt-huit patients consécutifs bénéficiant d'une chirurgie cardiaque non urgente ont été recrutés. L'administration de protamine par une pompe à perfusion à 25 mg·min-1 a été normalisée. Des échantillons de sang ont été prélevés avant et après l'administration de 150, 200, 250 et 300 mg de protamine et analysés pour déterminer le temps de coagulation activé et l'activité anti-IIa et -Xa. RéSULTATS: Après une dose cumulative moyenne (écart type) d'héparine de 67 700 (19 400) unités et une durée de CEC moyenne de 113 (71) min, les besoins en protamine variaient considérablement. Huit patients sur 25 (32 %) ont affiché une neutralisation complète de l'activité anti-IIa et -Xa au premier point de prélèvement (150 mg de protamine; rapport protamine : héparine, 0,3 [0,1]). Un rapport protamine/héparine de 0,5 (0,2) était suffisant pour la neutralisation de l'héparine chez > 90 % des patients. Après la CEC, un temps de coagulation activé bas à moyen était bien corrélé avec l'activité anti-IIa et -Xa. CONCLUSION: Le rapport protamine : héparine nécessaire pour neutraliser l'héparine non fractionnée (HNF) résiduelle suivant une CEC est variable. Un rapport protamine : héparine de 0,3 était suffisant pour neutraliser l'HNF chez certains patients, tandis qu'un rapport de 0,5 est suffisant pour neutraliser à la fois l'activité résiduelle des anti-IIa et celle des anti-Xa chez la plupart des patients. Des études plus vastes sont nécessaires pour confirmer ces résultats et évaluer leurs implications cliniques. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03787641); enregistrée le 26 décembre 2018.

Interpreting frequentist hypothesis tests: insights from Bayesian inference.

Randomized controlled trials are one of the best ways of quantifying the effectiveness of medical interventions. Therefore, when the authors of a randomized superiority trial report that differences in the primary outcome between the intervention group and the control group are "significant" (i.e., P ≤ 0.05), we might assume that the intervention has an effect on the outcome. Similarly, when differences between the groups are "not significant," we might assume that the intervention does not have an effect on the outcome. Nevertheless, both assumptions are frequently incorrect.In this article, we explore the relationship that exists between real treatment effects and declarations of statistical significance based on P values and confidence intervals. We explain why, in some circumstances, the chance an intervention is ineffective when P ≤ 0.05 exceeds 25% and the chance an intervention is effective when P > 0.05 exceeds 50%.Over the last decade, there has been increasing interest in Bayesian methods as an alternative to frequentist hypothesis testing. We provide a robust but nontechnical introduction to Bayesian inference and explain why a Bayesian posterior distribution overcomes many of the problems associated with frequentist hypothesis testing.Notwithstanding the current interest in Bayesian methods, frequentist hypothesis testing remains the default method for statistical inference in medical research. Therefore, we propose an interim solution to the "significance problem" based on simplified Bayesian metrics (e.g., Bayes factor, false positive risk) that can be reported along with traditional P values and confidence intervals. We calculate these metrics for four well-known multicentre trials. We provide links to online calculators so readers can easily estimate these metrics for published trials. In this way, we hope decisions on incorporating the results of randomized trials into clinical practice can be enhanced, minimizing the chance that useful treatments are discarded or that ineffective treatments are adopted.

RéSUMé: Les études randomisées contrôlées constituent l'un des meilleurs moyens de quantifier l'efficacité des interventions médicales. Par conséquent, lorsque les autrices et auteurs d'une étude randomisée superiorité signalent que les différences dans le critère d'évaluation principal entre le groupe d'intervention et le groupe témoin sont « significatives ¼ (c.-à-d. P ≤ 0,05), nous pourrions supposer que l'intervention a un effet sur le critère d'évaluation. De même, lorsque les différences entre les groupes ne sont « pas significatives ¼, nous pourrions supposer que l'intervention n'a pas d'effet sur le critère d'évaluation. Pourtant, ces deux hypothèses s'avèrent souvent incorrectes.Dans cet article, nous explorons la relation qui existe entre les effets réels d'un traitement et les déclarations de signification statistique fondées sur les valeurs P et les intervalles de confiance. Nous expliquons pourquoi, dans certaines circonstances, la probabilité qu'une intervention soit inefficace lorsque P ≤ 0,05 dépasse 25 % et la probabilité qu'une intervention soit efficace lorsque P > 0,05 dépasse 50 %.Au cours de la dernière décennie, nous avons assisté à un intérêt croissant pour les méthodes bayésiennes comme alternative aux tests d'hypothèses fréquentistes. Nous proposons une introduction robuste mais non technique à l'inférence bayésienne et expliquons pourquoi une distribution postérieure bayésienne surmonte bon nombre des problèmes associés aux tests d'hypothèses fréquentistes.Malgré l'intérêt actuel pour les méthodes bayésiennes, les tests d'hypothèses fréquentistes restent la méthode par défaut pour l'inférence statistique en recherche médicale. Par conséquent, nous proposons une solution provisoire au « problème de signification ¼ basée sur des mesures bayésiennes simplifiées (par exemple, facteur de Bayes, risque de faux positifs) qui peuvent être rapportées en même temps que les mesures traditionnelles des valeurs P et des intervalles de confiance. Nous calculons ces paramètres pour quatre études multicentriques bien connues. Nous fournissons des liens vers des calculatrices en ligne afin que les lectrices et lecteurs puissent facilement estimer ces mesures pour les études publiées. De cette façon, nous espérons que les décisions sur l'intégration des résultats des études randomisées dans la pratique clinique pourront être améliorées, minimisant ainsi le risque que des traitements utiles soient rejetés ou que des traitements inefficaces soient adoptés.

Defining major surgical complications using administrative data in Ontario: a validation study.

BACKGROUND: Although surgical complications are often included as an outcome of surgical research conducted using administrative data, little validation work has been performed. We sought to evaluate the diagnostic performance of an algorithm designed to capture major surgical complications using health administrative data. METHODS: This retrospective study included patients who underwent high-risk elective general surgery at a single institution in Ontario, Canada, from Sept. 1, 2016, to Sept. 1, 2017. Patients were identified for inclusion using the local operative database. Medical records were reviewed by trained clinicians to abstract postoperative complications. Data were linked to administrative data holdings, and a series of code-based algorithms were applied to capture a composite indicator of major surgical complications. We used sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy to evaluate the performance of our administrative data algorithm, as compared with data abstracted from the institutional charting system. RESULTS: The study included a total of 270 patients. According to the data from the chart audit, 55% of patients experienced at least 1 major surgical complication. Overall sensitivity, specificity, PPV, NPV and accuracy for the composite outcome was 72%, 80%, 82%, 70% and 76%, respectively. Diagnostic performance was poor for several of the individual complications. CONCLUSION: Our results showed that administrative data holdings can be used to capture a composite indicator of major surgical complications with adequate sensitivity and specificity. Additional work is required to identify suitable algorithms for several specific complications.

Patient Sex and Postoperative Outcomes after Inpatient Intraabdominal Surgery: A Population-based Retrospective Cohort Study.

BACKGROUND: Intraabdominal surgeries are frequently performed procedures that lead to a high volume of unplanned readmissions and postoperative complications. Patient sex may be a determinant of adverse outcomes in this population, possibly due to differences in biology or care delivery, but it is understudied. The authors hypothesized that there would be no association between patient sex and the risk of postoperative adverse outcomes in intraabdominal surgery. METHODS: This retrospective, population-based cohort study involved adult inpatients aged 18 yr or older who underwent intraabdominal surgeries in Ontario, Canada, between April 2009 and March 2016. The authors studied the association of patient sex on the primary composite outcome of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Inverse probability of exposure weighting based on propensity scores (computed using demographic characteristics such as rural residence status and median neighborhood income quintile, common comorbidities, and surgery- and hospital-specific characteristics) was used to estimate the adjusted association of sex on outcomes. RESULTS: The cohort included 215,846 patients (52.3% female). The primary outcome was observed in 24,712 (21.9%) females and 25,486 (24.7%) males (unadjusted risk difference, 2.8% [95% CI, 2.5 to 3.2%]; P < 0.001). After adjustment, the association between the male sex and the primary outcome was not statistically significant (adjusted risk difference, -0.2% [95% CI, -0.5 to 0.2%]; P = 0.378). CONCLUSIONS: In a large population of intraabdominal surgical patients, there was no differential risk between sexes in the composite outcome of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days.

Seven years on from the Canadian Airway Focus Group Difficult Airway Guidelines: an observational survey.

PURPOSE: Numerous clinical guidelines are available for management of the unanticipated difficult airway. It is unclear if practice recommendations are endorsed on regional, local, or individual levels. The objective of this observational study was to examine local and regional use of airway guidelines by anesthesiologists within a hospital partnership in Southwestern Ontario. METHODS: Using a paper survey, distributed locally to consultant and trainee anesthesiologists in a tertiary hospital, we examined individual clinical and educational practices regarding guideline use in airway management. Respondents were asked to report which published guideline they used for unanticipated airway difficulty. The effectiveness of dissemination of the national Canadian airway guidelines-the Canadian Airway Focus Group (CAFG) Difficult Airway Guidelines-was examined. We invited anesthesia department heads within the regional hospital partnership to complete an electronic survey investigating departmental adoption of guidelines. RESULTS: The response rate was 70% locally (79/112 anesthesiologists) and 52% regionally (11/21 department heads). Approximately 80% (64/79) of respondents reported using a formal clinical guideline if unanticipated difficulty with airway management was encountered. Seventy-two per cent of respondents (57/79) were aware of the published CAFG guidelines. Approximately 30% (16/51) of consultant anesthesiologists reported using the CAFG guidelines in clinical practice. Within the hospital partnership, 36% (4/11) of departments formally endorsed use of a specific airway management guideline. CONCLUSIONS: Despite widespread awareness of the national CAFG Difficult Airway Guidelines, they are not widely adopted in clinical practice. Further research is warranted to explore barriers to adoption of airway management guidelines for both individual anesthesiologists and anesthesia departments.

RéSUMé: OBJECTIF: De nombreuses lignes directrices cliniques sont disponibles pour la prise en charge des voies aériennes difficiles non anticipées. Nous ne savons pas si ces recommandations de pratique sont suivies aux niveaux régional, local ou individuel. L'objectif de cette étude observationnelle était d'examiner l'utilisation locale et régionale des lignes directrices sur les voies aériennes par des anesthésiologistes provenant d'un partenariat hospitalier dans le sud-ouest de l'Ontario. MéTHODE: À l'aide d'une enquête papier, distribuée localement aux anesthésiologistes et aux résidents en anesthésiologie d'un hôpital de soins tertiaires, nous avons examiné les pratiques cliniques et éducatives individuelles concernant l'utilisation des lignes directrices dans la prise en charge des voies aériennes. On a demandé aux répondants de divulguer les lignes directrices publiées qu'ils utilisaient lorsqu'ils étaient confrontés à des difficultés imprévues au niveau des voies aériennes. L'efficacité de diffusion des lignes directrices nationales canadiennes sur les voies aériennes­les Lignes directrices sur les voies aériennes difficiles du Canadian Airway Focus Group (CAFG)­a été examinée. Nous avons invité les chefs des départements d'anesthésiologie au sein du partenariat hospitalier régional à remplir un sondage électronique sur l'adoption des lignes directrices par leur département. RéSULTATS: Le taux de réponse était de 70 % au niveau local (79/112) et de 52 % au niveau régional (11/21 chefs de département). Environ 80 % (64/79) des répondants ont déclaré avoir utilisé des lignes directrices cliniques officielles en cas de difficultés imprévues dans la prise en charge des voies aériennes. Soixante-douze pour cent des répondants (57/79) avaient connaissance des lignes directrices publiées par le CAFG. Environ 30 % (16/51) des anesthésiologistes ont déclaré avoir utilisé les lignes directrices du CAFG dans leur pratique clinique. Au sein du partenariat hospitalier, 36 % (4/11) des départements ont officiellement appuyé l'utilisation d'une ligne directrice spécifique pour la prise en charge des voies aériennes. CONCLUSION: Malgré une importante sensibilisation aux Lignes directrices nationales sur les voies aériennes difficiles du CAFG, ces dernières ne sont pas largement adoptées dans la pratique clinique. D'autres recherches sont nécessaires pour explorer les obstacles à l'adoption de lignes directrices pour la prise en charge des voies aériennes tant par les anesthésiologistes que par les départements d'anesthésie.

Exploring and reconciling discordance between documented and preferred resuscitation preferences for hospitalized patients: a quality improvement study.

PURPOSE: A discordance, predominantly towards overtreatment, exists between patients' expressed preferences for life-sustaining interventions and those documented at hospital admission. This quality improvement study sought to assess this discordance at our institution. Secondary objectives were to explore if internal medicine (IM) teams could identify patients who might benefit from further conversations and if the discordance can be reconciled in real-time. METHODS: Two registered nurses were incorporated into IM teams at a tertiary hospital to conduct resuscitation preference conversations with inpatients either specifically referred to them (group I, n = 165) or randomly selected (group II, n = 164) from 1 August 2016 to 31 August 2018. Resuscitation preferences were documented and communicated to teams prompting revised resuscitation orders where appropriate. Multivariable logistic regression was used to determine potential risk factors for discordance. RESULTS: Three hundred and twenty-nine patients were evaluated with a mean (standard deviation) age of 80 (12) and Charlson Comorbidity Index Score of 6.8 (2.6). Discordance was identified in 63/165 (38%) and 27/164 (16%) patients in groups I and II respectively. 42/194 patients (21%) did not want cardiopulmonary resuscitation (CPR) and 15/36 (41%) did not prefer intensive care unit (ICU) admission, despite these having been indicated in their initial preferences. 93% (84/90) of patients with discordance preferred de-escalation of care. Discordance was reconciled in 77% (69/90) of patients. CONCLUSION: Hospitalized patients may have preferences documented for CPR and ICU interventions contrary to their preferences. Trained nurses can identify inpatients who would benefit from further in-depth resuscitation preference conversations. Once identified, discordance can be reconciled during the index admission.

RéSUMé: OBJECTIF: Il existe une discordance, qui tend surtout vers un sur-traitement, entre les préférences exprimées par les patients pour les interventions de maintien de la vie et celles documentées lors de l'admission à l'hôpital. Cette étude d'amélioration de la qualité avait pour objectif d'évaluer cette discordance au sein de notre institution. Les objectifs secondaires de notre étude étaient d'explorer la possibilité que les équipes de médecine interne (MI) identifient les patients qui pourraient bénéficier de conversations approfondies et de voir si la discordance pouvait être corrigée en temps réel. MéTHODE: Deux infirmières ont intégré des équipes de MI dans un hôpital tertiaire pour discuter avec les patients hospitalisés de leurs préférences en matière de réanimation entre le 1er août 2016 et le 31 août 2018; les patients leur étaient soit spécifiquement référés (groupe I, n = 165), ou sélectionnés au hasard (groupe II, n = 164). Les préférences en matière de réanimation ont été documentées et communiquées aux équipes, entraînant une révision des ordonnances de réanimation, le cas échéant. La régression logistique multivariée a été utilisée afin de déterminer les facteurs de risque potentiels de discordance. RéSULTATS: Trois cent vingt-neuf patients ont été évalués, d'un âge moyen (écart type) de 80 ans (12) et avec un score de 6,8 (2,6) à l'Indice de comorbidité de Charlson. Une discordance a été identifiée chez 63/165 (38 %) et 27/164 (16 %) patients dans les groupes I et II, respectivement. Au total, 42/194 patients (21 %) ne souhaitaient pas de réanimation cardiorespiratoire (RCR) et 15/36 (41 %) préféraient ne pas être admis à l'unité de soins intensifs (USI), malgré une mention dans leurs préférences initiales. Parmi les patients chez lesquels une discordance a été notée, 93 % (84/90) ont préféré une désescalade des soins. La discordance a pu être corrigée pour 77 % (69/90) des patients. CONCLUSION: La documentation des patients hospitalisés pourrait indiquer des préférences pour des interventions de RCR et d'admission à l'USI contraires aux véritables préférences. Des infirmières formées à cet effet peuvent identifier les patients hospitalisés qui bénéficieraient d'une conversation approfondie sur leurs préférences en matière de réanimation. Une fois identifiée, une discordance peut être corrigée lors de l'admission initiale.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 1. Difficult airway management encountered in an unconscious patient.

PURPOSE: Since the last Canadian Airway Focus Group (CAFG) guidelines were published in 2013, the literature on airway management has expanded substantially. The CAFG therefore re-convened to examine this literature and update practice recommendations. This first of two articles addresses difficulty encountered with airway management in an unconscious patient. SOURCE: Canadian Airway Focus Group members, including anesthesia, emergency medicine, and critical care physicians, were assigned topics to search. Searches were run in the Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL databases. Results were presented to the group and discussed during video conferences every two weeks from April 2018 to July 2020. These CAFG recommendations are based on the best available published evidence. Where high-quality evidence was lacking, statements are based on group consensus. FINDINGS AND KEY RECOMMENDATIONS: Most studies comparing video laryngoscopy (VL) with direct laryngoscopy indicate a higher first attempt and overall success rate with VL, and lower complication rates. Thus, resources allowing, the CAFG now recommends use of VL with appropriately selected blade type to facilitate all tracheal intubations. If a first attempt at tracheal intubation or supraglottic airway (SGA) placement is unsuccessful, further attempts can be made as long as patient ventilation and oxygenation is maintained. Nevertheless, total attempts should be limited (to three or fewer) before declaring failure and pausing to consider "exit strategy" options. For failed intubation, exit strategy options in the still-oxygenated patient include awakening (if feasible), temporizing with an SGA, a single further attempt at tracheal intubation using a different technique, or front-of-neck airway access (FONA). Failure of tracheal intubation, face-mask ventilation, and SGA ventilation together with current or imminent hypoxemia defines a "cannot ventilate, cannot oxygenate" emergency. Neuromuscular blockade should be confirmed or established, and a single final attempt at face-mask ventilation, SGA placement, or tracheal intubation with hyper-angulated blade VL can be made, if it had not already been attempted. If ventilation remains impossible, emergency FONA should occur without delay using a scalpel-bougie-tube technique (in the adult patient). The CAFG recommends all institutions designate an individual as "airway lead" to help institute difficult airway protocols, ensure adequate training and equipment, and help with airway-related quality reviews.

RéSUMé: OBJECTIF: Depuis la dernière publication des lignes directrices du Canadian Airway Focus Group (CAFG) en 2013, la littérature sur la prise en charge des voies aériennes s'est considérablement étoffée. Le CAFG s'est donc réuni à nouveau pour examiner la littérature et mettre à jour ses recommandations de pratique. Ce premier article de deux traite de la prise en charge des voies aériennes difficiles chez un patient inconscient. SOURCES: Des sujets de recherche ont été assignés aux membres du Canadian Airway Focus Group, qui compte des médecins anesthésistes, urgentologues et intensivistes. Les recherches ont été menées dans les bases de données Medline, EMBASE, Cochrane Central Register of Controlled Trials et CINAHL. Les résultats ont été présentés au groupe et discutés lors de vidéoconférences toutes les deux semaines entre avril 2018 et juillet 2020. Les recommandations du CAFG sont fondées sur les meilleures données probantes publiées. Si les données probantes de haute qualité manquaient, les énoncés se fondent alors sur le consensus du groupe. CONSTATATIONS ET RECOMMANDATIONS CLéS: La plupart des études comparant la vidéolaryngoscopie à la laryngoscopie directe indiquent un taux de réussite plus élevé à la première tentative et globalement avec la vidéolaryngoscopie, ainsi que des taux de complication inférieurs. Ainsi, les ressources le permettant, le CAFG recommande dorénavant l'utilisation de vidéolaryngoscopes avec le type de lame convenablement sélectionné pour faciliter toutes les intubations trachéales. En cas d'échec de la première tentative d'intubation trachéale ou d'échec de positionnement du dispositif supraglottique (DSG), d'autres tentatives peuvent être entreprises tant que la ventilation et l'oxygénation du patient le permettent. Néanmoins, le nombre total de tentatives devrait être limité, à trois ou moins, avant de déclarer un échec et de considérer les options de « stratégie de retrait ¼. En cas d'échec de l'intubation, les options de stratégie de retrait chez un patient toujours oxygéné comprennent l'éveil (si possible), la temporisation avec un DSG, une dernière tentative d'intubation trachéale à l'aide d'une technique différente, ou une cricothyroïdotomie. L'échec de l'intubation trachéale, de la ventilation au masque facial et de la ventilation via un DSG accompagné d'une hypoxémie présente ou imminente, définit une urgence « impossible de ventiler, impossible d'oxygéner ¼. Le bloc neuromusculaire doit alors être confirmé ou mis en place, et une tentative finale de ventilation au masque, de positionnement du DSG ou d'intubation trachéale avec une lame de vidéolaryngoscopie hyper-angulée peut être réalisée, si cette approche n'a pas encore été essayée. Si la ventilation demeure impossible, une cricothyroïdotomie d'urgence devrait être réalisée sans délai utilisant une technique de scalpel-bougie-tube (chez le patient adulte). Le CAFG recommande à toutes les institutions de désigner une personne comme « leader des voies aériennes ¼ afin d'assister à la mise en place de protocoles pour les voies aériennes difficiles, d'assurer une formation et un équipement adéquats et d'aider aux examens de la qualité en rapport avec les voies aériennes.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 2. Planning and implementing safe management of the patient with an anticipated difficult airway.

PURPOSE: Since the last Canadian Airway Focus Group (CAFG) guidelines were published in 2013, the published airway management literature has expanded substantially. The CAFG therefore re-convened to examine this literature and update practice recommendations. This second of two articles addresses airway evaluation, decision-making, and safe implementation of an airway management strategy when difficulty is anticipated. SOURCE: Canadian Airway Focus Group members, including anesthesia, emergency medicine, and critical care physicians were assigned topics to search. Searches were run in the Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL databases. Results were presented to the group and discussed during video conferences every two weeks from April 2018 to July 2020. These CAFG recommendations are based on the best available published evidence. Where high-quality evidence is lacking, statements are based on group consensus. FINDINGS AND KEY RECOMMENDATIONS: Prior to airway management, a documented strategy should be formulated for every patient, based on airway evaluation. Bedside examination should seek predictors of difficulty with face-mask ventilation (FMV), tracheal intubation using video- or direct laryngoscopy (VL or DL), supraglottic airway use, as well as emergency front of neck airway access. Patient physiology and contextual issues should also be assessed. Predicted difficulty should prompt careful decision-making on how most safely to proceed with airway management. Awake tracheal intubation may provide an extra margin of safety when impossible VL or DL is predicted, when difficulty is predicted with more than one mode of airway management (e.g., tracheal intubation and FMV), or when predicted difficulty coincides with significant physiologic or contextual issues. If managing the patient after the induction of general anesthesia despite predicted difficulty, team briefing should include triggers for moving from one technique to the next, expert assistance should be sourced, and required equipment should be present. Unanticipated difficulty with airway management can always occur, so the airway manager should have a strategy for difficulty occurring in every patient, and the institution must make difficult airway equipment readily available. Tracheal extubation of the at-risk patient must also be carefully planned, including assessment of the patient's tolerance for withdrawal of airway support and whether re-intubation might be difficult.

RéSUMé: OBJECTIF: Depuis la dernière publication des lignes directrices du Canadian Airway Focus Group (CAFG) en 2013, la littérature sur la prise en charge des voies aériennes s'est considérablement étoffée. Le CAFG s'est donc réuni à nouveau pour examiner la littérature et mettre à jour ses recommandations de pratique. Ce deuxième article traite de l'évaluation des voies aériennes, de la prise de décision et de la mise en œuvre sécuritaire d'une stratégie de prise en charge des voies aériennes lorsque des difficultés sont anticipées. SOURCES: Des sujets de recherche ont été assignés aux membres du Canadian Airway Focus Group, qui compte des médecins anesthésistes, urgentologues et intensivistes. Les recherches ont été réalisées dans les bases de données Medline, EMBASE, Cochrane Central Register of Controlled Trials et CINAHL. Les résultats ont été présentés au groupe et discutés lors de vidéoconférences toutes les deux semaines entre avril 2018 et juillet 2020. Les recommandations du CAFG sont fondées sur les meilleures données probantes publiées. Si les données probantes de haute qualité manquaient, les énoncés se fondent alors sur le consensus du groupe. CONSTATATIONS ET RECOMMANDATIONS CLéS: Avant d'amorcer la prise en charge des voies aériennes, une stratégie documentée devrait être formulée pour chaque patient, en fonction de l'évaluation de ses voies aériennes. L'examen au chevet devrait rechercher les prédicteurs de difficultés pour la ventilation au masque, l'intubation trachéale utilisant la vidéolaryngoscopie ou la laryngoscopie directe, l'utilisation d'un dispositif supraglottique, ainsi que pour la cricothyroïdotomie d'urgence. La physiologie du patient et ses problématiques contextuelles devraient également être évaluées. Les difficultés anticipées devraient inciter à prendre des décisions éclairées sur la façon la plus sécuritaire de procéder à la prise en charge des voies aériennes. L'intubation trachéale éveillée peut procurer une marge de sécurité supplémentaire lorsqu'on s'attend à ce que la vidéolaryngoscopie ou la laryngoscopie directe soient impossibles, lorsqu'on prévoit des difficultés pour plus d'un mode de prise en charge des voies aériennes (p. ex., intubation trachéale et ventilation au masque), ou lorsque la difficulté prévue coïncide avec des problèmes physiologiques ou contextuels importants. En cas de choix de prise en charge des voies respiratoires du patient après induction de l'anesthésie générale malgré les difficultés prévues, les directives à l'équipe devraient inclure les déclencheurs pour passer d'une technique à l'autre, l'aide d'experts disponibles et l'équipement requis disponible. Des difficultés imprévues lors de la prise en charge des voies aériennes peuvent toujours survenir, de sorte que la personne responsable de la prise en charge des voies aériennes devrait avoir une stratégie pour chaque patient, et l'établissement doit rendre facilement disponible le matériel pour la prise en charge des voies aériennes difficiles. L'extubation trachéale du patient à risque doit également être soigneusement planifiée, y compris l'évaluation de la tolérance du patient lors du retrait du dispositif de soutien des voies aériennes et d'une ré-intubation potentiellement difficile.

Risk of stroke and other adverse outcomes in patients with perioperative atrial fibrillation 1 year after non-cardiac surgery.

AIMS: To determine the 1-year risk of stroke and other adverse outcomes in patients with a new diagnosis of perioperative atrial fibrillation (POAF) after non-cardiac surgery. METHODS AND RESULTS: The PeriOperative ISchemic Evaluation (POISE)-1 trial evaluated the effects of metoprolol vs. placebo in 8351 patients, and POISE-2 compared the effect of aspirin vs. placebo, and clonidine vs. placebo in 10 010 patients. These trials included patients with, or at risk of, cardiovascular disease who were undergoing non-cardiac surgery. For the purpose of this study, we combined the POISE datasets, excluding 244 patients who were in atrial fibrillation (AF) at the time of randomization. Perioperative atrial fibrillation was defined as new AF that occurred within 30 days after surgery. Our primary outcome was the incidence of stroke at 1 year of follow-up; secondary outcomes were mortality and myocardial infarction (MI). We compared outcomes among patients with and without POAF using multivariable adjusted Cox proportional hazards models. Among 18 117 patients (mean age 69 years, 57.4% male), 404 had POAF (2.2%). The stroke incidence 1 year after surgery was 5.58 vs. 1.54 per 100 patient-years in patients with and without POAF, adjusted hazard ratio (aHR) 3.43, 95% confidence interval (CI) 2.00-5.90; P < 0.001. Patients with POAF also had an increased risk of death (incidence 31.37 vs. 9.34; aHR 2.51, 95% CI 2.01-3.14; P < 0.001) and MI (incidence 26.20 vs. 8.23; aHR 5.10, 95% CI 3.91-6.64; P < 0.001). CONCLUSION: Patients with POAF have a significantly increased risk of stroke, MI, and death at 1 year. Intervention studies are needed to evaluate risk reduction strategies in this high-risk population.

Simultaneous en bloc endotracheal tube insertion with GlideScope® Titanium™ video laryngoscope use: a randomized-controlled trial.

PURPOSE: Intubation-associated trauma with the GlideScope is rare, but when it occurs, it is likely due to advancing the endotracheal tube (ETT) blindly between the direct view of the oropharynx and the video view of the glottis. It is also occasionally difficult to advance the ETT to the glottic aperture despite a good view of the glottis on the monitor. One technique to potentially address both issues is to introduce the ETT en bloc with the GlideScope, thus visualizing the ETT tip throughout its entire path. We hypothesized that this en bloc technique could be faster and potentially easier than the standard technique. METHODS: Fifty patients with normal-appearing airways who required orotracheal intubation for elective surgery were randomly allocated to intubation with either the en bloc or the standard (GlideScope-first-then-ETT) technique. A three-dimensional printed clip was utilized to secure the ETT to the GlideScope during en bloc insertion. The primary outcome was time to intubation, defined from mask removal to first end-tidal carbon dioxide detection, recorded by a blinded observer. Secondary outcomes were subjective ease of intubation (100-mm visual analogue scale [VAS], 0 = easy; 100 = difficult), number of intubation attempts/failures, and incidence of oropharyngeal trauma (bleeding). RESULTS: The median [interquartile range (IQR)] intubation time was 36 [31-42] sec with the en bloc technique vs 41 [37-50] sec with the standard technique (difference in medians, 5 sec; 95% confidence interval [CI], 2 to 11; P = 0.008). The median [IQR] ease of intubation VAS was 11 [9-21] mm with the en bloc technique, and 15 [11-24] mm with the standard technique (difference in medians, 4 mm; 95% CI, -2 to 8; P = 0.19). Laryngoscopic grade and number of intubation attempts were similar between the groups; there was no oropharyngeal trauma noted. CONCLUSION: In this study of video laryngoscopy, intubation was slightly faster with the en bloc technique than with the standard GlideScope intubation technique, although the clinical importance of this difference is unknown. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02787629); registered 1 June 2016.

RéSUMé: OBJECTIF: Les traumatismes associés à l'intubation avec un GlideScope sont rares; quand ils surviennent, ils sont souvent provoqués par l'insertion du tube endotrachéal (TET) en aveugle entre la visualisation directe de l'oropharynx et la visualisation par vidéo de la glotte. Il arrive parfois qu'il soit difficile d'insérer le TET dans l'ouverture glottique malgré une bonne visualisation de la glotte sur le moniteur. Une technique permettant potentiellement de résoudre ces deux problèmes est l'introduction 'en bloc' du TET et du GlideScope, de manière à obtenir une vue de l'extrémité du TET tout au long de son parcours. Nous avons émis l'hypothèse que cette technique en bloc pourrait être à la fois plus rapide et potentiellement plus facile à réaliser que la technique standard. MéTHODE: Cinquante patients présentant des voies aériennes d'apparence normale et nécessitant une intubation orotrachéale pour une chirurgie non urgente ont été randomisés à être intubés soit par une technique en bloc, soit en utilisant la technique standard (GlideScope puis TET). Une pince imprimée en 3D a été utilisée pour attacher le TET au GlideScope pendant l'insertion en bloc. Le critère d'évaluation principal était le temps nécessaire à l'intubation, défini à partir du moment de retrait du masque jusqu'à la première détection de dioxyde de carbone télé-expiratoire, tel que mesuré par un observateur en aveugle. Les critères secondaires comprenaient la facilité subjective d'intubation (sur une échelle visuelle analogique [EVA] de 100 mm, où 0 = facile et 100 = difficile), le nombre de tentatives et d'échecs d'intubation, et l'incidence de lésions oropharyngées (saignement). RéSULTATS: Le temps d'intubation médian [écart interquartile (ÉIQ)] était de 36 [31­42] sec avec la technique en bloc vs 41 [37­50] sec avec la technique standard (différence de moyennes, 5 sec; intervalle de confiance [IC] 95 %, 2 à 11; P = 0,008). La facilité d'intubation médiane [ÉIQ] sur l'EVA était de 11 [9-21] mm avec la technique en bloc, et 15 [11-24] mm avec la technique standard (différence de moyennes, 4 mm; IC 95 %, -2 à 8; P = 0,19). La classification de la laryngoscopie et le nombre de tentatives d'intubation étaient similaires dans les deux groupes; aucun traumatisme oropharyngé n'a été enregistré. CONCLUSION: Dans cette étude vidéolaryngoscopique, l'intubation était légèrement plus rapide lors de l'utilisation de la technique en bloc que lors d'une technique d'intubation standard avec le GlideScope, bien que l'importance clinique de cette différence soit inconnue. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT02787629); enregistrée le 1er juin 2016.

Clinical impact of disinvestment in hydroxyethyl starch for patients undergoing coronary artery bypass surgery: a retrospective observational study.

PURPOSE: To examine the effect of discontinuing hydroxyethyl starch (HES) solutions on length of hospital stay, transfusion, risk of death, acute kidney injury (AKI), and dialysis. METHODS: We conducted a historical cohort study of linked administrative and clinical databases in patients undergoing coronary artery bypass surgery (CABG) on cardiopulmonary bypass. We used propensity scores to match patients who did not receive HES (after discontinuation) with patients exposed to HES (before discontinuation) and also controlled for albumin exposure. Hospital length of stay (the primary outcome) was analyzed using Fine-Gray proportional hazard regression, with hospital discharge as the outcome and death as a competing risk. Adverse outcomes were compared between matched patients using conditional logistic regression. RESULTS: We compared 1,085 propensity score-matched pairs (n = 2,170) from a pool of 2,757 patients. Discontinuation of HES was associated with shorter length of hospital stay, as evidenced by an increased probability of discharge (hazard ratio, 1.24; 95% confidence interval [CI], 1.14 to 1.35) and a reduced risk of red blood cell transfusion (odds ratio [OR], 0.68; 95% CI, 0.55 to 0.84), plasma transfusion (OR, 0.48; 95% CI, 0.34 to 0.66), and platelet transfusion (OR, 0.62; 95% CI, 0.44 to 0.87). Discontinuation of HES was not associated with in-hospital mortality (OR, 0.74; 95% CI, 0.36 to 1.54), AKI (OR, 0.84; 95% CI, 0.57 to 1.25), or dialysis (OR, 0.83; 95% CI, 0.25 to 2.73). CONCLUSIONS: For patients undergoing CABG on cardiopulmonary bypass, discontinuation of HES was associated with reduced hospital length of stay and reduced blood product transfusion, without measurable change in renal failure, dialysis rate, or in-hospital mortality. Our results should be interpreted with caution, though we found no evidence of harms associated with discontinuing HES. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02329158); registered 31 December, 2014.

Association between known or strongly suspected malignant hyperthermia susceptibility and postoperative outcomes: an observational population-based study.

PURPOSE: Whether current standards of care management for malignant hyperthermia (MH)-susceptible patients result in acceptable postoperative clinical outcomes at a population level is not known. Our objective was to determine if patients with susceptibility to MH experienced similar outcomes as patients without MH susceptibility after surgery under general anesthesia. METHODS: This was a retrospective, population-based cohort study from 1 April 2009 until 31 March 2016 in the Canadian province of Ontario. Participants were adults who underwent common in- or outpatient surgeries under general anesthesia. The exposure studied was either known or strongly suspected MH susceptibility as determined by usage of a specific physician billing code. The primary outcome was a composite of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Separate analyses were employed, based on whether a patient had in- or outpatient surgery. Inverse probability of exposure weighting based on the propensity score was used to estimate adjusted exposure effects. RESULTS: The cohort included 957,876 patients (583,254 in- and 374,622 outpatients). There were 2,900 (0.3%) patients with a known or strong suspicion of MH susceptibility. For inpatients, the primary outcome occurred in 146,192 (25.1%) of the non-MH-susceptible group and in 337 (20.1%) of the MH-susceptible group (unadjusted risk difference [RD], -5.0%; 95% confidence interval [CI], -6.9 to -3.1%; P < 0.001). In outpatients, the primary outcome occurred in 9,146 (2.4%) of the non-MH-susceptible group and in 32 (2.6%) of the MH-susceptible group (RD, 0.2%; 95% CI, -0.7 to 1.1%; P = 0.72). After adjustment, MH susceptibility was not associated with the primary outcome in either the inpatients (adjusted risk difference [aRD], 1.2%; 95% CI, -1.3 to 3.6%; P = 0.35) or outpatients (aRD, -0.1%; 95% CI -1.0 to 0.9%; P = 0.90). CONCLUSIONS: Among adults in Ontario who underwent common surgeries under general anesthesia from 2009 to 2016, known or strongly suspected MH was not associated with a higher risk of adverse postoperative outcomes. These findings support the current standard of care management for MH-susceptible patients.

RéSUMé: OBJECTIF: Nous ignorons si les normes actuelles de gestion des soins de patients susceptibles d'hyperthermie maligne (HM) aboutissent à des résultats cliniques postopératoires acceptables à l'échelle d'une population. Notre objectif a été de déterminer si des patients présentant une susceptibilité à l'HM présentaient une évolution comparable à celle des patients non connus susceptibles après chirurgie sous anesthésie générale. MéTHODES: Il s'agissait d'une étude de cohorte rétrospective, basée sur une population de la province canadienne de l'Ontario allant du 1er avril 2009 au 31 mars 2016. Les participants étaient des adultes, hospitalisés ou ambulatoires, ayant subi des interventions sous anesthésie générale. L'exposition étudiée était une susceptibilité à l'HM connue ou fortement suspectée, déterminée par l'utilisation d'un code de facturation spécifique des médecins. Le critère d'évaluation principal était un critère composite incluant les décès toutes causes confondues, les réadmissions hospitalières ou les complications postopératoires majeures qui étaient survenus dans un délai de 30 jours postopératoires. Des analyses séparées ont été utilisées, selon que les patients avaient été hospitalisés ou opérés en chirurgie d'un jour. La probabilité inverse de la pondération de l'exposition basée sur le score pour la propension a servi à estimer les effets ajustés de l'exposition. RéSULTATS: La cohorte a inclus 957 876 patients (583 254 patients hospitalisés et 374 622 patients ambulatoires). Parmi eux, 2 900 patients (0,3 %) avaient une susceptibilité à l'HM connue ou fortement suspectée. Pour les patients hospitalisés, le critère d'évaluation principal est survenu chez 146 192 (25,1 %) des patients du groupe non susceptible d'HM et chez 337 (20,1 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : −5,0 %; intervalle de confiance [IC] à 95 % : −6,9 % à −3,1 %; P < 0,001). Pour les patients ambulatoires, le critère d'évaluation principal est survenu chez 9 146 (2,4 %) des patients du groupe non susceptible d'HM et chez 32 (2,6 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : 0,2 %; IC à 95 % : −0,7 % à 1,1 %; P = 0,72). Après ajustement, la susceptibilité à l'HM ne s'est pas avérée associée au critère d'évaluation principal dans le groupe de patients hospitalisés (différence de risques ajustée [DRa], 1,2 %; IC à 95 % : −1,3 % à 3,6 %; P = 0,35) ou dans le groupe de patients ambulatoires (DRa : −0,1 %; IC à 95 % : −1,0 % à 0,9 %; P = 0,90). CONCLUSIONS: Parmi les adultes de la province de l'Ontario ayant subi des interventions chirurgicales usuelles sous anesthésie générale entre 2009 et 2016, l'HM connue ou fortement suspectée n'a pas été associée à un plus grand risque d'évolution postopératoire défavorable. Ces constatations sont en faveur du maintien des normes des soins actuels pour la gestion des patients susceptibles d'HM.

Efficacy of surface landmark palpation for identification of the cricoid cartilage in obstetric patients: A prospective observational study.

BACKGROUND AND AIMS: Rapid sequence induction, with the application of cricoid pressure is an accepted practice during induction of general anesthesia in pregnant patients to prevent pulmonary apiration. We found no prior studies assessing the accuracy of locating the cricoid cartilage by professional caregivers, and therefore conducted an observational study to assess the ability of different caregivers - anesthesia consultants, anesthesia residents, respiratory therapists (RTs), and nurses, in the obstetric care unit, to correctly identify the cricoid cartilage of parturients. We hypothesized that anesthesia consultants would be most accurate. MATERIAL AND METHODS: Institutional REB approval was obtained, as was written informed consent from all participants in the study. The subjects were made up of thirty healthy obstetric patients scheduled for elective cesarean delivery. Their cricoid cartilages were assessed by 53 caregivers (assessors). Localization of the cricoid cartilage by assessors was considered accurate if it was within 5 mm of the sonographically identified mark. The difficulty in localization was reported on a VAS scale and the time taken for localization was recorded. RESULTS: Data from 30 subjects and 53 assessors (13 anesthesia consultants, 12 residents, 13 RTs, and 15 nurses) performing a total of 60 evaluations (some assessors evaluated 2 subjects) were analyzed. About 60% of RTs, 53% of anesthesia residents, 40% of anesthesia consultants, and 13% of nurses correctly identified the cricoid cartilage. No differences in caregivers'perception of difficulty were found, but RTs were the quickest at identification (P < 0.001 vs anesthesia consultants; P = 0.002 vs residents; P = 0.071 vs nurses). CONCLUSION: RTs were the most successful and accurate in identifying the cricoid cartilage of parturients among the different groups of professional caregivers.

Sample size calculations for randomized clinical trials published in anesthesiology journals: a comparison of 2010 versus 2016.

PURPOSE: Although every randomized clinical trial (RCT) needs participants, determining the ideal number of participants that balances limited resources and the ability to detect a real effect is difficult. Focussing on two-arm, parallel group, superiority RCTs published in six general anesthesiology journals, the objective of this study was to compare the quality of sample size calculations for RCTs published in 2010 vs 2016. METHODS: Each RCT's full text was searched for the presence of a sample size calculation, and the assumptions made by the investigators were compared with the actual values observed in the results. Analyses were only performed for sample size calculations that were amenable to replication, defined as using a clearly identified outcome that was continuous or binary in a standard sample size calculation procedure. RESULTS: The percentage of RCTs reporting all sample size calculation assumptions increased from 51% in 2010 to 84% in 2016. The difference between the values observed in the study and the expected values used for the sample size calculation for most RCTs was usually > 10% of the expected value, with negligible improvement from 2010 to 2016. CONCLUSION: While the reporting of sample size calculations improved from 2010 to 2016, the expected values in these sample size calculations often assumed effect sizes larger than those actually observed in the study. Since overly optimistic assumptions may systematically lead to underpowered RCTs, improvements in how to calculate and report sample sizes in anesthesiology research are needed.

The use of point-of-care ultrasound to diagnose patent foramen ovale in elective hip and knee arthroplasty patients and its association with postoperative delirium.

PURPOSE: Hip and knee arthroplasty surgeries are associated with embolism of materials such as air, cement, and fat. Patent foramen ovale (PFO) is a common congenital cardiac condition that has been reported to lead to paradoxical embolism. This observational study aimed to investigate if the presence of a PFO was associated with an increased risk of postoperative delirium in patients undergoing primary elective hip or knee arthroplasties. METHOD: This was a prospective cohort study at a tertiary teaching hospital. We enrolled patients undergoing primary elective hip or knee arthroplasty who did not have any risk factors for embolism or delirium. Bedside transthoracic echocardiography (TTE) with a bubble study was performed on all patients to detect the presence of PFO. The primary outcome was postoperative delirium as assessed by the standardized Confusion Assessment Method. Secondary outcomes included the ease of performing a TTE bubble study in the perioperative setting, the quality of the TTE images, length of stay, major cardiovascular and neurologic complications, and effects of anesthetic or analgesic management techniques on delirium. RESULTS: Two hundred two patients completed the study. The median [interquartile range] duration of stay was 2 [2-3] days. Only 16 patients (8%) had a positive bubble study. Postoperative delirium was observed in only one patient. Major adverse events were not seen. The inter-rater reliability for the TTE image quality scores was fair (kappa statistic = 0.22). CONCLUSION: Given the very low incidence of PFO and postoperative delirium in this study, we could not form any conclusions regarding the impact of a PFO on important outcomes including delirium or other major adverse events. No recommendation can be made regarding screening for PFO in patients scheduled for lower extremity arthroplasty surgery. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02400892). Registered 27 March 2015.

The degree of adherence to CONSORT reporting guidelines for the abstracts of randomised clinical trials published in anaesthesia journals: A cross-sectional study of reporting adherence in 2010 and 2016.

BACKGROUND: Abstracts are intended to be concise summaries of the entire randomised clinical trial (RCT). Despite their importance, few studies have examined the reporting quality of abstracts in the anaesthesiology literature. OBJECTIVES: To examine the quality of RCT abstract reporting according to the CONSORT for Abstracts guidelines and determine whether recommended items omitted from the abstract were present in the body of the article. DESIGN: A cross-sectional study of RCTs. SETTING: This study was performed at the University of Western Ontario and University Hospital, London Health Sciences Centre. PARTICIPANTS: All RCTs meeting inclusion criteria that were published in 2010 or 2016 in six general anaesthesiology journals (Anaesthesia, Anesthesia & Analgesia, Anesthesiology, British Journal of Anaesthesia, Canadian Journal of Anesthesia and European Journal of Anaesthesiology). MAIN OUTCOME MEASURES: The 16 checklist items from the CONSORT for Abstracts statement were used to create a convenience score as a proxy for RCT abstract reporting quality, with each criterion measured as being reported in abstract, not reported in abstract but reported in full-text article, or not reported in abstract or full-text article. RESULTS: Of the 395 RCTs identified, 219 were published in 2010 and 176 were published in 2016. Out of the maximum possible score of 16, the median abstract score increased from 4 points [interquartile range (IQR): 3 to 5] in 2010 to 6 points [IQR: 5 to 8] in 2016. Although most checklist items showed improvement from 2010 to 2016, around 75% of RCTs in 2016 met fewer than half of the 16 items with no RCTs reporting all 16 items in the abstract. A majority of the RCTs had the information present in the full-text. In 2016, only 71 out of 176 (40%) of RCTs reported outcomes conforming to the CONSORT guidelines (with an effect size and a confidence interval around the effect size) in the Abstract. CONCLUSION: Abstracts for many anaesthesiology RCTs are incomplete selective summaries of the entire article.