The evolution and formalization of anesthesia assistant roles across Canada.

PURPOSE: The purpose of this Special Article is to document the evolution of the anesthesia assistant (AA) profession in Canada and summarize AA practice at Canadian institutions as it exists today, five decades after Quebec and 15 years after most other provinces formalized AA practice. SOURCE: Through the Management Committee of the Association of Canadian University Departments of Anesthesia (ACUDA), we conducted a purposeful sampling of all ACUDA chairs or their delegates. We requested the following data: history of AAs becoming a reality in their particular province or region; potential recruitment pools; training programs and curricula; pathway to credentialing; funding, pay, retention, recruitment, and status of union representation; and metrics. PRINCIPAL FINDINGS: Data were provided by 19 institutions in 8 provinces: Newfoundland and Labrador, Nova Scotia, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia. Given the different health care governance structures across the provinces, AA roles vary in terms of its associated technical, clinical, and educational responsibilities. The role of AAs in supporting anesthesia care through equipment maintenance and assistance with airway management, resuscitation, and administration of regional anesthesia seems to be well established, as is their role in providing brief intraoperative relief for anesthesiologists during a stable period of anesthesia. Anesthesia assistant duties continue to evolve, becoming more aligned with the specific institution and less dependent on the supervising anesthesiologist. Apart from the initial metrics collected during the Ontario ACT implementation pilot projects, we are not aware of any formal metrics, current or ongoing, being collected across Canada, related to either patient safety events or perioperative efficiency. CONCLUSIONS: This compilation of pan-Canadian AA data shows diverse models of practice and highlights the value to patients and the health care system as a whole of incorporating these allied professionals into the anesthesia care team (ACT). The present findings allow us to offer suggestions for consideration during discussions of retention, recruitment, program expansion, and cross-country collection of metrics and other data. We conclude by making six recommendations: 1. recognize that implementation of ACTs is a key element in solving the challenge of an increasing surgical backlog; 2. develop, or facilitate the development of, metrics and increase data-sharing nationally to enable health care authorities to better understand the importance of AAs in patient safety and perioperative efficiency; 3. develop and implement funding strategies to lower the barriers to AA training such as hospital-sponsored positions, ongoing salary support, and return-of-service arrangements; 4. ensure that salaries appropriately reflect the increased level of training and added levels of responsibility of certified AAs; 5. develop long-term strategies to ensure stable funding, recruitment and retention, and a better match between the number of AA training positions and the need for newly certified AAs; and 6. engage all stakeholders to acknowledge that AAs, as knowledgeable and specifically trained assistants, not only fulfill their defined clinical role but also contribute significantly to patient safety and clinical efficiency by assuming nondirect patient care tasks.

RéSUMé: OBJECTIF: Le but de cet article spécial est de documenter l'évolution de la profession d'assistant·e en anesthésie (AA) au Canada et de résumer la pratique des AA dans les établissements canadiens telle qu'elle existe aujourd'hui, cinquante ans après que le Québec et quinze ans après que la plupart des autres provinces ont officialisé la pratique des AA. SOURCES: Par l'entremise du Comité de gestion de l'Association canadienne universitaire des départements d'anesthésie (ACUDA), nous avons réalisé un échantillonnage ciblé de tou·tes les président·es de l'ACUDA ou de leurs délégué·es. Nous avons demandé les données suivantes : historique de la concrétisation de la profession d'AA dans leur province ou région; bassins de recrutement potentiels; programmes de formation et programmes d'études; voie d'accès à l'accréditation; financement, rémunération, rétention, recrutement et état de la représentation syndicale; et données métriques. CONSTATATIONS PRINCIPALES: Des données ont été fournies par 19 institutions dans 8 provinces : Terre-Neuve-et-Labrador, Nouvelle-Écosse, Québec, Ontario, Manitoba, Saskatchewan, Alberta et Colombie-Britannique. Compte tenu des différentes structures de gouvernance des soins de santé dans les provinces, les rôles des AA varient en termes de responsabilités techniques, cliniques et éducatives connexes. Le rôle des AA dans le soutien des soins d'anesthésie par l'entretien du matériel et l'aide à la prise en charge des voies aériennes, à la réanimation et à l'administration de l'anesthésie régionale semble bien établi, tout comme leur rôle dans la fourniture d'un bref soulagement peropératoire aux anesthésiologistes pendant une période stable d'anesthésie. Les tâches des assistant·es en anesthésie continuent d'évoluer, devenant plus alignées sur l'établissement spécifique et moins dépendantes de l'anesthésiologiste superviseur·e. À l'exception des mesures initiales recueillies dans le cadre des projets pilotes de mise en œuvre des ESA (équipes de soins en anesthésie) en Ontario, nous ne sommes au courant d'aucune mesure officielle, actuelle ou en cours, recueillie dans l'ensemble du Canada, concernant les événements liés à la sécurité des patient·es ou à l'efficacité périopératoire. CONCLUSION: Cette compilation de données pancanadiennes sur les AA présente divers modèles de pratique et souligne l'importance pour les patient·es et le système de soins de santé dans son ensemble d'intégrer ces professionnel·les connexes à l'équipe de soins d'anesthésie (ESA). Les résultats actuels nous permettent d'avancer des suggestions à prendre en compte lors des discussions sur le maintien en poste, le recrutement, l'expansion des programmes et la collecte de mesures et d'autres données à l'échelle du pays. Nous concluons en formulant six recommandations : 1. reconnaître que la mise en œuvre des ESA constitue un élément clé pour résoudre le problème de l'augmentation de l'arriéré chirurgical; 2. élaborer ou faciliter l'élaboration de mesures et accroître le partage des données à l'échelle nationale pour permettre aux autorités sanitaires de mieux comprendre l'importance des AA pour la sécurité des patient·es et l'efficacité périopératoire; 3. élaborer et mettre en œuvre des stratégies de financement pour réduire les obstacles à la formation des AA, comme les postes parrainés par les hôpitaux, le soutien salarial continu et les ententes de retour de service; 4. veiller à ce que les salaires reflètent de manière appropriée le niveau accru de formation et les niveaux de responsabilité accrus des AA certifié·es; 5. élaborer des stratégies à long terme pour assurer un financement, un recrutement et une rétention stables, ainsi qu'une meilleure adéquation entre le nombre de postes de formation des AA et le besoin de nouveaux et nouvelles AA certifié·es; et 6. inciter toutes les personnes impliquées à reconnaître que les AA, en tant qu'assistant·es compétent·es et spécialement formé·es, non seulement remplissent leur rôle clinique défini, mais contribuent également de manière significative à la sécurité des patient·es et à l'efficacité clinique en assumant des tâches de soins non directs aux patient·es.

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.

Frailty as a Predictor of Death or New Disability After Surgery: A Prospective Cohort Study.

OBJECTIVE: To compare the accuracy of the modified Fried Index (mFI) and the Clinical Frailty Scale (CFS) to predict death or patient-reported new disability 90 days after major elective surgery. BACKGROUND: The association of frailty with patient-reported outcomes, and comparisons between preoperative frailty instruments are poorly described. METHODS: This was a prospective multicenter cohort study. We determined frailty status in individuals ≥65 years having elective noncardiac surgery using the mFI and CFS. Outcomes included death or patient-reported new disability (primary); safety incidents, length of stay (LOS), and institutional discharge (secondary); ease of use, usefulness, benefit, clinical importance, and feasibility (tertiary). We measured the adjusted association of frailty with outcomes using regression analysis and compared true positive and false positive rates (TPR/FPR). RESULTS: Of 702 participants, 645 had complete follow up. The CFS identified 297 (42.3%) with frailty, the mFI 257 (36.6%); 72 (11.1%) died or experienced a new disability. Frailty was significantly associated with the primary outcome (CFS adjusted odds ratio, OR, 2.51, 95% confidence interval, CI, 1.50-4.21; mFI adjusted-OR 2.60, 95% CI 1.57-4.31). TPR and FPR were not significantly different between instruments. Frailty was the only significant predictor of death or new disability in a multivariable analysis. Need for institutional discharge, costs and LOS were significantly increased in individuals with frailty. The CFS was easier to use, required less time and had less missing data. CONCLUSIONS: Older people with frailty are significantly more likely to die or experience a new patient-reported disability after surgery. Clinicians performing frailty assessments before surgery should consider the CFS over the mFI as accuracy was similar, but ease of use and feasibility were higher.

Frailty and long-term postoperative disability trajectories: a prospective multicentre cohort study.

BACKGROUND: Frailty is associated with early postoperative outcomes. How frailty influences long-term postoperative recovery is poorly described. Our objective was to evaluate the association of frailty with postoperative disability trajectories in the year after surgery. METHODS: Prespecified 1-yr follow-up of a prospective multicentre cohort study. Patients ≥65 yr were assessed for frailty before major elective noncardiac surgery (Clinical Frailty Scale [CFS] and Fried Phenotype [FP]). The primary outcome was patient-reported disability score (using the WHO Disability Assessment Schedule 2.0) at baseline, 30, 90, and 365 days after surgery. Repeated measures linear regression estimated the association of preoperative frailty with changes in disability scores over time, adjusted for procedure. Group-based trajectory modelling was used to identify subgroup trajectories of people with frailty. RESULTS: One-year follow-up was complete for 687/702 (97.9%) participants. Frailty was associated with a significant difference in disability trajectory (P<0.0001). Compared with baseline, people with frailty experienced a decrease in disability score at 365 days (CFS frailty: -7.3 points, 95% confidence interval [CI] -10.2 to -4.5); (FP frailty: -5.4 points, 95% CI -8.5 to -2.3); people without frailty had no significant change in their disability score from baseline (no CFS frailty: +0.8 points, 95% CI -1.7 to 3.2; no FP frailty: +1.1 points, 95% CI -3.5 to 1.3). More than one-third of people with frailty experienced an early increase in disability before achieving a net decrease in disability. CONCLUSIONS: Decision-making and care planning should integrate the possible trade-offs between early adverse outcomes with longer-term benefit when frailty is present in older surgical patients.

Evaluation of a preoperative personalized risk communication tool: a prospective before-and-after study.

PURPOSE: Patients want personalized information before surgery; most do not receive personalized risk estimates. Inadequate information contributes to poor experience and medicolegal complaints. We hypothesized that exposure to the Personalized Risk Evaluation and Decision Making in Preoperative Clinical Assessment (PREDICT) app, a personalized risk communication tool, would improve patient knowledge and satisfaction after anesthesiology consultations compared with standard care. METHODS: We conducted a prospective clinical study (before-after design) and used patient-reported data to calculate personalized risks of morbidity, mortality, and expected length of stay using a locally calibrated National Surgical Quality Improvement Program risk calculator embedded in the PREDICT app. In the standard care (before) phase, the application's materials and output were not available to participants; in the PREDICT app (after) phase, personalized risks were communicated. Our primary outcome was knowledge score after the anesthesiology consultation. Secondary outcomes included patient satisfaction, anxiety, feasibility, and acceptability. RESULTS: We included 183 participants (90 before; 93 after). Compared with standard care phase, the PREDICT app phase had higher post-consultation: knowledge of risks (14.3% higher; 95% confidence interval [CI], 6.5 to 22.0; P < 0.001) and satisfaction (0.8 points; 95% CI, 0.1 to 1.4; P = 0.03). Anxiety was unchanged (- 1.9%; 95% CI, - 4.2 to 0.5; P = 0.13). Acceptability was high for patients and anesthesiologists. CONCLUSION: Exposure to a patient-facing, personalized risk communication app improved knowledge of personalized risk and increased satisfaction for adults before elective inpatient surgery. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03422133); registered 5 February 2018.

RéSUMé: OBJECTIF: Les patients veulent disposer d'informations personnalisées avant leur chirurgie, mais la plupart d'entre eux ne reçoivent pas d'estimations de leur risque personnalisées. Des informations inadéquates contribuent à une mauvaise expérience et à des plaintes médicolégales. Nous avons émis l'hypothèse qu'une exposition à l'application PREDICT (Personalized Risk Evaluation and Decision Making in Preoperative Clinical Assessment), un outil de communication du risque personnalisé, améliorerait les connaissances et la satisfaction des patients après leurs consultations en anesthésiologie comparativement à des soins standard. MéTHODE: Nous avons réalisé une étude clinique prospective (de type avant-après) et utilisé les données rapportées par les patients afin de calculer leur risque personnalisé de morbidité et de mortalité, ainsi que la durée de séjour anticipée à l'aide d'un calculateur de risque tiré du Programme national d'amélioration de la qualité chirurgicale que nous avons calibré localement et intégré à l'application PREDICT. Dans la phase de soins standard (avant), le contenu et les résultats de l'application n'étaient pas divulgués aux participants; dans la phase comportant l'application PREDICT (après), les risques personnalisés étaient communiqués. Notre critère d'évaluation principal était le score des connaissances des patients après la consultation en anesthésiologie. Les critères d'évaluation secondaires comprenaient la satisfaction des patients et leur niveau d'anxiété ainsi que la faisabilité et l'acceptabilité d'une telle approche. RéSULTATS: Nous avons inclus 183 participants (90 avant; 93 après). Comparativement à la phase de soins standard, la phase avec l'application PREDICT a démontré un niveau plus élevé de connaissances des risques post consultation (14,3 % plus élevé; intervalle de confiance [IC] 95 %, 6,5 à 22,0; P < 0,001) et de satisfaction (0,8 point; IC 95 %, 0,1 à 1,4; P = 0,03). L'anxiété est demeurée inchangée (− 1,9 %; IC 95 %, − 4,2 à 0,5; P = 0,13). L'acceptabilité était élevée, tant chez les patients que chez les anesthésiologistes. CONCLUSION: L'exposition des patients à une application de communication du risque personnalisé a amélioré leurs connaissances de leur risque personnalisé et augmenté la satisfaction des adultes avant une chirurgie non urgente et non ambulatoire. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03422133); enregistrée le 5 février 2018.

A Systematic Review of the Impact of Surgical Special Care Units on Patient Outcomes and Health Care Resource Utilization.

Perioperative intermediate care units (termed surgical special care units) have been widely implemented across health systems because they are believed to improve surveillance and management of high-risk surgical patients. Our objective was to conduct a systematic review to investigate the effects of a 3-level model of perioperative care delivery (ie, ward, surgical special care unit, or intensive care unit) compared to a 2-level model of care (ie, ward, intensive care unit) on postoperative outcomes. Our protocol was registered with PROSPERO, the international prospective register of systematic reviews (CRD42015025155). Randomized controlled studies and nonrandomized comparator studies were included. We performed a systematic search of Medline, Cumulative Index to Nursing and Allied Health Literature, Embase, and the Cochrane library (inception - 11/2017). The primary outcome was mortality; secondary outcomes included length of stay and hospital costs. We identified 1995 citations with our search, and 21 studies met eligibility criteria (2 randomized controlled studies and 19 nonrandomized comparator studies; 44,134 patients in total). Surgical special care units were characterized by continuous monitoring (12 studies), the absence of mechanical ventilation (8 studies), nurse-to-patient ratios (range, 1:2-1:4), and number of beds (median: 5; range: 3-33). Thirteen studies reported on mortality. Notable findings included no observed difference in overall in-hospital mortality, but an apparent increase in intensive care unit mortality in a 3-level model of care. This may reflect a decanting of lower acuity patients from the intensive care unit to the surgical special care unit. No significant difference was found in hospital length of stay; however, 2 studies demonstrated reductions in hospital costs with the implementation of a surgical special care unit. Significant clinical and methodological heterogeneity precluded pooled analysis. Given the prevalence of surgical special care units, the results of our review suggest that additional methodologically rigorous investigations are needed to understand the effect of these units on the surgical population.

Association of delay of urgent or emergency surgery with mortality and use of health care resources: a propensity score-matched observational cohort study.

BACKGROUND: Delay of surgery for hip fracture is associated with increased risk of morbidity and mortality, but the effects of surgical delays on mortality and resource use in the context of other emergency surgeries is poorly described. Our objective was to measure the independent association between delay of emergency surgery and in-hospital mortality, length of stay and costs. METHODS: We identified all adult patients who underwent emergency noncardiac surgery between January 2012 and October 2014 at a single tertiary care centre. Delay of surgery was defined as the time from surgical booking to operating room entry exceeding institutionally defined acceptable wait times, based on a standardized 5-level priority system that accounted for surgery type and indication. Patients with delayed surgery were matched to those without delay using propensity scores derived from variables that accounted for details of admission and the hospital stay, patient characteristics, physiologic instability, and surgical urgency and risk. RESULTS: Of 15 160 patients, 2820 (18.6%) experienced a delay. The mortality rates were 4.9% (138/2820) for those with delay and 3.2% (391/12 340) for those without delay (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.30-1.93). Within the propensity-matched cohort, delay was significantly associated with mortality (OR 1.56, 95% CI 1.18-2.06), increased length of stay (incident rate ratio 1.07, 95% CI 1.01-1.11) and higher total costs (incident rate ratio 1.06, 95% CI 1.01-1.11). INTERPRETATION: Delayed operating room access for emergency surgery was associated with increased risk of inhospital mortality, longer length of stay and higher costs. System issues appeared to underlie most delays and must be addressed to improve the outcomes of emergency surgery.

Predictors, Prognosis, and Management of New Clinically Important Atrial Fibrillation After Noncardiac Surgery: A Prospective Cohort Study.

BACKGROUND: Despite the frequency of new clinically important atrial fibrillation (AF) after noncardiac surgery and its increased association with the risk of stroke at 30 days, there are limited data informing their prediction, association with outcomes, and management. METHODS: We used the data from the PeriOperative ISchemic Evaluation trial to determine, in patients undergoing noncardiac surgery, the association of new clinically important AF with 30-day outcomes, and to assess management of these patients. We also aimed to derive a clinical prediction rule for new clinically important AF in this population. We defined new clinically important AF as new AF that resulted in symptoms or required treatment. We recorded an electrocardiogram 6 to 12 hours postoperatively and on the 1st, 2nd, and 30th days after surgery. RESULTS: A total of 211 (2.5% [8351 patients]; 95% confidence interval, 2.2%-2.9%) patients developed new clinically important AF within 30 days of randomization (8140 did not develop new AF). AF was independently associated with an increased length of hospital stay by 6.0 days (95% confidence interval, 3.5-8.5 days) and vascular complications (eg, stroke or congestive heart failure). The usage of an oral anticoagulant at the time of hospital discharge among patients with new AF and a CHADS2 score of 0, 1, 2, 3, and ≥4 was 6.9%, 10.2%, 23.0%, 9.4%, and 33.3%, respectively. Two independent predictors of patients developing new clinically important AF were identified (ie, age and surgery). The prediction rule included the following factors and assigned weights: age ≥85 years (4 points), age 75 to 84 years (3 points), age 65 to 74 years (2 points), intrathoracic surgery (3 points), major vascular surgery (2 points), and intra-abdominal surgery (1 point). The incidence of new AF based on scores of 0 to 1, 2, 3 to 4, and 5 to 6 was 0.5%, 1.0%, 3.1%, and 5.3%, respectively. CONCLUSIONS: Age and surgery are independent predictors of new clinically important AF in the perioperative setting. A minority of patients developing new clinically important AF with high CHADS2 scores are discharged on an oral anticoagulant. There is a need to develop effective and safe interventions to prevent this outcome and to optimize the management of this event when it occurs.

Professionalism in anesthesia.

PURPOSE: Is professionalism in medicine just another bureaucratic imposition on our practice or a fundamental concept for physicians at all stages in their career? In this review, the historical perspectives of professionalism are explored as well as the what, why, and how questions concerning this topic. SOURCE: The key words "professionalism" and "anesthesia" were used to conduct a search of the PubMed database, the policies and publications of relevant Canadian and international physician regulatory bodies and organizations, historical documents, and other internet publications. PRINCIPAL FINDINGS: Professionalism in anesthesia has a long history. While there are many definitions for professionalism, some very dated, all are based on virtues, behaviour, or professional identity. Professionalism plays a central role in the balance between physician autonomy and social contract, and it has a significant impact on patient safety and medicolegal litigation. CONCLUSION: Considerable evidence exists to suggest that professionalism must be treated seriously, particularly in these times of social accountability and budgetary pressures.

Postoperative real-time electrocardiography monitoring detects myocardial ischemia: a case report.

PURPOSE: This case report outlines the utility and challenges of remote continuous postoperative electrocardiography ECG) monitoring, which is routed through a secure smartphone to provide real-time detection and management of myocardial ischemia. CLINICAL FEATURES: A 42-yr-old male with previous myocardial infarction and angioplasty underwent a radical prostatectomy. At three hours and 45 min postoperatively, remote real-time ECG monitoring was initiated upon the patient's arrival on a regular surgical ward. Monitor alerts were routed to a study clinician's smartphone. About six hours postoperatively, alarms were received and horizontal ST segment depressions were observed. A 12-lead ECG validated the ST segment changes, prompting initiation of a metoprolol iv and a red blood cell transfusion. Approximately seven hours and 30 min postoperatively, the ST segments normalized. The patient was discharged on postoperative day 3 and followed for four years without any sequelae. CONCLUSION: This case report illustrates the use of remote ECG monitoring and clinician response in real time with the use of a smartphone. With each alert, a small ECG strip is transmitted to the smartphone for viewing. In our view, this technology and management system provides a possible means to interrupt myocardial ischemic cascades in real time and prevent postoperative myocardial infarction.

Perioperative Diastolic Dysfunction in Patients Undergoing Noncardiac Surgery Is an Independent Risk Factor for Cardiovascular Events: A Systematic Review and Meta-analysis.

BACKGROUND: The prognostic value of perioperative diastolic dysfunction (PDD) in patients undergoing noncardiac surgery remains uncertain, and the current guidelines do not recognize PDD as a perioperative risk factor. This systematic review aimed to investigate whether existing evidence supports PDD as an independent predictor of adverse events after noncardiac surgery. METHODS: Ovid MEDLINE, PubMed, EMBASE, the Cochrane Library, and Google search engine were searched for English-language citations in April 2015 investigating PDD as a risk factor for perioperative adverse events in adult patients undergoing noncardiac surgery. Two reviewers independently assessed the study risk of bias. Extracted data were verified. Random-effects model was used for meta-analysis, and reviewers' certainty was graded. RESULTS: Seventeen studies met eligibility criteria; however, 13 contributed to evidence synthesis. The entire body of evidence addressing the research question was based on a total of 3,876 patients. PDD was significantly associated with pulmonary edema/congestive heart failure (odds ratio [OR], 3.90; 95% CI, 2.23 to 6.83; 3 studies; 996 patients), myocardial infarction (OR, 1.74; 95% CI, 1.14 to 2.67; 3 studies; 717 patients), and the composite outcome of major adverse cardiovascular events (OR, 2.03; 95% CI, 1.24 to 3.32; 4 studies; 1,814 patients). Evidence addressing other outcomes had low statistical power, but higher long-term cardiovascular mortality was observed in patients undergoing open vascular repair (OR, 3.00; 95% CI, 1.50 to 6.00). Reviewers' overall certainty of the evidence was moderate. CONCLUSION: Evidence of moderate certainty indicates that PDD is an independent risk factor for adverse cardiovascular outcomes after noncardiac surgery.

Comparative assessment of two frailty instruments for risk-stratification in elderly surgical patients: study protocol for a prospective cohort study.

BACKGROUND: Frailty is an aggregate expression of susceptibility to poor outcomes, owing to age-, and disease-related deficits that accumulate within multiple domains. Older patients who are frail before surgery are at an increased risk of morbidity and mortality, and use a disproportionately high amount of healthcare resources. While frailty is now a well-established risk factor for adverse postoperative outcomes, the perioperative literature lacks studies that: 1) compare the predictive accuracy of different frailty instruments; 2) consider the impact of frailty on patient-reported outcome measures; and 3) consider the acceptability and feasibility of using frailty instruments in clinical practice. METHODS: We will conduct a multicenter prospective cohort study comparing the predictive accuracy of the modified Fried Index (mFI) with the Clinical Frailty Scale (CFS) among consenting patients aged 65 years and older having elective major non-cardiac surgery. The primary outcome will be disability free survival at 90 days after surgery, a patient-reported outcome measure. Secondary outcomes will include complications, length of stay, discharge disposition, readmission and total health system costs. We will compare the accuracy of frailty instruments using the relative true positive rate and relative false positive rate. These measures can be interpreted as the relative difference in the probability of one instrument identifying a true case of death or new disability compared to another instrument, or the relative difference in the probability of one instrument identifying a false case of death or new disability, respectively. We will also assess the acceptability and feasibility of each instrument. DISCUSSION: Frailty is an important prognostic factor in the growing population of older patients having surgery. This study will provide novel findings regarding the choice of an accurate, clinically useable frailty instrument in predicting patient reported outcomes, as well as morbidity, mortality and resource use. These findings will inform current practice and future research.

Nitrous oxide and serious morbidity and mortality in the POISE trial.

BACKGROUND: In this post hoc subanalysis of the Perioperative Ischemic Evaluation (POISE) trial, we sought to determine whether nitrous oxide was associated with the primary composite outcome of cardiovascular death, nonfatal myocardial infarction (MI), and nonfatal cardiac arrest within 30 days of randomization. METHODS: The POISE trial of perioperative ß-blockade was undertaken in 8351 patients. Nitrous oxide anesthesia was defined as the coadministration of nitrous oxide in patients receiving general anesthesia, with or without additional neuraxial blockade or peripheral nerve blockade. Logistic regression, with inverse probability weighting using estimated propensity scores, was used to determine the association of nitrous oxide with the primary outcome, MI, stroke, death, and clinically significant hypotension. RESULTS: Nitrous oxide was administered to 1489 (29%) of the 5133 patients included in this analysis. Nitrous oxide had no significant effect on the risk of the primary outcome (112 [7.5%] vs 248 [6.9%]; odds ratio [OR], 1.08; 95% confidence interval [CI], 0.82-1.44; 99% CI, 0.75-1.57; P = 0.58), MI (89 [6.0] vs 204 [5.6]; OR, 0.99; 95% CI, 0.75-1.31; 99% CI, 0.69-1.42; P = 0.94), stroke (6 [0.4%] vs 28 [0.8%]; OR, 0.85; 95% CI, 0.26-2.82; 99% CI, 0.17-4.11; P = 0.79), death (40 [2.7%] vs 100 [2.8%]; OR, 1.04; 95% CI, 0.6-1.81; 99% CI, 0.51-2.15; P = 0.88) or clinically significant hypotension (219 [14.7%] vs 544 [15.0%]; OR, 0.92; 95% CI, 0.74-1.15; 99% CI, 0.70-1.23; P = 0.48). CONCLUSIONS: In this post hoc subanalysis, nitrous oxide was not associated with an increased risk of adverse outcomes in the POISE trial patients. This analysis was limited by the observational nature of the data and the lack of information on the concentration and duration of nitrous oxide administration. Further randomized controlled trial evidence is required.

Characteristics and short-term prognosis of perioperative myocardial infarction in patients undergoing noncardiac surgery: a cohort study.

BACKGROUND: Each year, millions of patients worldwide have a perioperative myocardial infarction (MI) after noncardiac surgery. OBJECTIVE: To examine the characteristics and short-term outcome of perioperative MI. DESIGN: Cohort study. (ClinicalTrials.gov registration number: NCT00182039) SETTING: 190 centers in 23 countries. PATIENTS: 8351 patients included in the POISE (PeriOperative ISchemic Evaluation) trial. MEASUREMENTS: Four cardiac biomarker or enzyme assays were measured within 3 days of surgery. The definition of perioperative MI included either autopsy findings of acute MI or an elevated level of a cardiac biomarker or enzyme and at least 1 of the following defining features: ischemic symptoms, development of pathologic Q waves, ischemic changes on electrocardiography, coronary artery intervention, or cardiac imaging evidence of MI. RESULTS: Within 30 days of random assignment, 415 patients (5.0%) had a perioperative MI. Most MIs (74.1%) occurred within 48 hours of surgery; 65.3% of patients did not experience ischemic symptoms. The 30-day mortality rate was 11.6% (48 of 415 patients) among patients who had a perioperative MI and 2.2% (178 of 7936 patients) among those who did not (P < 0.001). Among patients with a perioperative MI, mortality rates were elevated and similar between those with (9.7%; adjusted odds ratio, 4.76 [95% CI, 2.68 to 8.43]) and without (12.5%; adjusted odds ratio, 4.00 [CI, 2.65 to 6.06]) ischemic symptoms. LIMITATION: Cardiac markers were measured only until day 3 after surgery, and additional asymptomatic MIs may have been missed. CONCLUSION: Most patients with a perioperative MI will not experience ischemic symptoms. Data suggest that routine monitoring of troponin levels in at-risk patients is needed after surgery to detect most MIs, which have an equally poor prognosis regardless of whether they are symptomatic or asymptomatic.

Perioperative myocardial ischemia and isolated systolic hypertension in non-cardiac surgery.

PURPOSE: To determine whether patients with isolated systolic hypertension (ISH) undergoing non-cardiac surgery have a higher incidence of perioperative myocardial ischemia than normotensive patients and hence a greater risk for perioperative adverse events. METHODS: After obtaining Research Ethics Board approval, patients were recruited to either an ISH group (systolic blood pressure [SBP] > 140 mmHg with diastolic blood pressure [DBP] < 90 mmHg) or a normotensive group (SBP < 140 mmHg and DBP < 90 mmHg), according to their resting preoperative blood pressure. The primary outcome was the overall incidence of perioperative myocardial ischemia (PMI) as determined by 48-hr ambulatory Holter monitoring. P values ≤ 0.05 were considered to be statistically significant. RESULTS: A total of 312 (150 ISH and 162 normotensive) patients completed the study. Orthopedic surgery was the most frequent surgical procedure in both groups. The overall incidence of PMI was 19.7% in the ISH group compared with 18.8% in the normotensive group (difference 0.9%; 95% confidence interval [CI], -7.9% to 9.8%). The overall incidence of adverse events was 4.0% in the ISH group compared with 1.9% in the normotensive group (difference 2.2%; 95% CI, -1.6% to 5.9%). CONCLUSION: In this study, we chose to examine ISH as potential cardiac risk factor for patients undergoing non-cardiac surgery. The incidence of myocardial ischemia, a surrogate outcome, was similar in the two groups. The relatively high incidence of myocardial ischemia (19.2%) was of particular interest in this relatively low cardiac risk surgical population. (ClinicalTrials.gov number, NCT01237652).