Diem Tran

Predicting New-Onset Postoperative Atrial Fibrillation in Cardiac Surgery Patients

OBJECTIVE To derive a simple clinical prediction rule identifying patients at high risk of developing new-onset postoperative atrial fibrillation (POAF) after cardiac surgery. DESIGN Retrospective analysis on prospectively collected observational data. SETTING A university-affiliated cardiac hospital. PARTICIPANTS Adult patients undergoing coronary artery bypass grafting and/or valve surgery. INTERVENTIONS Observation for the occurrence of new-onset postoperative atrial fibrillation. MEASUREMENTS AND MAIN RESULTS Details on 28 preoperative variables from 999 patients were collected and significant predictors (p<0.2) were inserted into multivariable logistic regression and reconfirmed with recursive partitioning. A total of 305 (30.5%) patients developed new-onset POAF. Eleven variables were associated significantly with atrial fibrillation. A multivariable logistic regression model included left atrial dilatation, mitral valve disease, and age. Coefficients from the model were converted into a simple 7-point predictive score. The risk of POAF per score is: 15.0%, if 0; 20%, if 1; 27%, if 2; 35%, if 3; 44%, if 4; 53%, if 5; 62%, if 6; and 70%, if 7. A score of 4 has a sensitivity of 44% and a specificity of 82% for POAF. A score of 6 has a sensitivity of 11% and a specificity of 97%. Bootstrapping with 5,000 samples confirmed the final model provided consistent predictions. CONCLUSIONS This study proposed a simple predictive score incorporating three risk variables to identify cardiac surgical patients at high risk of developing new-onset POAF. Preventive treatment should target patients ≥ 65 years with left atrial dilatation and mitral valve disease.

Impact of anesthetic handover on mortality and morbidity in cardiac surgery: a cohort study.

OBJECTIVE Clinical handover is a critical moment in patient care. The authors tested the hypothesis that handover of anesthesia care is associated with increased mortality and morbidity in patients undergoing cardiac surgery. DESIGN This was a single-center, retrospective cohort study of prospectively collected data. SETTING The study was conducted in a quaternary care cardiac surgery center and university research hospital. PARTICIPANTS All patients undergoing cardiac surgical procedures between April 1, 1999 and October 31, 2009 were included in the study. INTERVENTIONS Propensity-score matching was used to adjust for differences between patients who received intraoperative handover of anesthesia care and those who did not, and in-hospital mortality and morbidity were compared using multivariate logistic modeling. MEASUREMENTS AND MAIN RESULTS 14,421 patients met the inclusion criteria for this study; handover occurred in 966 cases (6.7%). After propensity-score matching, 7,137 patients were included for analysis. In-hospital mortality was 5.4% in the handover group and 4.0% in the non-handover group (match-adjusted odds ratio, 1.425; 95% confidence interval, 1.013-2.006; p = 0.0422); the incidence of major morbidity was 18.5% in the handover group and 15.6% in the non-handover group (match-adjusted odds ratio, 1.274; 95% confidence interval, 1.037-1.564; p = 0.0212). CONCLUSIONS Handover of anesthetic care during cardiac surgery is associated with a 43% greater risk of in-hospital mortality and 27% greater risk of major morbidity. Further studies are required to explore this relationship and to systematically evaluate and improve the process of handover.

Rocuronium vs. succinylcholine for rapid sequence intubation: a Cochrane systematic review†

This systemic review was performed to determine whether rocuronium creates intubating conditions comparable to those of succinylcholine during rapid sequence intubation of the trachea. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 2), MEDLINE (1966 to February Week 2 2015), and EMBASE (1988 to February 14 2015) for any randomised controlled trials or controlled clinical trials that reported intubating conditions comparing rocuronium and succinylcholine for rapid or modified rapid sequence intubation. The dose of rocuronium was at least 0.6 mg.kg−1 and succinylcholine was at least 1 mg.kg−1. Sixty‐six studies were identified and 50 included, representing 4151 participants. Overall, succinylcholine was superior to rocuronium for achieving excellent intubating conditions (risk ratio (95%CI) 0.86 (0.81 to 0.92), n = 4151) and clinically acceptable intubation conditions (risk ratio (95%CI) 0.97 (0.95–0.99), n = 3992). A high incidence of detection bias amongst the trials coupled with significant heterogeneity means that the quality of evidence was moderate for these conclusions. Succinylcholine was more likely to produce excellent intubating conditions when using thiopental as the induction agent: risk ratio (95%CI) 0.81 (0.73–0.88), n = 2302) with or without the use of opioids (risk ratio (95%CI) 0.85 (0.78–0.93), n = 2292 or 0.85 (0.76–0.95), n = 1428).

Effects of a change in entry-to-practice criteria for cardiovascular perfusion in Canada: results of a national survey

Introduction: Years of experience and level of education are two important determinants of a clinician’s expertise. While entry-to-practice criteria for admission to perfusion training in Canada changed from clinical experience-based criteria to education-based criteria in 2006, the effects of these changes have not been studied. Objective: To determine the academic and clinical backgrounds of perfusionists in Canada, ascertain perceptions about the adequacy of training and evaluate the effects of the changes on the composition of the perfusion community of Canada. Methods: An electronic questionnaire was distributed to all practicing perfusionists in Canada, addressing details regarding clinical experience, academic education and perceptions about the adequacy of training. Results: Two hundred and twenty-eight questionnaires were completed, representing a 72% response rate. Perfusionists admitted under academic-based criteria have significantly higher levels of education (100% degree holders vs 69.1%, p<0.001), but less antecedent clinical training and experience (median, IQR: 0, 0 – 4.5 years vs 2, 2 – 8 years, p<0.0001), are younger (median age range 31-35 years vs 51-55 years, p<0.0001), more likely to be female (58.7% vs 41.3%, p=0.006) and are significantly more likely to enter perfusion because of attraction to the type of work (p=0.045). Many perfusionists (70, 32%) in Canada believe themselves inadequately trained for their clinical assignments outside the OR. In addition, 19% of perfusionists plan to retire over the next 10 years. Conclusions: The introduction of education-based entry criteria has changed the academic and clinical experience levels of perfusionists in Canada. Strategies designed to better prepare perfusionists for their clinical assignments outside the OR are merited.

Remote solutions for telementoring point-of-care ultrasound echocardiography: The RESOLUTE study

To the Editor, Point-of-care ultrasound (POCUS), which has revolutionised patient assessment, traditionally relies on the availability of a skilled operator to acquire and interpret images. Although the relevant declarative knowledge needed to perform POCUS is generally available (e.g., medical literature, web-based videos), teaching the required psychomotor skills is challenging without the physical presence of an instructor. Telementoring is a novel, evolving technology in medical education that permits remote instruction of a skill through videoconferencing. We sought to demonstrate that the psychomotor skills required to perform cardiac POCUS can be acquired through telementoring. After institutional ethics review approval (REB 2016081401H), 33 intensive care unit nurses with no previous sonography training were recruited. Participants interacted with a high-fidelity transthoracic echocardiography simulator (VIMEDIX; CAE Healthcare, Ville St-Laurent, QC, Canada) connected via REACTS video conferencing software to a remotely located instructor (R.C.). Following a video-conferenced instructional period, each participant was remotely guided to obtain five standard POCUS views. The simulator was then randomized to one of four pre-set pathologies (anterior myocardial infarction, cardiac tamponade, dilated cardiomyopathy, ventricular fibrillation). The instructor then remotely guided the participant to obtain the views required to diagnose the underlying pathology. Both the subject and instructor were blinded to the pathology. To facilitate psychomotor instruction, two web cameras provided vantage points for the instructor to assess the probe’s position. Instruction of cardinal movements was simplified by colour-coding the probe. Additionally, we utilized the feature of REACTS software that allows the instructor to overlay a pointer (red dot) on the live-feed to direct probe placement on the mannequin (Figure). The instructional period needed to orient participants took a mean (SD) of 142 (40) sec, and the time required to obtain the five standardized POCUS images was 324 (116) sec. The remote instructor subsequently required 84 (49) sec to guide the participants through a focused POCUS examination and obtain a diagnosis of the underlying preset pathology. The acquired loops were subsequently reviewed by two experts (S.M., B.H.) who rated them using a previously validated scale for assessing POCUS image quality. Using the rapid assessment of competence in echocardiography score, both reviewers judged that more than 90% of the echo loops were of sufficient quality for basic image interpretation (scores were C 3), and each correctly identified 32 of 33 cardiac pathologies. We acknowledge that this simulator study has limitations, but we believe that the demonstration that psychomotor skills can be telementored has important E. K. H. Choo, MD (&) R. Chen, MD D. T. T. Tran, MD B. Sohmer, MD Division of Cardiac Anesthesiology, University of Ottawa Heart Institute, Ottawa, ON, Canada e-mail: choo.eugene@gmail.com

The effect of preoperative anemia on patients undergoing cardiac surgery: a propensity-matched analysis

It is unknown if anemia in the absence of transfusions is an independent risk factor for adverse outcomes in cardiac surgery, and if correction to higher hemoglobin targets impacts these outcomes. This is a retrospective review of 3848 cardiac surgery patients. Propensity matching was completed using 41 covariates. Intraoperative Anemia Analysis matched patients with or without anemia who did not receive intraoperative transfusions (n = 392/group), while Intraoperative Transfusion Analysis matched anemic patients treated conventionally with intraoperative transfusions to end cardiopulmonary bypass hemoglobin greater or less than 95 g/L (n = 261/group). Outcomes of death, renal failure, and 2 composite outcomes were assessed using paired analysis techniques. Study composite 1 consisted of prolonged ventilation, renal failure, myocardial infarction, stroke, or deep sternal wound infection, while composite 2 was the TRICS-III composite. In the Intraoperative Anemia Analysis, anemia was associated with mortality (P = 0.034), stroke (P = 0.021), renal failure (P = 0.015), and a significant increase in the composite measure (control 8.7% vs anemia 16.1%, P = 0.002). These findings were unchanged in patients who did not receive any postoperative transfusions. The Intraoperative Transfusion Analysis showed no difference in mortality or the composite outcome between groups. There was a significant increase in low cardiac output in the lower threshold group (P = 0.001). There were no differences in outcomes between those who did and did not receive postoperative transfusions (P > 0.05). Preoperative anemia in the absence of transfusions is a risk factor for morbidity and mortality after cardiac surgery, and there is no evidence that transfusion to higher end cardiopulmonary bypass hemoglobin levels impacted this risk.

Practice meta-environment of the cardiovascular perfusionist:

Though historically the development of cardiovascular perfusion grew out of the need for cardiopulmonary bypass, the application of technologies of extracorporeal support has more recently expanded beyond the traditional domain of the cardiac surgical operative and peri-operative environment. As a result, perfusionists are sometimes required to work in novel clinical settings. As part of our recent national survey to evaluate the effects of changes in entry-to-practice criteria introduced in Canada in 2006, we asked perfusionists if their current position as a perfusionist involves work outside the OR. We found that, in addition to regularly working in the Intensive Care Unit and Cardiac Catheterization Lab, 55.3% of respondents reported working “occasionally” in the Emergency Room and 74.7% reported working “occasionally” or “often” in other clinical areas. However, while 96% of respondents believed their training adequately prepared them for their job as a perfusionist, only 68% felt their training adequately prepared them for their duties outside the operating room. We also noted a trend that admission under experience-based entry-to-practice criteria was associated with a higher likelihood of perceived adequacy of training in preparation for duties outside the OR than education-based admission criteria (72% vs 59.4%, p=0.065). These findings raise important questions pertaining to the sufficiency of perfusion education in Canada and the influence of soft skills in preparing perfusionists for their duties, and indicate that a systematic study of the practice environment of cardiovascular perfusionists is timely.

Ischemic and bleeding outcomes after coronary artery bypass grafting among patients initially treated with a P2Y12 receptor antagonist for acute coronary syndromes: Insights on timing of discontinuation of ticagrelor and clopidogrel prior to surgery:

Background: Clinical outcomes in acute coronary syndrome patients treated with P2Y12 inhibitors who require urgent coronary artery bypass grafting (CABG) have not been well studied. Methods: We examined clinical outcomes in acute coronary syndrome patients in relation to the timing of CABG following P2Y12 inhibitor discontinuation (<72 h, 72 h to five days, >5 days). The primary ischemic outcome was a composite of death, reinfarction, need for revascularization, or stroke. The primary safety outcome was bleeding of at least moderate severity as defined by a Universal Definition of Perioperative Bleeding class ≥2. Results: Among 508 patients (95 ticagrelor, 413 clopidogrel), the timing of CABG following P2Y12 inhibitor discontinuation was <72 h in 32.1%, 72 h to five days in 23.2% and >5 days in 44.7%. Compared with CABG within 72 h, CABG 72 h to five days (adjusted odds ratio (OR) 0.35; 95% confidence interval (CI) 0.14–0.85; p=0.02) but not >5 days (adjusted OR 0.62; 95% CI 0.33–1.16; p=0.14) after P2Y12 inhibitor discontinuation was associated with lower odds of the primary ischemic outcome. Compared with CABG within 72 h, CABG 72 h to five days (adjusted OR 0.38; 95% CI 0.22–0.66; p=0.001) and >5 days (adjusted OR 0.33; 95% CI 0.20–0.53; p<0.001) after P2Y12 inhibitor discontinuation were associated with lower rates of Universal Definition of Perioperative Bleeding class ≥2 bleeding. Conclusions: CABG within 72 h after P2Y12 inhibitor discontinuation is associated with excess ischemia and bleeding. The rates of ischemic and bleeding events were comparable in patients undergoing CABG 72 h to five days compared with >5 days after P2Y12 inhibitor discontinuation.

The balance between short-term and long-term outcomes of bilateral internal thoracic artery skeletonization in coronary artery bypass surgery: a propensity-matched cohort study†

OBJECTIVES There is growing interest in the use of bilateral internal thoracic arteries (BITAs) for myocardial revascularization. This study sought to compare the balance between early benefits and long-term outcomes of skeletonized or non-skeletonized conduits and to determine whether differences in outcomes are affected by other patient risk factors. METHODS BITAs were used in 1504 cases with either SK or NSK conduits. Propensity matching was completed using 22 covariates identifying 441 pairs of patients. The primary outcomes are the sternal wound infection in the short term and the composite outcome of all-cause mortality, myocardial infarction, revascularization and congestive heart failure. Outcomes were assessed using paired analysis techniques and Cox proportional hazards regression models stratified using the matched pairs. RESULTS Incidences of in-hospital mortality and perioperative myocardial infarction were similar in both groups. There were fewer sternal wound infections in the SK group (5.4 vs 9.1%, P = 0.033). Homogeneity testing of the relative risk estimates confirmed that there was a protective effect of skeletonization in men that was not demonstrated in women (P = 0.020). SK had a protective effect in diabetics not seen in non-diabetics (P = 0.048). The composite outcome of all-cause mortality, myocardial infarction, revascularization and congestive heart failure at a median of 5.6 years was comparable in both groups (hazard ratio 0.81, 95% confidence interval 0.57-1.15). CONCLUSION Skeletonization results in better perioperative outcomes and comparable cardiac outcomes in patients undergoing BITA with the greatest benefit in men and patients with chronic obstructive pulmonary disease.

Suxamethonium or rocuronium for rapid sequence induction of anaesthesia? A reply

I thank Dr. Dinsmore for his comments on our systematic review comparing succinylcholine and rocuronium for rapid sequence intubation [1], which is the fourth update of the original paper reported in 2002 [2]. The study comparison of succinylcholine 1.0 mg.kg 1 vs. a minimum of 0.6 mg.kg 1 rocuronium was a relevant dosing question, as the efficacy of 1.0 mg.kg 1 rocuronium was not established practice at that time. The subgroup analyses for this study with the specific dosing comparisons were made a priori, as well as the primary outcome definition of ‘excellent intubating conditions’ in 2002. ‘Acceptable intubating conditions’ was a secondary outcome, encompassing both ‘excellent’ and ‘good’ intubating conditions. The Cochrane collaboration encourages the updating systematic reviews to accommodate data from new trials, especially if the conclusions of the systematic review may change. With this update, we have maintained our consistent methodology in reporting the primary outcome: excellent intubating conditions with the same subgroup analyses of rocuronium dosing. In the discussion, we concluded that ‘succinylcholine created significantly more excellent intubation conditions than rocuronium at doses of 0.6–0.7 mg.kg ’, but in the next sentence we also stated that ‘there was no statistically significant difference for the 0.9–1.0 mg.kg 1 or 1.2 mg.kg 1 groups, reaffirming the current practice of using 1 mg.kg 1 of rocuronium for rapid sequence intubation when succinylcholine is not clinically indicated’. This statement allowed us to report the answer toouroriginal researchquestion from 2002 comparing 1.0 mg.kg 1 of succinylcholine vs. 0.6 mg.kg 1 of rocuronium, but also to highlight the currentpracticeofusingahigherdoseof rocuroniumforrapid intubation. With regard to the resultant prolonged neuromuscular block with higher doses of rocuronium, this is the first update to mention the new reversal agent sugammadex. Its availability certainly makes the prolonged effects of rocuronium less concerning for those who have immediate access to it. Sugammadex is well suited for the treatment of unwanted residual muscle paralysis, but its use in difficult airway management or emergencies has not been studied. The availability of sugammadex is not consistent within the affluent nations and its cost is prohibitive for many countries around the world. Thus, the authors felt it was still prudent to continue to warn readers that 1.0 mg.kg 1 of rocuronium was equally effective as 1.0 mg.kg 1 of succinylcholine, at the cost of a much longer paralysis period. Certainly the clinical question addressed in this systematic review has been settled in current clinical practice, with the administration of 1.0 mg.kg 1 rocuronium to patients for rapid sequence induction when succinylcholine is not appropriate. Conversely, this review should also remind readers that, when selected appropriately, succinylcholine is still an excellent choice to produce the most optimal intubation conditions, especially in emergencies and when the airway is challenging to secure.