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Martin B.-J.,University of Calgary | Arora R.C.,Cardiac science Program
Critical Care | Year: 2013

Post-operative delirium is a common and dangerous complication of cardiac surgery. Many risk factors for delirium have been identified, but its pathogenesis remains largely elusive. A study by Kazmierski and colleagues investigates a more recently considered risk factor for delirium: perturbations in the hypothalamic pituitary axis and depression. This and further work may help define novel prevention and treatment strategies for delirium. © 2013 BioMed Central Ltd. Source

Collister D.,Seven Oaks General Hospital Renal Program | Komenda P.,Seven Oaks General Hospital Renal Program | Hiebert B.,Cardiac science Program | Gunasekara R.,Seven Oaks General Hospital Renal Program | And 6 more authors.
Annals of Internal Medicine | Year: 2016

Background: The efficacy of erythropoietin-stimulating agents (ESAs) for improving health-related quality of life (HRQOL) in anemia of chronic kidney disease (CKD) is unclear. Purpose: To determine the effect of ESAs on HRQOL at different hemoglobin targets in adults with CKD who were receiving or not receiving dialysis. Data Sources: Searches of PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to 1 November 2015, supplemented with manual screening. Study Selection: Randomized, controlled trials that evaluated the treatment of anemia with ESAs, including erythropoietin and darbepoetin, targeted higher versus lower hemoglobin levels, and used validated HRQOL metrics. Data Extraction: Study characteristics, quality, and data were assessed independently by 2 reviewers. Outcome measures were scores on the Short Form-36 Health Survey (SF-36), Kidney Dialysis Questionnaire (KDQ), and other tools. Data Synthesis: Of 17 eligible studies, 13 reported SF-36 outcomes and 4 reported KDQ outcomes. Study populations consisted of patients not undergoing dialysis (n = 12), those undergoing dialysis (n = 4), or a mixed sample (n = 1). Only 4 studies had low risk of bias. Pooled analyses showed that higher hemoglobin targets resulted in no statistically or clinically significant differences in SF-36 or KDQ domains. Differences in HRQOL were further attenuated in studies at low risk of bias and in subgroups of dialysis recipients. Limitation: Statistically significant heterogeneity among studies, few good-quality studies, and possible publication bias. Conclusion: ESA treatment of anemia to obtain higher hemoglobin targets does not result in important differences in HRQOL in patients with CKD. © 2016 American College of Physicians. Source

Jung P.,University of Manitoba | Pereira M.A.,University of Manitoba | Hiebert B.,Cardiac science Program | Song X.,Dalhousie University | And 3 more authors.
Journal of Thoracic and Cardiovascular Surgery | Year: 2015

Objective To determine if adding frailty measures to the EuroSCORE II improves model performance in predicting postoperative delirium. Methods In a prospective observational study in elective cardiac surgery patients, frailty was defined using the Modified Fried Criteria (MFC), the Short Physical Performance Battery (SPPB) and a 35-item Frailty Index (FI). The primary outcome was postoperative delirium, assessed using the Confusion Assessment Method (CAM). Results Seventy-two (54.1%) of the 133 participants met the MFC definition for frailty and 69 (51.9%) met the SPPB definition. Eighty-eight (66.2%) participants had an FI score ≥0.2, and 47 (35.3%) had a score ≥0.3. After adjusting for the EuroSCORE II, frail patients as identified by the MFC were at increased risk of postoperative delirium (adjusted odds ratio [OR], 5.05, 95% confidence interval [CI], 1.58-16.13). Patients in the "high risk frailty" SPPB category had even greater risk (adjusted OR, 8.26, 95% CI, 2.23-30.64). FI scores ≥0.3 were also associated with higher risk of delirium (adjusted OR, 3.72, 95% CI, 1.39-9.92). The inclusion of any of these definitions of frailty improved the discrimination of the EuroSCORE II in predicting postoperative delirium. Conclusions Frailty results in a 3-to 8-fold increase in risk of postoperative delirium, independent of the EuroSCORE II. "Frail" and "fit" may be considered 2 ends of a continuum, and the risk of postoperative delirium grows as one becomes increasingly frail. The addition of frailty improves the ability of the EuroSCORE II to predict postoperative delirium, pointing to opportunities for improved prevention and management. © 2015 The American Association for Thoracic Surgery. Source

Arenson B.G.,University of Manitoba | MacDonald L.A.,University of Manitoba | Grocott H.P.,University of Manitoba | Hiebert B.M.,Cardiac science Program | Arora R.C.,University of Manitoba
Journal of Thoracic and Cardiovascular Surgery | Year: 2013

Objectives: The etiology of postcardiac surgery delirium is complex. Our primary objective was to determine the effect of the postoperative environment on the prevalence of delirium by examining the in-hospital delirium rates in 2 postoperative intensive care units with differing physical infrastructure. We further sought to identify other risk factors associated with in-hospital delirium. Methods: The rates of postoperative delirium were retrospectively examined in consecutive cardiac surgery patients during 2 separate 6-month periods. Environment 1 was characterized by a lack of physical barriers between bed spaces and was windowless, and environment 2 consisted of private rooms with physical barriers for each patient and with wall-to-wall exterior windows. Univariate and multivariate analyses to determine the risk factors associated with in-hospital delirium, including the effect of environment, were undertaken. Results: Of the 1010 patients studied, 148 (14.7%) experienced in-hospital delirium after cardiac surgery. The prevalence of delirium was not significantly different between environments 1 and 2 (16.1% vs 13.5%; P =.25). However, in patients younger than 65 years, the proportion of intensive care unit days on which delirium occurred was greater in environment 1 than in environment 2 (5.4% vs 1.7%; P =.006). Postoperative stroke or transient ischemic attack, mechanical ventilation longer than 24 hours, age 65 years or older, concomitant coronary artery bypass grafting and valve surgery, prehospital admission benzodiazepine use, a requirement for any postoperative blood product transfusion, and postoperative renal insufficiency were identified as risk factors. Conclusions: The intensive care unit environment did not have a significant effect on the overall prevalence of delirium. However, that does not preclude the possibility that the intensive care unit environment might interact with other factors, such as age, in a complex manner. Attempts to reduce delirium by adjusting the intensive care unit environment alone will likely not be sufficient, and instead will require a more comprehensive multimodal approach. © 2013 by The American Association for Thoracic Surgery. Source

O'Blenes S.B.,Dalhousie University | Li A.W.,Dalhousie University | Chen R.,Dalhousie University | Arora R.C.,Cardiac science Program | Horackova M.,Dalhousie University
Annals of Thoracic Surgery | Year: 2010

Background: In a recent clinical trial, skeletal myoblast (SKMB) transplantation performed late after myocardial infarction (MI) did not improve left ventricular function. We hypothesized that (1) delaying SKMB transplantation until a chronic infarct scar has developed reduces engraftment, and (2) hepatocyte growth factor (HGF), a main regulator of SKMBs, is present in acute but not chronic MI, potentially influencing engraftment. Methods: Rats underwent coronary artery ligation followed by SKMB transplantation immediately (n = 12) or delayed by 5 weeks (n = 11). The volume of engrafted SKMBs was quantified 6 weeks later. Hepatocyte growth factor was evaluated by computerized analysis of immunohistochemical labeling of rat heart sections 48 hours, 1 week, 2 weeks, and 5 weeks after coronary artery ligation. The impact of HGF on SKMB proliferation and its ability to protect against oxidative stress and hypoxia was evaluated in vitro. Results: Skeletal myoblast transplantation immediately after MI resulted in an engraftment volume of 29.1 ± 2.9 mm3. However, delaying SKMB transplantation 5 weeks caused a 95% drop in engraftment (1.4 ± 0.3 mm3; p < 0.001). Hepatocyte growth factor labeling in MIs 48 hours after coronary artery ligation was similar to control myocardium (18.0 ± 2.0 versus 16.8 ± 1.3 units). However, HGF declined progressively at 1, 2, and 5 weeks after MI (9.1 ± 1.4, 4.2 ± 0.4, and 3.1 ± 0.6 units, respectively; p < 0.05 versus 48 hours). Hepatocyte growth factor caused a dose-dependent increase in SKMB proliferation in vitro and protected against oxidative stress and hypoxia. Conclusions: These results demonstrate that engraftment of SKMBs is impaired when transplantation is delayed until a chronic infarct has developed. Hepatocyte growth factor in MI declines with time and may enhance engraftment of SKMBs transplanted early after MI. Delivery of exogenous HGF to enhance SKMB engraftment in chronic infarcts warrants further investigation. © 2010 The Society of Thoracic Surgeons. Source

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