Daniel Bainbridge

Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study.

BACKGROUND:Cerebral deoxygenation is associated with various adverse systemic outcomes. We hypothesized, by using the brain as an index organ, that interventions to improve cerebral oxygenation would have systemic benefits in cardiac surgical patients. METHODS:Two-hundred coronary artery bypass patients were randomized to either intraoperative cerebral regional oxygen saturation (rSO2) monitoring with active display and treatment intervention protocol (intervention, n = 100), or underwent blinded rSO2 monitoring (control, n = 100). Predefined clinical outcomes were assessed by a blinded observer. RESULTS:Significantly more patients in the control group demonstrated prolonged cerebral desaturation (P = 0.014) and longer duration in the intensive care unit (P = 0.029) versus intervention patients. There was no difference in overall incidence of adverse complications, but significantly more control patients had major organ morbidity or mortality (death, ventilation >48 h, stroke, myocardial infarction, return for re-exploration) versus intervention group patients (P = 0.048). Patients experiencing major organ morbidity or mortality had lower baseline and mean rSO2, more cerebral desaturations and longer lengths of stay in the intensive care unit and postoperative hospitalization, than patients without such complications. There was a significant (r2 = 0.29) inverse correlation between intraoperative rSO2 and duration of postoperative hospitalization in patients requiring ≥10 days postoperative length of stay. CONCLUSION:Monitoring cerebral rSO2 in coronary artery bypass patients avoids profound cerebral desaturation and is associated with significantly fewer incidences of major organ dysfunction.

Does Off-pump Coronary Artery Bypass Reduce Mortality, Morbidity, and Resource Utilization When Compared with Conventional Coronary Artery Bypass? A Meta-analysis of Randomized Trials

The authors undertook a meta-analysis of 37 randomized trials (3369 patients) of off-pump coronary artery bypass surgery versus conventional coronary artery bypass surgery. No significant differences were found for 30-day mortality (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.58–1.80), myocardial infarction (OR, 0.77; 95%CI, 0.48–1.26), stroke (OR, 0.68; 95%CI, 0.33–1.40), renal dysfunction, intraaortic balloon pump, wound infection, rethoracotomy, or reintervention. However, off-pump coronary artery bypass surgery significantly decreased atrial fibrillation (OR, 0.58; 95%CI, 0.44–0.77), transfusion (OR, 0.43; 95%CI, 0.29–0.65), inotrope requirements (OR, 0.48; 95%CI, 0.32–0.73), respiratory infections (OR, 0.41; 95%CI, 0.23–0.74), ventilation time (weighted mean difference, −3.4 h; 95%CI, −5.1 to −1.7 h), intensive care unit stay (weighted mean difference, −0.3 days; 95%CI −0.6 to −0.1 days), and hospital stay (weighted mean difference, −1.0 days; 95%CI −1.5 to −0.5 days). Patency and neurocognitive function results were inconclusive. In-hospital and 1-yr direct costs were generally higher for conventional coronary artery bypass surgery versus off-pump coronary artery bypass surgery. Therefore, this meta-analysis demonstrates that mortality, stroke, myocardial infarction, and renal failure were not reduced in off-pump coronary artery bypass surgery surgery; however, selected short-term and mid-term clinical and resource outcomes were improved compared with conventional coronary artery bypass surgery.

Perioperative and anaesthetic-related mortality in developed and developing countries: a systematic review and meta-analysis

BACKGROUND The magnitude of risk of death related to surgery and anaesthesia is not well understood. We aimed to assess whether the risk of perioperative and anaesthetic-related mortality has decreased over the past five decades and whether rates of decline have been comparable in developed and developing countries. METHODS We did a systematic review to identify all studies published up to February, 2011, in any language, with a sample size of over 3000 that reported perioperative mortality across a mixed surgical population who had undergone general anaesthesia. Using standard forms, two authors independently identified studies for inclusion and extracted information on rates of anaesthetic-related mortality, perioperative mortality, cardiac arrest, American Society of Anesthesiologists (ASA) physical status, geographic location, human development index (HDI), and year. The primary outcome was anaesthetic sole mortality. Secondary outcomes were anaesthetic contributory mortality, total perioperative mortality, and cardiac arrest. Meta-regression was done to ascertain weighted event rates for the outcomes. FINDINGS 87 studies met the inclusion criteria, within which there were more than 21·4 million anaesthetic administrations given to patients undergoing general anaesthesia for surgery. Mortality solely attributable to anaesthesia declined over time, from 357 per million (95% CI 324-394) before the 1970s to 52 per million (42-64) in the 1970s-80s, and 34 per million (29-39) in the 1990s-2000s (p<0·00001). Total perioperative mortality decreased over time, from 10,603 per million (95% CI 10,423-10,784) before the 1970s, to 4533 per million (4405-4664) in the 1970s-80s, and 1176 per million (1148-1205) in the 1990s-2000s (p<0·0001). Meta-regression showed a significant relation between risk of perioperative and anaesthetic-related mortality and HDI (all p<0·00001). Baseline risk status of patients who presented for surgery as shown by the ASA score increased over the decades (p<0·0001). INTERPRETATION Despite increasing patient baseline risk, perioperative mortality has declined significantly over the past 50 years, with the greatest decline in developed countries. Global priority should be given to reducing total perioperative and anaesthetic-related mortality by evidence-based best practice in developing countries. FUNDING University of Western Ontario.

The efficacy of an intraoperative cell saver during cardiac surgery: a meta-analysis of randomized trials.

BACKGROUND: Cell salvage may be used during cardiac surgery to avoid allogeneic blood transfusion. It has also been claimed to improve patient outcomes by removing debris from shed blood, which may increase the risk of stroke or neurocognitive dysfunction. In this study, we sought to determine the overall safety and efficacy of cell salvage in cardiac surgery by performing a systematic review and meta-analysis of published randomized controlled trials. METHODS: A comprehensive search was undertaken to identify all randomized trials of cell saver use during cardiac surgery. MEDLINE, Cochrane Library, EMBASE, and abstract databases were searched up to November 2008. All randomized trials comparing cell saver use and no cell saver use in cardiac surgery and reporting at least one predefined clinical outcome were included. The random effects model was used to calculate the odds ratios (OR, 95% confidence intervals [CI]) and the weighted mean differences (WMD, 95% CI) for dichotomous and continuous variables, respectively. RESULTS: Thirty-one randomized trials involving 2282 patients were included in the meta-analysis. During cardiac surgery, the use of an intraoperative cell saver reduced the rate of exposure to any allogeneic blood product (OR 0.63, 95% CI: 0.43-0.94, P = 0.02) and red blood cells (OR 0.60, 95% CI: 0.39-0.92, P = 0.02) and decreased the mean volume of total allogeneic blood products transfused per patient (WMD −256 mL, 95% CI: −416 to −95 mL, P = 0.002). There was no difference in hospital mortality (OR 0.65, 95% CI: 0.25-1.68, P = 0.37), postoperative stroke or transient ischemia attack (OR 0.59, 95% CI: 0.20-1.76, P = 0.34), atrial fibrillation (OR 0.92, 95% CI: 0.69-1.23, P = 0.56), renal dysfunction (OR 0.86, 95% CI: 0.41-1.80, P = 0.70), infection (OR 1.25, 95% CI: 0.75-2.10, P = 0.39), patients requiring fresh frozen plasma (OR 1.16, 95% CI: 0.82-1.66, P = 0.40), and patients requiring platelet transfusions (OR 0.90, 95% CI: 0.63-1.28, P = 0.55) between cell saver and noncell saver groups. CONCLUSIONS: Current evidence suggests that the use of a cell saver reduces exposure to allogeneic blood products or red blood cell transfusion for patients undergoing cardiac surgery. Subanalyses suggest that a cell saver may be beneficial only when it is used for shed blood and/or residual blood or during the entire operative period. Processing cardiotomy suction blood with a cell saver only during cardiopulmonary bypass has no significant effect on blood conservation and increases fresh frozen plasma transfusion.

Dynamic 2D Ultrasound and 3D CT Image Registration of the Beating Heart

Two-dimensional ultrasound (US) is widely used in minimally invasive cardiac procedures due to its convenience of use and noninvasive nature. However, the low quality of US images often limits their utility as a means for guiding procedures, since it is often difficult to relate the images to their anatomical context. To improve the interpretability of the US images while maintaining US as a flexible anatomical and functional real-time imaging modality, we describe a multimodality image navigation system that integrates 2D US images with their 3D context by registering them to high quality preoperative models based on magnetic resonance imaging (MRI) or computed tomography (CT) images. The mapping from such a model to the patient is completed using spatial and temporal registrations. Spatial registration is performed by a two-step rapid registration method that first approximately aligns the two images as a starting point to an automatic registration procedure. Temporal alignment is performed with the aid of electrocardiograph (ECG) signals and a latency compensation method. Registration accuracy is measured by calculating the TRE. Results show that the error between the US and preoperative images of a beating heart phantom is 1.7plusmn0.4 mm, with a similar performance being observed in in vivo animal experiments.

Simultaneous integrated coronary artery revascularization with long-term angiographic follow-up

OBJECTIVE Traditionally integrated coronary artery revascularization has been described as a 2-stage procedure. We evaluated the safety and feasibility of 1-stage, simultaneous, hybrid, robotically assisted coronary artery bypass grafting surgery and percutaneous coronary intervention. METHODS Fifty-eight patients underwent simultaneous, integrated coronary artery revascularization in an operating theater equipped with angiographic equipment. Forty-five patients were men. The mean age was 59 years. All internal thoracic arteries were harvested with robotic assistance. All anastomoses were manually constructed through a small anterior non-rib-spreading incision without cardiopulmonary bypass on the beating heart. Immediately after and within the same operative suite, both angiographic confirmation of graft patency and percutaneous coronary intervention were performed. In 52 patients therapeutic anticoagulation was achieved with the direct thrombin inhibitor bivalirudin. RESULTS There were no deaths or wound infections. There was 1 perioperative myocardial infarction. One patient had a stroke, and 3 patients required re-exploration for bleeding. The median lengths of intensive care and hospital stay were 1 and 4 days, respectively. All patients were alive and symptom free at follow-up (mean, 20.2 months; range, 1.1-40.8 months). Long-term angiographic follow-up in 54 patients showed 49 (91%) patent grafts (mean, 9.0 months; range, 4.3-40.8 months). There were 7 in-stent restenoses and 2 occluded stents. CONCLUSION For multivessel coronary artery disease, simultaneous integrated coronary artery revascularization with bivalirudin is safe and feasible. This approach enables complete multivessel revascularization with decreased surgical trauma and postoperative morbidity. Further studies are necessary to better determine patient selection and long-term outcomes.

Patient-controlled versus nurse-controlled analgesia after cardiac surgery - : a meta-analysis

Objectif Ľanalgesie auto-controlee (AAC) est preconisee comme superieure a ľanalgesie traditionnelle controlee par ľinfirmiere (ACI), avec moins de risque pour le patient. La presente revue systematique et meta-analyse a cherche a determiner si ľAAC ameliore les resultats et exige moins de ressources cliniques que ľACI.BackgroundPatient-controlled analgesia (PCA) has been advocated as superior to conventional nurse-controlled analgesia (NCA) with less risk to patients. This systematic review and meta-analysis sought to determine whether PCA improves clinical and resource outcomes when compared with NCA.MethodsA comprehensive search was undertaken to identify all randomized controlled trials of PCAvs NCA. Medline, Cochrane Library, Embase, and conference abstract databases were searched from the date of their inception to August 2005. The primary postoperative outcome was defined as mean visual analogue scale (VAS) scores. Secondary postoperative outcomes included cumulative morphine equivalents, intensive care unit (ICU) and hospital length of stay, postoperative nausea and vomiting, sedation, respiratory depression, and all-cause mortality. Odds ratios or weighted mean differences (WMD) and their 95% confidence intervals (CI) were calculated for discrete and continuous outcomes, respectively.ResultsTen randomized trials involving 666 patients were included. Compared to NCA, PCA significantly reduced VAS at 48 hr (WMD -0.73, 95% CI -1.19, -0.27), but not at 24 hr (WMD -0.19, 95% CI -0.61, 0.24). Cumulative morphine equivalents consumed were significantly increased at 24 hr (WMD 6.84 mg, 95% CI 0.97, 12.72 mg), and at 48 hr (WMD 10.46 mg 95% CI 2.02, 18.9 mg) for PCA compared with NCA. Ventilation times, length of ICU stay, length of hospital stay, patient satisfaction scores, sedation scores, and incidence of postoperative nausea and vomiting, respiratory depression, severe pain, discontinuations, and death were not significantly different between groups, but these outcomes were generally under-reported.ConclusionsIn postcardiac surgical patients, PCA increases cumulative 24 and 48 hr morphine consumption, and improves 48-hr VAS compared with NCA.RésuméObjectifĽanalgésie auto-contrôlée (AAC) est préconisée comme supérieure à ľanalgésie traditionnelle contrôlée par ľinfirmière (ACI), avec moins de risque pour le patient. La présente revue systématique et méta-analyse a cherché à déterminer si ľAAC améliore les résultats et exige moins de ressources cliniques que ľACI.MéthodeUne vaste recherche a été entreprise pour découvrir toutes les études randomisées et contrôlées sur ľAAC vs ľACI. Les bases de données de Medline, Cochrane Library, Embase et des comptes rendus de conférences ont été fouillées de la date de leur création à août 2005. Le principal paramètre postopératoire était les scores à ľéchelle visuelle analogique (EVA). Les paramètres postopératoires secondaires étaient les équivalents-morphine cumulatifs, la longueur du séjour à ľunité des soins intensifs (USI) et à ľhôpital, les nausées et vomissements postopératoires, la sédation, la dépression respiratoire et toute cause de mortalité. Les risques relatifs ou les différences moyennes pondérées (DMP) et leurs intervalles de confiance (IC) de 95 % ont été respectivement calculés pour des résultats discrets et continus.RésultatsDix études randomisées comprenant 666 patients ont été retenues. Comparée à ľACI, ľAAC a significativement réduit les scores à ľEVA à 48 h (DMP -0,73, IC de 95 % -1,19, -0,27), mais non à 24 h (DMP -0,19, IC de 95 % -0,61, 0,24). La consommation ďéquivalents-morphine cumulatifs a été significativement plus élevée à 24 h (DMP 6,84 mg, IC de 95 % 0,97, 12,72 mg) et à 48 h (DMP 10,46 mg IC de 95 % 2,02, 18,9 mg) pour ľAAC comparée à ľACI. Les temps de ventilation, la longueur du séjour à ľUSI et à ľhôpital, les scores de satisfaction du patient, les scores de sédation et ľincidence de nausées et de vomissements postopératoires, la dépression respiratoire, la douleur sévère, les interruptions et la mort ne présentaient pas de différence intergroupe significative, mais ces paramètres étaient généralement sous-déclarés.ConclusionAprès une opération cardiaque, ľAAC augmente la consommation cumulative de morphine à 24 et 48 h et améliore les scores EVA à 48 h comparée à ľACI.

NSAID-analgesia, pain control and morbidity in cardiothoracic surgery

ObjectiveWhile narcotics remain the backbone of perioperative analgesia, the adjunctive role of other analgesics, including non-steroidal anti-inflammatory drugs (NSAIDs), is being recognized increasingly. This meta-analysis sought to determine whether adjunctive NSAIDs improve postoperative analgesia and reduce cumulative narcotic requirements.MethodsA comprehensive search was undertaken to identify all randomized trials, in cardiothoracic patients, of NSAIDs plus narcotics vs narcotics without NSAIDs. Medline, Cochrane Library, EMBASE, and abstract databases were searched up to September 2005. The primary outcome was visual analogue scale (VAS) pain score. Secondary outcomes included 24-hr cumulative morphine-equivalents, rescue medications required, mortality, myocardial infarction, atrial fibrillation, stroke, renal failure, hospital readmissions, and in-hospital costs.ResultsTwenty randomized trials involving 1,065 patients were included. A significant reduction in 24-hr VAS pain score was found in patients receiving NSAIDs [weighted mean difference (WMD) -0.91 points, 95% confidence interval (CI) -1.48 to -0.34 points]. In addition, patients required significantly less morphine-equivalents in the first 24 hr (WMD -7.67 mg, 95% CI -8.97 to -6.38 mg). No significant difference was found with respect to mortality [odds ratio (OR) 0.19, 95% CI 0.01 to 4.22], myocardial infarction (OR 0.71, 95% CI 0.09 to 5.71), renal dysfunction (OR 0.95, 95% CI 0.37 to 2.46), or gastrointestinal bleeding (OR 0.96, 95% CI 0.13 to 7.09).ConclusionIn patients less than 70 yr of age undergoing cardiothoracic surgery, the adjunctive use of NSAIDs with narcotic analgesia reduces 24-hr VAS pain score and narcotic requirements.RésuméObjectifLes narcotiques demeurent le pivot de ľanalgésie périopératoire, mais le rôle complémentaire ďautres analgésiques, dont les anti-inflammatoires non stéroidiens (AINS), est de plus en plus reconnu. La présente méta-analyse veut déterminer si les AINS ďappoint améliorent ľanalgésie postopératoire et réduisent les besoins cumulatifs de narcotiques.MéthodeNous avons recensé toutes les études randomisées sur des narcotiques, complétés ou non par des AINS, réalisées auprs de patients de cardiochirurgie thoracique. Les bases Medline, Cochrane Library, EMBASE et les résumés parus jusqu’à septembre 2005 ont été explorés. Le principal paramtre recherché était le score de douleur à ľéchelle visuelle analogique (EVA). Les paramtres secondaires étaient la consommation cumulative, sur 24 h, ďanalgésiques en équivalents-morphine, les besoins de médicaments ďappoint, la mortalité, la présence ďinfarctus du myocarde, la fibrillation auriculaire, ľaccident vasculaire, ľinsuffisance rénale, la réadmission hospitalire et le coût de ľhospitalisation.RésultatsVingt études randomisées regroupant 1 065 patients ont été retenues. Une réduction significative des scores de douleur, sur 24 h, a été trouvée chez ceux qui recevaient des AINS [différence moyenne pondérée (DMP) -0,91 points, intervalle de confiance de 95 % (IC) -1,48 à -0,34 points]. De plus, les patients ont demandé sensiblement moins ďéquivalents-morphine au cours des 24 premires heures (DMP -7,67 mg, IC de 95 % -8,97 à -6,38 mg). Il n’y avait aucune différence significative quant à la mortalité [risque relatif (RR) de 0,19, IC de 95 % 0,01 à 4,22], à ľinfarctus du myocarde (RR 0,71, IC de 95 % 0,09 à 5,71), à ľinsuffisance rénale (RR 0,5, IC de 95 % 0,37 à 2,46) ou au saignement gastrointestinal (RR 0,96, IC de 95 % 0,13 à 7,09).ConclusionChez les patients de moins de 70 ans qui subissent une opération cardiothoracique, ľusage ďAINS ďappoint avec ľanalgésie aux narcotiques réduit la douleur et les besoins de narcotiques sur 24 h.

Ľanalgésie auto-contrôlée versus contrôlée par le personnel infirmier après la chirurgie cardiaque — une méta-analyse

Objectif Ľanalgesie auto-controlee (AAC) est preconisee comme superieure a ľanalgesie traditionnelle controlee par ľinfirmiere (ACI), avec moins de risque pour le patient. La presente revue systematique et meta-analyse a cherche a determiner si ľAAC ameliore les resultats et exige moins de ressources cliniques que ľACI.BackgroundPatient-controlled analgesia (PCA) has been advocated as superior to conventional nurse-controlled analgesia (NCA) with less risk to patients. This systematic review and meta-analysis sought to determine whether PCA improves clinical and resource outcomes when compared with NCA.MethodsA comprehensive search was undertaken to identify all randomized controlled trials of PCAvs NCA. Medline, Cochrane Library, Embase, and conference abstract databases were searched from the date of their inception to August 2005. The primary postoperative outcome was defined as mean visual analogue scale (VAS) scores. Secondary postoperative outcomes included cumulative morphine equivalents, intensive care unit (ICU) and hospital length of stay, postoperative nausea and vomiting, sedation, respiratory depression, and all-cause mortality. Odds ratios or weighted mean differences (WMD) and their 95% confidence intervals (CI) were calculated for discrete and continuous outcomes, respectively.ResultsTen randomized trials involving 666 patients were included. Compared to NCA, PCA significantly reduced VAS at 48 hr (WMD -0.73, 95% CI -1.19, -0.27), but not at 24 hr (WMD -0.19, 95% CI -0.61, 0.24). Cumulative morphine equivalents consumed were significantly increased at 24 hr (WMD 6.84 mg, 95% CI 0.97, 12.72 mg), and at 48 hr (WMD 10.46 mg 95% CI 2.02, 18.9 mg) for PCA compared with NCA. Ventilation times, length of ICU stay, length of hospital stay, patient satisfaction scores, sedation scores, and incidence of postoperative nausea and vomiting, respiratory depression, severe pain, discontinuations, and death were not significantly different between groups, but these outcomes were generally under-reported.ConclusionsIn postcardiac surgical patients, PCA increases cumulative 24 and 48 hr morphine consumption, and improves 48-hr VAS compared with NCA.RésuméObjectifĽanalgésie auto-contrôlée (AAC) est préconisée comme supérieure à ľanalgésie traditionnelle contrôlée par ľinfirmière (ACI), avec moins de risque pour le patient. La présente revue systématique et méta-analyse a cherché à déterminer si ľAAC améliore les résultats et exige moins de ressources cliniques que ľACI.MéthodeUne vaste recherche a été entreprise pour découvrir toutes les études randomisées et contrôlées sur ľAAC vs ľACI. Les bases de données de Medline, Cochrane Library, Embase et des comptes rendus de conférences ont été fouillées de la date de leur création à août 2005. Le principal paramètre postopératoire était les scores à ľéchelle visuelle analogique (EVA). Les paramètres postopératoires secondaires étaient les équivalents-morphine cumulatifs, la longueur du séjour à ľunité des soins intensifs (USI) et à ľhôpital, les nausées et vomissements postopératoires, la sédation, la dépression respiratoire et toute cause de mortalité. Les risques relatifs ou les différences moyennes pondérées (DMP) et leurs intervalles de confiance (IC) de 95 % ont été respectivement calculés pour des résultats discrets et continus.RésultatsDix études randomisées comprenant 666 patients ont été retenues. Comparée à ľACI, ľAAC a significativement réduit les scores à ľEVA à 48 h (DMP -0,73, IC de 95 % -1,19, -0,27), mais non à 24 h (DMP -0,19, IC de 95 % -0,61, 0,24). La consommation ďéquivalents-morphine cumulatifs a été significativement plus élevée à 24 h (DMP 6,84 mg, IC de 95 % 0,97, 12,72 mg) et à 48 h (DMP 10,46 mg IC de 95 % 2,02, 18,9 mg) pour ľAAC comparée à ľACI. Les temps de ventilation, la longueur du séjour à ľUSI et à ľhôpital, les scores de satisfaction du patient, les scores de sédation et ľincidence de nausées et de vomissements postopératoires, la dépression respiratoire, la douleur sévère, les interruptions et la mort ne présentaient pas de différence intergroupe significative, mais ces paramètres étaient généralement sous-déclarés.ConclusionAprès une opération cardiaque, ľAAC augmente la consommation cumulative de morphine à 24 et 48 h et améliore les scores EVA à 48 h comparée à ľACI.

N-acetylcysteine in Cardiac Surgery: Do the Benefits Outweigh the Risks? A Meta-Analytic Reappraisal

OBJECTIVE N-acetylcysteine (NAC) reduces proinflammatory cytokines, oxygen free-radical production, and ameliorates ischemia reperfusion injury; therefore, it may theoretically reduce postoperative complications in cardiac surgery. The aim of this study was to determine, through systematic review and meta-analysis of all relevant randomized trials, whether NAC reduces mortality, morbidity, or resource utilization in cardiac surgery. DESIGN Meta-analysis. SETTING University hospitals. PARTICIPANTS A total of 1,407 patients from 15 randomized studies were included in the analysis. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS All randomized trials searched up to May 2009 comparing the use of NAC versus placebo during cardiac surgery in any language and reporting at least 1 predefined outcome were included. The random effect model was used to calculate odds ratios (ORs, 95% confidence intervals [CIs]) and weighted mean differences (WMD, 95% CI) for dichotomous and continuous variables, respectively. During cardiac surgery, the use of NAC did not significantly decrease acute renal failure requiring renal replacement therapy (OR = 1.05; 95% CI, 0.52-2.11; p = 0.90), new atrial fibrillation (OR = 0.67; 95% CI, 0.37-1.22; p = 0.19), or mortality (OR = 0.81; 95% CI, 0.39-1.68; p = 0.57). There were no differences in the incidence of incremental increase in serum creatinine concentration greater than 25% above baseline (OR = 0.86; 95% CI, 0.66-1.12; p = 0.26), acute myocardial infarction (OR = 0.69; 95% CI, 0.29-1.61, p =0.39), stroke (OR = 0.78; 95% CI, 0.30-2.03; p = 0.61), red blood cell transfusion requirement (OR = 0.77; 95% CI, 0.45-1.31; p = 0.33), re-exploration (OR = 1.33; 95% CI, 0.70-2.26; p = 0.29), or postoperative drainage (WMD = 33 mL; 95% CI,-125 to 191 mL; p = 0.69) between NAC and placebo. CONCLUSION Current evidence shows that the perioperative use of NAC has no proven benefit or risk on clinically important outcomes in patients undergoing cardiac surgery.