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Objective To characterize the institutional oxygen management practices during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery, including any potential changes during an 8-year study period. Design A retrospective cohort study. Setting A tertiary care cardiac surgical program. Participants Patients who underwent cardiac surgery involving CPB, with or without hypothermic circulatory arrest (HCA), between January 1, 2010, and December 31, 2017. Measurements and Main Results In addition to baseline patient characteristics, the authors recorded the partial pressures of arterial oxygen (Pa o 2), fraction of inspired oxygen, and mixed venous oxygen saturation during CPB of 696 randomly selected patients during an 8-year study period. The overall mean Pa o 2 was 255 ± 48 mmHg, without any significant change during the 8-year study period (p = 0.30). The mean Pa o 2 of HCA patients was significantly higher than in patients without HCA (327 ± 93 mmHg v 252 ± 45 mmHg, respectively; p Conclusions The current approach to oxygen management during CPB at the authors’ institution is within the range of hyperoxemic levels, and these practices have not changed over time. The impact of these practices on patients’ outcomes is not fully understood, and additional studies are needed to establish firm evidence to guide optimal oxygen management practice during CPB.

Blood transfusions are frequently administered in cardiac surgery. Despite a large number of published studies comparing a “restrictive” strategy with a “liberal” strategy, no clear consensus has emerged to guide blood transfusion practice in cardiac surgery patients. The purpose of this study was to identify, critically appraise, and summarize the evidence on the overall effect of restrictive transfusion strategies compared with liberal transfusion strategies on mortality, other clinical outcomes, and transfusion-related outcomes in adult patients undergoing cardiac surgery. We searched MEDLINE (OvidSP), EMBASE (OvidSP) and Cochrane CENTRAL (Wiley) from inception to 1 December 2017 and queried clinical trial registries and conference proceedings for randomized-controlled trials of liberal vs restrictive transfusion strategies in cardiac surgery. From 7,908 citations, we included ten trials (9,101 patients) and eight companion publications. Overall, we found no significant difference in mortality between restrictive and liberal transfusion strategies (risk ratio [RR], 1.08; 95% confidence interval [CI], 0.76 to 1.54; I2 = 33%; seven trials; 8,661 patients). The use of a restrictive transfusion strategy did not appear to adversely impact any of the secondary clinical outcomes. As expected, the proportion of patients who received red blood cells (RBCs) in the restrictive group was significantly lower than in the liberal group (RR, 0.68; 95% CI, 0.64 to 0.73; I2 = 56%; 5 trials; 8,534 patients). Among transfused patients, a restrictive transfusion strategy was associated with fewer transfused RBC units per patient than a liberal transfusion strategy. In adult patients undergoing cardiac surgery, a restrictive transfusion strategy reduces RBC transfusion without impacting mortality rate or the incidence of other perioperative complications. Nevertheless, further large trials in subgroups of patients, potentially of differing age, are needed to establish firm evidence to guide transfusion in cardiac surgery. PROSPERO (CRD42017071440); registered 20 April, 2018.

Background Outcome selection underpins clinical trial interpretation. Inconsistency in outcome selection and reporting hinders comparison of different trials' results, reducing the utility of research findings. Methods We conducted an iterative consensus process to develop a set of Core Outcome Measures for Perioperative and Anaesthetic Care (COMPAC), following the established Core Outcome Measures for Effectiveness Trials (COMET) methodology. First, we undertook a systematic review of RCTs in high-impact journals to describe current outcome reporting trends. We then surveyed patients, carers, researchers, and perioperative clinicians about important outcomes after surgery. Finally, a purposive stakeholder sample participated in a modified Delphi process to develop a core outcome set for perioperative and anaesthesia trials. Results Our systematic review revealed widespread inconsistency in outcome reporting, with variable or absent definitions, levels of detail, and temporal criteria. In the survey, almost all patients, carers, and clinicians rated clinical outcome measures critically important, but clinicians rated patient-centred outcomes less highly than patients and carers. The final core outcome set was: (i) mortality/survival (postoperative mortality, long-term survival); (ii) perioperative complications (major postoperative complications/adverse events; complications/adverse events causing permanent harm); (iii) resource use (length of hospital stay, unplanned readmission within 30 days); (iv) short-term recovery (discharge destination, level of dependence, or both); and (v) longer-term recovery (overall health-related quality of life). Conclusions This core set, incorporating important outcomes for both clinicians and patients, should guide outcome selection in future perioperative medicine or anaesthesia trials. Mapping these alongside standardised endpoint definitions will yield a comprehensive perioperative outcome framework.

Healthcare providers are facing a coronavirus disease pandemic. This pandemic may last for many months, stressing the Canadian healthcare system in a way that has not previously been seen. Keeping healthcare providers safe, healthy, and available to work throughout this pandemic is critical. The consistent use of appropriate personal protective equipment (PPE) will help assure its availability and healthcare provider safety. The purpose of this communique is to give both anesthesiologists and other front-line healthcare providers a framework from which to understand the principles and practices surrounding PPE decision-making. We propose three types of PPE including: 1) PPE for droplet and contact precautions, 2) PPE for general airborne, droplet, and contact precautions, and 3) PPE for those performing or assisting with high-risk aerosol-generating medical procedures.

Thromboelastography and rotational thromboelastometry are point-of-care (POC) viscoelastic tests used to help guide blood product administration. It is unclear whether these tests improve clinical or transfusion-related outcomes. The objective of this study was to appraise data from randomized trials evaluating the benefit of POC testing in cardiac surgery patients. Primary outcomes were the proportion of patients transfused with blood products and all-cause mortality. Medline (Ovid), EMBASE (Ovid), CENTRAL (the Cochrane Library-Wiley), Web of Science, Biosis, Scopus, and CINAHL databases, as well as clinical trial registries and conference proceedings were queried from inception to February 2018. We identified 1,917 records, 11 of which were included in our analysis (8,294 patients). Point-of-care testing was not associated with a difference in the proportion of patients transfused with any blood product (risk ratio [RR], 0.90; 95% confidence interval [CI], 0.79 to 1.02; I2 = 51%; four trials, 7,623 patients), or all-cause mortality (RR, 0.73; 95% CI, 0.47 to 1.13; I2 = 5%; six trials, 7,931 patients). Nevertheless, POC testing was weakly associated with a decrease in the proportion of patients receiving red blood cells (RBC) (RR, 0.91; 95% CI, 0.85 to 0.96; I2 = 0%; seven trials, 8,029 patients), and heterogeneous reductions in frozen plasma (FP) (RR, 0.58; 95% CI, 0.34 to 0.99; I2 = 87%; six trials, 7,989 patients) and platelets (RR, 0.66; 95% CI, 0.49 to 0.90; I2 = 65%; seven trials, 8,029 patients). Meta-analysis of the number of units of RBCs and FP was not possible due to heterogeneity in reporting, however POC testing significantly reduced the units of platelets transfused (standard mean difference, -0.09; 95% CI, -0.18 to 0.00; four trials, 7,643 patients). Our review indicates that in cardiac surgery patients, POC viscoelastic hemostatic testing is not associated with a reduction in the proportion of patients receiving any blood product or all-cause mortality. However, viscoelastic testing is weakly associated with a reduction in proportion of patients transfused with specific blood products. Presently, the benefits associated with viscoelastic testing in cardiac surgery patients are insufficiently robust to recommend routine implementation of this technology. PROSPERO (CRD4201706577). Registered 11 May 2017.

Historically, cardiac surgery patients have often been managed with supraphysiologic intraoperative oxygen levels to protect against the risks of cellular hypoxia inherent in the un-physiologic nature of surgery and cardiopulmonary bypass. This may result in excessive reactive oxygen species generation and exacerbation of ischemia-reperfusion injury. In this review, we synthesize all available data from randomized controlled trials (RCTs) to investigate the impact that hyperoxia has on postoperative organ dysfunction, length of stay, and mortality during adult cardiac surgery. We searched Medline, Embase, Scopus, and Cochrane Central Register of Controlled Trials databases using a high-sensitivity strategy for RCTs that compared oxygenation strategies for adult cardiac surgery. Our primary outcome was postoperative organ dysfunction defined by postoperative increases in myocardial enzymes, acute kidney injury, and neurologic dysfunction. Secondary outcomes were mortality, ventilator days, and length of stay in the hospital and intensive care unit. We identified 12 RCTs that met our inclusion criteria. Risk of bias was unclear to high in all but one trial. Significant heterogeneity in timing of the treatment period and the oxygenation levels targeted was evident and precluded meta-analysis. The large majority of trials found no difference between hyperoxia and normoxia for any outcome. Two trials reported reduced postoperative myocardial enzymes and one trial reported reduced mechanical ventilation time in the normoxia group. Hyperoxia had minimal impact on organ dysfunction, length of stay, and mortality in adult cardiac surgery. The current evidence base is small, heterogeneous, and at risk of bias. International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017074712). Registered 17 August 2017.

Objectives To determine if a restrictive transfusion threshold is noninferior to a higher threshold as measured by a composite outcome of mortality and serious morbidity. Design Transfusion Requirements in Cardiac Surgery (TRICS) III was a multicenter, international, open-label randomized controlled trial of two commonly used transfusion strategies in patients having cardiac surgery using a noninferiority trial design (ClinicalTrials.gov number, NCT02042898). Setting Eligible patients were randomized prior to surgery in a 1:1 ratio. Participants Potential participants were 18 years or older undergoing planned cardiac surgery using cardiopulmonary bypass (CPB) with a preoperative European System for Cardiac Operative Risk Evaluation (EuroSCORE I) of 6 or more. Interventions Five thousand patients; those allocated to a restrictive transfusion group received a red blood cell (RBC) transfusion if the hemoglobin concentration (Hb) was less than 7.5 g/dL intraoperatively and/or postoperatively. Patients allocated to a liberal transfusion strategy received RBC transfusion if the Hb was less than 9.5 g/dL intraoperatively or postoperatively in the intensive care unit or less than 8.5 g/dL on the ward. Measurements and Main Results The primary outcome was a composite of all-cause mortality, myocardial infarction, stroke, or new onset renal dysfunction requiring dialysis at hospital discharge or day 28, whichever comes first. The primary outcome was analyzed as a per-protocol analysis. The trial monitored adherence closely as adherence to the transfusion triggers is important in ensuring that measured outcomes reflect the transfusion strategy. Conclusion By randomizing prior to surgery, the TRICS III trial captured the most acute reduction in hemoglobin during cardiopulmonary bypass.

Objectives Although clinical practice guidelines recommend standard cefazolin antimicrobial prophylaxis (AP) dosing for cardiac surgery, limited data exist as to whether adequate concentrations are achieved in this patient population. The goal of our study was to characterize intraoperative cefazolin concentrations particularly at wound closure with regards to maintaining target cefazolin closure concentrations ≥40 mg/L. Methods Adults undergoing cardiac surgery with cardiopulmonary bypass (CPB) and receiving cefazolin AP according to protocol were studied. Blood samples were collected after the preoperative cefazolin dose, prior to intraoperative cefazolin doses and at wound closure. Intraoperative trough and closure concentrations were characterized and evaluated against a target threshold of ≥ 40 mg/L (≥8 mg/L unbound, assuming 80% protein binding). Results Fifty-five subjects (64.9 ± 10.4 years, 89.7 ± 16.5 kg, CLCR >50 mL/min/72 kg) completed the study. Total cefazolin concentrations were

Background Delirium and pain are common and serious postoperative complications. Subanaesthetic ketamine is often administered intraoperatively for postoperative analgesia and to spare postoperative opioids. Some evidence also suggests that ketamine prevents delirium. The primary purpose of this trial was to evaluate the effectiveness of ketamine in preventing postoperative delirium in older adults after major surgery. Secondary outcomes, viewed as strongly related to delirium, were postoperative pain and opioid consumption. Methods This was a multicentre, international, randomised trial that enrolled adults older than 60 undergoing major cardiac and noncardiac surgery under general anaesthesia. Participants were enrolled prior to surgery and gave written informed consent. We used a computer-generated randomisation sequence. Patients at study sites were randomised to one of three study groups in blocks of 15 to receive intraoperative administration of (i) placebo (intravenous normal saline), (ii) low dose ketamine (0.5 mg/kg) or (iii) high dose ketamine (1 mg/kg). Study drug was administered following induction of anaesthesia, prior to surgical incision. Participants, clinicians, and investigators were all masked to group assignment. Delirium and pain were assessed twice daily in the first three postoperative days using the Confusion Assessment Method and Visual Analog Scale, respectively. Postoperative opioid use was recorded, and hallucinations and nightmares were assessed. Analyses were performed by intention-to-treat and adverse events were evaluated. The Prevention of Delirium and Complications Associated with Surgical Treatments [PODCAST] trial is registered in clinicaltrials.gov; NCT01690988 Findings Between February 6, 2014 and June 26, 2016, 1360 patients assessed and 672 were randomised, with 222 in the placebo group, 227 in the low dose ketamine group, and 223 in the high dose ketamine group. There was no difference in postoperative delirium incidence between those in the combined ketamine groups and those who received placebo (19.45% vs. 19.82%, respectively; absolute difference, 0.36%; 95% CI, −6.07% to 7.38%; p=0.92). There were no significant differences among the three groups in maximum pain scores (p=0.88) or median opioid consumption (p=0.47) over time. There were more postoperative hallucinations (p=0.01) and nightmares (p=0.03) with escalating doses of ketamine. Adverse events (cardiovascular, renal, infectious, gastrointestinal, bleeding), whether viewed individually (P value for each >0.40) or collectively (82/222 [36.9%] in placebo group, 90/227 [39.6%] in low dose ketamine group, 91/223 in high dose ketamine group [40.8%]; P=0.69), did not differ significantly across the three groups. Interpretation The administration of a single subanaesthetic dose of ketamine to older adults during major surgery did not show evidence of reducing postoperative delirium, pain, or opioid consumption, and might cause harm by inducing negative experiences. Given current evidence and guidelines related to ketamine and postoperative analgesia, the unexpected secondary findings regarding pain and opioid consumption warrant replication or refutation in subsequent research. Funding The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The principal investigators (MSA and GAM) had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Purpose Selective antegrade cerebral perfusion (SACP) involving cannulation of either the axillary or innominate artery is a commonly used technique for maintaining cerebral blood flow (CBF) during the use of hypothermic cardiac arrest (HCA) for operations on the aortic arch. Nevertheless, asymmetrical CBF with hypoperfusion of the left cerebral hemisphere is a common occurrence during SACP. The purpose of this report is to describe an adjunctive maneuver to improve left hemispheric CBF during SACP by applying extrinsic compression to the left carotid artery.

Earlier extubation after cardiac surgery is reported to have benefits on length of stay and complication rates, but the influence on postoperative delirium remains unclear. We sought to determine the effect of earlier extubation on delirium after coronary artery bypass grafting.A single-center retrospective review of consecutive isolated coronary artery bypass grafting patients from January 1, 2010, to December 31, 2015, was conducted. Baseline demographic characteristics, preoperative comorbidities, intraoperative data, and postoperative data were collected. A multivariable logistic regression was performed with analysis limited to extubation within the first 24 hours postoperatively.We identified 2561 eligible patients. Delirium occurred in 13.9% (n = 357). Duration of postoperative mechanical ventilation was associated with higher delirium rates following adjustment, particularly after 12 to 24 hours (hourly odds ratio, 1.12; 95% confidence interval, 1.05-1.19; P .001). No association was observed during the time period from 0 to 12 hours (hourly odds ratio, 1.02; 95% confidence interval, 0.99-1.06; P = .218). Major adverse events were associated with duration of ventilation after 0 to 12 hours (hourly odds ratio, 1.08; 95% confidence interval, 1.03-1.14; P .002) but not after 12 to 24 hours (hourly odds ratio, 1.04; 95% CI, 0.96-1.14; P = .316). The overall rate of reintubation was 2.9% (n = 73).Our findings suggest that delirium rates increase with lengthier postoperative ventilation times. This study provides the basis for consideration of the appropriate selection of earlier extubation to minimize delirium in patients undergoing cardiac surgery.

This study characterizes the pharmacodynamics of antimicrobial prophylaxis and sternal wound infections following cardiac surgery. Duration of surgery and cefazolin plasma concentration during wound closure were independently associated with surgical site infection at 30 days. Furthermore, a duration of surgery of >346 min and a total cefazolin closure concentration of

HE INADVERTENT INTRODUCTION of air during cardiac surgery into the ascending aorta before aortic cross-clamping is a rare but potentially catastrophic complication. 1 Cardiac surgeons and anesthesiologists must be prepared to deal with this emergency, because rapid and decisive action can prevent or attenuate severe neurologic injury that may result from an air embolism. The authors present a case of an air embolism during mitral valve repair surgery that was treated successfully with early detection and management. A continuous quality improvement process following a previous instance of air embolism contributed to the successful outcome. CASE PRESENTATION * A 62-year-old woman with a history of severe mitral regurgitation, chronic atrial fibrillation, and mildly dysfunctional left ventricular systolic function presented for mitral valve repair. The patient was monitored with an electrocardiogram, pulse oximetry, a left radial arterial catheter, a right internal jugular pulmonary artery catheter, bispectral index (BIS) monitor (Aspect Medical Systems, Newton, MA), and cerebral oximetry monitoring (FORE-SIGHT, CASMED, Branford, CT). After median sternotomy, the patient was cannulated for cardiopulmonary bypass with an ascending aortic cannula, separate bicaval venous cannulation, an aortic root catheter for antegrade cardioplegia, and a retrograde coronary sinus cardioplegia cannula. Immediately after initiation of cardiopulmonary bypass and before application of the aortic cross-clamp, air was noted in the cardioplegia line. The surgeon instructed the perfusionist to immediately stop flushing through the aortic root catheter. The aorta then was inspected by transesophageal echocardiography, which showed air in the aortic arch and descending aorta. The BIS monitor showed an abrupt reduction from 28 to 0 and then recovered in less than a minute. The cerebral oximetry monitor also showed an abrupt bilateral reduction from 66 to 45 with quick recovery. The patient was placed immediately placed in steep Trendelenburg position, the mean arterial pressure was raised to 120 mmHg, and the patient was cooled to 241C. One hundred percent inspired fraction of oxygen was used during the resuscitation period to reduce bubble size. Retrograde perfusion via the superior vena cava at a flow of 500 mL/min for 5 minutes was performed with the aortic root vent turned on to aspirate air. Cardiopulmonary bypass then was resumed and the aortic cross-clamp was applied. The patient was maintained at 281C for the next hour and then slowly rewarmed to 35 degrees. The remainder of the surgery was uneventful, and the patient was weaned from bypass using epinephrine at 50/ng/kg/min.

BACKGROUND The effect of a restrictive versus liberal red-cell transfusion strategy on clinical outcomes in patients undergoing cardiac surgery remains unclear. METHODS In this multicenter, open-label, noninferiority trial, we randomly assigned 5243 adults undergoing cardiac surgery who had a European System for Cardiac Operative Risk Evaluation (EuroSCORE) I of 6 or more (on a scale from 0 to 47, with higher scores indicating a higher risk of death after cardiac surgery) to a restrictive red-cell transfusion threshold (transfuse if hemoglobin level was

Acute kidney injury (AKI) is a potentially serious complication of cardiac surgery. Anemia and red blood cell (RBC) transfusion have individually been identified as potentially modifiable risk factors, but their interrelationship with AKI has not been clearly defined. The purpose of this study was to explore the interrelationship of preoperative anemia, intraoperative anemia, and RBC transfusion on the day of surgery with AKI in cardiac surgery. This historical cohort study included 16 hospitals, each contributing data on approximately 100 consecutive patients who underwent cardiac surgery with cardiopulmonary bypass. Acute kidney injury was defined as a > 50% increase in creatinine levels during the first postoperative week. Multivariable regression was used to identify the interrelationship between preoperative anemia (hemoglobin

This is truly a special time for the Canadian Journal of Anesthesia. Not only is the Journal considered amongst the most prestigious of anesthesia journals, but this year it also marks its Diamond Jubilee. Indeed, the Journal has a rich 60-year history of serving the anesthesia and scientific communities as well as its own Canadian Anesthesiologists’ Society (CAS). Throughout this calendar year, we will recognize the Journal’s Diamond Jubilee by showcasing some of its seminal articles from the past along with invited accompanying commentaries. The intent of this initiative is to both recognize these important contributions over the past decades and to highlight the relevance of these articles by the way in which their messages have endured. In these many decades since its inception, the Journal has evolved substantially – an evolution that continues today with a change in the editorial board and with my assuming the role of Editor-in-Chief. Indeed, this celebratory year, beginning with this issue, represents a fitting opportunity to recognize the dedicated editorial vision of the Journal and the leadership from its helm. Beginning with the Journal’s founding editor, Dr. Roderick Gordon, and continuing through its transitions in leadership under Drs. Craig, Bevan, Hardy, and Miller, the Journal has remained centred on our Society’s mission. In 2014, the Journal is again in transition, this time from Donald Miller’s nine years of service as Editor-in-Chief to my own beginning tenure. Over the years, the Journal has progressed from an in-house ‘‘cottage industry’’ publication, often managed from stacks of paper on the living room floor, to the electronic online Editorial Manager and the resources available through our Society and our publisher, Springer, who have facilitated its continued growth. The complex evolution shepherded under Dr. Miller’s tenure could not have been accomplished without his substantive efforts – in part, this editorial serves to recognize and thank him for these efforts. Moving forward, the vision of the Journal will undoubtedly evolve with additional initiatives to be seen in the coming years. Whereas some of these efforts will continue the scientific goals of the Journal, others will focus on educating our membership, in particular, and other anesthesia practitioners, in general. Importantly, as the future of our Society often rests with the newly trained (and still in training) anesthesiologist, specific efforts will be directed towards this group. Nevertheless, all aspects of the Society need to be engaged, and the Journal will make substantive efforts to continue to improve its appeal to its general membership. Furthermore, the Journal provides a distinct resource not only to its Society and the broader anesthesia community but also to the general public. In this day and age with innumerable online resources for the public to gather medical information, the Journal can serve as a source for dissemination of accurate information, i.e., a resource for patients looking for answers. This engagement and empowerment of patients is an important consideration that needs to be promoted. At this time of transition, it is useful not only to evaluate our past—our 60 anniversary is an opportune time to accomplish this—but also to re-evaluate our purpose and core values. The mission statement of the Canadian Journal of Anesthesia focuses on ‘‘excellence in research and knowledge translation in anesthesia, pain, H. P. Grocott, MD (&) Department of Anesthesia & Perioperative Medicine, St. Boniface Hospital, University of Manitoba, CR3008 369 Tache Avenue, Winnipeg, MB R2H 2A6, Canada e-mail: hgrocott@sbgh.mb.ca

Cerebral desaturation occurs frequently in patients undergoing one-lung ventilation for thoracic surgery. The mechanism of this desaturation is unclear regarding its etiology. The objective of this study was to investigate whether or not decreases in cerebral oxygen saturation associated with one-lung ventilation were a consequence of decreased cardiac output. A blinded observational study was conducted in 23 patients undergoing one-lung ventilation with thoracic surgery. Eighteen patients completed the study. Cerebral oxygen saturation was monitored using near-infrared spectroscopy (FORE-SIGHT® monitor). Invasive blood pressure was monitored and hemodynamic variables were interrogated using the FloTrac® system. Anesthesia was maintained with sevoflurane with a F i O2 of 1.0. Post-hoc analysis involved a comparison between baseline and integrated changes in cerebral saturation, heart rate, stroke index, cardiac index, and stroke volume variability. All patients showed cerebral desaturation from a baseline of two-lung ventilation in the lateral decubitus position following institution of one-lung ventilation. The cardiac index was stable at these times, but with one-lung ventilation, the heart rate decreased and the stroke index increased to maintain a stable product. The integral of heart rate × time was inversely correlated with the integral of cerebral desaturation × time (linear regression analysis; P = 0.02; (df) = 16)). Cerebral oxygen desaturation was universal during one-lung ventilation in this study. There was no correlation between cerebral desaturation and cardiac output or other hemodynamic variables.

ObjectiveEcallantide is a recombinant peptide in the same class as aprotinin that inhibits plasma kallikrein, a major component of the contact coagulation and inflammatory cascades. Therefore, ecallantide was expected to reduce blood loss associated with cardiac surgery requiring cardiopulmonary bypass.MethodsThis prospective multinational, randomized, double-blind trial enrolled patients undergoing cardiac surgery using cardiopulmonary bypass for procedures associated with a high risk of bleeding. Patients were randomly assigned to ecallantide (n = 109) or tranexamic acid (high dose, n = 24; low dose, n = 85). Efficacy was assessed from the volume of packed red blood cells administered within the first 12 hours after surgery.ResultsThe study was terminated early after the independent data safety and monitoring board observed a statistically significantly higher 30-day mortality in the ecallantide group (12%) than in the tranexamic acid groups (4%, P = .041). Patients receiving ecallantide received more packed red blood cells within 12 hours of surgery than tranexamic acid-treated patients: median = 900 mL (95% confidence interval, 600–1070) versus 300 mL (95% confidence interval, 0–523) (P

Background Cerebral oximetry is a noninvasive technology using near-infrared spectroscopy (NIRS) to estimate regional cerebral oxygen saturation. Although NIRS cerebral oximetry is being increasingly used in many clinical settings, interdevice technologic differences suggest potential variation in the ability to accurately acquire brain oxygenation signals. The primary objective of this study was to determine if NIRS-derived regional cerebral oxygen saturation measurements accurately account for oxygen saturation contamination from extracranial tissue. Methods Twelve healthy volunteers had each of three NIRS devices (FORE-SIGHT [CAS Medical Systems Inc; Brandford, CT], INVOS 5100C-PB [Covidien; Boulder, CO], and EQUANOX Classic 7600 [Nonin Medical Inc; Plymouth, MN]) randomly applied to the forehead. After this, a circumferential pneumatic head cuff was positioned such that when inflated, hypoxia-ischemia would be produced in the extracranial scalp tissue beneath the NIRS cerebral oximeters. Comparisons among the three devices were made of the NIRS measurements before and following hypoxia-ischemia produced in the scalp tissue with inflation of the head cuff. Results The induction of extracranial hypoxia-ischemia resulted in a significant reduction in regional cerebral oxygen saturation measurements in all three NIRS devices studied. At 5 min postinflation of the pneumatic head cuff, the INVOS demonstrated a 16.6 ± 9.6% (mean ± SD) decrease from its baseline (P = 0.0001), the FORE-SIGHT an 11.8 ± 5.3% decrease from its baseline (P < 0.0001), and the EQUANOX a 6.8 ± 6.0% reduction from baseline (P = 0.0025). Conclusions Extracranial contamination appears to significantly affect NIRS measurements of cerebral oxygen saturation. Although the clinical implications of these apparent inaccuracies require further study, they suggest that the oxygen saturation measurements provided by cerebral oximetry do not solely reflect that of the brain alone.

Seizures after cardiac surgery are a serious complication. The antifibrinolytic agent tranexamic acid (TA), which has known proconvulsant properties, may be associated with postoperative seizures. We sought to determine the association between TA and other risk factors for seizures after cardiac surgery.We analyzed a database of consecutive cardiac surgery patients (April 2003 to December 2009) using multivariable logistic regression analysis to assess for seizure risk factors. Seizures occurred in 56 of 5,958 patients (0.94%). TA use was associated with an increased risk of seizures (odds ratio 7.4, 95% confidence interval 2.8-19.3; P 0.001). Multivariable logistic regression analysis revealed that the following factors were significantly associated with seizures: TA exposure; Acute Physiology, Age, and Chronic Health Evaluation (APACHE) II score 20; preoperative cardiac arrest; preoperative neurological disease; open chamber surgery; cardiopulmonary bypass time 150 min; and previous cardiac surgery. Seizures occurred at a median of 5.3 hr (interquartile range 2.4-15.1 hr) after the end of surgery. In all, 58.1% were grand mal, 14.5% were associated with a stroke, and 58.1% recurred in hospital. Altogether, 48.3% of the patients were able to discontinue anticonvulsant medications prior to discharge. Compared to the non-seizure group, seizure patients had an increased rate of postoperative neurological complications, defined as delirium and/or stroke (3.2% vs 19.6%, P 0.001), increased intensive care unit (ICU) length of stay (1.0 vs 4.7 days, P 0.001), and increased ICU mortality (1.4 % vs 9.7 %, P = 0.001).Our data suggest that multiple risk factors, including TA, are associated with seizures after cardiac surgery. Thus, the TA dose may be a readily modifiable risk factor for postoperative seizures.

Objective Higher mean arterial pressure during cardiopulmonary bypass may improve cerebral outcome associated with cerebral air embolism by increasing emboli clearance and collateral flow to salvage the ischemic penumbra. However, this may come at the expense of increased delivery of embolic load. This study was designed to investigate the influence of mean arterial pressures on cerebral functional and histologic outcome after cerebral air embolism during cardiopulmonary bypass in an established rat model. Methods Male Sprague–Dawley rats were exposed to 90 minutes of normothermic cardiopulmonary bypass with 10 cerebral air embolisms (0.3 μL/bolus) injected repetitively. Rats were randomized to 3 groups (n = 10, each) that differed in mean arterial pressure management during cardiopulmonary bypass: 50 mm Hg (low mean arterial pressure), 60 to 70 mm Hg (standard mean arterial pressure), and 80 mm Hg (high mean arterial pressure). Neurologic score was assessed on postoperative days 3 and 7 when cerebral infarct volumes were determined. Cognitive function was determined with the Morris water maze test beginning on postoperative day 3 and continuing to postoperative day 7. Results Neurologic score was better in high and standard mean arterial pressure groups versus low mean arterial pressure groups. High mean arterial pressure resulted in shorter water maze latencies compared with standard and low mean arterial pressure on postoperative days 6 and 7. Total infarct volume and number of infarct areas were not different among groups. Conclusions The use of higher mean arterial pressure during cardiopulmonary bypass in a rat model of cerebral air embolism conveyed beneficial effects on functional cerebral outcome with no apparent disadvantage of increased delivery of embolic load. Maintaining higher perfusion pressures in situations of increased cerebral embolic load may be considered as a collateral therapeutic strategy.