Mechanisms, Prevention, and Treatment of Atrial Fibrillation After Cardiac Surgery: A Narrative Review.

New onset of postoperative atrial fibrillation (AF) generally is recognized as a frequent and debilitating complication after cardiac surgery, contributing to a considerable health- care cost. Extensive research has been conducted to study the underlying mechanisms and risk factors of AF in the perioperative period. Many options have been suggested to lower the incidence, and the concurrent cost in health resources. This review attempts to synthesize the large body of existing literature on AF, as well as expand and illustrate the available knowledge on its management strategies. The latter incorporates recent developments in the anesthesthetic approach as well as in the pharmacologic arsenal. In addition, the current review provides a tool for understanding the pathophysiology of AF and for reducing the occurrence after cardiac surgery. By using it, clinicians can manage patients with AF in the perioperative period of cardiac surgery and minimize the relatively high economic cost that accompanies it.

Intraoperative xenon for prevention of delirium after on-pump cardiac surgery: a randomised, observer-blind, controlled clinical trial.

BACKGROUND: Older patients undergoing cardiac surgery have a 40-60% risk of developing postoperative delirium (POD), which is associated with increased morbidity and mortality. In animals, xenon has been found to be neuroprotective. Little is known about its neuroprotective effects in humans. We evaluated whether xenon anaesthesia prevents POD in patients undergoing cardiac surgery. METHODS: We conducted a randomised, observer-blind, controlled trial in which 190 patients 65 yr or older undergoing on-pump cardiac surgery were randomly allocated to xenon or sevoflurane anaesthesia. During cardiopulmonary bypass, propofol infusion was used for anaesthetic maintenance. Subjects were screened for POD daily during the first 5 postoperative days using the 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM) or with a CAM version for patients in ICU (CAM-ICU). Other methods to detect delirium, such as chart review, were also used. Secondary outcomes included the duration and severity of POD, and postoperative cognitive function. RESULTS: The overall incidence of POD was 41% (78/190). There was no statistically significant difference in the POD incidence between the xenon and sevoflurane groups (42.7% [41/96] vs 39.4% [37/94], P=0.583). The odds ratio for POD when comparing xenon with sevoflurane was 1.18 (95% confidence interval, 0.65-2.16). CONCLUSIONS: In older patients undergoing cardiac surgery, xenon anaesthesia did not result in a significant reduction in POD. Based on these results alone, use of xenon cannot be recommended for this purpose. CLINICAL TRIAL REGISTRATION: EudraCT: 2014-005370-11 (May 13, 2015; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-005370-11).

Is preoperative anxiety associated with postoperative delirium in older persons undergoing cardiac surgery? Secondary data analysis of a randomized controlled trial.

BACKGROUND: Although many studies have reported numerous risk factors for postoperative delirium, data are scarce about preoperative anxiety as a risk factor. The study aimed to investigate the association between preoperative anxiety and postoperative delirium in older patients undergoing cardiac surgery. METHODS: Secondary data analysis of a randomized, observer-blind, controlled trial. A total of 190 patients 65 years or older and admitted to the intensive care unit and cardiac surgery unit of a university hospital scheduled for elective on-pump cardiac surgery were included. State anxiety was measured preoperatively using the Amsterdam Preoperative Anxiety and Information Scale and the Visual Analogue Scale for anxiety. Incidence of delirium was measured during the first 5 postoperative days using the Confusion Assessment Method for Intensive Care Unit (when ventilated), or the 3 Minute Diagnostic Interview for Confusion Assessment Method (when extubated) and by daily chart review. RESULTS: Preoperative state anxiety was reported by 31% of the patients and 41% had postoperative delirium. A multiple step logistic regression analyses revealed no association between preoperative anxiety and postoperative delirium. Significant risk factors for postoperative delirium were age (OR = 1.10, 95% CI (1.03-1.18)), activities of daily living (0.69, 95% CI (0.50-0.96)), diabetes mellitus (OR = 3.15, 95% CI (1.42-7.00)) and time on cardiopulmonary bypass (OR = 1.01, 95% CI (1.00 to 1.02)). CONCLUSIONS: No relationship could be found between preoperative anxiety and postoperative delirium.

Xenon as an Adjuvant to Propofol Anesthesia in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Pragmatic Randomized Controlled Clinical Trial.

BACKGROUND: Xenon was shown to cause less hemodynamic instability and reduce vasopressor needs during off-pump coronary artery bypass (OPCAB) surgery when compared with conventionally used anesthetics. As xenon exerts its organ protective properties even in subanesthetic concentrations, we hypothesized that in patients undergoing OPCAB surgery, 30% xenon added to general anesthesia with propofol results in superior hemodynamic stability when compared to anesthesia with propofol alone. METHODS: Fifty patients undergoing elective OPCAB surgery were randomized to receive general anesthesia with 30% xenon adjuvant to a target-controlled infusion of propofol or with propofol alone. The primary end point was the total intraoperative dose of norepinephrine required to maintain an intraoperative mean arterial pressure >70 mm Hg. Secondary outcomes included the perioperative cardiorespiratory profile and the incidence of adverse and serious adverse events. RESULTS: Adding xenon to propofol anesthesia resulted in a significant reduction of norepinephrine required to attain the predefined hemodynamic goals (cumulative intraoperative dose: median [interquartile range]: 370 [116-570] vs 840 [335-1710] µg, P = .001). In the xenon-propofol group, significantly less propofol was required to obtain a similar depth of anesthesia as judged by clinical signs and the bispectral index (propofol effect site concentration [mean ± SD]: 1.8 ± 0.5 vs 2.8 ± 0.3 mg, P≤ .0001). Moreover, the xenon-propofol group required significantly less norepinephrine during the first 24 hours on the intensive care unit (median [interquartile range]: 1.5 [0.1-7] vs 5 [2-8] mg, P = .048). Other outcomes and safety parameters were similar in both groups. CONCLUSIONS: Thirty percent xenon added to propofol anesthesia improves hemodynamic stability by decreasing norepinephrine requirements in patients undergoing OPCAB surgery.

Serum protein S100 as marker of postoperative delirium after off-pump coronary artery bypass surgery: secondary analysis of two prospective randomized controlled trials.

BACKGROUND: To investigate the predictive value of S100 (biochemical marker of neuroglial injury) for the occurrence of postoperative delirium (POD) in patients undergoing off-pump coronary artery bypass (OPCAB)-surgery. METHODS: We enrolled 92 patients older than 18 years undergoing elective OPCAB-surgery. Serum-levels of S100 were determined at baseline (BL), end of surgery (EOS) and on the first postoperative day (PD1). Postoperatively, all-patients were evaluated daily until PD5 for the presence of POD using the confusion assessment method (CAM) or the confusion assessment method for the intensive care unit (CAM-ICU) for patients in the intensive care unit (ICU). RESULTS: The overall incidence of POD was 21%. S100-values on PD1 significantly predicted the occurrence of POD during the later hospital stay [area under the curve (AUC)=0.724 (95% confidence interval (CI): 0.619-0.814); p=0.0001] with an optimal cut-off level of 123 pg mL-1 (sensitivity 100%, specificity 44%). Below this value, the absence of POD was predicted correctly in 43.66% of patients without POD [negative predictive value (NPV) of 100% (95%CI: 88.8%-100.0%) - positive predictive value of 29.8% (95%CI: 18.4%-43.4%) and likelihood ratio (LR) of the negative result of 0.0]. CONCLUSIONS: S100-levels <123 pg mL-1 measured on PD1 reliably rule out the development of POD after elective OPCAB-surgery. This finding warrants testing whether S100-levels could be used for a risk stratification of cardiac surgical patients and for the initiation of preventive measures against POD in patients with high postoperative S100-levels.

Axillary Brachial Plexus Block Compared with Other Regional Anesthesia Techniques in Distal Upper Limb Surgery: A Systematic Review and Meta-Analysis.

Background: Several regional anesthesia (RA) techniques have been described for distal upper limb surgery. However, the best approach in terms of RA block success rate and safety is not well recognized. Objective: To assess and compare the surgical anesthesia and efficacy of axillary brachial plexus block with other RA techniques for hand and wrist surgery. The attainment of adequate surgical anesthesia 30 min after block placement was considered a primary outcome measure. Additionally, successful block outcomes were required without the use of supplemental local anesthetic injection, systemic opioid analgesia, or the need to convert to general anesthesia. Methods: We performed a systematic search in the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and CENTRAL. RCTs comparing axillary blocks with other brachial plexus block techniques, distal peripheral forearm nerve block, intravenous RA, and the wide-awake local anesthesia no tourniquet (WALANT) technique were included. Results: In total, 3070 records were reviewed, of which 28 met the inclusion criteria. The meta-analysis of adequate surgical anesthesia showed no significant difference between ultrasound-guided axillary block and supraclavicular block (RR: 0.94 [0.89, 1.00]; p = 0.06; I2 = 60.00%), but a statistically significant difference between ultrasound-guided axillary block and infraclavicular block (RR: 0.92 [0.88, 0.97]; p < 0.01; I2 = 53.00%). Ultrasound-guided infraclavicular blocks were performed faster than ultrasound-guided axillary blocks (SMD: 0.74 [0.30, 1.17]; p < 0.001; I2 = 85.00%). No differences in performance time between ultrasound-guided axillary and supraclavicular blocks were demonstrated. Additionally, adequate surgical anesthesia onset time was not significantly different between ultrasound-guided block approaches: ultrasound-guided axillary blocks versus ultrasound-guided supraclavicular blocks (SMD: 0.52 [-0.14, 1.17]; p = 0.12; I2 = 86.00%); ultrasound-guided axillary blocks versus ultrasound-guided infraclavicular blocks (SMD: 0.21 [-0.49, 0.91]; p = 0.55; I2 = 92.00%). Conclusions: The RA choice should be individualized depending on the patient, procedure, and operator-specific parameters. Compared to ultrasound-guided supraclavicular and infraclavicular block, ultrasound-guided axillary block may be preferred for patients with significant concerns of block-related side effects/complications. High heterogeneity between studies shows the need for more robust RCTs.

The patient with congenital heart disease in ambulatory surgery.

The number of patients with congenital heart disease (CHD) undergoing ambulatory surgery is increasing. Deciding whether a CHD patient is suitable for an ambulatory procedure is still challenging. Several factors must be considered, including the type of planned procedure, the complexity of the underlying pathology, the American Society of Anesthesiologists' Physical Status classification of the patient, and other patient-specific factors, including comorbidity, chronic complications of CHD, medication, coagulation disorders, and issues related to the presence of a pacemaker (PM) or cardioverter-defibrillator. Numerous studies reported higher perioperative mortality and morbidity rates in surgical patients with CHD than non-CHD patients. However, most of these studies were conducted in a cohort of hospitalized patients and may not reflect the ambulatory setting. The current review aims to provide the anesthesiologist with an overview and practical recommendations on selecting and managing a CHD patient scheduled for an ambulatory procedure.

Postoperative delirium and quality of life after transcatheter and surgical aortic valve replacement: A prospective observational study.

OBJECTIVE: In older patients, postoperative delirium is a frequently occurring complication after surgical aortic valve replacement, leading to an excess in postoperative morbidity and mortality. It remains controversial whether transcatheter aortic valve implantation and minimally invasive surgical aortic valve replacement can reduce the risk of postoperative delirium. This study aimed to compare the incidence of postoperative delirium after transcatheter aortic valve implantation and surgical aortic valve replacement and the impact on long-term outcomes. METHODS: Between September 2018 and January 2020, we conducted an observational, prospective cohort study in patients aged 70 years or more undergoing transcatheter aortic valve implantation or surgical aortic valve replacement. The primary end point was the incidence of in-hospital postoperative delirium during 5 postoperative days assessed with the Confusion Assessment Method. Secondary end points included perioperative inflammation, postoperative complications, health status (EuroQol 5-dimensional questionnaire 5 levels), and mortality up to 6 months. Transcatheter aortic valve implantation and surgical aortic valve replacement were compared using propensity weighting to account for important baseline differences (European System for Cardiac Operative Risk Evaluation II, age, and frailty). RESULTS: We included 250 patients with a mean (standard deviation) age of 80 (±5.8) years and a European System for Cardiac Operative Risk Evaluation score of 5 (±4.7). In the propensity-weighted analysis, those undergoing surgical aortic valve replacement (N = 166) had a higher incidence of postoperative delirium compared with transcatheter aortic valve implantation (N = 84) (51% vs 15%: P < .0001). Furthermore, patients undergoing surgical aortic valve replacement experienced more inflammation, a greater depth of anesthesia, and more intraoperative hypotension. After surgical aortic valve replacement, 41% of patients experienced an improved health status compared with 12% after transcatheter aortic valve implantation (P < .0001). No outcome differences were noted within the surgical aortic valve replacement groups. CONCLUSIONS: Transcatheter aortic valve implantation is associated with a lower risk for postoperative delirium. Nevertheless, patients undergoing surgical aortic valve replacement experience the greatest improvement in quality of life. Heart teams should consider these outcomes in shared decision-making in the choice of transcatheter aortic valve implantation or surgical aortic valve replacement.

Erector spinae plane block for postoperative analgesia in robotically-assisted coronary artery bypass surgery: Results of a randomized placebo-controlled trial.

STUDY OBJECTIVE: To investigate if an erector spinae plane (ESP) block decreases postoperative opioid consumption, pain and postoperative nausea and vomiting in patients undergoing robotically-assisted minimally invasive direct coronary artery bypass surgery (RAMIDCAB). DESIGN: A single-center, double-blind, prospective, randomized, placebo-controlled trial. SETTING: Postoperative period; operating room, post-anesthesia care unit (PACU) and hospital ward in a university hospital. PATIENTS: Sixty-four patients undergoing RAMIDCAB surgery via left-sided mini-thoracotomy and enrolled in the institutional enhanced recovery after cardiac surgery program. INTERVENTIONS: At the end of surgery, patients received an ESP catheter at vertebra T5 under ultrasound guidance and were randomized to the administration of either ropivacaine 0.5% (loading dose of 30 ml and three additional doses of 20 ml each, interspersed with a 6 h interval) or normal saline 0.9% (with an identical administration scheme). In addition, patients received multimodal analgesia including acetaminophen, dexamethasone and patient-controlled analgesia with morphine. Following the final ESP bolus and before catheter removal, the position of the catheter was re-evaluated by ultrasound. Patients, investigators and medical personnel were blinded for the group allocation during the entire trial. MEASUREMENTS: Primary outcome was cumulative morphine consumption during the first 24 h after extubation. Secondary outcomes included location and severity of pain, presence/extent of sensory block, duration of postoperative ventilation and hospital length of stay. Safety outcomes comprised the incidence of adverse events. MAIN RESULTS: Median (IQR) 24-h morphine consumption was not different between the intervention- and control-groups, 67 mg (35-84) versus 71 mg (52-90) (p = 0.25), respectively. Likewise, no differences were detected in secondary and safety endpoints. CONCLUSIONS: Following RAMIDCAB surgery, adding an ESP block to a standard multimodal analgesia regimen did not reduce opioid consumption and pain scores.

Efficacy of erector spinae plane block for minimally invasive mitral valve surgery: Results of a double-blind, prospective randomized placebo-controlled trial.

STUDY OBJECTIVE: To investigate if an erector spinae plane (ESP) block decreases postoperative opioid consumption, pain and postoperative nausea and vomiting in patients undergoing minimally invasive mitral valve surgery (MIMVS). DESIGN: A single-center, double-blind, prospective, randomized, placebo-controlled trial. SETTING: Postoperative period; operating room, post-anesthesia care unit (PACU) and hospital ward in a university hospital. PATIENTS: Seventy-two patients undergoing video-assisted thoracoscopic MIMVS via right-sided mini-thoracotomy and enrolled in the institutional enhanced recovery after cardiac surgery program. INTERVENTIONS: At the end of surgery, all patients received an ESP catheter at vertebra T5 under ultrasound guidance and were randomized to the administration of either ropivacaine 0.5% (loading of dose 30 ml and three additional doses of 20 ml with a 6 h interval) or normal saline 0.9% (with an identical administration scheme). In addition, patients received multimodal postoperative analgesia including dexamethasone, acetaminophen and patient-controlled intravenous analgesia with morphine. Following the final ESP bolus and before catheter removal, the position of the catheter was re-evaluated by ultrasound. Patients, investigators and medical personnel were blinded for the group allocation during the entire trial. MEASUREMENTS: Primary outcome was cumulative morphine consumption during the first 24 h after extubation. Secondary outcomes included severity of pain, presence/extent of sensory block, duration of postoperative ventilation and hospital length of stay. Safety outcomes comprised the incidence of adverse events. MAIN RESULTS: Median (IQR) 24-h morphine consumption was not different between the intervention- and control-group, 41 mg (30-55) versus 37 mg (29-50) (p = 0.70), respectively. Likewise, no differences were detected for secondary and safety endpoints. CONCLUSIONS: Following MIMVS, adding an ESP block to a standard multimodal analgesia regimen did not reduce opioid consumption and pain scores.

Association between improved compliance with enhanced recovery after cardiac surgery guidelines and postoperative outcomes: A retrospective study.

OBJECTIVE: Enhanced recovery after cardiac surgery is a multidisciplinary clinical care pathway that relies on a bundle of interventions, aiming to reduce the stress response to surgery and promote early recovery of organ function. In 2011, our institution introduced an institutional enhanced recovery after cardiac surgery program focusing on 9 central interventions, which have been expanded during the past decade by additional interventions now considered standard of care. After the recent publication of the enhanced recovery after cardiac surgery guidelines, we evaluated the relation between the compliance with these enhanced recovery after cardiac surgery guidelines and postoperative outcomes. METHODS: All patients enrolled in our enhanced recovery after cardiac surgery program in 2019 were included in this retrospective single-center audit. The primary outcome was compliance with 23 enhanced recovery after cardiac surgery guidelines. Secondary outcomes included occurrence of at least 1 postoperative complication and hospital length of stay. RESULTS: A total of 356 patients were included in this study. Compliance with the enhanced recovery after cardiac surgery guidelines was 64%. Postoperatively, 51% of the patients experienced at least 1 complication and had a median hospital length of stay of 6 days. Multivariable analysis showed that an increased compliance (per 10%) with the enhanced recovery after cardiac surgery guidelines was associated with a lower risk for any complication (odds ratio, 0.60; 95% confidence interval, 0.46-0.79; P = .0003) and a higher probability of earlier hospital discharge (hazard ratio, 1.25; 95% confidence interval, 1.10-1.43; P = .0008). CONCLUSIONS: This audit revealed a correlation between increased compliance with enhanced recovery after cardiac surgery guidelines and a reduction of postoperative complications and hospital length of stay. Future trials are needed to establish evidence-based recommendations for each separate intervention of the enhanced recovery after cardiac surgery guidelines and to create a minimum core-set of enhanced recovery after cardiac surgery interventions.

Erector spinae plane block for minimally invasive mitral valve surgery: a double-blind, prospective, randomised placebo-controlled trial-a study protocol.

INTRODUCTION: In the context of enhanced recovery after cardiac surgery, surgical techniques for mitral valve surgery have witnessed substantial modifications, from approaching the heart using open approaches with traditional sternotomy to thoracoscopic access via minithoracotomy. After cardiac surgery, acute postoperative pain is frequent and caused by surgical incision and retraction. Perioperative analgesia in cardiac surgery still relies mainly on opioids. Although neuraxial techniques could be a valuable non-opioid-based analgesia regimen, they can be associated with devastating complications in situations with (iatrogenic) coagulation abnormalities. Only two randomised clinical trials describe the erector spinae plane (ESP) block to provide sufficient postoperative analgesia following cardiac surgery with median sternotomy. Regarding postoperative analgesia after cardiac surgery with a minithoracotomy approach, adequately designed trials are still lacking. We, therefore, designed a double-blind, placebo-controlled trial to prove the hypothesis that the ESP block reduces opioid consumption in patients undergoing minimally invasive mitral valve surgery (MIMVS). METHODS AND ANALYSIS: Sixty-four patients undergoing MIMVS will be included in this double-blind, prospective, placebo-controlled trial. Patients will be randomised to receive an ESP block with a catheter with either intermittent ropivacaine 0.5% (ropi group) or normal saline 0.9% (placebo group). Both groups will receive patient-controlled intravenous analgesia with morphine following extubation. Primary endpoint is the 24-hour cumulative morphine consumption after extubation. Multiple secondary endpoints will be evaluated. ETHICS AND DISSEMINATION: The study is approved by the ethics committee of the University Hospitals Leuven, the Clinical Trials Centre of the University Hospitals Leuven and the 'Federaal Agentschap voor Geneesmiddelen en Gezondheidsproducten'. Dissemination of the study results will be via scientific papers. TRIAL REGISTRATION NUMBER: EudraCT identifier: 2019-001125-27.

Systemic Lidocaine Fails to Improve Postoperative Pain, But Reduces Time to Discharge Readiness in Patients Undergoing Laparoscopic Sterilization in Day-Case Surgery: A Double-Blind, Randomized, Placebo-Controlled Trial.

BACKGROUND AND OBJECTIVES: Perioperative systemic lidocaine provides postoperative analgesia, decreases opioid consumption, and facilitates rehabilitation in abdominal surgery. We hypothesized that systemic lidocaine has analgesic effects in women undergoing day-case laparoscopic sterilization. METHODS: Eighty women were randomized in this prospective, double-blind trial to receive either lidocaine (intravenous bolus of 1.5 mg/kg at induction of anesthesia, followed by an infusion of 1.5 mg · kg · h, which was continued until 30 minutes after arrival at the postanesthesia care unit [PACU]) or placebo. The primary end point was the proportion of patients with a numeric rating scale (NRS) of greater than 3, 30 minutes after arrival at the PACU. Secondary outcomes included total opioid consumption, postoperative pain scores, incidence of postoperative nausea and vomiting, and time to readiness for discharge. This clinical trial was registered (Eudra CT 2011-001315-31). RESULTS: Thirty minutes after PACU admission, the proportion of patients with an NRS score of greater than 3 did not differ between the groups (lidocaine group: 59% vs placebo group: 58%). The postoperative NRS for pain over the entire observation period was not significantly different between lidocaine and placebo groups (mean, 3.1 [SD, 0.7] vs 2.8 [SD, 0.6]; P = 0.4). Groups did not differ with respect to perioperative opioid consumption. Patients in the placebo group suffered significantly less from nausea (NRS: 0.1 [SD, 0.1] [placebo] vs 0.3 [SD, 0.1] [lidocaine]; P = 0.02) and required less postoperative nausea and vomiting rescue medication (1 patient in the placebo group vs 7 in the lidocaine group; P = 0.03). The time to meet hospital discharge criteria was significantly lower in the lidocaine group (median, 177 minutes [range, 96-408 minutes] vs 221 minutes [range, 121-420 minutes]; P = 0.02). The mean lidocaine plasma levels at the end of IV lidocaine infusion was 2.5 (SD, 1.1) µg/mL. CONCLUSIONS: In laparoscopic sterilization, systemic lidocaine reduces time to readiness for hospital discharge.

Xenon for the prevention of postoperative delirium in cardiac surgery: study protocol for a randomized controlled clinical trial.

BACKGROUND: Postoperative delirium (POD) is a manifestation of acute postoperative brain dysfunction that is frequently observed after cardiac surgery. POD is associated with short-term complications such as an increase in mortality, morbidity, costs and length of stay, but can also have long-term sequelae, including persistent cognitive deficits, loss of independence, and increased mortality for up to 2 years. The noble gas xenon has been demonstrated in various models of neuronal injury to exhibit remarkable neuroprotective properties. We therefore hypothesize that xenon anesthesia reduces the incidence of POD in elderly patients undergoing cardiac surgery with the use of cardiopulmonary bypass. METHODS/DESIGN: One hundred and ninety patients, older than 65 years, and scheduled for elective cardiac surgery, will be enrolled in this prospective, randomized, controlled trial. Patients will be randomized to receive general anesthesia with either xenon or sevoflurane. Primary outcome parameter will be the incidence of POD in the first 5 postoperative days. The occurrence of POD will be assessed by trained research personnel, blinded to study group, with the validated 3-minute Diagnostic Confusion Assessment Method (3D-CAM) (on the intensive care unit in its version specifically adapted for the ICU), in addition to chart review and the results of delirium screening tools that will be performed by the bedside nurses). Secondary outcome parameters include duration and severity of POD, and postoperative cognitive function as assessed with the Mini-Mental State Examination. DISCUSSION: Older patients undergoing cardiac surgery are at particular risk to develop POD. Xenon provides remarkable hemodynamic stability and has been suggested in preclinical studies to exhibit neuroprotective properties. The present trial will assess whether the promising profile of xenon can be translated into a better outcome in the geriatric population. TRIAL REGISTRATION: EudraCT Identifier: 2014-005370-11 (13 May 2015).