Xenon Anesthesia Research Articles

Xenon anesthesia during the oral cavity sanitation in child with consequences of perinatal brain damage

Halogenated inhalation anesthetics have some adverse effects, including the ability to have a negative effect on the developing brain in children, one of the manifestations of which are cognitive dysfunctions, especially in the younger age group. The article presents a clinical case of xenon in combined inhalation anesthesia in a child with the consequences of perinatal brain damage. During anesthesia, a spontaneous ventilation mode was applied with pressure support ventilation (PSV). There was noted high efficacy and safety xenon anesthesia in a dental treatment, the absence of the effect of anesthesia on cognitive function in a child with a compromised nervous system. It is advisable to further study the use of xenon in the pediatric dentistry anesthesia.

Protecting the Brain With Xenon Anesthesia for Neurosurgical Procedures.

Xenon possesses some, but not all, of the clinical features of an ideal anesthetic agent. Besides well-known advantages of rapid awakening, stable hemodynamics and lack of biotransformation, preclinical data lead to the expectation of xenon's advantageous use for settings of acute ongoing brain injury; a single randomized clinical trial using an imaging biomarker for assessing brain injury corroborated xenon's preclinical efficacy in protecting the brain from further injury. In this review, we discuss the mechanisms and hence the putative applications of xenon for brain protection in neurosurgery. Although the expense of this rare monoatomic gas will likely prevent its widespread penetration into routine clinical neurosurgical practice, we draw attention to the theoretical benefits of xenon anesthesia over other anesthetic regimens for awake craniotomy and for neurosurgery in older, high-risk, and sicker patients.

Xenon anesthesia for awake craniotomy: safety and efficacy.

The asleep-awake-asleep (AAA) craniotomy is a technique that offers the opportunity of having a patient fully cooperative during the awake phase, and minimizes the possible discomfort, due to the asleep phase. The aim of this prospective observational study was to test the use of xenon in the first asleep phase of an AAA craniotomy, in patients undergoing craniotomy for brain tumor resection. The data have been collected from 40 awake craniotomy procedures, performed in patients with cerebral tumor, treated with the AAA technique. Patients were treated with xenon during the asleep phase, and quality of mapping, complications and qualitative judgment of the experience given by the patients were recorded. The mapping was carried out as planned in 37 out of 40 cases. The doses of xenon administered during the first asleep phase of the anesthesia was 13±2 L. Time for awakening after xenon was switched off was 5±1 minute. A combination of xenon and regional anesthesia (with no need for additional systemic anesthetics) was adequate to accomplish craniotomy in 27/40 patients (67.5%). On the day after the operation, 37 patients recalled the testing procedure for mapping during the awake period, none had recollection of local anesthetic injections for regional anesthesia or sound associated with the neurosurgical drill. Five patients (12.5%) reported mild pain during tumor removal (VAS Score less than three). In this case series, xenon anesthesia was successfully used for the sedative phase of an awake craniotomy accomplished with an AAA approach.

Xenon anesthesia and beyond: pros and cons

Xenon is a colorless and odorless noble gas, licensed for human use as an anesthetic gas as well as a radiological marker. The MAC of this gas is about 63% but xenon anesthesia is associated with fast recovery of cognitive function and cardiovascular stability. Nevertheless, postoperative nausea and vomiting (PONV) incidence for xenon anesthesia is very high. It has been reported that Xenon has cytoprotective effects that may have therapeutic values in both CNS protection, and in organ graft preservation. Currently, there are few studies about the effect of xenon on ischemia reperfusion injury of transplantable organs and insufficient clinical data upon its effect on intracranial and cerebral perfusion pressure. We shortly review the pros and cons of xenon as an anesthetic agent.

Xenon Anesthesia and CT: Noninvasive Measures of Brain Anesthetic Concentration.

The existence of a barrier between anesthetic behavioral state transitions has been observed across phyla, but demonstrating that such a barrier exists and is not a pharmacokinetic artifact has not yet been possible in humans. Such an investigation requires temporally precise information regarding the brain concentration of anesthetic in order to demonstrate the specific pharmacokinetic-pharmacodynamic mismatch that is hysteresis. We propose a method to noninvasively determine brain tissue anesthetic concentration using computerized tomography and the radiopaque gaseous anesthetic xenon. Such a technique can be used to investigate pharmacokinetic-pharmacodynamic mismatches in humans.

Anesthesia Machine with Oxygen Absorber Compatible for Xenon Anesthesia

Anesthesia Machine with Oxygen Absorber Compatible for Xenon Anesthesia

The hip fracture surgery in elderly patients (HIPELD) study to evaluate xenon anaesthesia for the prevention of postoperative delirium: a multicentre, randomized clinical trial

BackgroundPostoperative delirium occurs frequently in elderly hip fracture surgery patients and is associated with poorer overall outcomes. Because xenon anaesthesia has neuroprotective properties, we evaluated its effect on the incidence of delirium and other outcomes after hip fracture surgery. MethodsThis was a phase II, multicentre, randomized, double-blind, parallel-group, controlled clinical trial conducted in hospitals in six European countries (September 2010 to October 2014). Elderly (≥75yr-old) and mentally functional hip fracture patients were randomly assigned 1:1 to receive either xenon- or sevoflurane-based general anaesthesia during surgery. The primary outcome was postoperative delirium diagnosed through postoperative day 4. Secondary outcomes were delirium diagnosed anytime after surgery, postoperative sequential organ failure assessment (SOFA) scores, and adverse events (AEs). ResultsOf 256 enrolled patients, 124 were treated with xenon and 132 with sevoflurane. The incidence of delirium with xenon (9.7% [95% CI: 4.5 -14.9]) or with sevoflurane (13.6% [95% CI: 7.8 -19.5]) were not significantly different (P=0.33). Overall SOFA scores were significantly lower with xenon (least-squares mean difference: −0.33 [95% CI: −0.60 to −0.06]; P=0.017). For xenon and sevoflurane, the incidence of serious AEs and fatal AEs was 8.0% vs 15.9% (P=0.05) and 0% vs 3.8% (P=0.06), respectively. ConclusionsXenon anaesthesia did not significantly reduce the incidence of postoperative delirium after hip fracture surgery. Nevertheless, exploratory observations concerning postoperative SOFA-scores, serious AEs, and deaths warrant further study of the potential benefits of xenon anaesthesia in elderly hip fracture surgery patients. Clinical trial registrationEudraCT 2009-017153-35; ClinicalTrials.gov NCT01199276.

Xenon as an adjuvant to sevoflurane anesthesia in children younger than 4years of age, undergoing interventional or diagnostic cardiac catheterization: A randomized controlled clinical trial.

Xenon has repeatedly been demonstrated to have only minimal hemodynamic side effects when compared to other anesthetics. Moreover, in experimental models, xenon was found to be neuroprotective and devoid of developmental neurotoxicity. These properties could render xenon attractive for the anesthesia in neonates and infants with congenital heart disease. However, experience with xenon anesthesia in children is scarce. We hypothesized that in children undergoing cardiac catheterization, general anesthesia with a combination of sevoflurane with xenon results in superior hemodynamic stability, compared to sevoflurane alone. In this prospective, randomized, single-blinded, controlled clinical trial, children with a median age of 12 [IQR 3-36] months undergoing diagnostic/interventional cardiac catheterization were randomized to either general anesthesia with 50-65vol% xenon plus sevoflurane or sevoflurane alone. The primary outcome was the incidence of intraprocedural hemodynamic instability, defined as the occurrence of: (i) a heart rate change >20% from baseline; or (ii) a change in mean arterial blood pressure >20% from baseline; or (iii) the requirement of vasopressors, inotropes, chronotropes, or fluid boluses. Secondary endpoints included recovery characteristics, feasibility criteria, and safety (incidence of emergence agitation and postoperative vomiting. After inclusion of 40 children, the trial was stopped as an a priori planned blinded interim analysis revealed that the overall rate of hemodynamic instability did not differ between groups [100% in both the xenon-sevoflurane and the sevoflurane group. However, the adjuvant administration of xenon decreased vasopressor requirements, preserved better cerebral oxygen saturation, and resulted in a faster recovery. Xenon anesthesia was feasible (with no differences in the need for rescue anesthetics in both groups). Our observations suggest that combining xenon with sevoflurane in preschool children is safe, feasible, and facilitates hemodynamic management. Larger and adequately powered clinical trials are warranted to investigate the impact of xenon on short- and long-term outcomes in pediatric anesthesia.

ДОСТАВКА КИСЛОРОДА, ГАЗОВЫЙ СОСТАВ И КИСЛОТНО-ОСНОВНОЕ СОСТОЯНИЕ АРТЕРИАЛЬНОЙ КРОВИ ВО ВРЕМЯ КСЕНОНОВОЙ АНЕСТЕЗИИ ПО ЗАКРЫТОМУ КОНТУРУ

Xenon is an inert gas being very close to an ideal anesthetic. Goal of the study: to evaluate changes in gases and acid-base balance of arterial blood during general xenon anesthesia with the closed circuit and to compare it with general anesthesia with sevoflurane. Methods. The article describes a prospective assessment of anesthesia with expanded hemodynamic monitoring in 50 patients undergoing planned surgery. Based on the main inhalation anesthetic (xenon or sevoflurane) patients were divided into two groups. The monitoring included blood gases and O 2 delivery; cardiac output was evaluated through analysis of arterial pressure pulse wave after calibration by transpulmonary thermodilution (PiCCO). Results. Xenon anesthesia did not result in serious disorders of acid-base balance and O2 delivery and compared to sevoflurane the metabolic acidosis was less frequent as well as the need to manage it. Changes in the lactate level provided the evidence that both inhalation anesthetics did not result in serious disorders of tissue perfusion and gas exchange.

Renal function following xenon anesthesia for partial nephrectomy—An explorative analysis of a randomized controlled study

BackgroundPerioperative preservation of renal function has a significant impact on morbidity and mortality in kidney surgery. Nephroprotective effects of the anesthetic xenon on ischemia-reperfusion injury were found in several experimental studies.ObjectiveWe aimed to explore whether xenon anesthesia can reduce renal damage in humans undergoing partial nephrectomy and to gather pilot data of possible nephroprotection in these patients.DesignA prospective randomized, single-blinded, controlled study.SettingSingle-center, University Hospital of Aachen, Germany between July 2013-October 2015.PatientsForty-six patients with regular renal function undergoing partial nephrectomy.InterventionsPatients were randomly assigned to receive xenon- (n = 23) or isoflurane (n = 23) anesthesia.Main outcome measuresPrimary outcome was the maximum postoperative glomerular filtration rate (GFR) decline within seven days after surgery. Secondary outcomes included intraoperative and tumor-related data, assessment of further kidney injury markers, adverse events and optional determination of renal function after 3–6 months.ResultsUnexpected radical nephrectomy was performed in 5 patients, thus they were excluded from the per-protocol analysis, but included in the intention-to-treat analysis. The maximum postoperative GFR decline was attenuated by 45% in the xenon-group (10.9 ml min-1 1.73 cm-2 versus 19.7 ml min-1 1.73 cm-2 in the isoflurane group), but without significance (P = 0.084). Occurrence of adverse events was reduced (P = 0.003) in the xenon group. Renal function was similar among the groups after 3–6 months.ConclusionXenon anesthesia was feasible and safe in patients undergoing partial nephrectomy with regard to postoperative renal function. We found no significant effect on early renal function but less adverse events in the xenon group. Larger randomized controlled studies in more heterogeneous collectives are required, to confirm or refute the possible clinical benefit on renal function by xenon.Trial registrationClinicalTrials.gov NCT01839084 and EudraCT 2012-005698-30

The switch of the binding behaviours between Xe and π system induced by the change of oxidation state of Cu ion

The interaction between a xenon atom and aromatic π electron system is generally of van der Waals force with a specifically weak strength. In this work, we suggest the introduction of Cu ion will highly affect the binding behaviour between the xenon and π systems. Once Cu2+ ion locates above the benzene ring, the binding is surprisingly strengthened to 11.98 kcal mol−1 at CCSD(T)/CBS level, which is significantly stronger than average strength of the H-bonds in Watson-Crick guanine-cytosine base pair. If the Cu2+ is reduced to Cu+, the interaction of interest returns to the weak van der Waals interaction again. This phenomenon indicates the oxidation state shift of Cu ion could regulate the binding strength of Xe with π systems, which would be important for their potential biological functions. This study may provide a plausible understanding of the recent experimental observations of xenon anaesthesia.

Intravenous Delivery of Xenon Incorporated in Thermosensitive Nano-Emulsions for Anesthesia.

Xenon anesthesia has several advantages over conventional anesthetics, however, it has not been widely used in clinical sites, since the cost and minimum alveolar concentration were higher than conventional inhalational anesthetics. The purpose of this study was to develop an optimum vehicle for stable intravenous delivery of xenon with sufficient concentration. Thermosensitive lipid based nano-emulsions (TS-LE) were prepared by blending medium chain triglyceride, polyethylene glycol-15-hydroxystearate, D-α tocopherol polyethylene glycol succinate and Poloxamer 188. Three folds higher xenon was loaded in TS-LE when it was prepared under 5.5 atm of xenon pressure compared to that under 1 atm of xenon pressure at 22 °C (11.4±0.7 vs. 3.82±0.34 mg/ml). Poloxamer 188 conferred thermosensitive viscosity and outer rigid structure on TS-LE, and the properties led to the enhanced stability of xenon compared to usual lipid emulsion. Induction of anesthesia was investigated by monitoring loss of forepaw righting reflex (LORR) in rats. The ED50 for LORR was 131.9 mg/kg and the anesthesia was maintained for 65.3±7.1 sec at a dose of 179 mg/kg in rats. When it is considered that TS-LE stably loads enough concentration of xenon for the induction of therapeutically sufficient anesthesia, TS-LE may be regarded as a promising candidate for intravenous xenon delivery.

Xenon anaesthesia for all, or only a select few?

Xenon anaesthesia for all, or only a select few?

Modern Equipment for Medical Xenon Anesthesia

The article highlights the role of Soviet and Russian scientists in the study and implementation in medical practice of ultra-pure xenon (Xe), whose characteristics are almost identical to an ideal anesthetic gas [1]. Emphasis is placed on the remarkable therapeutic properties of Xe revealed by anesthesiologists as well as during its use as a drug. Anesthesia and respiratory devices and modern equipment to adapt the devices to work with medical xenon are presented.

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial.

ObjectiveLike other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV). We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis.Methods220 subjects with elevated PONV risk (Apfel score ≥2) undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up.ResultsLogistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02–5.19, p = 0.044). Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138). After xenon, nausea occurred significantly earlier (p = 0.014), was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups.ConclusionIn our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea.Trial RegistrationEU Clinical Trials EudraCT-2008-004132-20ClinicalTrials.gov NCT00793663

Xenon Anesthesia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Xenon anesthesia has been studied for decades. However, no meta-analysis of randomized controlled trials (RCTs) on xenon anesthesia has been conducted. The aim of this study was to systematically review all available evidence from RCTs comparing xenon and other inhaled and IV anesthetics on anesthetic outcomes. Our meta-analysis attempted to quantify the effects of xenon anesthesia on clinical outcomes in relation to other anesthetics. We found 43 RCTs from PubMed, MEDLINE, CENTRAL, EMBASE, and CINAHL (until January 2015). A total of 31 studies comparing xenon (841 patients) with other inhaled agents (836 patients) and 12 studies comparing xenon (373 patients) with propofol (360 patients) were found. We evaluated clinical outcomes, such as intraoperative hemodynamics, emergence, and postoperative nausea and vomiting (PONV). Patients undergoing xenon anesthesia had a lower heart rate and higher mean arterial pressure (MAP) intraoperatively than those receiving volatile anesthesia (mean difference = -6 min⁻¹ [99% confidence interval {99% CI} -10.0 to -2.3]; mean difference = 9 mm Hg [99% CI 3.1-14.4]) and propofol anesthesia (mean difference = -10 min⁻¹ [99% CI -12.4 to -6.6]; mean difference = 7 mm Hg [99% CI 0.85-13.2]). Compared with baseline, intraoperative MAP remained relatively stable (change < 5.5%, 99% CI within ±20% of the baseline) under xenon anesthesia, but MAP decreased by ≥15% under volatile (mean difference = -17 mm Hg [99% CI -29.5 to - 4.9], percentage change = -17.5%) and propofol (mean difference = -14 mm Hg [99% CI -26.1 to -2.5], percentage change = -15.0%) anesthesia. Patients had faster emergence from xenon than from volatile anesthesia: eyes opening (versus all volatile agents: mean 4 vs 7 minutes, percentage change = -49.8% [99% CI -55.1% to -44.0%]), tracheal extubation (versus all volatile agents: mean 4 vs 8 minutes percentage change = -44.6% [99% CI -57.3% to -28.1%]), orientation (versus sevoflurane: mean 5 vs 10 minutes, percentage change = -45.1% [99% CI -58.5% to -28.1%]), countdown (versus sevoflurane: mean 6 vs 10 minutes, percentage change = -41.7% [99% CI -50.3% to -31.6%]; versus isoflurane: mean 6 vs 14 minutes, percentage change = -57.7% [99% CI -65.7% to -48.3%]), and reaction on demand (versus sevoflurane: mean 4 vs 8 minutes, percentage change = -53.2% [99% CI -65.7% to -35.6%]). However, xenon anesthesia increased the risks of PONV (incidence 34.4% vs 19.9%; risk ratio = 1.72 [99% CI 1.10-2.69], risk difference = 0.19 [99% CI 0.04-0.33]). Xenon anesthesia provides relatively more stable intraoperative blood pressure, lower heart rate, and faster emergence from anesthesia than volatile and propofol anesthesia. However, xenon is associated with a higher incidence of PONV.

Consciousness and Complexity during Unresponsiveness Induced by Propofol, Xenon, and Ketamine

A common endpoint of general anesthetics is behavioral unresponsiveness, which is commonly associated with loss of consciousness. However, subjects can become disconnected from the environment while still having conscious experiences, as demonstrated by sleep states associated with dreaming. Among anesthetics, ketamine is remarkable in that it induces profound unresponsiveness, but subjects often report "ketamine dreams" upon emergence from anesthesia. Here, we aimed at assessing consciousness during anesthesia with propofol, xenon, and ketamine, independent of behavioral responsiveness. To do so, in 18 healthy volunteers, we measured the complexity of the cortical response to transcranial magnetic stimulation (TMS)--an approach that has proven helpful in assessing objectively the level of consciousness irrespective of sensory processing and motor responses. In addition, upon emergence from anesthesia, we collected reports about conscious experiences during unresponsiveness. Both frontal and parietal TMS elicited a low-amplitude electroencephalographic (EEG) slow wave corresponding to a local pattern of cortical activation with low complexity during propofol anesthesia, a high-amplitude EEG slow wave corresponding to a global, stereotypical pattern of cortical activation with low complexity during xenon anesthesia, and a wakefulness-like, complex spatiotemporal activation pattern during ketamine anesthesia. Crucially, participants reported no conscious experience after emergence from propofol and xenon anesthesia, whereas after ketamine they reported long, vivid dreams unrelated to the external environment. These results are relevant because they suggest that brain complexity may be sensitive to the presence of disconnected consciousness in subjects who are considered unconscious based on behavioral responses.

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

BackgroundPostoperative 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/DesignOne 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.DiscussionOlder 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 registrationEudraCT Identifier: 2014-005370-11 (13 May 2015).

Xenon anaesthesia for patients undergoing off-pump coronary artery bypass graft surgery: a prospective randomized controlled pilot trial

Off-pump coronary artery bypass (OPCAB) surgery carries a high risk for haemodynamic instability and perioperative organ injury. Favourable haemodynamic effects and organ-protective properties could render xenon an attractive anaesthetic for OPCAB surgery. The primary aim of this study was to assess whether xenon anaesthesia for OPCAB surgery is non-inferior to sevoflurane anaesthesia with regard to intraoperative vasopressor requirements. Forty-two patients undergoing elective OPCAB surgery were enrolled in this prospective, single-blind, randomized controlled pilot trial. Patients were randomized to either xenon (50-60 vol%) or sevoflurane (1.1-1.4 vol%) anaesthesia. Primary outcome was intraoperative noradrenaline requirements necessary to achieve predefined haemodynamic goals. Secondary outcomes included safety variables such as the occurrence of adverse events (intraoperatively and during a 6-month follow-up after surgery) and the perioperative cardiorespiratory and inflammatory profile. Baseline and intraoperative data did not differ between groups. Xenon was non-inferior to sevoflurane, as xenon patients required significantly less noradrenaline intraoperatively to achieve the predefined haemodynamic goals {geometric mean 428 [95% confidence interval (CI) 312, 588] vs 1702 [1267, 2285] µg, P<0.0001}. No differences were found for safety. Significantly more sevoflurane patients developed postoperative delirium (POD) (hazard ratio 4.2, P=0.044). The average arterial pressure was lower in the sevoflurane group {median75 [interquartile range (IQR) 6] vs 72 [4] mmHg, P=0.002}. No differences were found for other haemodynamic parameters, the respiratory profile and the perioperative release of inflammatory cytokines, troponin T, serum protein S-100β and erythropoietin. Compared with sevoflurane, xenon anaesthesia allows a significant reduction in vasopressor administration in OPCAB surgery. Moreover, xenon anaesthesia was associated with a lower risk for POD, a finding that has to be confirmed in larger studies. ClinicalTrials.gov (NCT01757106) and EudraCT (2012-002316-12).

Elevated Serum Levels of Erythropoietin after Xenon Anesthesia in Cardiac Surgery: A Secondary Analysis of a Randomized Controlled Trial

Objectives: The noble gas xenon has recently been amended to the list of prohibited substances because it is supposed to trigger the production of HIF-1α and subsequently erythropoietin. While any performance-enhancing treatments are strictly prohibited in sport competitions researcher and clinician have opened a debate about the potential transfer of these promising findings into clinical context. Methods: The objective of this study was to evaluate the effect of xenon anesthesia on serum levels of erythropoietin in patients that underwent cardiac surgery. Therefore we performed a secondary analysis of serum samples and dataset of patients from a prospective randomized controlled trial in cardiac surgery. Serum levels of erythropoietin and testosterone were measured in serum samples that were collected prior to surgery, at admission to the ICU and 24 hours thereafter. In 30 patients, we evaluated the effect of xenon anesthesia on the perioperative serum levels of erythropoietin and its association with testosterone and postoperative hemoglobin levels. Results: Patients in the xenon group showed a significant increase of circulating serum levels of erythropoietin 24 hours after xenon anesthesia (12.9 ± 7.4 versus 8.7 ± 4.3 at baseline; p = 0.017) The testosterone levels were comparable between the xenon and sevoflurane group. The postoperative hemoglobin levels trended to be higher in the xenon group, whereas no difference was found with respect to the intraoperative administration of fluids or blood products (Fig. 1). Conclusion: This study provides first evidence for a xenon triggered effect on circulating serum levels of erythropoietin during cardiac surgery. Further validation in a larger trial is needed.