J.-H. Baumert

Xenon or propofol anaesthesia for patients at cardiovascular risk in non-cardiac surgery

BACKGROUND The results of two European multi-centre trials on xenon anaesthesia led to the hypothesis that a xenon-based anaesthetic would keep left ventricular (LV) and circulatory function more stable than a propofol-based anaesthetic, in patients with coronary artery disease (CAD). METHODS In a prospective, randomized design, 40 patients of ASA classes III and IV with known CAD were anaesthetized for elective non-cardiac surgery with either xenon (n=20) or propofol (n=20), each combined with remifentanil. Target criteria were intraoperative LV function as evaluated by transoesophageal echocardiography (TOE: Tei index, circumferential fibre shortening), arterial pressure, and heart rate (HR). RESULTS Mean arterial pressure was decreased with propofol but was stable at pre-anaesthetic level with xenon (P<0.02) and HR was lower with xenon (P<0.01). The Tei index (also known as myocardial performance index) improved from 0.53 (0.14) to 0.45 (0.10) after 1 h with xenon and changed from 0.50 (0.14) to 0.55 (0.20) with propofol anaesthesia [means (SD); P=0.01 between the groups]. Deviation of circumferential fibre shortening from expected value after 1 h was -2 (14)% with xenon and -14 (18)% with propofol [means (SD); P=0.03]. There were no perioperative signs of acute myocardial ischaemia (TOE, ECG, and troponin T release). CONCLUSIONS Xenon anaesthesia provided a higher arterial pressure level than propofol, with no signs of cardiovascular compromise, in patients with CAD. Echocardiographic indices showed better LV function with xenon.

Xenon does not prolong neuromuscular block of rocuronium.

With the exception of xenon, the interaction between muscle relaxants and inhaled anesthetics is known. We therefore compared the pharmacodynamics of rocuronium during xenon anesthesia versus a total IV anesthesia with propofol. Anesthesia was induced with propofol and remifentanil in both the xenon and propofol groups (each n = 20). The xenon group received xenon via face mask until an end-expiratory concentration of 60% was maintained for 1 min. Meanwhile, the acceleromyograph (TOF-Watch SX®) was calibrated and a frequent train-of-four stimulation of the musculus adductor pollicis was started. After stabilization of the signal for 5 min, a single bolus of 0.6 mg/kg rocuronium was injected. Anesthesia was maintained with xenon and remifentanil (xenon group) or with propofol and remifentanil (propofol group). There were no significant differences between the groups concerning the onset time (xenon group 125 ± 33 and propofol group 144 ± 43 s), duration (xenon group 33.2 ± 10.8 and propofol group 32.6 ± 8.4 min), recovery index (xenon group 9.4 ± 6.6 and propofol group 8.4 ± 5.3 min), and clinical recovery (xenon group 18.0 ± 10.2 and propofol group 17.1 ± 8.5 min). We conclude that the neuromuscular blocking effects of rocuronium are not different when given during propofol versus xenon anesthesia.

Xenon does not modify mivacurium induced neuromuscular block.

Objectif Ľinteraction entre le mivacurium et les anesthesiques inhales est bien connue, exception faite du xenon. Nous avons compare la pharmacodynamie du mivacurium pendant ľanesthesie au xenon vs ľanesthesie exclusivement iv avec du propofol.PurposeThe interaction between mivacurium and inhaled anesthetics is known, with the exception of xenon. We compared the pharmacodynamics of mivacurium during xenon anesthesia vs total iv anesthesia with propofol.MethodsThis randomized controlled trial was carried out in the Aachen University Hospital. Forty-two adult patients ASA I or II, aged 18 to 60 yr, were randomized to receive either xenon or propofol anesthesia. Anesthesia was induced with propofol and remifentanil in both groups (each n = 21). The xenon group received xenon via facemask until an end-expiratory concentration of 60% was reached for one minute. Meanwhile, the acceleromyograph was calibrated and a train-of-four stimulation of the adductor pollicis muscle was started. After stabilization of the signal for five minutes, a single bolus of 0.16 mg·kg-1 mivacurium was injected. Anesthesia was maintained with xenon and remifentanil or with propofol and remifentanil.ResultsThere were no significant differences between groups with respect to onset time (xenon 180 ± 64 vs propofol 195 ± 77 sec; P = 0.39), duration (xenon 16.18 ± 4.97 vs propofol 15.68 ± 6.17 min; P = 0.73), recovery index (xenon 5.63 ± 2.48 vs propofol 5.73 ± 2.12 min; P = 0.42) and clinical recovery (xenon 8.75 ± 2.57 vs propofol 9.28 ± 2.28 min; P = 0.22).ConclusionWe conclude that the neuromuscular blocking effects of mivacurium are similar when given during propofol vs xenon anesthesia.RésuméObjectifĽinteraction entre le mivacurium et les anesthésiques inhalés est bien connue, exception faite du xénon. Nous avons comparé la pharmacodynamie du mivacurium pendant ľanesthésie au xénon vs ľanesthésie exclusivement iv avec du propofol.MéthodeĽessai randomisé et contrôlé a été mené au Aachen University Hospital. Quarante-deux patients adultes, ďétat physique ASA I ou II, de 18 à 60 ans, ont reçu au hasard une anesthésie au xénon ou au propofol. Ľinduction a été faite avec du propofol et du rémifentanil chez les patients des deux groupes (chacun n = 21). Le xénon a été administré au masque jusqu’à une minute de concentration télé-expiratoire à 60 %. Entre-temps, ľaccéléromyographe a été calibré et une stimulation en train-dequatre de ľadducteur du pouce a été amorcée. Aprés un signal stable de cinq minutes, un bolus unique de 0,6 mg·kg-1 de mivacurium a été injecté. Ľanesthésie a été maintenue avec du xénon et du rémifentanil ou du propofol et du rémifentanil.RésultatsIl n’y a pas eu de différence intergroupe significative quant au délai ďinstallation du bloc (xénon 180 ± 64 vs propofol 195 ± 77 s ; P = 0,39), à sa durée (xénon 16,18 ± 4,97 vs propofol 15,68 ± 6,17 min ; P = 0,73), à ľindice de récupération (xénon 5,63 ± 2,48 vs propofol 5,73 ± 2,12 min ; P = 0,42) et à la récupération clinique (xénon 8,75 ± 2,57 vs propofol 9,28 ± 2,28 min ; P = 0,22).ConclusionLes effets neuromusculaires bloquants du mivacurium sont similaires pendant ľanesthésie au propofol ou au xénon.

Le xénon ne modifie pas le bloc neuromusculaire induit par le mivacurium

Objectif Ľinteraction entre le mivacurium et les anesthesiques inhales est bien connue, exception faite du xenon. Nous avons compare la pharmacodynamie du mivacurium pendant ľanesthesie au xenon vs ľanesthesie exclusivement iv avec du propofol.PurposeThe interaction between mivacurium and inhaled anesthetics is known, with the exception of xenon. We compared the pharmacodynamics of mivacurium during xenon anesthesia vs total iv anesthesia with propofol.MethodsThis randomized controlled trial was carried out in the Aachen University Hospital. Forty-two adult patients ASA I or II, aged 18 to 60 yr, were randomized to receive either xenon or propofol anesthesia. Anesthesia was induced with propofol and remifentanil in both groups (each n = 21). The xenon group received xenon via facemask until an end-expiratory concentration of 60% was reached for one minute. Meanwhile, the acceleromyograph was calibrated and a train-of-four stimulation of the adductor pollicis muscle was started. After stabilization of the signal for five minutes, a single bolus of 0.16 mg·kg-1 mivacurium was injected. Anesthesia was maintained with xenon and remifentanil or with propofol and remifentanil.ResultsThere were no significant differences between groups with respect to onset time (xenon 180 ± 64 vs propofol 195 ± 77 sec; P = 0.39), duration (xenon 16.18 ± 4.97 vs propofol 15.68 ± 6.17 min; P = 0.73), recovery index (xenon 5.63 ± 2.48 vs propofol 5.73 ± 2.12 min; P = 0.42) and clinical recovery (xenon 8.75 ± 2.57 vs propofol 9.28 ± 2.28 min; P = 0.22).ConclusionWe conclude that the neuromuscular blocking effects of mivacurium are similar when given during propofol vs xenon anesthesia.RésuméObjectifĽinteraction entre le mivacurium et les anesthésiques inhalés est bien connue, exception faite du xénon. Nous avons comparé la pharmacodynamie du mivacurium pendant ľanesthésie au xénon vs ľanesthésie exclusivement iv avec du propofol.MéthodeĽessai randomisé et contrôlé a été mené au Aachen University Hospital. Quarante-deux patients adultes, ďétat physique ASA I ou II, de 18 à 60 ans, ont reçu au hasard une anesthésie au xénon ou au propofol. Ľinduction a été faite avec du propofol et du rémifentanil chez les patients des deux groupes (chacun n = 21). Le xénon a été administré au masque jusqu’à une minute de concentration télé-expiratoire à 60 %. Entre-temps, ľaccéléromyographe a été calibré et une stimulation en train-dequatre de ľadducteur du pouce a été amorcée. Aprés un signal stable de cinq minutes, un bolus unique de 0,6 mg·kg-1 de mivacurium a été injecté. Ľanesthésie a été maintenue avec du xénon et du rémifentanil ou du propofol et du rémifentanil.RésultatsIl n’y a pas eu de différence intergroupe significative quant au délai ďinstallation du bloc (xénon 180 ± 64 vs propofol 195 ± 77 s ; P = 0,39), à sa durée (xénon 16,18 ± 4,97 vs propofol 15,68 ± 6,17 min ; P = 0,73), à ľindice de récupération (xénon 5,63 ± 2,48 vs propofol 5,73 ± 2,12 min ; P = 0,42) et à la récupération clinique (xénon 8,75 ± 2,57 vs propofol 9,28 ± 2,28 min ; P = 0,22).ConclusionLes effets neuromusculaires bloquants du mivacurium sont similaires pendant ľanesthésie au propofol ou au xénon.

A comparison of waste gas concentrations during xenon or nitrous oxide anaesthesia

Background and objective: The aim of this study was to compare waste gas concentrations during xenon or nitrous oxide anaesthesia. Methods: A total of 64 patients were included in this study. Gas concentrations were measured with a mass spectrometer during anaesthesia. The probes were taken beside the patients head and thorax and at a height of 180 cm above and at the floor level. Results: In both groups, waste gas concentrations peak after intubation and extubation. Waste gas levels during xenon anaesthesia are low compared with nitrous oxide. Conclusions: The low waste gas levels of xenon seem to be beneficial compared to nitrous oxide.

Influence of a 30 minute break on cognitive function in resident anaesthetists on a daily routine: A-982

pare for a routine procedure for a stable team and a complex procedure for an ad-hoc team? Communication within anaesthetic teams is dependent on; staff experience, difficulty of procedure, time-pressure and team dynamics. Can debriefing heighten team reflection and enhance team understanding for dynamic and complex scenarios? Materials and Methods: 30 hours of video taped orthopaedic procedures (15 operations) have been analysed for specific team interactions. This abstract isolates two anaesthetic teams for illustration. Results and Discussions: Communication categories relating to situational awareness are mapped below Frequencies differ as illustrated:

Xenon does not prolong neuromuscular block of vecuronium bromide: A-562

Clinic of Anaesthesiology, University Clinic Aachen, Aachen, Germany Background and Goal of Study: To investigate the influence of the noble gas xenon on the neuromuscular blocking effects of vecuronium bromide we compared these effects during xenon and with those during a total intravenous anaesthesia (TIVA) with propofol. Materials and Methods: With approval by the local ethics committee, 40 patients were included in this prospective randomized trial after they gave their written informed consent. The study design is based on the “Good Clinical Research Practice Guidelines” (1). Anaesthesia was induced with propofol and remifentanil in both groups. Then xenon was administered via face mask until an endexpiratory concentration of 60% was reached for one minute. Calibration of the acceleromyograph (TOF-Watch SX®) and a train of four stimulation every 15 seconds was started. A single bolus of vecuronium bromide (0.1 mg kg 1 2xED95) was injected after stabilisation of the TOF-Watch SX® signal. Anaesthesia was maintained with Xenon or propofol and remifentanil. Statistical analysis was done with the wilcoxon rank sum test. Results and Discussion: Data are shown in the table: X xenon-group, P propofol-group, T5 onset-time, T25 duration, T25-0.8 recovery, SD standard deviation and Q quartile; All data are in seconds.