Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible.

Effects of ketamine on precipitated opiate withdrawal.

OBJECTIVE: N-methyl-D-aspartate antagonists were shown to be effective in suppressing the symptoms of opiate withdrawal. Intravenous anesthetic, ketamine, is the most potent N-methyl-D-aspartate antagonist available in clinical practice. The present study was designed to evaluate the effects of subanesthetic ketamine infusion, as little human data are available on ketamine in precipitated opiate withdrawal. MATERIALS AND METHODS: A total of 58 opiate-dependent patients were enrolled in a randomized, placebo-controlled, double-blind study. Patients underwent rapid opiate antagonist induction under general anesthesia. Prior to opiate antagonist induction patients were given either placebo (normal saline) or subanesthetic ketamine infusion of 0.5 mg/kg/h. Further evaluations were divided into three phases: anesthetic, early postanesthetic (48 hours), and remote at 4 months after procedure. Cardiovascular, respiratory, renal, and gastrointestinal responses to opiate antagonist induction were monitored during anesthesia phase. Changes in plasma cortisol concentrations were measured as stress-response markers. Evaluations during early postanesthetic phase were based on Subjective and Objective Opiate Withdrawal Scales. Remote effects were assessed according to questionnaire based on Addiction Severity Index. RESULTS: Altogether, 50 patients were included in the final analysis. Ketamine group presented better control of withdrawal symptoms, which lasted beyond ketamine infusion itself. Significant differences between Ketamine and Control groups were noted in anesthetic and early postanesthetic phases. There were no differences in effects on outcome after 4 months. CONCLUSION: In this study, subanesthetic ketamine infusion was an effective adjuvant in the correction of acute precipitated opiate withdrawal although it had no long-term effects on treatment of opiate dependence.

[Safety and effectiveness of opiate antagonist detoxification under general anesthesia]. / Opioidu antagonistu ankstyvosios indukcijos metodika taikant bendraja anestezija. Proceduros saugumas ir efektyvumas.

OBJECTIVE: To evaluate safety and effectiveness of opiate antagonist detoxification under general anesthesia according to available prospective and retrospective data. METHODS: We analyzed all detoxification cases that were performed in Vilnius University Emergency Hospital in the period of 2002-2005. Data of 65 patients from prospective, randomized, double-blind, placebo-controlled study and 21 retrospective cases were included in the study. RESULTS: Full opiate receptor blockade was achieved in 85 cases (98.84%). No complications related to detoxification procedure or general anesthesia were recorded. Differences in procedure protocols and possible implications for clinical practice are discussed. CONCLUSIONS: The protocol of the prospective study may be recommended as a safe and effective detoxification method.