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 patient's 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.

Randomized controlled trial of the haemodynamic and recovery effects of xenon or propofol anaesthesia.

BACKGROUND: There is limited clinical experience with xenon in a large number of patients. We present intra- and postoperative haemodynamic and recovery data comparing xenon and total intravenous anaesthesia with propofol. METHODS: A total of 160 patients aged 18-60 years (ASA I and II) undergoing elective surgery took part in this prospective non-blinded randomized controlled trial. After local ethics committee approval and written informed consent, patients were allocated randomly to either the xenon or the propofol group. Anaesthesia was induced with propofol and remifentanil and was maintained with xenon at 60% (minimal alveolar concentration 0.95) or with propofol 0.1-0.12 mg kg(-1) min(-1). Remifentanil was titrated to clinical need in both groups. RESULTS: The two study groups were comparable with respect to age, weight, height, gender and ASA classification. Baseline in heart rate and systolic arterial pressure (SAP) were comparable in both groups. Following induction, SAP initially decreased but returned to baseline values over 15 min in the xenon group and differed significantly from the propofol group. Heart rate decreased significantly only in the xenon group and remained at stable values. Occurrence and duration of hypertension, hypotension and bradycardia showed no significant difference between groups. Patient recovery time in the post-anaesthetic care unit and recovery from anaesthesia was similar in the two groups. CONCLUSIONS: After induction the xenon/opioid regimen maintains systolic blood pressure at baseline levels and a low heart rate. No differences between groups were found in haemodynamic stability during anaesthesia. Recovery from xenon anaesthesia was similar to that observed in the propofol group.