Xenon anaesthesia produces better early postoperative cognitive recovery than sevoflurane anaesthesia.

BACKGROUND AND OBJECTIVE: Xenon anaesthesia may have the potential to reduce postoperative cognitive impairment after general anaesthesia. This randomized double-blind controlled trial was designed to compare the early postoperative cognitive recovery after xenon and sevoflurane anaesthesia. METHODS: After institutional ethics approval, we obtained informed written consent from 60 adults, with American Society of Anesthesiologists I or II status, scheduled for elective surgery with an estimated surgery time between 60 and 360 min. Patients were randomized to receive xenon or sevoflurane anaesthesia. Both groups received a remifentanil infusion adjusted to clinical needs based on patients' haemodynamic and state entropy of less than 60. In cases of state entropy of at least 60 during the first 15 min after induction, patients in the xenon group received a propofol infusion targeted to state entropy of less than 60. The primary end-point of the study was the early postoperative cognitive recovery evaluated by the Short Orientation Memory Concentration Test. RESULTS: There was no significant difference in the mean preoperative Short Orientation Memory Concentration Test values between groups (sevoflurane 2.7 +/- 3.2 and xenon 3.2 +/- 2.6; P, 0.53). Awakening was significantly faster in the xenon group (sevoflurane 8 +/- 4 min and xenon 3 +/- 1 min; P < 0.001). Patients receiving xenon presented significantly lower Short Orientation Memory Concentration Test scores at 30 min (sevoflurane 6.7 +/- 5.9 and xenon 3.3 +/- 3.1; P 0.003) and 60 min (xenon 2.1 +/- 3 and sevoflurane 5 +/- 4.1; P 0.003) after extubation. CONCLUSION: Xenon anaesthesia was associated with faster emergence and with better early postoperative cognitive recovery than sevoflurane anaesthesia.