[N2O-free sevoflurane anesthesia. Clinical evaluation]

Abstract

Background: The characteristics of sevoflurane make it able to be used without N2O avoiding its undesirable effects to this associates. The aim of the study is to evaluate the clinical characteristics of sevoflurane anesthesia "N2O free" in comparison to sevoflurane anesthesia with N2O.

Methods: 920 patient undergoing elective surgery in 12 centers were included in this study. All the patients were monitored with routine monitoring. The patients were randomized in two groups: group Air in which the anesthesia was maintained with sevoflurane in Air:O2; group N2O in which the anesthesia was maintained with sevoflurane in N2O:O2. Opioids were administered as necessary (changes of the heart rate and/or of the arterial pressure > 20% in comparison to the baseline values). For each patient we evaluated the consumption of opioids, the time from discontinuation of the sevoflurane and the extubation and full recovery, defined as presence of a complete cognitive function; the quality of awakening, the incidence of postoperative nausea and vomiting (PONV) and the quality of postoperative analgesia.

Results: We didn't observe differences between the two groups. In conclusions, omitting N2O during sevoflurane anesthesia can be considered a safe technique, avoiding the acute and chronic side effects associated with the use of N2O, without modifying the intraop consumption of opioid, the recovery and the early postoperative incidence of nausea, vomiting and analgesia.