A novel balanced anesthesia shortens time to emergence in patients undergoing modified radical mastectomy: a randomized prospective trial

In balanced anesthesia, protocol during the last 30 min is very important to guarantee rapid emergence and smooth extubation. In clinical practice, sevoflurane and propofol are often used in combination to achieve a better anesthetic effect and less adverse reaction. Approximately 30 min before surgical completion, sevoflurane inhalation is often discontinued and propofol is adjusted to keep sufficient depth of anesthesia. However, propofol-based anesthesia may delay time to emergence due to its unpredictable interindividual variability. In contrast, sevoflurane can be rapidly excreted unchanged from the respiratory tract, and more importantly, with minimal variability. This study aimed to investigate the effect of a novel balanced anesthesia protocol, that is propofol-based intravenous induction, propofol-sevoflurane combined maintenance, and total sevoflurane inhalation during the last 30 min of the surgery, on the time to emergence/extubation. In our study, a total of 100 female patients undergoing modified radical mastectomy were enrolled. All patients received propofol-based intravenous anesthesia for induction followed by propofolsevoflurane combined maintenance. Approximately 30 min before the end of surgery, sevoflurane was continually inhaled without propofol infusion in group Sev (n=50), while propofol was only infused in group Pro (n=50). The primary outcome was the time to emergence/extubation. The second outcomes included time to respiratory recovery, and duration of post-anesthesia care unit (PACU) stay. The hemodynamic parameters and incidences of postoperative adverse events such as hypoxemia, nausea, vomiting, dizziness, and emergence agitation (EA) were also assessed. The time to emergence/extubation in group Sev was shorter than that in group Pro (12.74±4.31 vs. 17.74±4.27 min, P