Effect of low dose rocuronium in preventing ventilation leak for flexible laryngeal mask airway during radical mastectomy.

The flexible laryngeal mask airway (FLMA) is becoming more and more popular in general anesthesia during surgery of head, neck and upper chest. But very limited information has been published about whether muscle relaxant was necessary or not for anesthesia with FLMA. To investigate whether low-dose muscle relaxant is necessary in preventing ventilation leak of FLMA in radical mastectomy, forty-eight female patients undergoing radical mastectomy were enrolled in the study. They were randomly divided into low-dose muscle relaxant (LD-MR) group and non-muscle relaxant (non-MR) group. All the included patients received total intravenous anesthesia (with propofol, fentanyl and remifentanil) and controlled mechanical ventilation with FLMA during the surgery. Patients in LD-MR group received 0.4 mg/kg rocuronium during anesthesia induction, while patients in non-MR group received equivalent volumes of physiological saline. Insertion time was shorter in LD-MR group than that in non-MR group (P < 0.05). Peak airway pressures and ventilation leak volumes at 10, 20 and 30 minutes were lower in LD-MR group than those in non-MR group (P < 0.05). No difference was found between LD-MR and non-MR group in terms of emergence time, FLMA extraction time, and maximum tidal volumes before FLMA extraction. The results show that low-dose rocuronium could reduce the ventilation leak for mechanical ventilation with FLMA during radical mastectomy without prolonging the emergence time.