Complications associated with removal of the laryngeal mask airway: a comparison of removal in deeply anaesthetised versus awake patients.

The purpose of the study was to compare the incidence of complications (coughing, biting, retching, vomiting, excessive salivation and airway obstruction) associated with removal of the laryngeal mask airway. The laryngeal mask airway was used in 100 adults undergoing urological procedures. The patients were randomly assigned to two groups. In 50 patients the laryngeal mask was removed by a nurse when the patient responded to commands in the recovery area. In the other 50 patients it was removed by the anaesthetist with the patient deeply anaesthetized in theatre. The majority of patients were elderly men who had relatively short procedures. The incidence of gastric regurgitation was assessed by measurement of pH of secretions at the tip of the laryngeal mask airway. Complications occurred more frequently in the awake patients (P < 0.01). Most were minor and occurred before removal of the laryngeal mask airway during emergence in the recovery room. Airway obstruction occurred in three patients in whom the laryngeal mask was removed in the recovery room. In two of these patients the oxygen saturation decreased below 80% and the other to 90%. No decrease in arterial oxygenation occurred in the anaesthetised patients in whom the laryngeal mask was removed by the anaesthetist. In 14 patients in the awake group the pH of secretions at the tip of the laryngeal mask was < or = 3 compared with only four patients in the anaesthetised group (P < 0.05). It is concluded that it may be safer to remove the laryngeal mask airway whilst the patients are deeply anaesthetised in the operating room than when they are awake in the recovery room.