Propofol causes less postoperative pharyngeal morbidity than thiopental after the use of a laryngeal mask airway

The insertion of a laryngeal mask airway (LMA) may result in postoperative sore throat. The choice of induction drug on airway morbidity after LMA insertion may be important. We performed this study to compare the incidence of postoperative pharyngeal morbidity after the insertion of a LMA in 340 patients administered either 2 mg/kg propofol (group P) or thiopental 5 mg/kg (group T) for induction of anesthesia. Patients were maintained at 1-2 minimum alveolar anesthetic concentration sevoflurane in 50% oxygen/air. Spontaneous or assisted spontaneous ventilation was maintained. An investigator blinded to group allocation visited patients at 2, 12, and 24 h postoperatively. Adverse responses were noted (yes/no) at each time point including sore throat, sore mouth, sore jaw, hoarseness, dysphonia, and dysphagia. At 2 h postoperatively, the incidence of sore throat, dysphagia, and postoperative nausea and vomiting in group T was higher than in group P (24% vs 13% for sore throat, 15% vs 3% for dysphagia, 20% vs 11% for nausea, 14% vs 6% for vomiting, P < 0.05). The number-needed-to-treat to prevent sore throat and dysphagia was 10 and 8, respectively (95% confidence intervals, 5-43). We concluded that, when propofol, rather than thiopental, is used for the induction of anesthesia, it results in a lower incidence of early pharyngeal morbidity and postoperative nausea and vomiting after the insertion of a LMA.