A Comparison of the Laryngeal Tube, Laryngeal Mask Airway ClassicTM and Laryngeal Mask Airway ProsealTM during General Anesthesia

Background: The laryngeal tube is a variant of the esophageal obturator airway.We compared laryngeal tube (LT), laryngeal mask airway classic TM (LMA) and laryngeal mask airway Proseal TM (PLMA) as a airway management device during general anesthesia.Methods: Forty-five fasted healthy adult patients were enrolled in this study into one of three groups in a randomized, single-blinded protocol.Group 1 was to receive LT for airway management, LMA for Group 2, and PLMA for Group 3. General anesthesia was induced identically in three groups with thiopental sodium 5 mg/kg followed rocuronium 0.6 mg/kg.90 seconds later, LT, LMA or PLMA was placed for airway management.Blood pressure and heart rate were measured immediately pre-induction control value, post-insertion of device 0 min, 1 min, 3 min and 5 min.We also compared times of insertion, the amounts of secretion, blood stain, and postoperative sore throat.Results: There was no significant change of SBP, DBP and HR within three groups.All the groups showed stable hemodynamic results.The success rate on the first attempt was 93.6% (14/15, Group 1), 93.6% (14/15, Group 2) and 86.6% (13/15, Group 3).Minimum cuff volume to prevent gas leakage was 69.9 ± 0.5 ml (Group 1), 11.1 ± 4.3 ml (Group 2) and 11.9 ± 3.2 ml (Group 3).The corresponding cuff pressure was 61.6 ± 22.0 cmH2O (Group 1), 4.8 ± 0.9 cmH2O (Group 2) and 4.6 ± 1.5 cmH2O (Group 3).Moderate, severe sore throat was 20% (3/15, Group 1), 6.6% (1/15, Group 2) and 6.6% (1/15, Group 3).Moderate, profuse secretion was 40% (6/15, Group 1), 20% (3/15, Group 2) and 13.3% (2/15, Group 3).There was a 20% (3/15, Group 1) and 13.3% (2/15, Group 3) blood stain.But there was no blood stain for the Group 2. There was a 20% (3/15) gas leakage in Group 1, so we had to insert gas intermittently, but there were no gastric distension, regurgitation, aspiration, hypoxia, airway