Influence of head position and neuromuscular block on the clinical efficacy of supraglottic airway devices. A prospective randomized study to compare the laryngeal tube suction (LT™) with the ProSeal™ laryngeal mask

In the present study the laryngeal tube suction (LTS (TM)) was compared with the ProSeal (TM) laryngeal mask (PLMA) with respect to the influence of different head positions and neuromuscular block (NMB) on the clinical efficacy. In 54 patients seal pressures were observed according to a protocol for five pre-defined head positions before and after NMB. Regurgitation was observed using methylene blue as an indicator. Postoperatively a standardized interview was performed to rate subjective patient complaints. The LTS and PLMA provide a comparable seal and neuromuscular block did not impair the performance of both devices. With the PLMA the seal deteriorated with extension of the neck and with the LTS more airway manipulations were necessary to keep the airway patent. No signs of aspiration were observed in either group but of the patients in the LTS group four noticed hoarseness in the postoperative course. Altogether the subjective postoperative complaints were rated as mild to moderate in both groups.