A comparison of the laryngeal mask airway ProSeal™ and the laryngeal tube airway in paralyzed anesthetized adult patients undergoing pressure-controlled ventilation

We compared the laryngeal mask airway ProSeal™ (PLMA™) and the laryngeal tube airway (LTA), two new extraglottic airway devices, with respect to: 1) insertion success rates and times, 2) efficacy of seal, 3) ventilatory variables during pressure-controlled ventilation, 4) tidal volume in different head/neck positions, and 5) airway interventional requirements. One-hundred-twenty paralyzed anesthetized ASA physical status I and II adult patients were randomly allocated to the PLMA™ or LTA for airway management. A standardized anesthesia protocol was followed by two anesthesiologists experienced with both devices. The criteria for an effective airway included a minimal expired tidal volume of 6 mL/kg during pressure-controlled ventilation at 17 cm H2O with no oropharyngeal leak or gastric insufflation. First attempt success rates at achieving an effective airway were similar (PLMA™: 85%; LTA: 87%), but after 3 attempts, success was more frequent for the PLMA™ (100% versus 92%, P = 0.02). Effective airway time was similar. Oropharyngeal leak pressure was larger for PLMA™ at 50% maximal recommended cuff volume (29 ± 7 versus 21 ± 6 cm H2O, P < 0.0001), but was similar at the maximal recommended cuff volume (33 ± 7 versus 31 ± 8 cm H2O). Tidal volumes (614 ± 173 versus 456 ± 207 mL, P < 0.0001) were larger and ETco2 (33 ± 9 versus 40 ± 11 mm Hg, P = 0.0001) lower for the PLMA™. The number of airway interventions was significantly less frequent for the PLMA™. Airway obstruction was more common with the LTA. When comparing mean tidal volumes in different head/neck positions, the quality of airway was unchanged in 56 of 60 patients (93%) with the PLMA™ and 42 of 55 (76%) with the LTA (P = 0.01). The PLMA™ offers advantages over the LTA in most technical aspects of airway management in paralyzed patients undergoing pressure-controlled ventilation