A clinical evaluation of four disposable laryngeal masks in adult patients.

STUDY OBJECTIVE: To compare the clinical use of four disposable laryngeal masks (DLMs): the Ambu laryngeal mask [Ambu LM], Solus, Laryngeal Mask Airway (LMA) Unique, and Soft Seal.

DESIGN: Prospective, randomized study.

SETTING: Operating room and recovery area of a university-affiliated ambulatory surgery unit.

PATIENTS: 200 adult ASA physical status I, II, and III patients, scheduled for ambulatory procedures.

INTERVENTIONS: Patients underwent insertion of the DLM by nonexperienced residents.

MEASUREMENTS: The time and number of attempts needed for insertion, quality of ventilation, airway sealing pressure at 60 cmH(2)O of intracuff pressure, and complications were all evaluated.

MAIN RESULTS: Ease of insertion was greater (P = 0.03) and first attempt success rate was higher with the Ambu LM (78%) and LMA Unique (80%). The Solus most often needed three attempts to be placed (12 cases); the Ambu LM needed three similar attempts in two cases; the LMA Unique in 4 cases; and the Soft Seal in 5 cases (P = 0.018). The LMA Unique achieved the highest rate of optimal ventilation (46/49 cases) of the 4 groups. Airway sealing pressure was significantly higher with the Soft Seal (27.3 +/- 5 mmHg), compared to the Ambu LM (23.7 +/- 5 mmHg), the Solus (20.9 +/- 4 mmHg), and the LMA Unique (22.1 +/- 6 mmHg) (P < 0.001). Blood staining of the DLM on removal was most frequent with the Soft Seal (38%).

CONCLUSIONS: The Ambu LM and LMA Unique DLMs appear to be easier to insert by inexperienced residents and are less traumatic for the patient. The Soft Seal achieves a higher airway seal than other devices, but it causes more mucosal trauma. The Solus had the highest insertion failure rate of the 4 groups.