Comparison of The Laryngeal Mask Airway Supreme™ Versus Unique™ in Edentulous Geriatric Patients

After Ethical Committee approval and written informed consent were obtained, sixty edentulous patients (American Society of Anesthesiologists physical status (ASA) grade I-III, aged over 65 years) undergoing elective surgery were included into the study. Patients with dentures had to remove their dentures before surgery at the ward. The supraglottic airway device was inserted into each patient in a random order. A statistician independent of the clinical investigators generated the randomization sequence using a computerized program. Patients were excluded if they had a known or predicted difficult airway, a body mass index > 35 kg/m2, or were at risk of aspiration. All cases were conducted by anesthetists who had experience over 5 years of LMA insertion.

Demographic parameters, Mallampati classification and the duration of surgery were recorded. Patients were routinely monitored using ECG, non-invasive blood pressure measurement, pulse oximetry and end-tidal carbon dioxide tension. Depth of anesthesia was monitored with bispectral index (BIS).

Patients were premedicated with midazolam 0.02 mg/kg when venous access was obtained. After 3 min preoxygenation with 100 % oxygen via face mask, anesthesia was induced with fentanyl 1-2 µg/kg and propofol 1-2 mg/kg. When the BIS value was 40-60 the predetermined supraglottic airway device was inserted according to the manufacturer's recommendations. The supraglottic airway devices were deflated fully before insertion. Size 4 LMA was used for those with a weight of 50-70 kg and size 5 LMA for those between 70-100 kg. After insertion, each device was inflated with a hand-held airway manometer (Rusch, Germany) to an intracuff pressure of 60 cm H2O.

An effective airway was defined as the presence of normal thoracoabdominal movement and a square-wave end-tidal carbon dioxide trace. General anesthesia was maintained with sevoflurane, O2 and N2O.

Insertion time was defined as the time from picking up the airway device until connection to the airway circuit. Ease of insertion was graded by the attending anesthesiologist as easy, fair or difficult. If after three attempts insertion was still not successful, the other device was used. If insertion of the other device also failed the patient was endotracheally intubated.