A Comparison of the classic and a modified laryngeal mask airway (OPLAC™) in adult patients

Background: A modified disposable laryngeal mask airway (LMA) (Oro-Pharyngo-Laryngeal Airway Cap, OPLAC™) was developed in our department. In this study, we compared the performance of the LMA Classic™ with that of the OPLAC. Methods: This was a randomized, single-blinded, crossover study involving 60 paralyzed, anesthetized adult patients. Both devices were inserted into each patient in different sequences after anesthesia had been induced. In 30 patients, the LMA was inserted first and in 30 patients, the OPLAC was inserted first. The success rate, insertion time, fiberoptic view, peak airway pressure, sealing pressure, incidence of gastric insufflations, trace of blood on the device, and incidence of postoperative sore throat were evaluated. Results: The success rate of placement on the first attempt was high for both devices. The insertion time was significantly shorter and better engagement was noted on fiberoptic view with the OPLAC than with the LMA. The sealing pressure was significantly higher and the incidence of gastric insufflations was significantly lower with the OPLAC. The overall incidence of sore throat was 13.33%. Conclusions: Both devices have comparable airflow resistance and are easy to insert. The OPLAC requires less insertion time, has less variation on insertion time, fits better into the laryngopharynx, is less likely to cause gastric insufflations, and has a higher sealing pressure.