A prospective randomized controlled study to compare two supraglottic airway devices LMA-ProtectorTM and LMA-ProSealTM in anaesthetized patients

Background: Laryngeal mask airway (LMA)-ProSeal^TM has been in use for a long time and has stood the test of time. LMA Protector^TM is a composite of various supraglottic devices, and like LMA ProSeal, it promises high oropharyngeal leak pressures and gastric access. It has a preformed curved shaft like LMA Fastrack^TM, LMA Supreme^TM and LMA Auragain^TM, and it is a single-use device like LMA Supreme^TM and LMA unique^TM. Besides, LMA Protector^TM has two unique features: a dual gastric port and an in-built intracuff pressure monitor.

We found sparse literature on LMA Protector, and only a few research papers compare LMA Protector with LMA ProSeal. We aimed to compare the device's clinical performance regarding oropharyngeal leak pressure (OLP) and LMA insertion time, the ease of orogastric tube insertion, and the severity of sore throat.

Results: OLP was significantly higher in the LMA Protector group compared to the LMA ProSeal group (34.8±3.5cmH20 vs 31.7±4.5 cmH20, p = 0.001). LMA insertion time was considerably longer with LMA Protector (25.7±5.2 sec vs 23.4±5.3 sec; p = 0.047).  The ease of LMA insertion was comparable. Gastric tube insertion was grade 1 in the majority of patients. Incidence and severity of postoperative sore throat at 2 and 24 hours were similar in both groups.

Conclusion: Compared to LMA ProSeal^TM, LMA Protector^TM achieved a better oropharyngeal seal by attaining higher oropharyngeal leak pressures. LMA Protector's observed 7.5% initial insertion failure rate though statistically insignificant as a key clinical consideration when first-attempt success is critical. Insertion characters of both the devices were similar.