Pilot study evaluating the efficacy and safety of second generation supraglottic airway devices in adult surgical patients.

• Register: ANZCTR
• Last refreshed on: 23 January 2017
• Main ID: ACTRN12617000083392
• Date of registration: 16/01/2017
• Prospective Registration: Yes
• Primary sponsor: Royal Brisbane and Womens Hospital
• Public title: Pilot study evaluating the efficacy and safety of second generation supraglottic airway devices in adult surgical patients.
• Scientific title: Efficacy and safety of second generation supraglottic airway devices in adult surgical patients: a prospective pilot study.
• Date of first enrolment: 1/02/2017
• Target sample size: 160
• Recruitment status: Not yet recruiting
• URL: http://www.anzctr.org.au/ACTRN12617000083392.aspx
• Study type: Interventional
• Study design: Non-randomised trial Parallel
• Phase: Not Applicable

Health Condition(s) or Problem(s) studied

Malpositioned airway device

Intervention(s)

The following interventions placed by the consultant anaesthetist, the supraglottic airway devices the LMA-Supreme 'Registered Trademark', LMA-Protector 'Registered Trademark' and i-gel 'Registered Trademark' devices inserted with blind or video-guided methods will be sequentially allocated to each study participant for use as airway management during anaesthesia. Blind or video-guided insertion will be at the clinical discretion of the treating anaesthetist based on skills and preference. Maximum of three attempts will be allowed for each intervention insertion, at which time standard care device is used. Anatomical details will be recorded during insertion for each device using both the blind and video-guided insertion methods. Postoperative incidence of sore throat, dysphagia and dysphonia will also be assessed. Characteristics of each of these supraglottic airway devices (SADs), also termed laryngeal mask airways (LMAs), are as follows:

The LMA-Supreme 'Registered Trademark' (The Laryngeal Mask Company, Le Rocher, Victoria, Mahe,Seychelles) combines features of earlier devices, such as the LMA-ProSeal 'Registered Trademark' (high oropharyngeal seal cuff, gastric access and bite block – to facilitate ventilation, airway protection and airway obstruction, respectively), the LMA-Fastrach 'Registered Trademark' (fixed curve tube and guiding handle – to facilitate insertion and fixation) and the LMA-Unique 'Registered Trademark' (single use – prevention of disease transmission). Furthermore, the LMA-Supreme 'Registered Trademark' incorporates additional features: the anatomically shaped airway tube incorporates a drain tube within its lumen to separate the ventilation and digestive tracts; an elongated cuff at the distal drainage orifice and a 10 degree slant to fit better in the oesophageal tube; an oval-shaped tube to match better the shape of the mouth and to reduce rotation in the pharynx; a strengthened inner cuff to prevent airway obstruction from infolding; and epiglottic fins to prevent airway obstruction from epiglottic downfolding.

The LMA-Protector 'Registered Trademark' (Teleflex Medical, Athlone, Westmead, Ireland) is a later single-use CE-marked and TGA (Therapeutic Goods Administration, Australia) approved laryngeal mask that has similar features to the LMA-Supreme 'Registered Trademark', but has similarities to the LMA-Classic 'Registered Trademark' and LMA-ProSeal 'Registered Trademark', as this device is made entirely from medical-grade silicone. This makes it more flexible and potentially less traumatic than the rigid LMA-Supreme 'Registered Trademark' which is made of polyvinyl chloride. The LMA-Protector 'Registered Trademark' provides access to, and functional separation of the ventilation and digestive tracts. The anatomically shaped airway tube is elliptical in cross-section and ends distally at the laryngeal mask, with the cuff is designed to conform to the contours of the hypopharynx. The LMA-Protector 'Registered Trademark' contains two drainage channels, which emerge as separate ports proximally and enter a chamber, located behind the cuff bowl, which is a new feature. The chamber communicates distally with the upper oesophageal sphincter. Removal of gastric fluid through the upper oesophageal sphincter can be realized by attaching a suction tube to the male suction port or by insertion of a gastric tube through the female drainage port to the stomach.

The i-gel 'Registered Trademark' is an innovative second generation SAD, designed to create a non-inflatable, anatomical seal of the pharyngeal, laryngeal and perilaryngeal structures while avoiding compression trauma. The shape, softness and contours accurately mirror the perilaryngeal anatomy, requiring no cuff inflation.