Comparison of I-gel to the Laryngeal Mask Airway
Condition: Endotracheal Intubation; Supraglottic Airway
Study type: Interventional

Summary: 
      The purpose of this study is to evaluate a new disposable supra-glottic airway device, the
      i-gel airway (Intersurgical Ltd., Wokingham, England). We propose to test its ease of
      insertion, position within the airway, drain tube patency and anatomic sealing properties
      during mechanical ventilation in non-obese anesthetized patients undergoing elective general
      surgery. The study device will be compared to the current standard in the industry, the LMA
      Unique.
    

Detailed description: 
      During the past decade, several pharyngeal airways have been introduced for airway
      management, such as the Laryngeal Mask Airway (LMA), the Cobra perilaryngeal airway, the
      Esophageal Tracheal Combitube (ETC), the EasyTube, the Laryngeal Tube6, and the Streamlined
      Liner of the Pharyngeal Airway (SLIPA). These airway devices have become very popular because
      of their ability to maintain an airway without perturbing the trachea and can be used in
      patients without muscle relaxation who are only lightly anesthetized.

      The LMA Classic (cLMA) generally provides an adequate airway, but certain problems remain:

        1. In 8-33% of LMA placements, more than one attempt is required.

        2. It is sometimes difficult to advance the LMA without extending the neck (which is
           contraindicated in some patients).

        3. The device does not protect the airway from aspiration of gastric contents.

        4. It does not provide an airtight seal around the larynx (the usual pressures causing
           leakage of gas being 15-20 cm H20). Consequently, the device may function poorly during
           positive-pressure ventilation.

        5. The esophagus is included within the rim of the LMA in 10-15% of patients, directly
           exposing the esophagus to positive airway pressures. This often results in insufflation
           of the stomach and postoperative discomfort.

      The LMA Unique (uLMA) is a disposable, inflatable supraglottic airway device that is based on
      the LMA Classic design which has been used as the "model" in the industry. It has been listed
      as a commonly accepted device for routine and rescue airway management and is now listed in
      the American Society of Anesthesiologists (ASA) Difficult Airway Management Algorithm as an
      airway conduit for tracheal intubation.

      The i-gel (Intersurgical Ltd., Wokingham, England) is a cuffless, single-use supraglottic
      airway device designed to provide a more effective seal than the uLMA, thus eliminating
      problems 3-5 described above with the addition of a gastric drain. Made of a gel-like
      thermoplastic elastomer, the i-gel has an anatomically-designed mask that allows quick, easy
      insertion and can accurately position itself over the laryngeal framework to provide a
      reliable perilaryngeal seal without the need for an inflatable cuff. In a preliminary study,
      the peak airway pressures were found to be above 30 cm H2O with a sustained leak pressure of
      24 cm H2O versus an average of 18-21 cm H2O seen with the cLMA. According to the 100 patient
      trial, the i-gel is easier to insert, it has better sealing properties and there is no cuffed
      inflates.

      This clinical study has been designed to compare the i-gel and the uLMA, as to ease of
      placement, ventilation during mechanical ventilation, proper positioning, seal pressures, the
      patency of the drain tube, and finally, any complications with their use. Fiberoptic
      observations through each device will provide information in relation to the epiglottis and
      the distal opening of the device.
    

Intervention name(s): i-gel airway (Intersurgical Ltd., Wokingham, England); Laryngeal Mask Airway-Unique
Intervention type(s): Device; Device
Intervention description(s): supra-glottic airway device; supra-glottic airway device
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Endotracheal Intubation; Supraglottic Airway