Clinical trial NCT01592760: Air-Q® SP Versus Air-Q® and I-gel: A Randomized Clinical Trial
Official title: Comparison of the Air-Q® Self-Pressurizing (SP) Intubating Laryngeal Airway With the Air-Q® Intubating Laryngeal Airway and I-gel for Airway Maintenance in Adults Under General Anesthesia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Laryngeal Masks
Keywords: air-Q SP
air-Q
i-gel
supraglottic airway device
laryngeal mask airway
Lead sponsor: University of Wisconsin, Madison
Sponsor class: OTHER
First posted: 2012-05-07
Enrollment: 225
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The air-Q Self-Pressurizing Intubating Laryngeal Airway (aILA SP) is a modification of the air-Q Intubating Laryngeal Airway (aILA). Besides the i-gel, it is the only breathing tube that sits above the vocal cords that does not require inflation of a cuff with air. The purpose of this study is to compare the ability of the aILA-SP to maintain patency of a patient's airway during general anesthesia with that of the aILA and i-gel devices. As a measure of this ability, we hypothesized that the airway sealing pressures will be equal between the aILA-SP and aILA, but superior when comparing the aILA-SP to the i-gel (i-gel will be lower).

Detailed description: Laryngeal mask airways (LMAs) are a group of airway devices, alternatively referred to as supraglottic airways (SGAs), used in anesthesia that are positioned in the back of the throat (pharynx) above (supra) the glottis (windpipe opening) and the vocal cords. This is in contradistinction to a tracheal tube, which is an airway device that is placed through the vocal cords and extends to a position below the glottis (infraglottic) and resides in the trachea (windpipe). Since their first approval for use in the United States by the US Food and Drug Administration in the early 1990s, the application of SGAs has become more widespread. Initially, they were only used in anesthetized patients who were breathing on their own (i.e., spontaneously ventilating). This was, in large part, due to a relatively low airway seal pressure, the pressure with which the device seals against the throat, thereby, keeping the air pushed in by a breathing machine (ventilator) from getting into the stomach or leaking out around the device and out through the mouth - in either case, not going into the patient's lungs. The relatively low airway seal pressure (18 - 20 cmH2O) did not allow for the use of muscle relaxant (paralyzing) drugs and positive pressure ventilation. Successive generations of SGAs by a variety of manufacturers have overcome and continue to attempt to overcome limitations of earlier devices. In addition, accumulated clinical experience has made anesthesia providers more comfortable with their use. No SGA, however, is yet ideal, and incremental changes continue to appear to improve airway management and reduce airway morbidity (e.g., sore throat, jaw pain, etc.).

The air-Q® Intubating Laryngeal Airway (aILA, Mercury Medical, Clearwater, FL) is a newer, commercially-available, SGA designed for use as a primary airway and as an intubation conduit. It is available in polyvinyl chloride (PVC)-based, single use and silicone-based, reusable models. Information on its safety and effectiveness from a randomized, controlled trial in adults, undergoing general anesthesia, compared to that of the silicone-based, reusable aILA versus the LMA-Proseal™ (pLMA, North America, San Diego, CA), the current "gold standard" for SGA airway seal pressure, is available.

The air-Q® Self-Pressurizing (SP) Intubating Laryngeal Airway (aILA-SP, Mercury Medical, Clearwater, FL) is a commercially-available, modification of the silicone-based, reusable aILA. Its overall design is identical to the aILA, but incorporates a communication orifice between the air tube and cuff, which regulates airflow into and from the cuff during periods of positive pressure and spontaneous ventilation. As such, it incorporates a self-pressurizing cuff that does not require manual inflation. Such a cuff may be advantageous insofar as it dynamically adjusts its intra-cuff pressure and fit with the patient's pharyngeal and periglottic anatomy, which may lead to a reduction in airway morbidity, while still providing the high seal pressure afforded by the aILA design.

Lastly, the i-gel (Intersurgical Inc., Liverpool, NY) is a commercially-available SGA that uses a thermoplastic elastomer to create a non-inflating, anatomically-conforming, periglottic cuff. Studies have shown it to be an easily inserted, effective airway device with a lower incidence of sore throat and neck complaints. With exception to the aILA-SP, it is the only other commercially-available SGA that does not require cuff inflation.

To date, no reports are available on the clinical performance of the aILA-SP in relation to other SGAs. Thus, the primary purpose of this study is to compare the airway seal pressure (ASP) of the aILA-SP against the aILA and i-gel in adults undergoing general anesthesia. Airway seal pressure is the most common surrogate for ventilatory capacity used in SGA studies.

Eligibility criteria: Inclusion Criteria:

* ≥ 18 years;
* scheduled for an elective surgery or procedure; and
* general anesthesia with placement of a SGA planned.

Exclusion Criteria:

* \< 18 years of age;
* non-English speaking;
* known or believed to be pregnant;
* prisoner;
* has impaired decision-making capacity;
* has symptomatic untreated gastroesophageal reflux;
* has had a prior esophagectomy;
* has a known or suspected hiatal hernia;
* has vomited within twenty-four hours of the surgery or procedure;
* has known oral pathology making a proper SGA fit unlikely; or
* has any condition for which the primary anesthesia care team deems intubation with a tracheal tube to be necessary.

Primary outcomes:
measure: Airway Seal Pressure After Device Placement
timeFrame: Measured within 5 minutes after device placement/study initiation
Secondary outcomes:
measure: Device Placement Time
timeFrame: Measured at device placement/study initiation
measure: Device Placement Success Rate
timeFrame: Measured at the time of attempted study device placement immediately after the induction of general anesthesia
measure: Device Ease of Insertion
timeFrame: Reported by the device operator at the time successful device placement is recorded.
measure: Device Position in Relation to the Vocal Cords
timeFrame: Measured within 5 minutes of successful study device placement
measure: Device Use Time (Min)
timeFrame: Measured between successful device placement and device removal for any reason, approximately 2 hours
measure: Incidence of Gastric Insufflation
timeFrame: Measured within 5 minutes of device placement/study initiation
measure: Incidence of Gastric Aspiration
timeFrame: Measured between successful device placement and device removal for any reason.
measure: Incidence of Oropharyngeal Injury
timeFrame: Measured in the post-anesthesia care unit/recovery room within 15 minutes after device removal
measure: Overall Clinical Usefulness
timeFrame: Reported by the device operator at the time of device removal
measure: Oropharyngolaryngeal Morbidity at Discharge
timeFrame: Measured prior to discharge from phase II of the post-anesthesia care unit/recovery room
measure: Oropharyngolaryngeal Morbidity at 24 Hours Post-operatively
timeFrame: Measured at 24 hours after device placement/study initiation
Other outcomes:
Locations:
city: Madison
country: United States
facility: University of Wisconsin Hospital and Clinics
state: Wisconsin
Study officials:
affiliation: Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health
name: Richard E Galgon, MD, MS
role: PRINCIPAL_INVESTIGATOR
References:
citation: Galgon RE, Schroeder KM, Han S, Andrei A, Joffe AM. The air-Q((R)) intubating laryngeal airway vs the LMA-ProSeal(TM) : a prospective, randomised trial of airway seal pressure. Anaesthesia. 2011 Dec;66(12):1093-100. doi: 10.1111/j.1365-2044.2011.06863.x. Epub 2011 Aug 22.