Air-Q® SP Versus Williams Intubating Airway for Single-Operator FOI

Despite the introduction of videolaryngoscopes, flexible bronchoscopic intubation (FBI), also known as fiberoptic intubation (FOI), remains a critical method for achieving tracheal intubation in patients with difficult airways. Unfortunately, however, FOI often requires two-operators for success. One operator is required to manipulate the flexible bronchoscope through the patient's upper airway and into their trachea, while the second operator applies one or more maneuvers (e.g., jaw thrust, anterior jaw lift, or lingual retraction) with or without the use of a commercially-available fiberoptic intubating airway.

Previous studies have demonstrated the effectiveness of the currently available FIAs, but also illustrate the frequent need for an assistant for successful FOI. In this study, an assistant performed a jaw lift and a chin lift in all subjects as well.

The air-Q and air-Q SP are commercially-available supraglottic airways (SGAs) that can be used for primary airway maintenance or as a conduit for FOI, as can be the Williams, Ovassapian, and Berman Intubating Airways. The air-Q products have the same overall geometrical design, but differ in their cuff inflating mechanisms, where the air-Q uses a traditional pilot balloon valve, while the air-Q SP utilizes a self-inflating cuff that dynamically adjusts according to the relative resistances to airflow between the patient's lungs and the device's cuff. In prior trials comparing the air-Q and air-Q SP with the two other commercially-available SGAs, the air-Q and air-Q SP bowl design provided a partial or full view of the vocal cords in 80-92% of subjects without requiring any additional airway maneuvers applied by an assistant (e.g., jaw thrust, anterior jaw lift, or lingual retraction) (Galgon, 2011; Galgon, 2015). Presumably, in these situations, successful tracheal intubation using the air-Q or air-Q SP could have been achieved by a single operator versus requiring one or more assistants. However, this potential performance advantage has not yet been tested. Therefore, the purpose of this study is to compare use of the air-Q SP against the WA for FBI performed by a single operator.

The air-Q SP, rather than the air-Q, is chosen for this study because its lack of a pilot balloon valve allows its stem to be easily shortened to ease device removal over the coaxially placed tracheal tube. The WA is chosen for this study because it has performed best in past trials and is the airway routinely used by the study principal investigator (PI) for FBI. Both devices are commercially-available and being used in the study in accordance with their labeled intended use.

Inclusion criteria

• Adult patients (≥18 years);
• The patient is scheduled for an elective surgery or procedure that will take place in the UWHC main operating room, outpatient surgical center, or ambulatory procedure center; and
• The patient's primary anesthesia care team has planned for general anesthesia with orotracheal intubation for airway maintenance.

Exclusion criteria

• The patient is < 18 years of age;
• The patient is non-English speaking;
• The patient is known or believed to be pregnant;
• The patient is a prisoner;
• The patient has impaired decision-making capacity;
• The patient is at increased risk for aspiration, including non-fasted or emergency surgery, and cases of uncontrolled gastroesophageal reflux disease, hiatal hernia, gastroparesis, esophageal dysmotility, prior esophagectomy, and/or emesis within twenty-four hours of the surgery or procedure;
• The patient has limited mouth opening or oropharyngeal anatomy making successful placement of the study airway conduit unlikely;
• The patient has airway exam features, a medical condition, or a past airway management history, which prompts the attending anesthesiologist to plan to maintain spontaneous ventilation during tracheal intubation;
• The patient pre-operatively is requiring supplemental oxygen;
• The patient has moderate to severe cardiac disease, as evidenced by a left ventricular ejection fraction of ≤ 50% on the most recent echocardiogram, severe aortic valve stenosis, atrial fibrillation with a resting pre-operative heart rate of ≥ 90 beats per minute, and/or known, multi-vessel coronary artery, managed conservatively with medical management or by intervention with multiple coronary artery stents or coronary bypass grafting; and
• The patient has an allergy to glycopyrrolate.