Abstract

 

 

Objectives: The battery-powered Airtraq Optical Laryngoscope (AOL) is a new disposable device developed to facilitate orotracheal intubation in patients with normal and difficult airways, but there are only limited data on its use in clinical practice. We therefore evaluated the AOL in patients requiring orotracheal intubation and determined whether successful tracheal intubation correlates with conventional laryngoscopic view grading (CLV).

 

Design: Patients with previously experienced difficult conventional tracheal intubation, anatomic features predictive for difficult conventional laryngoscopy (CL) and tracheal intubation, and/or obesity were given preferential enrollment into the study. Therefore, this clinical investigation represents data of a prospective, but non-consecutive observational study.

 

Setting: The study was performed at a community hospital with a reference center for the management of thyroid diseases.

 

Patients: Two hundred and forty-eight patients undergoing elective thyroid surgery were investigated.

 

Operators: The operators (10 staff anesthetists, 2 anesthesia residents, and 2 qualified anesthesia nurses) were novice users of the AOL. They first received formal hands-on training on a suitable airway model, were instructed during the first 10 applications on patients, and performed AOL-assisted laryngoscopy and tracheal intubation attempts on from 14 to a maximum of 20 (median: 18) patients.

 

Interventions: CLV was performed with a standard  Macintosh laryngoscope using gentle lifting force without external laryngeal manipulation: grade 1, visualization of the entire laryngeal aperture; grade 2, visualization of just the posterior portion of the laryngeal aperture; grade 3, visualization of only the arytenoids; grade 4, visualization of only the epiglottis; and grade 5, visualization of just the soft palate. Laryngoscopy with the AOL was performed using the same technique as for CL. When the laryngeal aperture was in the center of the view finder, AOL-assisted tracheal intubation, with the tracheal tube (TT) placed in the tube-guide channel on the right side of the AOL blade, was attempted.

 

Measurements and Main Results:  Laryngeal views of grade 1 to 5 at CL were obtained in 86, 74, 48, 38, and 2 patients, respectively. The success rate of AOL-assisted tracheal intubation at the first attempt was 97 percent (241/248 patients); the causes of primary failures of tracheal intubation were failed identification of anatomical structures in one patient and failed TT advancement during laryngeal passage in 6 patients. Minor problems and difficulties with impeded blade insertion due to limited mouth opening and/or restricted pharyngeal space and impeded TT advancement during laryngeal passage were encountered in altogether 10 and 12 percent, respectively; impeded TT advancement during tracheal passage was rarely a problem. There were no problems with poor visibility due to the presence of secretions and/or fogging of the optical system. The remaining 7 patients required a second attempt for successful tracheal intubation with downsized TTs for atraumatic laryngeal passage in 2 patients. 

 

Conclusions: Provided formal instruction, the success of AOL-assisted orotracheal intubation performed by novice users was not affected by CLV. The AOL proved to be uniquely useful for routine and difficult laryngoscopy and tracheal intubation.  

 

 

Introduction