Abstract

 

 

Objectives: We evaluated the Standard Adult GlideScope Video Laryngoscope (GVL) in patients requiring orotracheal intubation and determined whether successful tracheal intubation correlates with conventional laryngoscopic view grading (CLV).

 

Design: Patients with a previously experienced difficult conventional tracheal intubation, anatomic features predictive for difficult conventional laryngoscopy (CL), 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: Three hundred and thirty-four patients undergoing elective thyroid surgery were investigated.

 

Operators: The operators (12 staff anesthetists, 2 anesthesia residents, and 2 qualified anesthesia nurses) were novice users of the GVL. They first received formal hands-on training on an airway model and were then instructed during the early series of performance on patients by an experienced GVL user. They performed GLV-assisted laryngoscopy and tracheal intubation attempts on from 18 to a maximum of 25 (median: 22) 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. The laryngeal views obtained with the GVL were evaluated using the same technique as for CL and the 5-grade scoring system. When laryngeal structures were visible, GVL-assisted tracheal intubation was attempted using the Schroeder directional tracheal tube stylet (DS) for manipulation of the tracheal tube (TT) through the laryngeal aperture.  

 

Measurements and Main Results:  Laryngeal views of grade 1 to 5 at CL were obtained in 112, 93, 53, 67, and 9 patients, respectively. The success rate of GLV-assisted tracheal intubation at the first attempt was 97 percent (324/334 patients) with laryngeal views of grade 1, 2, and 3 in 268, 54, and 2 patients, respectively; the causes of primary failures of tracheal intubation were failed identification of anatomical structures in 2 patients and failed TT advancement in 6 patients, and DS malfunction in 2 patients. Minor problems and difficulties with impeded TT advancement during oropharyngeal, laryngeal, and/or tracheal passage were encountered in altogether 32  percent; impeded blade insertion due to limited mouth opening and/or restricted pharyngeal space and poor visibility due to the presence of secretions were rarely a problem and poor visibility due to fogging of the camera sysem was never a problem. The remaining 10 patients required a second attempt for successful tracheal intubation

 

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

 

 

Introduction