The clinical assessment of Glidescope in orotracheal intubation under general anesthesia

The aims of this study were to further evaluate the efficacy and safety of the GlideScope as a device to aid orotracheal intubation, and to further determine whether the GlideScope can provide a better laryngeal view in patients predicted to have a difficult laryngoscopy compared to the Macintosh laryngoscope.

Ninety-one adult patients, ASA physical status I-II, scheduled for elective plastic and intraoral surgery under general anesthesia requiring orotracheal intubation were included in this study. The laryngeal view was estimated by the classification of Cormack-Lehane and the orotracheal intubation was then performed using a GlideScope. The times required for full visualization of the glottis and for the successful tracheal intubation were recorded, respectively. Noninvasive blood pressure and heart rate were also recorded before (baseline values) and immediately after induction (postinduction values), at intubation and every minute for 5 min after intubation. In patients preoperatively predicted to have a difficult laryngoscopy, the laryngeal views obtained by a GlideScope and a Macintosh laryngoscope were also compared.

All patients were successfully intubated using a GlideScope, of which 97% (88/91) required only one attempt. In the patients with successful intubation at one attempt, the times required for full visualization of the glottis and for successful tracheal intubation were 21+/-9 s and 38+/-11 s, respectively. The orotracheal intubation caused significant increases in blood pressure and heart rate compared to the postinduction values, and the maximal values of blood pressure and heart rate during the observation were significantly higher than the baseline values. In 27 patients preoperatively predicted to have a difficult laryngoscopy, the laryngeal views in using the GlideScope were significantly better than those in using the Macintosh laryngoscope. The incidence of minor upper airway trauma was 3.4% in all patients.

The orotracheal intubation using a GlideScope had advantages of easy and simple operation, excellent laryngeal view, and the ability to provide an improved laryngeal view in the patients with a difficult laryngoscopy. The general anesthesia of clinical standard depth was able to suppress the pressor response, but not temporary tachycardiac response to the orotracheal intubation using a GlideScope.