Study objectives: To evaluate the efficacy and safety of the Glidescope videolaryngoscope as a device to aid nasotracheal intubation, and to determine whether the GSVL provides a better laryngeal view in patients with difficult laryngoscopy compared with the Macintosh laryngoscope.
Design: Prospective, clinical study.
Setting: Two university hospitals.
Patients: 156 healthy adult ASA physical status I and II undergoing elective plastic and intraoral surgery with general anesthesia.
Interventions: After anesthesia induction with intravenous injection of fentanyl 2 microg/kg, propofol 2 mg/kg, and vecuronium 0.1 mg/kg, nasotracheal intubation was performed using GSVL.
Measurements: Preoperative airway measurements were taken to predict potential difficult airways. During nasotracheal intubation using GSVL, laryngeal views, times required for full visualization of glottis and successful intubation, difficulty encountered and auxiliary maneuvers adopted, and upper airway trauma were recorded. The laryngeal views obtained by GSVL and by Macintosh laryngoscope were compared.
Main results: The laryngeal views obtained by GSVL in all patients were Cormack and Lehane (C&L) grades I and II, and the success rate of intubation using GSVL at one attempt was 98.1%. The times required for visualization of the glottis and successful intubation were 40.2 +/- 11.5 s and 52.7 +/- 12.3 seconds, respectively. Patients with C&L grade II needed more auxiliary maneuvers to achieve successful intubation than did those with C&L grade I (P < 0.001). In 36 patients with potential difficult airways, the frequency of difficult laryngoscopy (C&L grades III and IV) with the Macintosh laryngoscope (58.3%) was significantly higher than with the GSVL (0%, P < 0.05). The frequency of minor upper airway trauma was 4.5%.
Conclusions: The GSVL is an effective device for nasotracheal intubation and may be incorporated easily into routine clinical practice. Compared with the Macintosh laryngoscope, the GSVL can provide an improved laryngeal view in the patient with difficult airway.