Indirect versus direct laryngoscopy for routine nasotracheal intubation.

Study Objective: To compare the effectiveness of the indirect laryngoscopes, Airtraq (A) and GlideScope (G), with the Macintosh (M) laryngoscope in routine nasotracheal intubation.

Design: Randomized, single-blinded study.

Setting: University-affiliated, tertiary-care hospital.

Patients: 62 adult, ASA physical status 1 and 2 patients with normal airways requiring nasotracheal intubation for dental or maxillofacial surgery.

Intervention: Patients in Groups A and G underwent nasal intubation with the Airtraq and GlideScope, respectively, while laryngoscopy in Group M was performed with the Macintosh blade.

Measurements: Performance of the intubating tools was judged by the ease [Intubation Difficulty Scale (IDS) and numeric rating scale (NRS)] and time to intubation (laryngoscopy and endotracheal tube advancement). In addition, hemodynamic parameters, severity of postoperative sore throat, and posture of the intubator were recorded.

Main Results: IDS score was significantly lower with the Airtraq and GlideScope than with the Macintosh laryngoscope (mean ± SD: A 0.1 ± 0.3, G 0.3 ± 0.6, M 0.8 ± 1.0; P = 0.013). NRS reported by the intubators showed a similar preference for indirect over direct laryngoscopy (A 0.9 ± 0.7, G 1.1 ± 0.6, M 1.9 ± 1.1; P = 0.001). Duration of laryngoscopy and endotracheal tube insertion was similar in all groups. No significant intergroup differences in hemodynamic parameters were recorded. Postoperative sore throat was significantly reduced using the GlideScope compared with the other devices (P = 0.048).

Conclusion: The Airtraq and GlideScope facilitated nasotracheal intubation more so than the Macintosh laryngoscope in adults with apparently normal airways.