Comparison of the Pentax-AWS airway scope with the Macintosh laryngoscope for nasotracheal intubation: a randomized, prospective study

Study Objective - To evaluate the effectiveness of the Pentax-AWS Airway Scope (AWS) in comparison to the Macintosh laryngoscope during nasotracheal intubation. Design - Prospective randomized study. Setting - Operating room of a university-affiliated hospital. Patients 90 ASA physical status 1 and 2 adults, aged 18 to 72 years, scheduled for orthodontia surgery requiring nasotracheal intubation. Interventions - Patients were randomly assigned to three groups to undergo tracheal intubation with a Macintosh laryngoscope (Group Mac; n = 30), AWS with its tip inserted into the vallecula for indirect elevation of the epiglottis (Group AWS-I; n = 30), or AWS with its tip positioned posterior to the epiglottis for direct elevation of the epiglottis (Group AWS-D; n = 30). Measurements - Percentage of glottic opening (POGO) score at the time of laryngeal exposure, time required for intubation, and intubation difficulty scale (IDS) were measured. The frequency of postoperative sore throat and hoarseness also were noted. Main Results - Patient demographics did not differ among the groups. In Groups AWS-I and AWS-D, IDS scores were reduced significantly, and the percentages of glottic opening were significantly improved, compared with the Macintosh group. Time to place the endotracheal tube was significantly shortest in Group AWS-I. In one case from each group, intubation within two attempts failed and a different approach was required. Conclusion - The AWS offers better intubation conditions than the Macintosh laryngoscope during nasotracheal intubation. The AWS may be used to elevate the epiglottis both directly and indirectly for nasotracheal intubation