Pentax-AWS® improves laryngeal view compared with Macintosh blade during laryngoscopy and facilitates easier intubation

Background : The PENTAX-AWS® (AWS), combined with PBLADE® is a novel tracheal intubation device which allows indirect visualization of the vocal cords without the alignment of the oral, pharyngeal axes required for direct laryngoscopy. Intubation procedure can be monitored on a built-in CCD monitor. Methods : We compared the laryngeal view obtained with the Macintosh laryngoscope with that obtained with the AWS in 100 patients scheduled for elective anesthesia. Laryngeal view was determined by Cormack & Lehane classification modified by Cook, first using the Macintosh laryngoscope with the patient's head and neck in the sniffing position, followed by the AWS with the head and neck in a neutral position. The time taken to pass the endotracheal tube, the incidence of tube impingement on the arytenoids and the total number of intubation attempts were also recorded. Results : The best laryngeal view obtained with the Macintosh laryngoscope in 100 cases were Grade I:65, IIa:16, IIb:8, IIIa:6, IIIb:5, IV:0. With AWS, the laryngeal views obtained were all grade I. The total time to pass the tube with the AWS was 19.5±7.9s and the number of intubation attempts was 1.05±0.2. The Cormack grade obtained with the Macintosh laryngoscope did not affect the AWS view. The tube touched the right arytenoid in 5 cases but successful intubation was achieved by adjusting the blade direction. Conclusions : We conclude that the PENTAX-AWS® provides a better laryngeal view than the Macintosh laryngoscope and facilitates easier intubation under vision in a higher proportion of patients.