[Pentax-AWS improves laryngeal view compared with Macintosh blade during laryngoscopy and facilitates easier...

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.

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.

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 +/- 7.9 s 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.

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.