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Letters to the Editor: Letters & Announcements

The Airway Scope May Be Less Effective for Tracheal Intubation Under Direct Daylight in a Prehospital Environment

Xue, Fu S. MD; Yuan, Yu J. MD; Wang, Qiang MD; Xiong, Jun MD

Author Information
doi: 10.1213/ANE.0b013e3181f98c98
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To the Editor

We believe that there is a study design limitation as part of the recent report by Komatsu et al.1 purporting to compare tracheal intubation using the Airway Scope (AWS) and Macintosh laryngoscopes. Although the objective of the study was to evaluate the two devices in a setting simulating emergency tracheal intubation in a prehospital environment, it was conducted in a controlled operating room environment under room light. In an actual prehospital emergency situation, tracheal intubation may be required in patients lying on the ground in direct daylight. During tracheal intubation in a manikin lying supine on the ground, Ueshima et al.2 found that in room light and in the dark, there were no significant differences in intubation time between the AWS, Airtraq®, or Macintosh laryngoscopes. In daylight, however, although tracheal intubation was always successful using the Macintosh and Airtraq® laryngoscopes, when using the AWS, only 1 of 15 participants could successfully intubate the trachea.

The reason for the difficulty with the AWS under daylight is that it is impossible or difficult to see the glottis because of reflection of the sunlight on the monitor display. This is a common flaw of all video laryngoscopes requiring an LCD monitor to view the glottis, such as the original Glidescope®, Glidescope® Cobalt, Storz V-Mac, and McGrath® videolaryngoscopes. Also, we have found that making a shade for the monitor or attaching a reflection prevention filter over the LCD monitor is ineffective in solving this problem. However, the Glidescope® Ranger is a portable, compact, battery-operated version of the original Glidescope®, with a transreflective screen, which allows the operator to use it in bright sunlight. It is designed for military or emergency use in the prehospital setting.3

Fu S. Xue, MD

Yu J. Yuan, MD

Qiang Wang, MD

Jun Xiong, MD

Department of Anesthesiology

Plastic Surgery Hospital

Chinese Academy of Medical Sciences and

Peking Union Medical College

Beijing, People's Republic of China

[email protected]


1. Komatsu R, Kamata K, Sessler DI, Ozaki M. Airway Scope and Macintosh laryngoscope for tracheal intubation in patients lying on the ground. Anesth Analg 2010;111:427–31
2. Ueshima H, Asai T. Tracheal intubation in daylight and in the dark: a randomised comparison of the Airway Scope, Airtraq, and Macintosh laryngoscope in a manikin. Anaesthesia 2010;65:684–7
3. Nakstad AR, Sandberg M. The GlideScope Ranger video laryngoscope can be useful in airway management of entrapped patients. Acta Anaesthesiol Scand 2009;53:1257–61
© 2011 International Anesthesia Research Society