Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications

Greenland, K. B., Edwards, M. J., Hutton, N. J., Challis, V. J., Irwin, M. G. and Sleigh, J. W. (2010) Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications. British Journal of Anaesthesia, 105 5: 683-690. doi:10.1093/bja/aeq239


Author Greenland, K. B.
Edwards, M. J.
Hutton, N. J.
Challis, V. J.
Irwin, M. G.
Sleigh, J. W.
Title Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications
Journal name British Journal of Anaesthesia   Check publisher's open access policy
ISSN 0007-0912
1471-6771
Publication date 2010-11-01
Year available 2010
Sub-type Article (original research)
DOI 10.1093/bja/aeq239
Volume 105
Issue 5
Start page 683
End page 690
Total pages 8
Place of publication Oxford, U.K.
Publisher Oxford University Press
Language eng
Abstract Background. The sniffing position is often considered optimal for direct laryngoscopy. Another concept of airway configuration involving a laryngeal vestibule axis and two curves has also been suggested. We investigated whether this theory can be supported mathematically and if it supports the sniffing position as being optimal for direct laryngoscopy. Methods. Magnetic resonance imaging scans were performed in 42 normal adult volunteers. The airway passage was divided into two curves - primary (oro-pharyngeal curve) and secondary (pharyngo-glotto-tracheal curve). Airway configuration was evaluated in the neutral, extension, head lift, and sniffing positions. The airway passage, point of inflection (where the two curves meet), its tangent, and the line of sight were plotted on each scan. Results. The point of inflection lay within the laryngeal vestibule in all positions. The head lift and sniffing positions caused the tangent to the point of inflection to approximate the horizontal plane. The sniffing, extension, and head lift positions caused a reduction in the area between the line of sight and the airway curve compared with the neutral position. Conclusions. A two-curve theory is proposed as a basis for explaining airway configuration. The changes in these curves with head and neck positioning support the sniffing position as optimal for direct laryngoscopy. Application of this new concept to other forms of laryngoscopy should be investigated. © 2010 The Author. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved.
Keyword Anaesthetic techniques
Laryngoscopy
Equipment
Airway
Intubation
Tracheal
Position
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2011 Collection
School of Medicine Publications
 
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Created: Sun, 07 Nov 2010, 10:15:19 EST