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Cricoid yoke: the effect of surface area and applied force on discomfort experienced by conscious volunteers

Published online by Cambridge University Press:  02 June 2005

A. E. Campbell
Affiliation:
University of Wales College of Medicine, Department of Anaesthetics and Intensive Care Medicine, Cardiff, UK
A. Turley
Affiliation:
University of Wales College of Medicine, Department of Anaesthetics and Intensive Care Medicine, Cardiff, UK
A. R. Wilkes
Affiliation:
University of Wales College of Medicine, Department of Anaesthetics and Intensive Care Medicine, Cardiff, UK
J. E. Hall
Affiliation:
University of Wales College of Medicine, Department of Anaesthetics and Intensive Care Medicine, Cardiff, UK
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Extract

Summary

Background and objective: The application of cricoid force is central to techniques that reduce the risk of gastric regurgitation and the subsequent pulmonary aspiration associated with obstetric and emergency anaesthesia. The discomfort associated with cricoid force in awake preoperative patients increases the incidence of coughing, struggling and pain during induction of anaesthesia. This study determined if increasing the surface area of a cricoid yoke reduced the associated discomfort in volunteers.

Methods: Fifty volunteers participated in a randomized single-blinded study. The cricoid yoke was positioned using standard anatomical landmarks and forces of 10, 20, 30 and 40 N were applied in a random order for 20 s, using two different yoke attachments with surface areas of 3 and 10 cm2. A rest of 30 s was allowed between the application of forces. Discomfort was graded by volunteers on a scale from 0 to 10 (0: no discomfort; 10: worse discomfort imaginable). A score of 10 was allocated if the volunteers could not tolerate the applied force for 20 s.

Results: Median scores for the small yoke were always higher than those for the large yoke at each force. There were significant differences between the scores for the small and large yokes at 10 and 20 N (P < 0.001) and 30 N (P = 0.0233), but there was no significant difference at 40 N.

Conclusions: The larger yoke was tolerated better by volunteers when clinically relevant cricoid forces were applied.

Type
Original Article
Copyright
© 2003 European Society of Anaesthesiology

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