Cricoid pressure impedes tracheal intubation with the Pentax-AWS Airwayscope ® : a prospective randomized trial

• Published in: British journal of anaesthesia : BJA Vol. 116; no. 3; pp. 413 - 416
• Main Authors: Komasawa, N., Kido, H., Miyazaki, Y., Tatsumi, S., Minami, T.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-03-2016
• Subjects: Adult; Aged; Aged, 80 and over; Cricoid Cartilage - physiology; Equipment Design; Female; Glottis; Humans; Intubation, Intratracheal - instrumentation; Laryngoscopes; Laryngoscopy; Male; Middle Aged; Pressure; Prospective Studies; Time Factors; cricoid cartilage; airway management; tracheal intubation
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/aev438

Abstract
Background
It is unclear how cricoid pressure affects tracheal intubation with the Pentax-AWS Airwayscope
®
(AWS). We conducted a prospective randomized clinical trial in anaesthetized patients.
Methods
Sixty patients were allocated to either the cricoid pressure (CP) group (
n
=30) or the sham group (
n
=30). We compared the two groups with regard to intubation time, number of attempts required for insertion of the Intlock blade (disposable blade of the AWS) and tracheal intubation, percentage of glottic opening (POGO) score, and subjective difficulty of both laryngoscopy and passage of a tube through the glottis.
Results
Intubation time was significantly longer in the CP group (
median
45[
IQR
40–59] s) than in the sham group (32[28–45] s) (
P
=0.003, 95% CI for median difference 5–24 s). The number required for insertion of the Intlock blade did not differ between the groups (
P
=0.08), but the number for tracheal intubation was significantly higher in the CP group (1 attempt in 14 patients, 2 in 7, 3 in 9) than in the sham group (1 attempt in 24 patients, 2 in 6;
P
=0.002). POGO score did not differ significantly between the groups (
P
=0.60), nor did the subjective difficulty of laryngoscopy (
P
=0.06). The visual analogue scale score for passage of a tube through the glottis was significantly higher in the CP group than in the sham group
(P
<0.001).
Conclusions
Cricoid pressure impedes tracheal intubation using the AWS, and is associated with longer intubation time, which can be attributed to increased difficulty in the passage of a tube through the glottis.
Clinical Trial registry number
UMIN000018209.