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Randomized Controlled Trial
. 2024 Mar;281(3):1401-1407.
doi: 10.1007/s00405-023-08386-y. Epub 2023 Dec 29.

A comparative evaluation of the sniffing, the simple head extension and the head hyperextension positions for laryngoscopic view and intubation difficulty in adults undergoing direct laryngoscopy

Y H Hadhoud  1 , Mohamed A Baraka  1 , Mohamed Saleh  2 , Ahmed M Refaat  3
Affiliations
Randomized Controlled Trial

A comparative evaluation of the sniffing, the simple head extension and the head hyperextension positions for laryngoscopic view and intubation difficulty in adults undergoing direct laryngoscopy

Y H Hadhoud et al. Eur Arch Otorhinolaryngol. 2024 Mar.

Abstract

Objective: This work aimed to compare between the laryngoscopy positions; sniffing, simple head extension and head hyperextension positions to assess whether the laryngeal view, intubation time and intubation difficulty could improve with one of these positions than the others.

Design: Prospective randomized three arms clinical trial.

Setting: Operation room, the phoniatrics unit [removed for blind peer review].

Participants: The study included 75 cases with 25 cases in each group. Group "A" with head in the sniffing position, Group "B" with the head in simple extension position, Group "C" with head in hyperextension position.

Results: The three groups were compared regarding intubation time and laryngoscopic view time. Intubation time showed statistically significant difference between the three groups. Mean of sniffing group (No. = 25) was 13.19 s (± 3.35). Mean of simple extension group (No. = 25) was 11.29 s (± 3.14). Mean of Hyperextension group (No. = 25) was 14.39 s (± 4.14). Laryngoscopic view time showed statistically highly significant difference between the three groups. Mean of sniffing group (No. = 25) was 17.19 s (± 7.27). Mean of simple group (No. = 25) was 12.18 s (± 4.46). Mean of hyperextension group (No. = 25) was 17.08 s (± 6.51).

Conclusion: Comparing the sniffing, the simple extension and the hyperextension positions, the simple extension position showed the best time regarding intubation time and laryngoscopic view time.

Keywords: Hyperextended position; Laryngeal view; Simple extended position; Sniffing position; Suspension laryngoscopy.

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Conflict of interest statement

No conflicts of interest to declare in this study.

Figures

Fig. 1
Fig. 1
Intra-operative lateral X-rays of an informed anaesthetized patient, his head and neck were put in the three positions with the laryngoscope blade and the intubation tube inside
Fig. 2
Fig. 2
The distribution of the mean of intubation time among patients in the sniffing, the simple extension and the hyperextension groups. The figure shows that the mean of intubation time of the simple extension group (11.29) was approximately 20% lower than hyperextension group (13.19) and 10% lower than the sniffing group (14.39)
Fig. 3
Fig. 3
The distribution of the mean of laryngoscopic view time among patients in the sniffing, the simple extension and the hyperextension groups. The figure shows that the mean of laryngoscopic view time of the simple extension group (12.18) was approximately 30% lower than hyperextension group (17.08) and the sniffing group (17.19)
Fig. 4
Fig. 4
M–P angles in a non-anaesthetized volunteer with the head and neck been put in the three positions without using the laryngoscope blade
Fig. 5
Fig. 5
Laryngoscopic view showing anterior commissure exposed
See this image and copyright information in PMC

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