Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2023 Aug 1;40(8):560-567.
doi: 10.1097/EJA.0000000000001838. Epub 2023 Apr 13.

Effect of head and neck positions on tracheal intubation using a McGRATH MAC video laryngoscope: A randomised, prospective study

Affiliations
Randomized Controlled Trial

Effect of head and neck positions on tracheal intubation using a McGRATH MAC video laryngoscope: A randomised, prospective study

Hyerim Kim et al. Eur J Anaesthesiol. .

Abstract

Background: Different head and neck positions may affect video laryngoscopy in terms of laryngeal exposure, intubation difficulty, advancement of the tracheal tube into the glottis and the occurrence of palatopharyngeal mucosal injury.

Objective: We investigated the effects of simple head extension, head elevation without head extension and the sniffing position on tracheal intubation using a McGRATH MAC video laryngoscope.

Design: A randomised, prospective study.

Setting: Medical centre governed by a university tertiary hospital.

Patients: A total of 174 patients undergoing general anaesthesia.

Methods: Patients were randomly allocated to one of three groups: simple head extension (neck extension without a pillow), head elevation only (head elevation with a pillow of 7 cm and no neck extension) and sniffing position (head elevation with a pillow of 7 cm and neck extension).

Main outcomes: During tracheal intubation using a McGRATH MAC video laryngoscope in three different head and neck positions, we assessed intubation difficulty by several methods: a modified intubation difficulty scale score, time taken for tracheal intubation, glottic opening, number of intubation attempts, requirements for other manoeuvres (lifting force or laryngeal pressure) for laryngeal exposure and advancement of the tracheal tube into the glottis. The occurrence of palatopharyngeal mucosal injury was evaluated after tracheal intubation.

Results: Tracheal intubation was significantly easier in the head elevation group than in the simple head extension ( P = 0.001) and sniffing positions ( P = 0.011). Intubation difficulty did not differ significantly between the simple head extension and sniffing positions ( P = 0.252). The time taken for intubation in the head elevation group was significantly shorter than that in the simple head extension group ( P < 0.001). A lifting force or laryngeal pressure was required less frequently for tube advancement into the glottis in the head elevation group than in the simple head extension ( P = 0.002) and sniffing position groups ( P = 0.012). The need for a lifting force or laryngeal pressure for tube advancement into the glottis was not significantly different between the simple head extension and sniffing positions ( P = 0.498). Palatopharyngeal mucosal injury occurred less frequently in the head elevation group than in the simple head extension group ( P = 0.009).

Conclusion: The head elevation position facilitated tracheal intubation using a McGRATH MAC video laryngoscope compared with a simple head extension or sniffing position.

Trial registry number: ClinicalTrials.gov (NCT05128968).

PubMed Disclaimer

Similar articles

Cited by

References

    1. Benumof JL. Difficult laryngoscopy: obtaining the best view. Can J Anaesth 1994; 41:361–365.
    1. Adnet F, Baillard C, Borron SW, et al. Randomized study comparing the “sniffing position” with simple head extension for laryngoscopic view in elective surgery patients. Anesthesiology 2001; 95:836–841.
    1. Greenland KB, Edwards MJ, Hutton NJ, et al. Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications. Br J Anaesth 2010; 105:683–690.
    1. van Zundert A, Pieters B, van Zundert T, Gatt S. Avoiding palatopharyngeal trauma during videolaryngoscopy: do not forget the ’blind spots’. Acta Anaesthesiol Scand 2012; 56:532–534.
    1. Levitan RM, Heitz JW, Sweeney M, Cooper RM. The complexities of tracheal intubation with direct laryngoscopy and alternative intubation devices. Ann Emerg Med 2011; 57:240–247.

Publication types

Associated data