Background
With the popularisation of video laryngoscopy, the difficulty of tracheal intubation has greatly reduced. This study explored the suitability of traditional airway assessment methods for tracheal intubation using video laryngoscopy.
Methods
A total of 1047 patients undergoing general anaesthesia were enrolled. Before anaesthesia, body mass index (BMI) was measured. Traditional airway assessment methods such as the modified Mallampati classification (MMC), upper lip bite test (ULBT), thyromental distance (TMD), mouth opening (MO), and neck movement (NM) been rigorously evaluated. During tracheal intubation, the grading of glottis exposure (Cormack-Lehane) was recorded, along with the intubation duration and one-time intubation success rate. Additionally, the use of other improvement methods, such as applying pressure to the laryngeal node or utilising alternative intubation positions, was observed.
Results
The proportion of Cormack-Lehane ≤ 2 in MMC with 1 or 2, ULBT with 1, TMD with 1, and NM with 1 were much higher than that of Cormack-Lehane ≥ 3 (P < 0.05). However, there were no significant differences in MO or BMI between different glottic exposure grades (P > 0.05). Multiple logistic regression analysis showed that MMC, ULBT, TMD, and NM were independent risk factors for glottic exposure grading (P < 0.05). With the increase in variable grading, the intubation duration prolonged, and there were significant differences in MMC with 1 or 2 vs. 3 or 4, ULBT with 1 vs. 2 or 3, TMD with 1 vs. 2 or 3, MO with 1 vs. 2 or 3, and NM with 1 vs. 2 (P < 0.05).
Conclusion
Traditional airway assessment indicators continue to provide guidance for tracheal intubation under video laryngoscopy, and there is currently no necessity to develop new methods for airway evaluation.
Trial registration
Chinese Clinical Trial Register: ChiCTR2200057603) on 15 March 2022.
