# Incidence and predictors of difficult videolaryngoscopy using a hyperangulated device in elective surgical patients: a prospective cohort study in China

## TL;DR

This study found that 2.1% of patients had difficult videolaryngoscopy using a hyperangulated device, with interincisor distance and Mallampati grades as key predictors.

## Contribution

The study identifies specific predictors of difficult videolaryngoscopy in Chinese elective surgical patients using a hyperangulated device.

## Key findings

- The incidence of difficult videolaryngoscopy was 2.1% in the study cohort.
- Interincisor distance was inversely associated with difficult videolaryngoscopy.
- Mallampati grades III and IV were significant predictors of difficult videolaryngoscopy.

## Abstract

While the utilization of video laryngoscope has become increasingly prevalent, the incidence of difficult videolaryngoscopy and its associated factors remain largely undefined. Therefore, this study was undertaken to determine the incidence of difficult videolaryngoscopy using a hyperangulated device, and to identify associated factors, specifically within a cohort of elective surgical patients in China presenting with normal airway anatomy.

This study was a prospective cohort investigation that included 4,902 adult patients who underwent single-lumen tracheal intubation using a video laryngoscope. Data encompassing participants’ demographic characteristics, preoperative airway assessments, and intubation procedure details were systematically collected. Patients were categorized into two groups based on the Cormack-Lehane classification, with difficult videolaryngoscopy defined as a Cormack-Lehane grade of ≥ 3. The incidence of difficult videolaryngoscopy was documented. Subsequently, logistic regression analysis was performed to investigate factors associated with its occurrence.

The findings indicated that the incidence of difficult videolaryngoscopy was 2.1%. Multivariate logistic regression analysis demonstrated a statistically significant effect of interincisor distance on the incidence of difficult videolaryngoscopy (OR = 0.669, 95% CI = 0.490–0.913, P = 0.011). Additionally, a statistically significant association was found between Mallampati grade III-IV and difficult videolaryngoscopy (Mallampati grade III: OR = 3.200, 95% CI = 1.813–5.650, P < 0.001; Mallampati grade IV: OR = 2.899, 95% CI = 1.567–5.361, P = 0.001).

The incidence of difficult videolaryngoscopy was 2.1% in this cohort when using a hyperangulated videolaryngoscope. The interincisor distance and Mallampati grades (III and IV) are independently predictors for difficult videolaryngoscopy with this blade type.

www.chictr.org.cn/. Identifier ChiCTR220058009, 26 March 2022.