# Predicting Difficult Tracheal Intubation in Head and Neck Cancer Patients with Osteoradionecrosis: Development of the ORN-Difficult-Airway-Score

## TL;DR

This study develops a new scoring system to predict difficult tracheal intubation in head and neck cancer patients with osteoradionecrosis.

## Contribution

The novel ORN-Difficult-Airway Score is introduced for risk stratification of difficult intubation in patients with osteoradionecrosis.

## Key findings

- ORN patients had restricted mouth opening and higher Mallampati classes.
- Hyperangulated videolaryngoscopy showed better success rates than direct laryngoscopy in ORN patients.
- A preoperative score was developed using bedside parameters to predict difficult intubation.

## Abstract

Background: Osteoradionecrosis (ORN) following head and neck radiotherapy has been demonstrated to induce structural and functional alterations of the upper airway, with the potential to complicate the process of tracheal intubation. Despite its clinical relevance, there is a paucity of systematic evidence on airway characteristics in ORN and reliable predictors of difficult tracheal intubation. This study compares preoperative airway parameters and tracheal intubation outcomes in irradiated patients with and without ORN and introduces a novel preoperative ORN-Difficult-Airway Score for risk stratification. Methods: In this retrospective cohort study, airway assessments, tracheal intubation methods, and perioperative visualization parameters were evaluated in 105 patients following head and neck radiotherapy. Group differences between non-ORN and ORN were analyzed using chi-square tests. A preoperative ORN-Difficult-Airway Score was constructed using exclusively bedside parameters, based on statistically and clinically relevant predictors. Results: Patients with ORN showed significantly restricted mouth opening (p < 0.001), higher Mallampati classes, particularly Mallampati IV, and a greater need for fiberoptic tracheal intubation (p < 0.01). Direct laryngoscopy (DL) was significantly less feasible in ORN, while hyperangulated videolaryngoscopy (VL) yielded consistently positive visualization (first-pass success (FPS) 100% in both groups). Under DL, FPS was lower in ORN (54.2% vs. 79.5%), resulting in an odds ratio of 0.305. Based on observed predictors, ORN status, mouth opening <3 cm, Mallampati class, restricted neck reclination, and history of difficult intubation, a preoperative ORN-Difficult-Airway Score was developed. Conclusions: ORN has been associated with distinct alterations in airway anatomy and visualization, resulting in increased tracheal intubation complexity after head and neck radiotherapy. The proposed ORN-Difficult-Airway Score presents a clinically practical, bedside-applicable approach to stratifying the risk of tracheal intubation in this population. Prior to clinical implementation, prospective validation in larger cohorts is warranted.