Analysis of Risk Factors of Potentially Difficult Endotracheal Intubation: A Retrospective Observational Study of 154 Patients with Scoliosis at a Single Center in China

BACKGROUND: Glottic entrance stenosis is an important cause of difficult airway intubation and may be potentially associated with scoliosis. This retrospective study from a single center in China aimed to investigate the parameters and risk factors associated with glottic entrance stenosis by evaluating 154 patients with scoliosis who underwent posterior surgical correction, internal fixation, and fusion. MATERIAL/METHODS: A total of 161 patients diagnosed with scoliosis from 2018 to 2020 were included and grouped by classification, and 7 of them were excluded from the risk factor analysis. All patients underwent posterior surgical correction, internal fixation, and fusion. Basic data, scoliosis-related information, and radiological image were collected. Sagittal and transverse diameter and cross-section area were measured. A new definition of glottic entrance stenosis was proposed based on the traditional formula for prediction of tracheal tuba diameter. RESULTS: The percentage of transverse stenosis in these patients was 35.4%, and the incidence of sagittal stenosis and area stenosis were 9.9% and 12.4% respectively, while 37.9% of scoliosis patients also have at least 1 type of glottic entrance stenosis. Longer course of disease is a proven risk factor for sagittal stenosis (P=0.037). Smaller lumbar lordosis indicates higher risk of transverse stenosis (P=0.024). Wedged vertebrae are a risk factor for area stenosis (P=0.024). CONCLUSIONS: This study comprehensively measured glottic entrance parameters in patients with scoliosis, proposed a new definition of glottic entrance stenosis, and found that longer course of disease, smaller lumbar lordosis, and wedged vertebrae were risk factors for sagittal stenosis, transverse stenosis, and area stenosis, respectively.