CT-DERIVED AIRWAY ANATOMY AND ITS ASSOCIATION WITH DIFFICULT MASK VENTILATION AND INTUBATION: A RETROSPECTIVE STUDY
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Keywords
CT airway anatomy, difficult mask ventilation, difficult intubation, glottic cross-sectional area, preoperative airway assessment, Bihar
Abstract
Background:Preoperative airway assessment remains one of the most critical responsibilities of an anaesthesiologist. Traditional clinical tools including the modified Mallampati test (MMT), thyromental distance (TMD), and body mass index (BMI) show variable sensitivity and specificity in predicting difficult mask ventilation (DMV) and difficult intubation (DI). Computed tomography (CT) of the neck and chest allows direct, objective measurement of airway anatomy. However, its routine preoperative application in predicting airway difficulty has not been systematically studied in the north Bihar region of India.
Objectives:To determine whether specific CT-derived airway anatomical parameters — including minimum glottic cross-sectional area (mGCSA), subglottic diameter, anteroposterior pharyngeal distance, and prevertebral soft tissue thickness — are independently associated with difficult mask ventilation and difficult intubation in adult surgical patients.
Methodology:A retrospective observational study was conducted from April 2025 to September 2025 at Radha Devi Jageshwari Memorial Medical College & Hospital, Muzaffarpur, Bihar. Records of 120 adult patients (≥18 years) who underwent elective surgery under general anaesthesia and had a preoperative CT neck/chest scan were reviewed. CT measurements and intraoperative airway management records were extracted and analysed using SPSS v25. Logistic regression was employed to identify independent CT predictors.
Results:Of 120 patients, DMV occurred in 21 (17.5%) and DI in 18 (15.0%). Reduced mGCSA (≤120 mm²; OR 4.82, 95% CI 1.94–11.97, p=0.001), narrow subglottic transverse diameter (≤12 mm; OR 3.71, 95% CI 1.45–9.48, p=0.006), and increased prevertebral soft tissue thickness (≥7 mm; OR 3.19, 95% CI 1.21–8.42, p=0.019) were independently associated with difficult intubation. Reduced anteroposterior pharyngeal distance (≤11 mm; OR 4.11, 95% CI 1.62–10.44, p=0.003) was the strongest independent predictor of DMV.
Conclusion:CT-derived airway anatomical parameters, particularly minimum glottic cross-sectional area and anteroposterior pharyngeal distance, are significant independent predictors of airway difficulty and may supplement conventional clinical assessment, especially in high-risk surgical populations in resource-constrained tertiary settings.
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Dr. Vaghasia Aartiben Arvindbhai
Assistant Professor, Department of Anasthesiology, Radha Devi Jageshwari Memorial Medical College & Hospital, Turki, Muzaffarpur, Bihar, India
Dr. Tekwani Parmanand Holaram
Assistant Professor, Department of Radio-Diagnosis, Smt. B K Shah Medical Institute and Research Centre, Sumandeep Vidyapeeth deemed to be University, Vadodara, Gujarat, India
Dr. Alok Pritam
Assistant Professor (Statistics), Department of Community Medicine, Radha Devi Jageshwari Memorial Medical College & Hospital, Turki, Muzaffarpur, Bihar, India
