Year: 2026 | Month: April | Volume: 16 | Issue: 4 | Pages: 306-316
DOI: https://doi.org/10.52403/ijhsr.20260438
Comparative Accuracy of Bedside Airway Assessment Tests for Predicting Difficult Laryngoscopy and Tracheal Intubation: A Prospective Observational Study
Lidiya George1, Krithika Karnapooshanam2, Nirupama Kamaraj3, Krishna Prasanth Baalann4
1Assistant Professor, Department of Anaesthesiology, Bharath Medical College & Hospital, Bharath Institute of Science & Technology, Chennai, Tamil Nadu.
2Assistant Professor, Department of General Medicine, Rajalakshmi Medical College & Hospital, Tamil Nadu.
3Assistant Professor, Department of Community Medicine, Sri Venkateshwara Medical College Hospital & Research Institute, Puducherry.
4Assistant Professor & Epidemiologist, Department of Community Medicine, Sree Balaji Medical College & Hospital, Bharath Institute of Science & Technology, Chennai, Tamil Nadu.
Corresponding Author: Dr. Nirupama Kamaraj
ABSTRACT
Background: Unanticipated difficult laryngoscopy and tracheal intubation remain important causes of anaesthesia-related morbidity despite the routine use of preoperative airway assessment. Numerous bedside airway assessment tests are available; however, their individual predictive accuracy is variable and often unreliable.
Aim: To compare the diagnostic accuracy of commonly used preoperative bedside airway assessment tests in predicting difficult laryngoscopy and difficult tracheal intubation.
Materials and Methods: This prospective observational study included 300 adult patients undergoing elective surgery under general anaesthesia requiring orotracheal intubation. Preoperative airway assessment included Modified Mallampati Classification, thyromental distance, sternomental distance, inter-incisor gap, upper lip bite test, and neck circumference. Direct laryngoscopy was performed using a Macintosh laryngoscope, and laryngoscopic view was graded using the Cormack–Lehane classification. Difficult laryngoscopy was defined as Cormack–Lehane grade III or IV, and difficult tracheal intubation as the need for more than two attempts or additional airway manoeuvres. Sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy were calculated for each airway assessment test.
Results: Difficult laryngoscopy was observed in 32 patients (10.7%), and difficult tracheal intubation in 26 patients (8.7%). No single airway assessment test demonstrated both high sensitivity and high specificity. The upper lip bite test showed the highest individual diagnostic accuracy, while distance-based parameters demonstrated higher specificity than sensitivity. Combined airway assessment using two or more abnormal predictors significantly improved sensitivity and negative predictive value compared with individual tests.
Conclusion: Individual bedside airway assessment tests have limited reliability in predicting difficult laryngoscopy and tracheal intubation. A combined, multivariable airway assessment approach offers superior predictive performance and should be routinely adopted to enhance airway preparedness and patient safety.
Key words: Airway assessment, difficult laryngoscopy, difficult intubation, Mallampati classification, upper lip bite test, Cormack–Lehane classification