Year: 2026 | Month: August | Volume: 16 | Issue: 8 | Pages: 28-37
DOI: https://doi.org/10.52403/ijhsr.20260803
Preoperative Ultrasound Assessment of Skin-to-Tongue Mucosal Distance for Prediction of Difficult Laryngoscopy
Ketki Jangid1, Amit Kumar2, Phalguni3, Rajani Sharma4, Mansi Bhatti5, Ritika Godara6, Shivangi Sharma7, Kamlesh K Shekhawat8
1,2,5,6,7,8Department of Anaesthesiology, Pacific Institute of Medical Sciences, Sai Tirupati University, Udaipur, Rajasthan
3Department of Anaesthesiology, Kalyan Singh Super Speciality Cancer Institute, Lucknow, Uttar Pradesh
4Department of Microbiology, Rajmata Vijaya Raje Scindia Government Medical College, Bhilwara, Rajasthan
Corresponding Author: Ketki Jangid
ABSTRACT
Background: Accurate preoperative prediction of a difficult airway is essential in anesthetic practice. Traditional bedside evaluations, such as the Modified Mallampati Test (MMT), are subjective and demonstrate limited standalone predictive accuracy. This study evaluated the utility of ultrasonographic measurement of the skin-to-tongue mucosal distance as a quantitative predictor of difficult laryngoscopy.
Methods: This prospective observational study included 100 adult patients with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for elective surgery under general anesthesia requiring endotracheal intubation. Preoperative assessment included the MMT and ultrasonographic measurement of the skin-to-tongue mucosal distance. Based on predefined cutoffs, patients were categorized into three groups: Group A (3.5–5.4 cm), Group B (5.5–5.8 cm), and Group C (>5.8 cm). The primary outcome was the incidence of difficult laryngoscopy, defined as a Modified Cormack–Lehane (MCL) grade ≥2b.
Results: The overall incidence of difficult laryngoscopy was 21.0%. Increasing skin-to-tongue mucosal distance was significantly associated with a higher incidence of difficult laryngoscopy (0.0% in Group A, 22.9% in Group B, and 61.9% in Group C; p < 0.001). Using a cutoff value of >5.8 cm, ultrasonographic skin-to-tongue mucosal distance predicted difficult laryngoscopy with a sensitivity of 61.9%, specificity of 89.9%, positive predictive value (PPV) of 61.9%, and negative predictive value (NPV) of 89.9%. In comparison, a Modified Mallampati Class III/IV demonstrated lower sensitivity (33.3%) but higher specificity (96.2%), with a PPV of 70.0% and an NPV of 84.4%.
Conclusion: Ultrasonographic measurement of the skin-to-tongue mucosal distance demonstrated moderate sensitivity and high specificity for predicting difficult laryngoscopy. Compared with the Modified Mallampati Test, ultrasound showed higher sensitivity while providing objective anatomical quantification of airway structures. These findings suggest that preoperative airway ultrasound may serve as a valuable adjunct to conventional bedside airway assessment.
Key words: Airway management; difficult laryngoscopy; airway ultrasound; point-of-care ultrasound; Modified Mallampati Test; preoperative airway assessment.