Computed tomography for difficult airways diagnostics

The objective was to determine the effectiveness of computed tomography for difficult laryngoscopy diagnosis.

Materials and methods. We examined 60 patients who underwent preoperative computed tomography of the head and neck and assessed the risk of difficult airways using the LEMON scale. The following CT signs were studied: the thickness of the tongue and soft tissues at the level of the vocal folds, the vertical distance from the highest point of the hyoid bone to the body of the mandible, the thickness of the epiglottis, the length of the epiglottis, the location of the vocal folds at the level of the cervical vertebrae, the atlanto-occipital gap, the gap between the first and the second cervical vertebrae, the distance between the vocal folds. After induction of anesthesia, patients were divided into 2 groups depending on the results of laryngoscopy according to the Cormack–Lehane classification. The diagnostic ability of the clinical features of the LEMON scale and CT findings was calculated using ROC-AUC analysis in patients in the difficult and normal airway groups.

Results. The analysis of the obtained data showed that the LEMON scale has an average diagnostic ability (AUC 0.697 p ≤ 0.023 CI–0.534–0.860); the sensitivity of the method was 26.7%, specificity – 95.6%, compared with CT diagnostics. The most effective CT-predictor is the thickness of the tongue (sensitivity – 80%, specificity – 77.8%), to a lesser extent – the vertical distance from the highest point of the hyoid bone to the mandible and the thickness of the epiglottis (sensitivity 73%, 60% and specificity 66.7% , 62.4%, respectively).

Conclusion. The use of computed tomography is effective in identifying predictors of difficult laryngoscopy. Radiation methods for diagnosing difficult laryngoscopy are more sensitive compared to the LEMON scale. The diagnostic criteria for difficult laryngoscopy are thickness of the tongue – 75.75 mm, vertical distance from the highest point of the hyoid bone to the mandible – 20.85 mm, and thickness of the epiglottis – 2.65 mm.

1. Dubrovin K.V., Zaytsev A.Yu., Svetlov V.A. et al. Predicting difficult airways in the practice of an anesthesiologist and emergency physician. Messenger of anesthesiology and resuscitation, 2020, vol. 17, no. 6, pp. 63–71. (In Russ.) DOI: 10.21292/2078-5658-2020-17-6-63-71.

2. Zaytsev A.Yu., Svetlov V.A., Dubrovin K.V. Difficult airways. How not to scare and make no mistake. Мoscow: Geotar-Media, 2020, pp. 128. ISBN 978-5-9704-5368-1. (In Russ.)

3. Klimov A.A., Mаlаkhovа A.A., Kаmnev S.А., Subbotin V.V. Use of predictive El-Ganzouri score in evaluation of difficult airway in obese patients. Messenger of anesthesiology and resuscitation, 2018, vol. 15, no. 2, pp. 38–44. (In Russ.) DOI: 10.21292/2078-5658-2018-15-2-38-44.

4. Korneev A.V., Orudzheva S.A., Kudryavtsev A.N. Specific features of difficult airways in patients with face and neck burns. Messenger of anesthesiology and resuscitation, 2019, vol. 16, no. 6, pp. 67–73. (In Russ.) DOI: 10.21292/2078-5658-2019-16-6-67-73.

5. Korneev A.V., Orudzheva S.A., Kudryavtsev A.N., Ponomarev A.A. A new method of assessing airways and selecting the method of tracheal intubation in patients with burns of face and neck during planned surgery. Messenger of anesthesiology and resuscitation, 2020, vol. 17, no. 6, pp. 15–21. (In Russ.) DOI: 10.21292/2078-5658-2020-17-6-15-21.

6. Maiorov M.O., Federiakin D.V., Belevskii E.V., Silaev V.N., Tokareva S.I. Prognostic value of the intubation difficulty scale in bariatric surgery. Messenger of anesthesiology and resuscitation, 2023, vol. 20, no. 2, pp. 29–35. (In Russ.). DOI: 10.24884/2078-5658-2022-20-2-29-35.

7. Nabiev F.Kh., Dobrodeev A.S., Libin P.V. Comprehensive evaluation of Angle’s classification class ii dental-facial anomalies accompanied by obstructive sleep apnea. Issues of Reconstructive and Plastic Surgery, 2015, vol. 18, no. 4(55), pp. 47–56. (In Russ.) DOI: 10.17223/1814147/55/8.

8. Ben Ner D., Carmel-Neiderman N.N., Fliss D.M. et al. The interaction between craniofacial computed tomographic dimensional parameters and bmiin obstructive sleep apnea. Journal of Maxillofacial and Oral Surgery, 2019, vol. 18, pp. 299–306. DOI: 10.1007/s12663-018-1140-1.

9. Dai Y., Walline J.H., Wu Y. Incidence and diagnostic validity of difficult airway in emergency departments in China: a cross-sectional survey. Journal of Thoracic Disease. 2023, vol. 15, no. 2, pp. 434. DOI: 10.21037/jtd-22-199.

10. Endlich Y., Lee J., Culwick M.D. Difficult and failed intubation in the first 4000 incidents reported on webAIRS. Anaesthesia and Intensive Care. 2020, vol. 48, no. 6, pp. 477–487. DOI:10.1177/0310057X20957657.

11. Grimes D., MacLeod I., Taylor T. et al. Computed tomography as an aid to planning intubation in the difficult airway. British Journal of Oral and Maxillofacial Surgery, 2016, vol. 54, no. 1, pp. 80–82. DOI: 10.1016/j.bjoms.2015.09.034.

12. Han Y.Z., Tian Y., Zhang H. et al. Radiologic indicators for prediction of difficult laryngoscopy in patients with cervical spondylosis. Acta Anaesthesiologica Scandinavica, 2018, vol. 62, no. 4, pp. 474–482. DOI: 10.1111/aas.13078.

13. Ji C., Ni Q., Chen W. Diagnostic accuracy of radiology (CT, X-ray, US) for predicting difficult intubation in adults: A meta-analysis. Journal of Clinical Anesthesia, 2018, vol. 45, pp. 79–87. DOI: 10.1016/j.jclinane.2017.12.023.

14. Jugpal T.S., Garg A., Sethi G.R. et al. Multi-detector computed tomography imaging of large airway pathology: A pictorial review. World J Radiol, 2015, vol. 7, no. 12, pp. 459–474. DOI: 10.4329/wjr.v7.i12.459.

15. Lee H.C., Kim M.K., Kim Y.H. et al. Radiographic predictors of difficult laryngoscopy in acromegaly patients. Journal of Neurosurgical Anesthesiology, 2019, vol. 31, no. 1, pp. 50–56. DOI: 10.1097/ANA.0000000000000471.

16. Liu B., Song Y., Liu K. Radiological indicators to predict the application of assistant intubation techniques for patients undergoing cervical surgery. BMC Anesthesiology, 2020, vol. 20, no. 1, pp. 1–8. DOI: 10.1186/s12871-020-01153-0.

17. Naguib M., Malabarey T., AlSatli R.A. et al. Predictive models for difficult laryngoscopy and intubation. A clinical, radiologic and three-dimensional computer imaging study. Canadian Journal of Anesthesia, 1999, vol. 46, pp. 748–759. DOI: 10.1007/BF03013910.

18. Qu Y., Tian Y., Fang J. et al. Preoperative radiological indicators for prediction of difficult laryngoscopy in patients with atlantoaxial dislocation. Heliyon, 2024, vol. 10, no. 1, e23435. DOI: 10.1016/j.heliyon.2023.e23435.

19. Trambadia D.N., Yadav P., Sargunaraj A. Preoperative Assessment to Predict Difficult Airway Using Multiple Screening Tests. Cureus, 2023, vol. 15, no. 10, e46868. DOI: 10.7759/cureus.46868.

20. Yoon S., Oh H., Yoon H.K. et al. Radiographic predictors of difficult McGrath MAC videolaryngoscopy in patient undergoing cervical spine surgery. Journal of Neurosurgical Anesthesiology, 2022, vol. 34, no. 1, pp. 57–63. DOI: 10.1097/ANA.0000000000000717.