{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T10:02:13Z","timestamp":1784628133611,"version":"3.55.0"},"reference-count":29,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T00:00:00Z","timestamp":1784592000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: The prediction of difficult laryngoscopic view remains an important component of preoperative airway assessment. Conventional bedside tests are widely used, but their diagnostic performance may be limited by subjectivity and interobserver variability. Focused upper airway ultrasonography may provide objective anatomical information and complement standard clinical evaluation. This study aimed to evaluate the diagnostic accuracy of focused upper airway ultrasonographic and conventional anthropometric measurements for predicting difficult laryngoscopic view in adult patients scheduled for tracheal intubation. Materials and Methods: This single-center, prospective, observational study included 212 adult patients with American Society of Anesthesiologists physical status I\u2013III who were scheduled for elective surgery under general anesthesia requiring tracheal intubation. Preoperative airway assessment included the Modified Mallampati classification, upper lip bite test, mouth opening, thyromental distance, and sternomental distance. Focused ultrasonographic measurements included hyoid\u2013skin distance and epiglottis\u2013skin distance. Difficult laryngoscopic view was defined as a Cormack\u2013Lehane grade III\u2013IV view recorded during the initial direct laryngoscopic assessment. Diagnostic performance was evaluated using receiver operating characteristic curve analysis, and independent predictors were assessed using multivariable logistic regression. Results: Difficult laryngoscopic view was identified in 44 of 212 patients (20.8%). Patients with difficult laryngoscopic view had significantly higher body weight and body mass index, smaller mouth opening, and greater hyoid\u2013skin distance. Hyoid\u2013skin distance was significantly greater in patients with difficult laryngoscopic view than in those without difficult laryngoscopic view (12.00 \u00b1 2.79 mm vs. 10.33 \u00b1 3.16 mm; p = 0.002). Mouth opening was significantly smaller in patients with difficult laryngoscopic view (4.39 \u00b1 0.72 cm vs. 4.74 \u00b1 0.99 cm; p = 0.030). Epiglottis\u2013skin distance did not differ significantly between groups. In receiver operating characteristic analysis, hyoid\u2013skin distance showed an area under the curve of 0.682, with a cut-off value of \u226512.05 mm, sensitivity of 47.73%, and specificity of 83.33%. In multivariable logistic regression analysis, body mass index and hyoid\u2013skin distance were independently associated with difficult laryngoscopic view, whereas greater mouth opening had a protective effect. The combined multivariable model showed an area under the curve of 0.734; however, at a probability cut-off value of 0.5, its sensitivity was low at 15.9%, despite high specificity of 97.0%. Conclusions: Focused upper airway ultrasonography may provide complementary objective information when used together with conventional preoperative airway assessment. Hyoid\u2013skin distance was independently associated with difficult laryngoscopic view and demonstrated relatively high specificity; however, its discriminatory performance was modest and its sensitivity was limited. Therefore, hyoid\u2013skin distance and the combined model should not be interpreted as standalone screening tools for excluding difficult laryngoscopic view. Their main clinical value may be as adjunctive parameters that support risk stratification and advance airway management planning in selected patients.<\/jats:p>","DOI":"10.3390\/medicina62071408","type":"journal-article","created":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T08:14:27Z","timestamp":1784621667000},"page":"1408","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparison of Focused Upper Airway Ultrasonographic and Anthropometric Measurements for Predicting Difficult Intubation: A Prospective Observational Study"],"prefix":"10.3390","volume":"62","author":[{"given":"Sami","family":"Eksert","sequence":"first","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ecem","family":"Kahraman","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Serdar","family":"\u0130nan","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fatih","family":"\u015eim\u015fek","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet Emin","family":"\u0130nce","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Can","family":"\u00c7elik","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G\u00f6k\u00e7e Sezen","family":"Ayd\u0131n","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hasan","family":"Soylu","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4012-4131","authenticated-orcid":false,"given":"Murtaza","family":"Kaya","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, Kutahya Health Science University, 43000 Kutahya, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G\u00f6khan","family":"\u00d6zkan","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6781-9334","authenticated-orcid":false,"given":"Mehmet Burak","family":"E\u015fkin","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Reanimation, G\u00fclhane Training and Research Hospital, University of Health Sciences, General Dr. Tevfik Sa\u011flam Cd. No:1, Etlik, 06010 Ankara, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1097\/ALN.0000000000004002","article-title":"2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway","volume":"136","author":"Apfelbaum","year":"2022","journal-title":"Anesthesiology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1007\/BF03012147","article-title":"The unanticipated difficult airway with recommendations for management","volume":"45","author":"Crosby","year":"1998","journal-title":"Can. J. Anaesth."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.4103\/ija.ija_1210_25","article-title":"All India Difficult Airway Association 2025 Guidelines for the management of unanticipated difficult airway in adults under general anaesthesia","volume":"69","author":"Myatra","year":"2025","journal-title":"Indian J. Anaesth."},{"key":"ref_4","first-page":"CD008874","article-title":"Airway physical examination tests for detection of difficult airway management in apparently normal adult patients","volume":"5","author":"Roth","year":"2018","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1097\/00000542-200508000-00027","article-title":"Predicting difficult intubation in apparently normal patients: A meta-analysis of bedside screening test performance","volume":"103","author":"Shiga","year":"2005","journal-title":"Anesthesiology"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Wang, Z., Jin, Y., Zheng, Y., Chen, H., Feng, J., and Sun, J. (2024). Evaluation of preoperative difficult airway prediction methods for adult patients without obvious airway abnormalities: A systematic review and meta-analysis. BMC Anesthesiol., 24.","DOI":"10.1186\/s12871-024-02627-1"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Riveros-Perez, E., Avella-Molano, B., and Rocuts, A. (2025). Airway ultrasound: A narrative review of present use and future applications in anesthesia. Healthcare, 13.","DOI":"10.3390\/healthcare13131502"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1053\/j.sult.2023.12.006","article-title":"Bedside ultrasound: The silent guardian for upper airway assessment and management","volume":"45","author":"Chang","year":"2024","journal-title":"Semin. Ultrasound CT MR"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"740","DOI":"10.1213\/ANE.0000000000005839","article-title":"Airway ultrasound as predictor of difficult direct laryngoscopy: A systematic review and meta-analysis","volume":"134","author":"Carsetti","year":"2022","journal-title":"Anesth. Analg."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Gomes, S.H., Simoes, A.M., Nunes, A.M., Pereira, M.V., Teoh, W.H., Costa, P.S., Kristensen, M.S., Teixeira, P.M., and P\u00eago, J.M. (2021). Useful ultrasonographic parameters to predict difficult laryngoscopy and difficult tracheal intubation: A systematic review and meta-analysis. Front. Med., 8.","DOI":"10.3389\/fmed.2021.671658"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1053\/j.jvca.2023.02.036","article-title":"Diagnostic performance of airway ultrasound for the assessment of difficult laryngoscopy: A systematic review and meta-analysis","volume":"37","author":"Jaramillo","year":"2023","journal-title":"J. Cardiothorac. Vasc. Anesth."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1097\/EJA.0000000000001805","article-title":"Pre-operative ultrasound prediction of difficult airway management in adult patients: A systematic review of clinical evidence","volume":"40","author":"Giordano","year":"2023","journal-title":"Eur. J. Anaesthesiol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"World Medical Association (2025). World Medical Association Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Participants. JAMA, 333, 71\u201374.","DOI":"10.1001\/jama.2024.21972"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Von Elm, E., Altman, D.G., Egger, M., Pocock, S.J., Gotzsche, P.C., Vandenbroucke, J.P. (2007). The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for reporting observational studies. PLoS Med., 4.","DOI":"10.1371\/journal.pmed.0040296"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1111\/j.1365-2044.1987.tb04039.x","article-title":"Difficult tracheal intubation: A retrospective study","volume":"42","author":"Samsoon","year":"1987","journal-title":"Anaesthesia"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1213\/00000539-200302000-00053","article-title":"A comparison of the upper lip bite test with modified Mallampati classification in predicting difficulty in endotracheal intubation: A prospective blinded study","volume":"96","author":"Khan","year":"2003","journal-title":"Anesth. Analg."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Palaczynski, P., Smereka, J., Zawadzka-Kaczmarek, K., Kuklinski, J., Misiolek, H., Domka, J., Danel, J., and Bialka, S. (2025). Thyromental Height Test as a Method for Predicting Difficult Intubation in Patients with Obesity: A Prospective Observational Study. J. Clin. Med., 14.","DOI":"10.3390\/jcm14186352"},{"key":"ref_18","first-page":"539","article-title":"Preoperative airway ultrasound assessment in the sniffing position: A prospective observational study","volume":"73","author":"Greif","year":"2023","journal-title":"Braz. J. Anesthesiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"629","DOI":"10.4103\/ija.IJA_270_19","article-title":"Ultrasound measurement of anterior neck soft tissue and tongue thickness to predict difficult laryngoscopy: An observational analytical study","volume":"63","author":"Yadav","year":"2019","journal-title":"Indian J. Anaesth."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.jcrc.2016.01.029","article-title":"Predicting difficult laryngoscopy using ultrasound measurement of distance from skin to epiglottis","volume":"33","author":"Pinto","year":"2016","journal-title":"J. Crit. Care"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1105","DOI":"10.1111\/j.1365-2044.1984.tb08932.x","article-title":"Difficult tracheal intubation in obstetrics","volume":"39","author":"Cormack","year":"1984","journal-title":"Anaesthesia"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"885","DOI":"10.1097\/00000542-200611000-00007","article-title":"Incidence and predictors of difficult and impossible mask ventilation","volume":"105","author":"Kheterpal","year":"2006","journal-title":"Anesthesiology"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.12669\/pjms.344.15364","article-title":"Upper lip bite test for prediction of difficult airway: A systematic review","volume":"34","author":"Faramarzi","year":"2018","journal-title":"Pak. J. Med. Sci."},{"key":"ref_24","first-page":"844539","article-title":"Ultrasound-based airway assessment in obese patients as a valuable tool for predicting difficult airway: An observational study","volume":"74","author":"Tasdemir","year":"2024","journal-title":"Braz. J. Anesthesiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1111","DOI":"10.1046\/j.1365-2044.2003.03412.x","article-title":"Prediction of difficult laryngoscopy in obese patients by ultrasound quantification of anterior neck soft tissue","volume":"58","author":"Ezri","year":"2003","journal-title":"Anaesthesia"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1556","DOI":"10.1111\/anae.16751","article-title":"Point-of-care ultrasound of the upper airway in difficult airway management: A systematic review and meta-analysis","volume":"80","author":"Soni","year":"2025","journal-title":"Anaesthesia"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Alt\u0131nsoy, K.E., and Bayhan, B.U. (2025). Ultrasound-Measured Skin-to-Epiglottis Distance as a Predictor of Difficult Intubation in Obese Patients: A Prospective Observational Study. J. Clin. Med., 14.","DOI":"10.3390\/jcm14062092"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Yuan, J., Ye, H., Tan, X., Zhang, H., and Sun, J. (2024). Determinants of difficult laryngoscopy based on upper airway indicators: A prospective observational study. BMC Anesthesiol., 24.","DOI":"10.1186\/s12871-024-02543-4"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1093\/bja\/aex051","article-title":"Can tongue thickness measured by ultrasonography predict difficult tracheal intubation?","volume":"118","author":"Yao","year":"2017","journal-title":"Br. J. Anaesth."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/7\/1408\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T09:11:16Z","timestamp":1784625076000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/7\/1408"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,21]]},"references-count":29,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["medicina62071408"],"URL":"https:\/\/doi.org\/10.3390\/medicina62071408","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,21]]}}}