Journal of Maxillofacial and Oral Surgery

, Volume 17, Issue 4, pp 563–569 | Cite as

Ultrasound as an Assessment Method in Predicting Difficult Intubation: A Prospective Clinical Study

  • Simin AbrahamEmail author
  • J. Himarani
  • S. Mary Nancy
  • S. Shanmugasundaram
  • V. B. Krishnakumar Raja
Original Article



Aim of the study is to predict the difficulty in intubation preoperatively using ultrasonography.


One hundred and thirty-seven patients underwent ultrasound followed by surgery under general anesthesia. A experienced radiologist examined the airway and performed measurements of specific airway parameters: visualization of hyoid bone, visualization of vocal cords through thyroid cartilage, visualization of epiglottis, distance from base of tongue to hyoid bone, distance of hyomental region distance of thyrohyoid region, distance between skin and fat pad thickness to thyroid cartilage, thickness of submental region, distance from epiglottis to skin (above hyoid), and visualization of cricothyroid membrane. After performing ultrasound, patient was presented for surgery. An experienced anesthesiologist who is associated with this study did all the laryngoscopy and intubation.


We were able to visualize all relevant anatomical structures in all the participants using ultrasound. The receiver operating characteristic curve analysis results showed that hyomental is ≤ 1.09 (P value < 0.01) to classify difficult in intubation.


The study shows that ultrasound can reliably image all the airway structures. This study suggests that hyomental distance is a more valid criterion in predicting difficult intubation. Further, case control study is needed for assessing the ease of intubation.


Airway Intubation Ultrasonography Laryngoscopy 



I am extremely thankful to Dr. Santhosh Pasupuleti, Radiologist, for helping, guiding and teaching me about ultrasound. I would like to thank my colleagues in the department for all their support, help, and constructive criticism and in making this an invaluable and enjoyable experience.

Compliance with Ethical Standards

Ethical Approval

Ethical clearance certificate obtained from institutional review board. All procedures performed in studies involving human participants were in accordance with ethical standards of institutional research committee and with 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Informed Consent

Informed consent obtained from the involved human participants.


  1. 1.
    Ramadhani SAL, Mohammed LA, Rocke DA et al (1996) Sternomental distance as the sole predictor of difficult laryngoscopy in obstetric anaesthesia. Br J Anaesth 77:312–316CrossRefGoogle Scholar
  2. 2.
    Wilson WC, Benumof JL (1998) Respiration in anesthesia pathophysiology and clinical update: pathophysiology, evaluation and treatment of the difficult airway. Anesthesiol Clin N Am 16:29–75CrossRefGoogle Scholar
  3. 3.
    Gupta PK, Gupta K, Dwivedi AND, Jain M (2011) Potential role of ultrasound in anaesthesia and intensive care. Anaesth Essays Res 5(1):11–19CrossRefGoogle Scholar
  4. 4.
    Terkawi AS, Karakitsos D, Elbarbary M, Blaivas M, Durieux ME (2013) Ultrasound for the anaesthesiologists: present and future. Sci World J 2013. CrossRefGoogle Scholar
  5. 5.
    Cormack RS, Lehane J (1984) Difficult tracheal intubation in obstetrics. Anaesthesia 39:1105–1111CrossRefGoogle Scholar
  6. 6.
    Vasudevan A, AB Adhe (2008) Predictors of difficult intubation—a simple approach. Internet J Anesthesiol 20(2):2Google Scholar
  7. 7.
    Management of Unanticipated Difficult Intubation (2010) [Blog] Pennsylvania Patient Safety Advisory. Available at:
  8. 8.
    Sustic A et al (2007) Role of ultrasound in the airway management of critically ill patients. Crit Care Med 35:173–177CrossRefGoogle Scholar
  9. 9.
    Gupta AK, Mohamad O, Showkat N, Imtiyaz N, Anjali M (2010) Predictors of difficult intubation: study in Kashmiri population. Br J Med Practitioners 3(1):307Google Scholar
  10. 10.
    Prasad A et al (2011) Comparison of sonography and computed tomography as imaging tool for assessment of airway structures. J Ultrasound Med 30:965–972CrossRefGoogle Scholar
  11. 11.
    Singh M, Chan VWS, Prasad GA (2010) Use of sonography for airway assessment an observational study. J Ultrasound Med 29:79–85CrossRefGoogle Scholar
  12. 12.
    Chau CW, Chan HH, Wong CP, Wong TW, Lau CC (2010) Sonographic measurement of the epiglottis in normal Chinese adults. Hong Kong J Emerg Med 17(5):429–434CrossRefGoogle Scholar
  13. 13.
    Dastidar P, Heinonen T, Numminen J, Rautiainen M, Laasonen E (1999) Semi-automatic segmentation of computed tomographic images in volumetric estimation of nasal airway. Eur Arch Otorhinolaryngol 256:192–198CrossRefGoogle Scholar
  14. 14.
    Bakker NH, Lohuis PJ, Menger DJ, Trenité GJN, Fokkens WJ, Grimbergen CA (2005) Objective computerized determination of the minimum cross-sectional area of the nasal passage on computed tomography. Laryngoscope 115:1809–1812CrossRefGoogle Scholar
  15. 15.
    ChouHC W (1993) Mandibulohyoid distance in difficult laryngoscopy. Br J Anaesth 71:335–339CrossRefGoogle Scholar
  16. 16.
    Naguib M, Scamman FL, O’Sullivan C et al (2006) Predictive performance of three multivariate difficult tracheal intubation models: a double-blind, case-controlled study. Anaesth Analg 102:818–824CrossRefGoogle Scholar
  17. 17.
    Hui CM, Tsui BC (2014) Sublingual ultrasound as an assessment method for predicting difficult intubation: a pilot study. Anaesthesia 69:314–319CrossRefGoogle Scholar
  18. 18.
    Law JA, Broemling N, Cooper RM, Drolet P, Duggan LV, Griesdale DE, Hung OR, Jones PM, Kovacs G, Massey S, Morris IR, Mullen T, Murphy MF, Preston R, Naik VN, Scott J, Stacey S, Turkstra TP, Wong DT (2013) The difficult airway with recommendations for management—part 2—the anticipated difficult airway. Can J Anaesth 60:1119–1138CrossRefGoogle Scholar
  19. 19.
    Laura F, Cavallone MD, Vannucci A (2013) Extubation of the difficult airway and extubation failure. Int Anaesth Res Soc 116(2):368–383Google Scholar
  20. 20.
    Balakrishnan M, Kuriakose R, Koshy RC (2004) Radiation induced changes in the airway—anaesthetic implications. South Afr J Anaesth Analg 10:19–21Google Scholar
  21. 21.
    Kristensen MS, Teoh WH, Graumann O, Laursen CB (2014) Ultrasonography for clinical decision-making and intervention in airway management: from the mouth to the lungs and pleurae. Insights Imaging 5:253–279CrossRefGoogle Scholar
  22. 22.
    Fiadjoe JE, Stricker P, Gurnaney H, Nishisaki A, Rabinowitz A, Gurwitz A, McCloskey JJ, Ganesh A (2012) Ultrasound-guided tracheal intubation—a novel intubation technique. Anesthesiology 117(6):1389–1391CrossRefGoogle Scholar
  23. 23.
    Tsui BCH et al (2008) Sublingual airway ultrasound imaging. Can J Anaesth 55(11):790–791CrossRefGoogle Scholar
  24. 24.
    Kundra P, Mishra SK, Ramesh A (2011) Ultrasound of the airway. Indian J Anaesth 55:456–462CrossRefGoogle Scholar

Copyright information

© The Association of Oral and Maxillofacial Surgeons of India 2018

Authors and Affiliations

  1. 1.Department of Oral and Maxillofacial SurgerySRM Dental CollegeRamapuram, ChennaiIndia

Personalised recommendations