Correlation between neck circumference measurement and obesity type with difficult intubation in obese patients undergoing elective surgery



Obesity, Difficult intubation, Neck circumference, BMI


Background/Aim: The number of obese patients undergoing elective surgery is increasing day by day. However, there are conflicting data in the literature about factors predicting difficult tracheal intubation in obese patients. The aim of this study was to evaluate the commonly used predictors of difficult intubation in obese patients (body mass index (BMI) >35 kg/m2) who wish to undergo elective surgery and to examine the association of neck circumference and obesity type with difficult intubation. Methods: This observational, cross-sectional, prospective study was performed after obtaining approval from the ethics committee. Obese patients over the age of 18 years, requiring tracheal intubation, undergoing elective surgery, and with a BMI greater than 35 were included in this study. Patients with a history of cervical spine anomaly or trauma, congenital facial anomaly or trauma affecting this region, those who would undergo emergency surgery, patients with a known history of difficult airway or upper respiratory tract disease, and those with planned awake intubation were excluded from the study. Preoperative anesthetic evaluation was performed for all patients, their relevant measurements were obtained, and medical histories were taken as required for the study. The association of the patients’ BMI, Mallampati classification, thyromental distance, Cormack–Lehane grade, obstructive sleep apnea, neck circumference, and obesity type with difficult intubation was evaluated. Preoperative and peroperative measurements were recorded in the follow-up forms. Results: A total of 85 patients, 62 females and 23 males, between the ages of 19 and 77 years were included in this study. A significant difference was found in the patients’ BMI, neck circumference, thyromental distance, Mallampati classifications, and Cormack–Lehane grades in terms of intubation difficulty (P<0.001, P<0.001, P<0.001, P<0.01, P<0.01, respectively). Patients who underwent difficult intubation had lower thyromental distance but greater BMI, neck circumference, Mallampati classification, and Cormack–Lehane grade. It was determined that a neck circumference of >50 cm increased the risk of difficult intubation 8.323 times. Conclusion: Neck circumference and thyromental distance are significant predictors for difficult intubation and laryngoscopy in morbidly obese patients.


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Henderson JJ, Popat MT, Latto IP, Pearce AC; Difficult Airway Society. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia. 2004 Jul;59(7):675-94. doi: 10.1111/j.1365-2044.2004.03831.x.

Lundstrøm LH, Møller AM, Rosenstock C, Astrup G, Wetterslev J. High body mass index is a weak predictor for difficult and failed tracheal intubation: a cohort study of 91,332 consecutive patients scheduled for direct laryngoscopy registered in the Danish Anesthesia Database. Anesthesiology. 2009 Feb;110(2):266-74. doi: 10.1097/ALN.0b013e318194cac8.

Aceto P, Perilli V, Modesti C, Ciocchetti P, Vitale F, Sollazzi L. Airway management in obese patients. Surg Obes Relat Dis. 2013 Sep-Oct;9(5):809-15. doi: 10.1016/j.soard.2013.04.013

Bray, G.A., et al., Management of obesity. The Lancet, 2016. 387(10031): p. 1947-1956.

Hodgson LE, Murphy PB, Hart N. Respiratory management of the obese patient undergoing surgery. J Thorac Dis. 2015 May;7(5):943-52. doi: 10.3978/j.issn.2072-1439.2015.03.08.

Moon TS, Fox PE, Somasundaram A, Minhajuddin A, Gonzales MX, Pak TJ, et al. The influence of morbid obesity on difficult intubation and difficult mask ventilation. J Anesth. 2019 Feb;33(1):96-102. doi: 10.1007/s00540-018-2592-7.

Gonzalez H, Minville V, Delanoue K, Mazerolles M, Concina D, Fourcade O. The importance of increased neck circumference to intubation difficulties in obese patients. Anesth Analg. 2008 Apr;106(4):1132-6. doi: 10.1213/ane.0b013e3181679659.

Wilson ME, Spiegelhalter D, Robertson JA, Lesser P. Predicting difficult intubation. Br J Anaesth. 1988 Aug;61(2):211-6. doi: 10.1093/bja/61.2.211. PMID: 3415893.

Bond A. Obesity and difficult intubation. Anaesth Intensive Care. 1993 Dec;21(6):828-30. doi: 10.1177/0310057X9302100614.

Brodsky JB, Lemmens HJ, Brock-Utne JG, Vierra M, Saidman LJ. Morbid obesity and tracheal intubation. Anesth Analg. 2002 Mar;94(3):732-6. doi: 10.1097/00000539-200203000-00047.

Sinha A, Jayaraman L, Punhani D. Predictors of difficult airway in the obese are closely related to safe apnea time! J Anaesthesiol Clin Pharmacol. 2020 Jan-Mar;36(1):25-30. doi: 10.4103/joacp.JOACP_164_19.

Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance. Anesthesiology. 2005 Aug;103(2):429-37. doi: 10.1097/00000542-200508000-00027.

Neligan PJ, Porter S, Max B, Malhotra G, Greenblatt EP, Ochroch EA. Obstructive sleep apnea is not a risk factor for difficult intubation in morbidly obese patients. Anesth Analg. 2009 Oct;109(4):1182-6. doi: 10.1213/ane.0b013e3181b12a0c.

Kim WH, Ahn HJ, Lee CJ, Shin BS, Ko JS, Choi SJ, et al. Neck circumference to thyromental distance ratio: a new predictor of difficult intubation in obese patients. Br J Anaesth. 2011 May;106(5):743-8. doi: 10.1093/bja/aer024.

Bindra A, Prabhakar H, Singh GP, Ali Z, Singhal V. Is the modified Mallampati test performed in supine position a reliable predictor of difficult tracheal intubation? J Anesth. 2010 Jun;24(3):482-5. doi: 10.1007/s00540-010-0905-6.

Juvin P, Lavaut E, Dupont H, Lefevre P, Demetriou M, Dumoulin JL, et al. Difficult tracheal intubation is more common in obese than in lean patients. Anesth Analg. 2003 Aug;97(2):595-600. doi: 10.1213/01.ANE.0000072547.75928.B0.

Riad W, Vaez MN, Raveendran R, Tam AD, Quereshy FA, Chung F, et al. Neck circumference as a predictor of difficult intubation and difficult mask ventilation in morbidly obese patients: A prospective observational study. Eur J Anaesthesiol. 2016 Apr;33(4):244-9. doi: 10.1097/EJA.0000000000000324.

Butler PJ, Dhara SS. Prediction of difficult laryngoscopy: an assessment of the thyromental distance and Mallampati predictive tests. Anaesth Intensive Care. 1992 May;20(2):139-42. doi: 10.1177/0310057X9202000202.

Shailaja S, Nichelle SM, Shetty AK, Hegde BR. Comparing ease of intubation in obese and lean patients using intubation difficulty scale. Anesth Essays Res. 2014 May-Aug;8(2):168-74. doi: 10.4103/0259-1162.134493.

Özdilek A, Beyoglu CA, Erbabacan ŞE, Ekici B, Altındaş F, Vehid S, et al. Correlation of Neck Circumference with Difficult Mask Ventilation and Difficult Laryngoscopy in Morbidly Obese Patients: an Observational Study. Obes Surg. 2018 Sep;28(9):2860-7. doi: 10.1007/s11695-018-3263-3

Langeron O, Birenbaum A, Le Saché F, Raux M. Airway management in obese patient. Minerva Anestesiol. 2014 Mar;80(3):382-92.

Ezri T, Medalion B, Weisenberg M, Szmuk P, Warters RD, Charuzi I. Increased body mass index per se is not a predictor of difficult laryngoscopy. Can J Anaesth. 2003 Feb;50(2):179-83. doi: 10.1007/BF03017853.

Hora F, Nápolis LM, Daltro C, Kodaira SK, Tufik S, Togeiro SM, Nery LE. Clinical, anthropometric and upper airway anatomic characteristics of obese patients with obstructive sleep apnea syndrome. Respiration. 2007;74(5):517-24. doi: 10.1159/000097790.

Siyam MA, Benhamou D. Difficult endotracheal intubation in patients with sleep apnea syndrome. Anesth Analg. 2002 Oct;95(4):1098-102, table of contents. doi: 10.1097/00000539-200210000-00058.

Kim JA, Lee JJ. Preoperative predictors of difficult intubation in patients with obstructive sleep apnea syndrome. Can J Anaesth. 2006 Apr;53(4):393-7. doi: 10.1007/BF03022506. PMID: 16575040.

Raju Vegesna AR, Al-Anee KN, Bashah MMM, Faraj JH. Airway management in bariatric surgery patients, our experience in Qatar: A prospective observational cohort study. Qatar Med J. 2020 Mar 2;2020(1):2. doi: 10.5339/qmj.2020.2

Ünal Kantekin Ç, Erkoç M, Talih G. The measurement of skin to epiglottis length for difficult airway prediction by ultrasonography in obese pregnant women: Prospective cohort study. Journal of Surgery and Medicine. 2019; 3(10): 759-762.

Bray GA, Heisel WE, Afshin A, Jensen MD, Dietz WH, Long M, et al. The Science of Obesity Management: An Endocrine Society Scientific Statement. Endocr Rev. 2018 Apr 1;39(2):79-132. doi: 10.1210/er.2017-00253.

Shearer ES. Obesity anaesthesia: the dangers of being an apple. Br J Anaesth. 2013 Feb;110(2):172-4. doi: 10.1093/bja/aes471.

Coe AJ, Saleh T, Samuel T, Edwards R. The management of patients with morbid obesity in the anaesthetic assessment clinic. Anaesthesia. 2004 Jun;59(6):570-3. doi: 10.1111/j.1365-2044.2004.03733.x.

Kurt AK. Birinci Basamakta Obezite Yönetimi. Aile Hekimliği. 2019;11(2):55-60.






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Çelik G, Zengin S, Orhon Ergün M, Umuroğlu T. Correlation between neck circumference measurement and obesity type with difficult intubation in obese patients undergoing elective surgery. J Surg Med [Internet]. 2021 Sep. 1 [cited 2024 Jun. 13];5(9):912-6. Available from: