[1. Ramachandran SK, Allan Klock P. Definition and incidence of the difficult airway. In: Hagberg CA (ed). Benumof and Hagberg’s Airway Management. 3rd ed. Philadelphia: Elsevier Saunders; 2013: 201-20810.1016/B978-1-4377-2764-7.00008-7]Search in Google Scholar
[2. Brodsky JB, Lemmens HJ, Brock-Utne JG, Vierra M, Saidman LJ. Morbid obesity and tracheal intubation. Anesth Analg 2002; 94: 732-736. doi: 10.1097/00000539-200203000-00047]Search in Google Scholar
[3. Adnet F, Borron SW, Racine SX, Clemessy JL, Fournier JL, Plaisance P, et al. The intubation difficulty scale (IDS): proposal and evaluation of a new score characterizing the complexity of endotracheal intubation. Anesthesiology 1997; 87: 1290-129710.1097/00000542-199712000-00005]Search in Google Scholar
[4. Dohrn N, Sommer T, Bisgaard J, Rønholm E, Larsen JF. Difficult tracheal intubation in obese gastric bypass patients. Obes Surg 2016; 26: 2640-2647. doi: 10.1007/s11695-016-2141-0]Search in Google Scholar
[5. De Baerdemaeker LEC, Van Limmen JGM, Van Nieuwenhove Y. How should obesity be measured and how should anesthetic drug dosage be calculated?. In: Leykin Y, Brodsky JB (eds.). Controversies in the anesthetic management of the obese surgical patient. 2013. Milan: Springer Verlag; 2013: 15-30. doi: 10.1007/978-88-470-2634-6_2]Search in Google Scholar
[6. Lundstrřm 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; 110: 266-274. doi: 10.1097/ALN.0b013e318194cac8]Search in Google Scholar
[7. Hagberg CA, Vogt-Harenkamp C, Kamal J. A retrospective analysis of airway management in obese patients at a teaching institution. J Clin Anesth 2009; 21: 348-351. doi: 10.1016/j.jclinane.2008.09.009]Search in Google Scholar
[8. Sheff SR, May MC, Carlisle SE, Kallies KJ, Mathiason MA, Kothari SN. Predictors of a difficult intubation in the bariatric patient: does preoperative body mass index matter? Surg Obes Relat Dis 2013; 9: 344-349. doi: 10.1016/j.soard.2012.02.004]Search in Google Scholar
[9. Holmberg TJ, Bowman SM, Warner KJ, Vavilala MS, Bulger EM, Copass MK, et al. The association between obesity and difficult prehospital tracheal intubation. Anesth Analg 2011;112: 1132-1138. doi: 10.1213/ANE.0b013e31820effcc]Search in Google Scholar
[10. De Jong A, Molinari N, Pouzeratte Y, Verzilli D, Chanques G, Jung B, et al. Dif?cult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units. Br J Anaesth 2015; 114: 297-306. doi: 10.1093/bja/aeu373]Search in Google Scholar
[11. Ezri T, Gewürtz G, Sessler DI, Medalion B, Szmuk P, Hagberg C, et al. Prediction of difficult laryngoscopy in obese patients by ultrasound quantification of anterior neck soft tissue. Anaesthesia 2003; 58: 1111-1114. doi: 10.1046/j.1365-2044.2003.03412.x]Search in Google Scholar
[12. 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; 50: 179-183. doi: 10.1007/BF03017853]Search in Google Scholar
[13. 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; 106: 743-748. doi: 10.1093/bja/aer024]Search in Google Scholar
[14. 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; 106: 1132-1136. doi: 10.1213/ane.0b013e3181679659]Search in Google Scholar
[15. 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; 97: 595-600. doi: 10.1213/01.ANE.0000072547.75928.B0]Search in Google Scholar
[16. Voyagis GS, Kyriakis KP, Dimitriou V, Vrettou I. Value of oropharyngeal Mallampati classification in predicting difficult laryngoscopy among obese patients. Eur J Anaesthesiol 1998;15: 330-334. doi:10.1046/j.1365-2346.1998.00301.x]Search in Google Scholar
[17. 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; 109: 1182-1186. doi:0 10.1213/ane.0b013e3181b12a0c]Search in Google Scholar
[18. Ezri T, Warters RD, Szmuk P, Saad-Eddin H, Geva D, Katz J, et al. The incidence of class “zero” airway and the impact of Mallampati score, age, sex, and body mass index on prediction of laryngoscopy grade. Anesth Analg 2001; 93: 1073-1075. doi: 10.1097/00000539-200110000-00055]Search in Google Scholar
[19. Marrel J, Blanc C, Frascarolo P, Magnusson L. Videolaryngoscopy improves intubation condition in morbidly obese patients. Eur J Anaesthesiol 2007; 24: 1045-1049. doi: 10.1017/ S0265021507000889]Search in Google Scholar
[20. Bathory I, Granges JC, Frascarolo P, Magnusson L. Evaluation of the Video Intubation Unit in morbid obese patients. Acta Anaesthesiol Scand 2010; 54: 55-58. doi: 10.1111/j.1399-6576.2009.02119.x]Search in Google Scholar
[21. Aziz MF, Brambrink AM, Healy DW, Willett AW, Shanks A, Tremper T, et al. Success of Intubation Rescue Techniques after Failed Direct Laryngoscopy in Adults: A Retrospective Comparative Analysis from the Multicenter Perioperative Outcomes Group. Anesthesiology 2016; 125: 656-666. doi: 10.1097/ALN.0000000000001267]Search in Google Scholar
[22. Asai T. Avoiding repeated attempts at tracheal intubation. Can videolaryngoscopes be the answer? Anesthesiology 2016; 125: 615-617. doi: 10.1097/ALN.0000000000001268]Search in Google Scholar
[23. Fox WTA, Harris S, Kennedy NJ. Prevalence of difficult intubation in a bariatric population, using the beach chair position. Anaesthesia 2008; 63: 1339-1342. doi: 10.1111/j.1365-2044.2008.05639.x]Search in Google Scholar
[24. Rao SL, Kunselman AR, Schuler HG, DesHarnais S. Laryngoscopy and tracheal intubation in the head-elevated position in obese patients: a randomized, controlled, equivalence trial. Anesth Analg 2008; 107: 1912-1918. doi: 10.1213/ane.0b013e31818556ed]Search in Google Scholar