Title: Comparison of Difficult Intubation and Neck Circumference to Thyromental Distance Ratio, in Obese and Non-Obese: A Clinical Study
Authors: Nadia Rose, Dr Maya G, Dr Anil Sathyadas
DOI: https://dx.doi.org/10.18535/jmscr/v5i3.212
Abstract
Background: This study was conducted to assess whether intubation is more difficult in obese patients compared to non-obese and to assess the ability of ratio of the neck circumference to thyromental distance (NC/TM), to predict difficult intubation in obese patients.
Methods: This study is a cross sectional study. After obtaining institutional approval, consenting patients were enrolled in this study. The incidence of difficult tracheal intubation in 166 obese (BMI≥25 kg/ m2) and 166 non-obese patients was compared. Difficult intubation was determined using the Intubation Difficulty Scale (IDS≥5).Airway assessment indices were evaluated for their relation to IDS. NC/TM was calculated and its ability to predict difficult intubation in obese patients as well as non obese patients was assessed.
Results: Difficult intubation was more frequent in obese patients than in non-obese patients (14.5% vs 7.2 %;P =0.031). NC/TM at a cut-off ≥ 4.99 showed the high sensitivity, specificity and a positive likelihood ratio, and large area under the curve on ROC curve in the obese.
Conclusion: Difficult intubation defined by IDS were common in obese patients compared to non-obese. Neck circumference to thyromental distance ratio ≥ 4.99 yielded a very high sensitivity, specificity and positive likelihood ratio in the obese group. Therefore, it may be used as a screening test for predicting difficult intubation in the obese.
Keywords: airway management; obesity; risk assessment; tracheal intubation.
References
1. Shiga T,Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in appar-ently normal patients. Anesthesiology 2005 Aug;103(2):429-37.
2. Samsoon GL, Young JR. Difficult tracheal intubation: A retrospective study. Anaesthesia 1987 May;42(5):487-90
3. Wilson ME, Spiegelhalter D, Robertson JA, Lesser P. Predicting difficult intubation. Br J Anaesth 1988 Aug;61 (2): 211-6
4. Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, et al. Prediction of difficult mask ventilation. Anesthesiology 2000 May;92(5):1229-36
5. Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia1984 Nov;39(11):1105-11
6. Smita Prakash, Amitabh Kumar, Shyam Bhandari, ParulMullick, Rajvir Singh,1 and Anoop Raj Gogia. Difficult larynges-copy and intubation in the Indian population: An assessment of anatomical and clinical risk factors. Indian J Anaesth. 2013 Nov-Dec; 57(6): 569–575.
7. Adnet F, Borron SW, Racine SX, Clemessy JL, Fournier JL, PlaisanceP, et al. The Intubation Difficulty Scale (IDS): Proposal and evaluation of a new score characterizing the complexity of endotracheal intubation. Anesthesiology 1997 Dec;87(6):1290-7
8. W. H. Kim1, H. J. Ahn1, C. J. Lee1, B. S. Shin1, J. S. Ko1, S. J. Choi1 and S. A. Ryu. Neck circumference to thyromental distance ratio: a new predictor of difficult intubation in obese patients Br. J. Anaesth. 2011; May;106(5):743-8
9. WHO/IASO/ITO. Asia Pacific Perspective: Redefining obesity and its treatment World Health Organization, Western Pacific Region;2000
10. Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia.Lancet1961;2: 404– 618.
11. Finucane, Brendan T., Tsui, Ban C.H., Santora, Albert. Principles of Airway Management, 4th ed. 2011, Evaluation of the airway
12. Lee A, Fan LT, Gin T, Karmakar MK, NganKee WD. A systemicreview (meta-analysis) of the accuracy of the Mallam patitests to predict the difficult airway. Anesth Analg2006;102: 1867– 78
13. Juvin P1, Lavaut E, Dupont H, Lefevre P, Demetriou M, Dumoulin JL, Desmonts JM. Difficult tracheal intubation is more common in obese than in lean patients. Anaesthesia analogue 2003; 97:595–600
14. Ezri T, Gewürtz G, Sessler DI, Medalion B, Szmuk P, Hagberg C, Susmallian S. Prediction of Difficult Laryngoscopy in Obese Patients by Ultrasound Quantifi-cation of Anterior Neck Soft Tissue. Anae-sthesia 2003 Nov; 58(11): 1111–1114.
15. Lundstrøm LH1, 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 regist-ered in the Danish Anaesthesia Database.
16. Gonzalez, Hélène MD; Minville, Vincent MD, MSc; Delanoue, Khedija MD; Mazerolles, Michel MD; Concina, Dominique MD; Fourcade, Olivier MD, PhD.The Importance of Increased Neck Circumference to Intubation Difficulties in Obese Patients. Anesthesia & Analgesia: April 2008 - 106 - Issue 4
17. R.L. Horner, R.H. Mohiaddin, D.G. Lowell, S.A. Shea, E.D. Burman, D.B. longmore, A. Guz Sites and sizes of fat deposits around the pharynx in obese patients with obstructive sleep apnoea and weight matched controls EurResp J, 1989: 613–622
18. Brodsky JB1, Lemmens HJ, Brock-Utne JG, Vierra M, SaidmanLJ.: Morbid obesity and tracheal intubation. Anaest-hesia analogue 2002 Mar;94(3):732-6
19. A.S.Hiremath, D.R.Hillman, A.l.James, W.J. Noffsinger,P.R.Platt. Relation betw-een difficult tracheal intubation and obst-ructive sleep apnea. BJA 1998;80:606-611
20. L. H. Lundstrøm, M. Vester-Andersen1, A. M. Møller1, S. Charuluxananan3, J. L’Hermite4 and J. Wetterslev. Poor prognostic value of the modified Mallampati score: a meta-analysis involving 177 088 patients .The Danish Anaesthesia Database
21. G. Iohom a1c1, M. Ronayne a1 and A. J. Cunningham a1: European Journal of Anaesthesiology January 2003
22. Rose DK, Cohen MM. The airway: problems and predictions in 18,500 patients. Can J Anaesth 1994; 41:372-83.
23. Hyoung-Yong Moon, Chong WhaBaek, Jin-Seo Kim, Gill Hoi Koo, Jin-Yun Kim et al. The causes of difficult trac-heal intubation and preoperative assess-ments in different age groups. Korean J Anesthesiol 2013 April 64(4): 308-314
24. Dr. Sunanda Gupta1 Dr. Rajesh Sharma KR2 Dr. DimpelJain :Airway Assessment : Predictors of difficult airway. Indian J. Anaesth. 2005: 49(4): 257-262. 5
25. McGill IW. Technique in endotracheal anaesthesia. Br Med J 1930; 2:817.
26. Schmitt HJ, Kirmse M, Radespiel-Troger M; Ratio of patient’s height to thyromental distance improves prediction of difficult laryngoscopy. Anaesthesia and Intensive Care 2002; 30: 763–5.
27. P. A. Baker, A. Depuydt and J. M. D. Thompson Thyromental distance measurement – fingers don’t rule .Anaesthesia Volume 64 August 2009 , Issue 8, pages 878–882
28. Türkan, Selma MD,;Ateş, Yeşim MD,; Cuhruk, Handan MD,; Tekdemir, İbrahimMD.Should We Reevaluate the Variables for Predicting the Difficult Airway in Anesthesiology?. Anesthesia & Analgesia: May 2002 - Volume 94 - Issue 5 :1340-1344.
29. S. Shailaja, S. M. Nichelle, A. Kishan Shetty, and B. Radhesh Hegde .Comparing ease of intubation in obese and lean patients using intubation difficulty scale Anesth Essays Res. 2014 May-Aug; 8(2): 168–174.