Advanced Biomedical Research

The predictive value of the ratio of neck circumference to thyromental distance in comparison with four predictive tests for difficult laryngoscopy in obstetric patients scheduled for caesarean delivery

Authors

Department of Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Preoperative assessment of anatomical landmarks andclinical factors help detect potentially difficult laryngoscopies. The aim of the present study was to compare the ability to predict difficult visualization of the larynx from thefollowing preoperative airway predictive indices, in isolation and combination: Neck circumference to thyromental distance (NC/TMD), neck circumference (NC), modified Mallampatitest (MMT), the ratio of height to thyromental distance (RHTMD), and the upper-lip-bite test (ULBT).
Materials and Methods: We collected data on657 consecutive patients scheduled for elective caesarean delivery under general anesthesia requiring endotracheal intubation and then evaluated all five factors before caesarean. An experienced anesthesiologist, not informed of the recorded preoperative airway evaluation, performed the laryngoscopy and grading (as per Cormack and Lehane's classification). Sensitivity, specificity, and positive and negative predictive values for each airway predictor in isolation and in combination were determined.
Results: Difficult laryngoscopy (Grade 3 or 4) occurred in 53 (8.06%) patients. There were significant differences in thyromental distance (TMD), RHTMD, NC, and NC/TMD between difficult visualization of larynx and easy visualization of larynx patients (P < 0.05).The main end-point area under curve (AUC) of the receiver-operating characteristic (ROC) was lower for MMT (AUC = 0.497; 95% Confidence Interval = CI,0.045-0.536) and ULBT (AUC = 0.500, 95% CI, 0.461-0.539) compared to RHTMD, NC, TMD, and NC/TMD score ([AUC = 0.627, 95% CI, 0.589-0.664], [AUC = 0.691; 95% CI, 0.654-0.726], [AUC = 0.606; 95% CI, 0.567-0.643], [AUC = 0.689;95% CI, 0.625-0.724], respectively), and the differences of six ROC curves were statistically significant (P < 0.05).
Conclusion: The NC/TM Discomparable with NC, RHTMD, and ULBT for the prediction of difficult laryngoscopy in caes are an delivery.

Keywords

1. Hawkins JL, Koonin LM, Palmer SK, Gibbs CP. Anesthesia-related deaths during obstetric delivery in the United States, 1979-1990. Anesthesiology 1997;86:277-84.  Back to cited text no. 1
    
2. Palanisamy A, Mitni AA, Tsen LC. General anesthesia for cesarean delivery at a tertiary care hospital from 2000 to 2005: A retrospective analysis and 10-year update. Int J Obstet Anesth 2011;20:6-10.  Back to cited text no. 2
    
3. Randell T. Prediction of difficult intubation. Acta Anesthesiol Scand 1996;40:1016-23.  Back to cited text no. 3
    
4. Henderson JJ, Popat MT, Latto IP, Pearce AC, Difficult Airway Society. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia 2004;59:675-94.  Back to cited text no. 4
    
5. Merah NA, Foullkes-Crabbe DJ, Kushimo OT, Ajayi PA. Prediction of difficult laryngoscopy in a population of Nigerian obstetric patients. West Afr J Med 2004;23:38-41.  Back to cited text no. 5
    
6. Boutonnet M, Faitot V, Keita H. Airway management in obstetrics. Ann Fr Anesth Reanim 2011;30:651-64.  Back to cited text no. 6
    
7. Rao DP, Rao VA. Morbidly obese parturient: Challenges for the anaesthesiologist, including managing the difficult airway in obstetrics. What is new? Indian J Anaesth 2010;54:508-21.  Back to cited text no. 7
[PUBMED]  Medknow Journal  
8. Farcon EL, Kim MH, Marx GF. Changing Mallampati score during labour. Can J Anaesth 1994;41:50-1.  Back to cited text no. 8
    
9. Arné J, Descoins P, Fusciardi J, Ingrand P, Ferrier B, Boudigues D, et al. Preoperative assessment for difficult intubation in general and ENT surgery: Predictive value of a clinical multivariate risk index. Br J Anaesth 1998;80:140-6.  Back to cited text no. 9
    
10. Oates JD, Macleod AD, Oates PD, Pearsall FJ, Howie JC, Murray GD. Comparison of two methods for predicting difficult intubation. Br J Anaesth 1991;66:305-9.  Back to cited text no. 10
    
11. El-Ganzouri AR, McCarthy RJ, Tuman KL, Tanck EN, Ivankovich AD. Preoperative airway assessment: Predictive value of a multivariative risk index. Anesth Analg 1997;84:419-21.  Back to cited text no. 11
    
12. Naguib M, Scamman FL, O'Sullivan C, Aker J, Ross AF, Kosmach S, et al. Predictive performance of three multivariate difficult tracheal intubation models: A double-blind, case-controlled study. Anesth Analg 2006;102:818-24.  Back to cited text no. 12
    
13. Wilson ME, Spiegelhalter D, Robertson JA, Lesser P. Predicting difficult intubation. Br J Anaesth 1988;61:211-6.  Back to cited text no. 13
    
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;106:1132-6.  Back to cited text no. 14
    
15. Khan ZH, Kashfi A, Ebrahimkhani E. A comparison of the upper lip bite test (a simple new technique) with modified Mallampati classification in predicting difficulty in endotracheal intubation: A prospective blinded study. Anesth Analg 2003;96:595-9.  Back to cited text no. 15
    
16. Eberhart LH, Arndt C, Cierpka T, Schwanekamp J, Wulf H, Putzke C. The reliability and validity of the upper lip bite test compared with the Mallampati classification to predict difficult laryngoscopy: An external prospective evaluation. Anesth Analg 2005;101:284-9.  Back to cited text no. 16
    
17. 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;103:429-37.  Back to cited text no. 17
    
18. Türkan S, Ateº Y, Cuhruk H, Tekdemir I. Should we reevaluate the variables for predicting the difficult airway in anesthesiology? Anesth Analg 2002;94:1340-4.  Back to cited text no. 18
    
19. Salimi A, Farzanegan B, Rastegarpour A, Kolahi AA. Comparison of the upper lip bite test with measurement of thyromental distance for prediction of difficult intubations. Acta Anaesthesiol Taiwan 2008;46:61-5.  Back to cited text no. 19
    
20. Honarmand A, Safavi MR. Prediction of difficult laryngoscopy in obstetric patients scheduled for Caesarean delivery. Eur J Anaesthesiol 2008;25:714-20.  Back to cited text no. 20
    
21. Safavi M, Honarmand A, Zare N. A comparison of the ratio of patient's height to thyromental distance with the modified Mallampati and the upper lip bite test in predicting difficult laryngoscopy. Saudi J Anaesth 2011;5:258-63.  Back to cited text no. 21
[PUBMED]  Medknow Journal  
22. Samsoon GL, Young JR. Difficult tracheal intubation: A retrospective study. Anaesthesia 1987;42:487-90.  Back to cited text no. 22
    
23. Savva D. Prediction of difficult tracheal intubation. Br J Anaesth 1994;73:149-53.  Back to cited text no. 23
    
24. 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;106:743-8.  Back to cited text no. 24
    
25. Lewis M, Keramati S, Benumof JL, Berry CC. What is the best way to determine oropharyngeal classification and mandibular space length to predict difficult laryngoscopy? Anesthesiology 1994;81:69-75.  Back to cited text no. 25
    
26. Mallampati SR, Gatt SP, Gugino LD, Desai SP, Waraksa B, Freiberger D, et al. A clinical sign to predict difficult tracheal intubation: A prospective study. Can Anaesth Soc J 1985;32:429-34.  Back to cited text no. 26
    
27. Birnbach DJ, Browne IM. Anesthesia for obstetrics. In: Miller RD, editor. Textbook of Anesthesia. Philadelphia: Churchil Livingstone Co; 2010. p. 2221.  Back to cited text no. 27
    
28. Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia. Lancet 1961;2:404-6.  Back to cited text no. 28
    
29. Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia 1984;39:1105-11.  Back to cited text no. 29
    
30. Krage R, van Rijn C, van Groeningen D, Loer SA, Schwarte LA, Schober P. Cormack-Lehane classification revisited. Br J Anaesth 2010;105:220-7.  Back to cited text no. 30
    
31. Schniederjans MJ. Mathematical partitioning of the receiver operating curve: A diagnostic tool for medical decision making. Socioecon Plann Sci 1985;19:125-35.  Back to cited text no. 31
    
32. Hanley JA, McNeil BJ. The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 1982;143:29-36.  Back to cited text no. 32
    
33. Calder I. Useless ritual? Anaesthesia 2002;57:612.  Back to cited text no. 33
    
34. Brodsky JB, Lemmens HJ, Brock-Utne JG, Vierra M, Saidman LJ. Morbid obesity and tracheal intubation. Anesth Analg 2002;94:732-6.  Back to cited text no. 34
Advanced Biomedical Research
Volume 2014, september
September 2014
Pages 1-7