Brazilian Journal of Anesthesiology
Brazilian Journal of Anesthesiology
Original Investigation

A prospective validation and comparison of three multivariate models for prediction of difficult intubation in adult patients

Uma validação prospectiva e comparação de três modelos multivariados para previsão de intubação difícil em pacientes adultos

Gustavo P. Bicalho; Roberto C. Bessa Jr.; Marcos G.C. Cruvinel; Fabiano S. Carneiro; Jayme C. Bueno; Carlos H.V. Castro

Downloads: 0
Views: 735


Several bedside clinical tests have been proposed to predict difficult tracheal intubation. Unfortunately, when used alone, these tests show less than ideal prediction performance. Some multivariate tests have been proposed considering that the combination of some criteria could lead to better prediction performance. The goal of our research was to compare three previously described multivariate models in a group of adult patients undergoing general anesthesia.

This study included 220 patients scheduled for elective surgery under general anesthesia. A standardized airway evaluation which included modified Mallampati class (MM), thyromental distance (TMD), mouth opening distance (MOD), head and neck movement (HNM), and jaw protrusion capacity was performed before anesthesia. Multivariate models described by El-Ganzouri et al., Naguib et al., and Langeron et al. were calculated using the airway data. After anesthesia induction, an anesthesiologist performed the laryngoscopic classification and tracheal intubation. The sensitivity, specificity, and receiver operating characteristic (ROC) curves of the models were calculated.

The overall incidence of difficult laryngoscopic view (DLV) was 12.7%. The area under curve (AUC) for the Langeron, Naguib, and El-Ganzouri models were 0.834, 0.805, and 0.752, respectively, (Langeron > El-Ganzouri, p = 0.004; Langeron = Naguib, p = 0.278; Naguib = El-Ganzouri, p = 0.101). The sensitivities were 85.7%, 67.9%, and 35.7% for the Langeron, Naguib, and El-Ganzouri models, respectively.

The Langeron model had higher overall prediction performance than that of the El-Ganzouri model. Additionally, the Langeron score had higher sensitivity than the Naguib and El-Ganzouri scores, and therefore yielded a lower incidence of false negatives.


Airway management;  Anesthesiology;  Intubation;  Laryngoscopy;  Predictive value of tests



Vários testes clínicos à beira do leito foram propostos para prever intubação traqueal difícil. Infelizmente, quando usados sozinhos, esses testes mostram um desempenho de previsão abaixo do ideal. Alguns testes multivariados foram propostos considerando que a combinação de alguns critérios poderia levar a um melhor desempenho de predição. O objetivo de nossa pesquisa foi comparar três modelos multivariados previamente descritos em um grupo de pacientes adultos submetidos à anestesia geral.


Este estudo incluiu 220 pacientes agendados para cirurgia eletiva sob anestesia geral. Uma avaliação padronizada das vias aéreas que incluiu classe de Mallampati modificada (MM), distância tireomentoniana (DTM), distância de abertura bucal (DAB), movimento de cabeça e pescoço (MCP) e capacidade de protrusão da mandíbula foi realizada antes da anestesia. Modelos multivariados descritos por El-Ganzouri et al., Naguib et al. e Langeron et al. foram calculados usando os dados das vias aéreas. Após a indução anestésica, um anestesiologista realizou a classificação laringoscópica e a intubação traqueal. As curvas de sensibilidade, especificidade e curvas ROC dos modelos foram calculadas.


A incidência global de visão laringoscópica difícil (VLD) foi de 12,7%. A área sob a curva (AUC) para os modelos de Langeron, Naguib e El-Ganzouri foram 0,834, 0,805 e 0,752, respectivamente, (Langeron>El-Ganzouri, p=0,004; Langeron=Naguib, p=0,278; Naguib=El-Ganzouri, p=0,101). As sensibilidades foram de 85,7%, 67,9% e 35,7% para os modelos de Langeron, Naguib e El-Ganzouri, respectivamente.


O modelo de Langeron teve desempenho geral de predição superior ao do modelo de El-Ganzouri. Além disso, o escore de Langeron apresentou maior sensibilidade do que os escores de Naguib e El-Ganzouri e, portanto, apresentou menor incidência de falsos negativos.


Manejo de vias aéreas; Anestesiologia; Intubação; Laringoscopia; Valor preditivo dos testes


1 FE Kelly, TM Cook Seeing is believing: getting the best out of videolaryngoscopy Br J Anaesth, 117 Suppl 1 (2016), pp. i9-i13

2 T.M. Cook, N. Woodall, C. Frerk, F.N.A. Project Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia Br J Anaesth, 106 (2011), pp. 617-631

3 C. Frerk, V.S. Mitchell, A.F. McNarry, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults Br J Anaesth, 115 (2015), pp. 827-848

4 J.L. Apfelbaum, C.A. Hagberg, R.A. Caplan, et al. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway Anesthesiology, 118 (2013), pp. 251-270

5 S.R. Mallampati, S.P. Gatt, L.D. Gugino, et al. A clinical sign to predict difficult tracheal intubation: a prospective study Can Anaesth Soc J, 32 (1985), pp. 429-434

6 B. Krobbuaban, S. Diregpoke, S. Kumkeaw, et al. The predictive value of the height ratio and thyromental distance: four predictive tests for difficult laryngoscopy Anesth Analg, 101 (2005), pp. 1542-1545

7 W.H. Kim, H.J. Ahn, C.J. Lee, et al. Neck circumference to thyromental distance ratio: a new predictor of difficult intubation in obese patients Br J Anaesth, 106 (May) (2011), pp. 743-748

8 GL Samsoon, JR Young Difficult tracheal intubation: a retrospective study Anaesthesia, 42 (1987), pp. 487-490

9 T. Shiga, Z. Wajima, T. Inoue, et al. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance Anesthesiology, 103 (2005), pp. 429-437

10 D. Roth, N.L. Pace, A. Lee, et al. Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review Anaesthesia, 74 (2019), pp. 915-928

11 A.R. el-Ganzouri, R.J. McCarthy, K.J. Tuman, et al. Preoperative airway assessment: predictive value of a multivariate risk index Anesth Analg, 82 (1996), pp. 1197-1204

12 M. Naguib, F.L. Scamman, C. O’Sullivan, et al. Predictive performance of three multivariate difficult tracheal intubation models: a double-blind, case-controlled study Anesth Analg, 102 (2006), pp. 818-824

13 O. Langeron, P. Cuvillon, C. Ibanez-Esteve, et al. Prediction of difficult tracheal intubation: time for a paradigm change Anesthesiology, 117 (2012), pp. 1223-1233

14 R.S. Cormack, J. Lehane Difficult tracheal intubation in obstetrics Anaesthesia, 39 (1984), pp. 1105-1111

15 E.R. DeLong, D.M. DeLong, DL Clarke-Pearson Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach Biometrics, 44 (1988), pp. 837-845

16 T. Asai, S. Matsumoto, K. Fujise, et al. Comparison of two Macintosh laryngoscope blades in 300 patients Br J Anaesth, 90 (2003), pp. 457-460

17 J. Huh, H.Y. Shin, S.H. Kim, et al. Diagnostic predictor of difficult laryngoscopy: the hyomental distance ratio Anesth Analg, 108 (2009), pp. 544-548

18 S. Kheterpal, D. Healy, M.F. Aziz, et al. Incidence, predictors, and outcome of difficult mask ventilation combined with difficult laryngoscopy: a report from the multicenter perioperative outcomes group Anesthesiology, 119 (2013), pp. 1360-1369

19 SM Yentis Predicting difficult intubation—worthwhile exercise or pointless ritual? Anaesthesia, 57 (2002), pp. 105-109

20 P. Cortellazzi, L. Minati, C. Falcone, et al. Predictive value of the El-Ganzouri multivariate risk index for difficult tracheal intubation: a comparison of Glidescope videolaryngoscopy and conventional Macintosh laryngoscopy Br J Anaesth, 99 (2007), pp. 906-911

Submitted date:

Accepted date:

611fea5ea9539572d05914d3 rba Articles
Links & Downloads

Braz J Anesthesiol

Share this page
Page Sections