Details
Category: Volume 07 Issue 07 July 2019
Hits: 1191

Title: Diagnostic significance of Mallampatti grading of difficult airway for endotracheal intubation

Authors: Dr Lokendra Gupta, Dr Devyani Misra

 DOI: https://dx.doi.org/10.18535/jmscr/v7i7.87

Abstract

Objective: To evaluate the diagnostic significance of Mallampatti grading of difficult airway for endotracheal intubation.

Methods: This was a prospective blinded study conducted in 249 patients. The demographic data was collected from patient’s attendant. Patients were evaluated for Modified Mallampatti grading (MMG) before surgery. An experienced anesthesiologist, not aware of the recorded pre-operative airway evaluation, performed the laryngoscopy and grading as per Cormack and Lehane’s classification.

Results: Among study population, most of the patients were with Mallampatti grading 1 (47.4%). The prevalence of difficult airway for endotracheal intubation was 17.7%. For difficult intubation, the diagnostic value of Mallampatti grading was significant (AUC=0.63, p=0.006) but with low sensitivity 34.09% (95% CI=20.5-49.9) and high specificity 88.78% (95% CI=83.6-92.8). The positive likelihood ratio (+LR), negative likelihood ratio (-LR), positive predictive value (+PV) and negative predictive value (-PV) were found to be 3.04%, 0.74%, 39.5% and 86.3%, respectively.

Conclusion: The predictor test MMG for DI has only poor to moderate discriminative power when used alone. No test has 100% sensitivity, and inevitably some difficult tracheal intubations are missed and some false positives may occur, but they should be as few as possible. Even with the varying results of the commonly used airway assessment tests we still use them, and every anesthesiologist should be familiar with the difficult airway algorithm.

Keywords: Difficult airway, Endotracheal intubation, Diagnostic significance, Mallampatti grading.

References

  1. Ali MA, Qamar-ul-Hoda M, Samad K. Comparison of upper lip bite test with Mallampati test in the prediction of difficult intubation at a tertiary care hospital of Pakistan. J Pak Med Assoc 2012;62:1012-5. 
  2. Gupta S, Pareek S, Dulara SC. Comparison of two methods for predicting difficult intubation in obstetric patients. Middle East J Anesthesiol 2003;17:275-85.
  3. 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.
  4. Janssens M, Hartstein G. Management of difficult intubation. Eur J Anaesthesiol 2001;18:3–12.
  5. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients: A meta-analysis of bedside screening test performance. 2005;103:429–37.
  6. Yentis SM, Lee DJ. Evaluation of an improved scoring system for the grading of direct laryngoscopy. Anaesthesia 1998;53:1041-4.
  7. Samsoon GL, Young JR. Difficult tracheal intubation: A retrospective study. Anaesthesia 1987;42:487-90. 
  8. SrinivasanC, Kuppuswamy Comparison of validity of airway assessment tests for predicting difficult intubation. Indian Anaesth Forum 2017; 18: 63-8.
  9. Tse JC, Rimm EB, Hussain A. Predicting difficult endotracheal intubation in surgical patients scheduled for general anesthesia: A prospective blind study. Anesth Analg 1995;81:254-8
  10. Hester CE, Dietrich SA, White SW, Secrest JA, Lindgren KR, Smith T, et al. Acomparison of preoperative airway assessment techniques: The modified Mallampati and the upper lip bite test. AANA J 2007;75:177-82. 
  11. Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia 1984;39:1105-11.
  12. Koh LK, Kong CE, Ip-Yam PC. The modified Cormack-Lehane score for the grading of direct laryngoscopy: Evaluation in the Asian population. Anaesth Intensive Care 2002;30:48-51.
  13. Mallampati SR, Gatt SP, Gugino LD, Desai SP, Waraksa B, Freiberger D, et al. Aclinical sign to predict difficult tracheal intubation: A prospective study. Can Anaesth Soc J 1985;32:429-34.
  14. Khan ZH, Kashfi A, Ebrahimkhani B. 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.
  15. Savva D. Prediction of difficult tracheal intubation. Br J Anaesth 1994;73:149-53. 
  16. Patel B, Khandekar R, Diwan R, Shah A. Validation of modified mallampati test with addition of thyromental distance and sternomental distance to predict difficult endotracheal intubation in adults. Indian J Anaesth 2014;58:171-5. 
  17. Eberhart LH, Arndt C, Cierpka T, Schwanekamp J, Wulf H, Putzke C, et al. 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.
  18. Butler PJ, Dhara SS. Prediction of difficult laryngoscopy: An assessment of the thyromental distance and Mallampati predictive tests. Anaesth Intensive Care 1992;20:139-42.

Corresponding Author

Dr Lokendra Gupta

Senior Resident, Emergency Medicine, KGMU, Lucknow, UP, India