Comparison and evaluation of various bedside tests to predict difficult endotracheal intubation.

ABSTRACT

Introduction: As difficult laryngoscopy is a multifactorial problem, therefore any preoperative assessment of difficult tracheal intubation should have high sensitivity and specificity and result in minimal false positive and false negative values. This study was conducted in an attempt to devise a method of predicting difficult intubation and to assess the reliability of six simple bedside tests to predict difficult intubation. Material and Methods: This double blind prospective study involved 100 adult patients posted for elective surgery under general anesthesia. The airways were assessed for modified Mallampati test, Thyromental Distance, Sternomental Distance, Inter incisor gap; Atlanto-Occipital joint extension and Upper Lip bite Test. The laryngoscopic view and difficulty of intubation were noted. The sensitivity, specificity, positive and negative predictive values were calculated. Results: No method either individual or in combination with others had 100% sensitivity. The Modified Mallampati test had 76% sensitivity. Upper Lip bite Test had 98.66% specificity. The combination of Modified Mallampati test and Inter incisor gap had 52% sensitivity and 86.66% specificity. Conclusion: The “composite intubation difficulty score” is an easy and reliable method of predicting difficult intubation.