A Comparison Between Measured Maxillopharyngeal Angle On Lateral Cervical Radiograph with Modified Mallampati Classification In Predicting Difficult Larnygoscopy: A Blinded Interventional Study

ABSTRACT

@#Background: Existing techniques of predicting difficult laryngoscopy are inadequate requiring evaluation of Maxillopharyngeal Angle (MP-A) on lateral cervical radiograph described. Objectives: This study aimed to compare MP-A test with Modified Mallapati Test (MMT) in predicting their diagnostic values and Area Under Curve of Receiver Operating Characteristic Curve (AUCROCC) of both test. Methods: This is a double blinded interventional study of 93 patients. Each patient’s MMT score was assessed during preoperative assessment and subsequent MP-A test done by obtaining lateral cervical radiograph with the head in neutral position. Laryngeal view was assessed using Cormack-Lehane grade after induction of anesthesia, was used as reference standard to determine the diagnostic values of MMT and MP-A respectively. Results: The MP-Acompared to MMT in predicting difficult larngoscopy had higher sensitivity (77.78 vs 44.44) specificity (88.10 vs 67.86) and accuracy (87.10 vs 65.59) with higher Odd Ratio(26.12 vs 1.68). The AUCROCC was significantly higher in MP-A test 0.83(95%CI 0.67, 0.99) (P = 0.001) vs MMT 0.56(95%CI 0.36, 0.76) (P = 0.546) with LR+ of 6.53 vs 1.38. Conclusion: The Maxillopharyngeal Angle test was superior in predicting difficult laryngoscopy as compared to Modified Mallampati Test.difficult intubation