INTEROBSERVER RELIABILITY OF 10 TESTS USED FOR PREDICTING DIFFICULT TRACHEAL INTUBATION

Purpose: To determine inter-observer reliability of ten preoperative a irway assessment tests used for predicting difficult tracheal intubati on. Method: We prospectively assessed 59 patients undergoing elective surgery requiring tracheal intubation at a large metropolitan teaching hospital. Two experienced observers independently conducted the airwa y assessment tests on the same group of patients. Inter-observer relia bility was examined using Kappa (K) and intraclass correlation coeffic ient (ICC). Results: Two tests - mouth opening (ICC = 0.93) and chin p rotrusion (ICC = 0.89) - had excellent inter-observer reliability. Sev en tests - thyromental distance (ICC = 0.74), subluxation (K = 0.66), atlanto-occipital extension distance (ICC = 0.67) and angle (K = 0.66) , profile classification (K = 0.58), ramus length (ICC = 0.53), oropha ryngeal best view (K = 0.49) - were moderately reliable. One test - Ma llampati technique of assessing oropharyngeal view (K = 0.31) - had po or reliability. Conclusion: Many of the preoperative airway tests have only moderate inter-observer reliability. This may provide some insig ht into why previous research has failed to show that the tests accura tely predict difficult tracheal intubation.