BACKGROUND: Preoperative airway assessment tests have been presented to help in anticipating a difficult airway. We conducted this study to compare five methods in prediction of difficult laryngoscopy: Neck circumference (NC), NC to thyromental distance ratio (NC/ @entity9321 ), the @entity5529 ( @entity5529 ), upper lip bite test (ULBT) and Mallampati test (MMT). These five methods are the most commonly used ones and have different powers for it. It was not clear which of these methods predicts difficult laryngoscopy better. MATERIALS AND METHODS: Six hundred consecutive @entity1 participated in this study. NC, NC/ @entity9321 and @entity5529 were measured, and ULBT and MMT were performed and recorded. The laryngoscopy view was graded according to @entity2653 ( @entity2653 ) and difficult laryngoscopy was defined as @entity2653 grades 3 and 4. Accuracy of tests in predicting difficult laryngoscopy was assessed using the area under a receiver-operating characteristic curve. RESULTS: The area under the curve in ULBT and @entity5529 were significantly larger than that in @entity9321 , NC and MMT. No statistically significant differences were noted between @entity9321 , NC and MMT (all P > 0.05) (ULBT = @entity5529 > NC/ @entity9321 > @entity9321 = NC = MMT). @entity5529 (>22.7 cm) exhibited the highest sensitivity (sensitivity = 64.77, 95% confidence interval [CI]: 53.9-74.7) and the most specific test was ULBT (specificity = 99.41%, 95% CI: 98.3-99.9). CONCLUSION: @entity5529 and ULBT as simple preoperative bedside tests have a higher level of accuracy compared to NC/ @entity9321 , @entity9321 , NC, MMT in predicting a difficult airway.

Comparison of five methods in predicting difficult laryngoscopy: Neck circumference, neck circumference to thyromental distance ratio, the XXXX , upper lip bite test and Mallampati test.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity9321 :: ('MESH:D049310', 'Disease') :: ['TMD'] @entity2653 :: ('MESH:C538175', 'Disease') :: ['CLS', "Cormack and Lehane's scale"] @entity5529 :: ('MESH:C535290', 'Disease') :: ['ratio of height to thyromental distance', 'RHTMD']
@entity5529 :: (MESH:C535290,Disease) :: ['ratio of height to thyromental distance']
