The evaluation of maximum condyle-tragus distance can predict difficult airway management without exposing upper respiratory tract; a prospective observational study

Abstract Background Routine preoperative methods to assess airway such as the interincisor distance (IID), Mallampati classification, and upper lip bite test (ULBT) have a certain risk of respiratory tract exposure virus spread. Condyle-tragus maximal distance(C-TMD) can be used airway, does not require patient expose tract, but its value in predicting difficult laryngoscopy compared other indicators (Mallampati IID, ULBT) remains unknown. The purpose this study was observe C-TMD predict influence on intubation time attempts, provide new idea for assessment during epidemic. Methods Adult patients undergoing general anesthesia tracheal were enrolled. ULBT, each evaluated before initiation anesthesia. primary outcome time. secondary outcomes defined Cormack-Lehane Level > grade 2 number attempts. Results Three hundred four successfully enrolled completed study, 39 identified laryngoscopy. shorter with C-TMD>1 finger group 46.8 ± 7.3 s, C-TMD<1 50.8 8.6 s ( p <0.01). First attempt success rate higher 98.9% than 87.1% P correlation between 0.317 (Spearman coefficient, <0.001), area under ROC curve 0.699 < 1 width most consistent (? = 0.485;95%CI:0.286–0.612) OR 10.09 (95%CI: 4.19–24.28), sensitivity 0.469 0.325–0.617), specificity 0.929 0.877–0.964), positive predictive 0.676 0.484–0.745), negative 0.847 0.825–0.865). Conclusion Compared classification has tract. Trial registration registered October 21, 2019 Chinese Clinical Registry ChiCTR1900026775 ).