Recently, a new bedside screening test to predict the occurrence of a difficult laryngoscopy has been developed as a substitute for the Mallampati classification. The Upper-Lip-Bite test (ULBT) evaluated the patient’s ability to reach or completely cover the upper lip with the lower incisors. It is often accepted that new predictive tools should undergo an external evaluation before the tool is used in clinical practice. Thus, we evaluated this test with respect to applicability, interobserver reliability, and discriminating power and compared it with the Mallampati-score (using Samsoon and Young’s modification). The ULBT could not be applied in 12% of all patients (Mallampati score, <1%). However, the interobserver reliability was better for the ULBT (κ = 0.79 versus κ = 0.59). The discriminating power to predict a patient with difficult laryngoscopy was evaluated in 1425 consecutive patients. Both tests were assessed simultaneously in these patients by two specially trained independent observers. After the induction of anesthesia, the laryngoscopic view was assessed by the attending anesthesiologist using the classification of Cormack and Lehane. A grade I or II was called easy laryngoscopy and grade III and IV difficult laryngoscopy. The discriminating power for both tests was low (0.60 for the ULBT [95% confidence interval, 0.57–0.63] and 0.66 [0.63–0.69]) for the Mallampati score), indicating that both tests are poor predictors as single screening tests.
IMPLICATIONS: The Upper-Lip-Bite test (ULBT) is a bedside screening test to detect difficult laryngoscopy, which was evaluated and compared with the Mallampati score in 1425 patients. The ULBT did not sufficiently discriminate between patients presenting with easy and difficult laryngoscopy and was less sensitive than the Mallampati score.
Department of Anesthesiology and Critical Care Medicine, Philipps-University Marburg, Germany
Accepted for publication December 13, 2004.
Address correspondence and reprint requests to Leopold Eberhart, Department of Anesthesiology and Critical Care Medicine, Philipps-University Marburg, Baldingerstrasse 1, 35043 Marburg, Germany. Address e-mail to email@example.com.