Laryngeal exposure during laryngoscopy is better in the 25° back-up position than in the supine position

Background. Good visualization of the glottis is important for tracheal intubation. This study evaluated whether the 25 degrees back-up position improves the quality of the laryngeal view during laryngoscopy. Methods. Laryngoscopy with a curved blade was performed on 40 anaesthetized patients. The patients were randomly assigned to two groups. Laryngeal views were captured with a rigid 0 degrees endoscope. Views were recorded for each patient in Group A (n=20) during laryngoscopies performed with the patient lying first in the supine position and then in the 25 degrees back-up position. Laryngeal views for patients in Group B (n=20) were first captured while the patient was in the 25 degrees back-up position and then while the patient was in the flat supine position. An anaesthetist blinded to the position graded the quality of the images using the percentage of glottic opening (POGO) score. Results. Comparing the two positions, mean (SD) POGO scores increased significantly from 42.2 (27.4)% in supine position to 66.8 (27.6)% in 25 degrees back-up position (P < 0.0001). Conclusions. During laryngoscopy, the laryngeal view, as assessed by POGO scores, improves significantly in the 25 degrees back-up position when compared with the flat supine position.