Videolaryngoscopic Intubation and Difficult Airway Classification (VIDIAC) accuracy in the prediction of first-pass nasal intubation using a video laryngoscope.

BACKGROUND: The Cormack-Lehane (CL) classification and the percentage of glottic opening (POGO) score are used for glottic views during direct laryngoscopy; however, no standard scoring exists for video-laryngoscopy. The Video Laryngoscopic Intubation and Difficult Airway Classification (VIDIAC) model was recently proposed to grade glottic views during video-laryngoscopy. This study aimed to evaluate the diagnostic accuracy of the VIDIAC score in predicting first-pass nasal intubation success using the Touren video laryngoscope in patients undergoing head and neck surgery.

METHODS: After ethical approval and clinical trial registration, patients aged 18-65 years, planned for surgery under general anesthesia with nasal intubation, were recruited. Patient with a mouth opening ≤2.5 cm, planned for awake intubation, emergency procedure or rapid sequence induction was excluded. Nasal intubation was done using an appropriate size flexible endotracheal tube using Touren VL. VIDIAC scoring was done on the best view of the glottis in a single attempt, without using an external laryngeal maneuver (ELM). Use of ELM, Magill forceps and any airway-related adverse events were noted.

RESULTS: A total of 131 participants completed the study. 121 (92.4%) patients had successful first-pass nasal intubation. For first-pass nasal intubation, the sensitivity, specificity, positive predictive values and negative predictive values of the VIDIAC score were 92.6%, 70%, 97.5%, and 43.8%, respectively. The VIDIAC score demonstrated an area under the Receiver Operating Characteristic curve of 0.876 (95% CI: 0.728-1.000).

CONCLUSIONS: With high sensitivity and positive predictive value, the VIDIAC score shows potential in predicting successful first-pass nasal intubation; however, low specificity and negative predictive value limit its overall clinical utility.