Addition of flexible laryngoscopy to anesthesiological parameters improves prediction of difficult intubation in laryngeal surgery.

Introduction: Among the numerous scores for difficult intubation assessment, there is no single score that is specific for laryngeal surgery. The parameters identified by this research will provide a foundation for developing a new score for preoperative airway assessment specific for laryngeal surgery.

Material and methods: This prospective pilot clinical study included 50 patients over 18 scheduled for microscopic laryngeal surgery. The following anesthesiological and surgical parameters were analyzed: flexible laryngoscopy, general and clinical data, inter-incisor gap (IIG), modified Mallampati score (MMP), S-lux, thyromental distance, sternomental distance, mandibular measurements, etc. Difficult intubation was defined according to the Intubation Difficulty Scale (IDS), and the patients were divided into difficult (DI) and normal (NI) intubation.

Results: According to the IDS scale, 17 (34%) intubations were characterized as difficult. Patients in the DI group were male ( P = 0.033) and had apnea during sleep ( P = 0.021). Other statistically significant parameters were IIG below 4 cm, reclination, neck girth, and MMP. Flexible laryngoscopy showed a high statistical significance of P = 0.0001. These parameters have an AUC of 0.955, with χ 2 = 43.268, P < 0.0001.

Conclusions: The combination of the statistically significant parameters shows excellent accuracy in laryngeal surgery. This combination can form a basis to develop a preoperative airway assessment score specific to laryngeal surgery.