ABSTRACT
Objective: To evaluate the clinical value of Truview™ EVO2 optic laryngoscope by comparing it with the Macintosh laryngoscope in patients receiving cervical vertebral surgery. Methods: One hundred patients scheduled for elective cervical vertebral surgery were enrolled in this randomized crossover study. After induction, the patients' glottis in group A (n=50) was displayed by Macintosh laryngoscope and the Cormack-Lehane (C/L) grade was recorded, and then optic laryngoscope was employed to display the laryngeal structure. The order of laryngoscopy attempts was reversed in group B (n=50). Parameters recorded included demographics,airway assessment features (BMI, thyromental distance, mandibular size, mouth opening, mallampati oropharyngeal scale,and neck movement), C/L grade, laryngoscopic force applied, duration of intubation, difficulties of laryngeal view and injury of upper airway. Results: There were no significant difference in demographics, airway assessment features,C/L grade and duration of intubation between the 2 groups,whereas the laryngoscopic force in group A was significantly lower than that in group B (P < 0.05). The C/L grade obtained with optic laryngoscope was 69:26:5 (I:II:III),which was significantly better than that with Macintosh laryngoscope (26:46:28,P<0.001). A poor laryngeal view of 5% was obtained with optic laryngoscope,which was significantly better than that with Macintosh laryngoscope (28%, P<0.001). There was significant association between airway assessment features and C/L grade or laryngoscopic force (P<0.05). Conclusion: The Truview™ EVO2 optic laryngoscope has better glottic view and lighter laryngoscopic force than those of Macintosh laryngoscope,and may have potential advantages for managing the difficult airways for cervical vertebral surgery.