Radiological indicators to predict the application of assistant intubation techniques for patients undergoing cervical surgery

Abstract

Background We aimed to distinguish the preoperative radiological indicators to predict the application of assistant techniques during intubation for patients undergoing selective cervical surgery. Methods A total of 104 patients were enrolled in this study. According to whether intubation was successfully accomplished by simple Macintosh laryngoscopy, patients were divided into Macintosh laryngoscopy group (n = 78) and Assistant technique group (n = 26). We measured patients’ radiographical data via their preoperative X-ray and MRI images, and compared the differences between two groups. Binary logistic regression model was applied to distinguish the meaningful predictors. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to describe the discrimination ability of indicators. The highest Youden’s index corresponded to an optimal cut-off value. Results Ten variables exhibited significant statistical differences between two groups (P < 0.05). Based on logistic regression model, four further showed correlation with the application of assistant techniques, namely, perpendicular distance from hard palate to tip of upper incisor (X2), atlanto-occipital gap (X9), angle between a line passing through posterior-superior point of hard palate and the lowest point of the occipital bone and a line passing through the anterior-inferior point and the posterior-inferior point of the second cervical vertebral body (Angle E), and distance from skin to hyoid bone (MRI 7). Angle E owned the largest AUC (0.929), and its optimal cut-off value was 19.9° (sensitivity = 88.5%, specificity = 91.0%). the optimal cut-off value, sensitivity and specificity of other three variables were X2 (30.1 mm, 76.9, 76.9%), MRI7 (16.3 mm, 69.2, 87.2%), and X9 (7.3 mm, 73.1, 56.4%). Conclusions Four radiological variables possessed potential ability to predict the application of assistant intubation techniques. Anaesthesiologists are recommended to apply assistant techniques more positively once encountering the mentioned cut-off values.

Comparative analysis of popular predictors for difficult laryngoscopy using hybrid intelligent detection methods

“…Label-1 is associated with difficult laryngoscopy, and the result is consistent with previous study [ 4 ]. Label-2 is associated with occipito-atlanto complex and is related to mandibular protrusion [ 6 ]. The incidence of airway difficulties in patients with occipito-atlanto complex lesions was higher than that in patients with disease below the complex [ 48 ].…”

“…These three labels are: Label-1: Vertical gap between hyoid’s highest point to mandibulae [ 4 ]. Label-2: Atlanto-occipital distance [ 6 ]. Label-3: The corner between the lower margin of the second vertebrae cervicale and the lower margin of the sixth vertebrae cervicale in neutral position [ 5 ].…”

“…Label-1: Vertical distance from the highest point of hyoid bone to mandibular body [ 4 ]. Label-2: Atlanto-occipital gap [ 6 ]. Label-3: The ratio of the angle between a line passing through the bottom of the second cervical vertebra and a line passing through the bottom of the sixth cervical vertebra in the neutral position [ 5 ].…”

“…Another predictor, the corner between the second vertebrae cervicale’s inferior edge and the sixth vertebrae cervicale’s bottom edge in neutral position has been shown to have the potential to be an accurate indicator for cervical spondylopathy patients' difficult laryngoscopy prediction [ 5 ]. The atlanto-occipital gap may reflect reduced range of motion and mild atlanto-occipital fusion, and has proven to have the potential ability to detect difficult laryngoscopy [ 6 ]. Our study applies the above three predictors to detect challenging laryngoscopy in cases of cervical spondylopathy, the predictive performance under single factor and multiple indicators will be uniformly verified for the first time.…”

Risk factors affecting the difficulty of fiberoptic nasotracheal intubation

“…Before tracheal intubation, the anesthesiologist evaluates airway difficulty, such as neck mobility, mouth opening range [11], thyromental distance [12], and Mallampati grade [13,14]. Moreover, a method using radiographic findings as an airway evaluation has been introduced recently [15]. In addition, the difficulty of endotracheal intubation is evaluated through the evaluation of Cormack-Lehane laryngoscopic grade during intubation [9,16].…”