Influencing Factors Of Difficult Laryngeal Exposure Under Suspensive Laryngoscope

Objective:With the continuous development of medical level,the laryngoscope under laryngeal minimally invasive surgery has become a routine operation of otolaryngology department,the technology can achieve most of the patients with surgery,get good cure,but as a result of the design of the laryngoscope itself characteristic,as well as the individual’s own anatomical differences,not all patients of the glottis can fully exposed in operation,this is referred to in this study the glottis.The purpose of this study is to explore the following questions: 1.To analyze whether the physical parameters and upper airway measurement parameters involved in this study can provide prediction ability of difficult glottis;2.Accurate ultrasonic examination of the measured tongue thickness and condyle activity as independent predictors of glottis difficulty.Methods:A prospective case cohort study was designed to include adult patients undergoing laryngoscopic microsurgery under general anesthesia.Preoperative assessment included: height,weight,body mass index,mallampatia rating,nail and chin distance,degree of mouth opening,upper lip bite rating,indirect laryngoscopy rating,anatomic parameters of upper airway measured by ultrasound(including tongue thickness and condylar range of motion),etc.The main observation was whether intraoperative glottis exposure was difficult.Analysis of variables in patients with difficulty in glottic exposure and non-glottic exposure in patients with difficulty in whether there is a difference;Using statistical methods,univariate analysis was conducted on the influencing factors with differences,and the variables with significant statistical significance in the univariate analysis were included in the multivariate Logistic regression analysis,independent predictors were screened and identified,and a comprehensive prediction model was established.Results:After screening,159 patients were successfully included in the statistical analysis,including 16 patients with difficulty in glottic exposure under support laryngoscope and 143 patients with non-difficulty.Firstly,the physical parameters and upper airway anatomicalparameters involved in this study were analyzed in the two groups,and the cut-off points of the factors with differences in clinical data analysis were set up.The results showed that each parameter was analyzed by single factor in turn.Gender,BMI,neck circumference,chin distance,M grade,upper lip biting grade,tongue thickness and condylar convex activity were significantly different(P < 0.05).The results showed that BMI > 25kg/m2,neck circumference > 40 cm,chin distance < 70 cm,tongue thickness > 60 mm,condylar convex activity > 10 mm were all glottic exposure during operation.The results show that the area under the ROC curve of condylar convex activity and tongue thickness is 0.881 and 0.845,which means that the two factors have higher predictive value.Conclusion:The physical parameters and upper airway measurement parameters involved in this study can provide the prediction ability of difficult glottis.Accurate measurement of tongue thickness and condylar motion can be used as independent predictors of difficult glottis.