| Objective: At present,there are many clinical methods for evaluating difficult airway.Wilson risk score is widely used in many countries to predict difficult airway because of its simple operation,economic,non-invasive and other clinical advantages.However,there is no reliable clinical observation data to prove whether this method is effective or effective in predicting difficult airway in Chinese patients.And in recent years,with the development of visualization technology,the use of ultrasonic measurement of upper airway anatomic parameters to evaluate and predict the difficult airway as a novel evaluation method,which can intuitively observe the anatomical structure of airway and has a certain value.However,compared with the classic difficult airway assessment method,the Wilson risk score,it is not known which is the better or worse predictive effect of the two methods for the difficult airway.Therefore,the purpose of this study was to explore the following questions: 1.Whether Wilson risk score was effective in predicting difficult airway in Chinese patients;2.The value of upper airway anatomical parameters measured by ultrasound and Wilson risk score in predicting difficult airway was compared.Methods: The first part: A prospective case cohort study was conducted to evaluate the assessment of difficult airway before general endotracheal intubation anesthesia in adults who met the inclusion criteria.The clinical assessment included: the Wilson risk score,which scores 5 factors [weight,jaw movement(interincisor gap and subluxation),head and neck movement,receding mandible,and buck teeth],the modified Mallampati test,the thyromental distance,and the inter-incisor distance and so on.The primary outcome was difficult tracheal intubation.The secondary outcome was difficult laryngoscopy.The receiver operating characteristic curves(ROC)and the area under the curve(AUC)were utilized to analyze the capacity of each assessment parameter.The optimal predictive value of the parameters and the corresponding odds ratio,sensitivity,specificity,positive predictive value,negative predictive value,and its 95% CI were determined by the Youden index.The second part: A prospective case cohort study was conducted to evaluate the assessment of difficult airway before general endotracheal intubation anesthesia in adults who met the inclusion criteria.The clinical assessment included: the upper airway anatomic parameters measured by ultrasound(the distance from the skin to the 1/3 tongue,tongue thickness,hyoid-mental distance,condylar mobility),the Wilson risk score,which scores 5 factors [weight,jaw movement(interincisor gap and subluxation),head and neck movement,receding mandible,buck teeth],the modified Mallampati test,the thyromental distance,and the inter-incisor distance and so on.The primary outcome was difficult tracheal intubation.The secondary outcome was difficult laryngoscopy.The receiver operating characteristic curves(ROC)and the area under the curve(AUC)were utilized to analyze the capacity of each assessment parameter.The optimal predictive value of the parameters and the corresponding odds ratio,sensitivity,specificity,positive predictive value,negative predictive value,and its 95% CI were determined by the Youden index.Logistic regression analysis was performed on the upper airway anatomical parameters measured by ultrasound to predict difficult tracheal intubation and difficult laryngoscopy respectively.According to the corresponding odds ratio,a comprehensive ultrasonic evaluation model of difficult airway was established.The value of predicting difficult airway was compared between ultrasonic evaluation model and Wilson risk score.Results: The first part: A total of 1544 patients were enrolled in this study,in whom 106(6.87%)had difficult laryngoscopy and 37(2.40%)had difficult intubation.There were no significant differences in the weight(P >0.05),and the other four risk factors were statistically significant(P <0.001).In predicting difficult intubation,the area under the curve of the Wilson risk score was 0.91 and the optimal predictive criteria was >1.The area under the ROC curve of the modified Mallampati test is 0.65.The area under the ROC curve of the thyromental distance is 0.81.The area under the ROC curve of the inter-incisor distance is 0.91.Compared with the modified Mallampati test and the thyromental distance,the Wilson risk score has a higher predictive value,and the difference was statistically significant(P <0.05).Compared with the inter-incisor distance,the Wilson risk score has the same predictability as the inter-incisor distance(P =0.854).The second part: A total of 2030 patients were enrolled in this study,in whom 127(6.26%)had difficult laryngoscopy and 55(2.71%)had difficult intubation.In predicting difficult intubation,the area under the curve of the Wilson risk score was 0.79.The area under the ROC curve of the ultrasonic evaluation model is 0.88.Compared with the area of Wilson risk score,the area of the ultrasonic evaluation model was significantly higher,and the difference was statistically significant(P <0.01).In predicting difficult laryngoscopy,the area under the curve of the Wilson risk score was 0.76.The area under the ROC curve of the ultrasonic evaluation model is 0.83.Compared with the area of Wilson risk score,the area of the ultrasonic evaluation model was significantly higher,and the difference was statistically significant(P <0.05).Conclusion: 1.Wilson risk score has certain diagnostic value in predicting difficult intubation in Chinese patients,but the predictive effects of weight factors were not good,and the inter-incisor distance are not suitable for Chinese patients.The inappropriate positive predictive cut-off value setting may impair its predictive performance.2.The anatomic parameters of upper airway measured by ultrasound have independent predictive value of difficult airway,and its predictive performance is superior to that of Wilson risk score. |
