Accuracy of middle finger length in predicting depth of placement of oral endotracheal tubes in patients of different ages / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the accuracy of the middle finger length in predicting the depth of placement of oral endotracheal tube (ETT) in patients of different ages.Methods One hundred and twenty patients of both sexes,of American Society of Anesthesiologists physical status Ⅰ-Ⅲ,undergoing elective surgery under general anesthesia requiring insertion of ETT,were divided into adult (18-84 yr) group (n =98) and children (5-14 yr) group (n =22) according to age.After anesthesia induction,the length of trachea was measured through mouth with a fiberoptic bronchoscope,and the patients were endotracheally intubated with the depth of three times the length of the left middle finger.The length from ETT tip to carina was measured after positioning.The optimal depth of placement of ETT was calculated,and the rate of appropriate placement depth of ETT was calculated.Linear correlation of three times the length of the middle finger with the optimal placement depth of ETT was analyzed.Results The rate of appropriate placement depth of ETT was 88％,the excessively deep placement of ETT was 7％,and the excessively shallow placement of ETT was 5％ in adult group.The rate of appropriate placement depth of ETT was 90％,the excessively deep placement of ETT was 10％,and no excessively shallow placement of ETT was found in children group.The tip and cuff of ETT were all in the main trachea in the two groups.The optimal placement depth of ETT was positively correlated with three times the length of the left middle finger (r =0.774,P＜0.01) in adult group and (r=0.911,P＜0.01) in children group.Conclusion Three times the length of the left middle finger can predict the appropriate placement depth of oral ETT in patients of 18-84 yr and 5-14 yr.