第3、4气管软骨环至上中切牙的距离与体表标志的关系及其临床价值

目的研究第3、4气管软骨环至上中切牙的距离与胸骨长度的关系，为经皮扩张气管切开术（PDT）患者外退气管导管提供参考数据。方法第一阶段选择重症医学科行传统气管切开术的患者112例，纤维支气管镜直视下测量第3、4气管软骨环至上中切牙的距离（D），并以胸骨长度进行一元线性相关分析。第二阶段选择重症医学科气管插管且需行PDT的患者76例，随机分为观察组（A组）和对照组（B组）。A组患者先按第一阶段得出的回归方程计算出D值，然后以D为导向外退气管导管，而B组患者仅凭临床医师经验外退气管导管，待导管尖端退至预定位置后行PDT。观察两组患者手术耗时、一次退管成功率，再次气管插管率的情况。结果112例正常成人胸骨长度15．7-25．1cm，平均（19．3±1．5）cm，D为17．7～23．6cm，平均（18．4±1．6）cm，D与胸骨长度存在显著相关性（r=0．87，P〈0．00。与B组比较，A组患者PDT耗时明显减少（11．2±1-3）min vs（13．3±1．2）min，P=0．000]。结论胸骨长度预测出的第3、4气管软骨环至上中切牙的个体化距离可以指导PDT患者退管，并减少其手术时间。

Correlation and its clinical value between the distance from the third and fourth tracheal cartilage ring to central incisor and the length of sternum.

Objective To study the correlation between the distance trom the third ano tourm tracheal cam- lage ring to central incisor and the length of sternum, and provide parameter for dropping back of catheter in percutane- ous dilatational tracheostomy. Methods At the first stage, the distance from the third and fourth tracheal cartilage ring to central incisor （D value） was measured by fiberoptic bronchoscopy in 112 pattients who underwent the standard surgical tracheostomy. Furthermore, the correlation between D value and the length of sternum was analyzed through linear regression. At the second stage, 76 patients with endotracheal intubation were randomly divided into the obser-vation group and the control group. In the observation group, the endotracheal intubation was dropped back based on the distance calculated in the formula. Meanwhile, in the control group, the endotracheal intubation was dropped back just with the clinician＇s experience, where percutaneous dilatational tracheostomy was performed after the catheter tip arrived at the preset place. And then the procedure time, a successful rate of dropped-back endotracheal intubation, and the rate of re-intubation were analyzed in the two groups respectively. Results The mean sternum length of 112 normal adults was （19.3±1.5） era （range 15.7 cm to 25.1 era ）, the average D value was （18.4±1.6） cm （range 17.7 to 23.6 era）. Compared with that in the control group, the procedure lime in observation group was significantly shortened （11.2± 1.3） min vs. （13.3±1.2） rnin, P=0.000]. Conclusion D value can be estimated precisely by linear formulas according to one＇s sternum in adults, which can guide the procedure of pereutaneous dilatational tracheostomy and reduce operating time.