Roberts J T, Ali H H, Shorten G D
Department of Anesthesia, Massachusetts General Hospital, Boston 02114.
J Clin Anesth. 1993 Jul-Aug;5(4):302-5. doi: 10.1016/0952-8180(93)90123-v.
(1) To evaluate a device of the authors' design, the laryngeal indices caliper, which quantitates the position of the anterior edges of the larynx relative to the upper teeth and the external auditory canals; (2) to determine how relative laryngeal position affects ease of direct laryngoscopy with a Macintosh #3 laryngoscope.
Randomized, double-blind study.
Inpatient surgery center at a university medical center.
101 renal lithotripter patients.
Patients were measured with the laryngeal indices caliper prior to induction of general endotracheal anesthesia. They were then given a sleep dose of thiopental sodium (4 mg/kg) and paralyzed with a bolus dose of succinylcholine (1 mg/kg).
Of the measurements taken or calculated, only laryngeal tilt (LT) showed a significant correlation with grade of difficulty of laryngoscopy. When the anterior surface of the thyroid cartilage was tilted more than 20 degrees anteriorly to a line perpendicular to the laryngeal indices line, the vocal cords could not be seen in 83% of the patients.
(1) Laryngeal tilt is a good predictor of difficulty of laryngoscopy with a Macintosh #3 laryngoscope; (2) the laryngeal indices caliper is a simple pocket device to measure LT indirectly.
（1）评估作者设计的一种装置——喉部指数卡尺，该装置可量化喉部前缘相对于上齿和外耳道的位置；（2）确定喉部相对位置如何影响使用麦金托什3号喉镜进行直接喉镜检查的难易程度。
随机双盲研究。
大学医学中心的住院手术中心。
101例肾结石碎石术患者。
在全身气管内麻醉诱导前，用喉部指数卡尺对患者进行测量。然后给予患者硫喷妥钠睡眠剂量（4mg/kg），并静脉推注琥珀酰胆碱（1mg/kg）使其麻痹。
在进行的测量或计算中，只有喉部倾斜度（LT）与喉镜检查的困难程度呈显著相关。当甲状软骨前表面相对于与喉部指数线垂直的线向前倾斜超过20度时，83%的患者无法看到声带。
（1）喉部倾斜度是使用麦金托什3号喉镜进行喉镜检查困难程度的良好预测指标；（2）喉部指数卡尺是一种简单的袖珍装置，可间接测量喉部倾斜度。
