超声引导小儿喉罩定位的应用探讨

摘要

Objective To evaluate the efficacy of ultrasound-guided laryngeal mask airway (LMA) in children.Methods ASA Ⅰ and Ⅱ children (aged 1 to 6 years) scheduled for orthopedic surgery of limbs were recruited in this study.ALMA was inserted after induction of general anesthesia.After mechanical ventilation for 5 minutes,the air-filled cuff was deflated and then inflated with saline.Ultrasonography was then performed by a high frequency linear-array transducer to confirm the correct placement of the LMA.Results The LMA can be easily recognized on the transverse view of the thyroid cartilage notch,appearing as a circle around the glottis,which was called the dumbbell sign.On the sagittal view of the thyroid cartilage,the LMA has an archlike appearance which ended below the thyroid cartilage.Oblique scan over the cricoid cartilage shows the tip of LMA is located at the upper portion of the esophagus.Conclusions Filling the LMA cuff with saline instead of air allows better LMA visualization by ultrasound.This method enhances correct positioning of the LMA,which is crucial to ensure safe ventilation.%目的 探讨超声引导小儿喉罩定位的可行性.方法 选择美国麻醉医师协会(American Society of Anesthesiologists,ASA)麻醉分级Ⅰ～Ⅱ级、年龄1～6岁拟于全麻下行择期四肢骨科手术的患儿,麻醉诱导后常规置入喉罩,机械通气5min后用生理盐水替换空气充满套囊,使用高频线阵超声探头对喉罩进行定位.结果 位置正确时,甲状软骨切迹上横轴位切面显示喉罩轮廓清晰,套囊呈圆形对称分布于声门两侧,形似“哑铃”;甲状软骨旁矢状位切面显示喉罩呈弧形条状,末端位于甲状软骨以下;环状软骨水平斜轴位切面显示喉罩尖端位于食管入口.结论 以生理盐水代替空气填充套囊可以让喉罩在超声下清晰显像,这一技术可快速确定喉罩是否移位,保证通气安全.