Lee Steven M, Wojtczak Jacek A, Cattano Davide
McGovern Medical School, Department of Anesthesiology, UTHealth at Houston, Houston, TX, USA.
University of Rochester, Department of Anesthesiology, Rochester, New York, USA.
J Ultrason. 2017 Dec;17(71):229-234. doi: 10.15557/JoU.2017.0033. Epub 2017 Dec 29.
Internal neck anatomy landmarks and their relation after placement of an extraglottic airway devices have not been studied extensively by the use of ultrasound. Based on our group experience with external landmarks as well as internal landmarks evaluation with other techniques, we aimed use ultrasound to analyze the internal neck anatomy landmarks and the related changes due to the placement of the Laryngeal Mask Airway Unique.
Observational pilot investigation. Non-obese adult patients with no evidence of airway anomalies, were recruited. External neck landmarks were measured based on a validated and standardized method by tape. Eight internal anatomical landmarks, reciprocal by the investigational hypothesis to the external landmarks, were also measured by ultrasound guidance. The internal landmarks were re-measured after optimal placement and inflation of the extraglottic airway devices cuff Laryngeal Mask Airway Unique.
Six subjects were recruited. Ultrasound measurements of hyoid-mental distance, thyroid-cricoid distance, thyroid height, and thyroid width were found to be significantly ( < 0.05) overestimated using a tape measure. Sagittal neck landmark distances such as thyroid height, sternal-mental distance, and thyroid-cricoid distance significantly decreased after placement of the Laryngeal Mask Airway Unique.
The laryngeal mask airway Unique resulted in significant changes in internal neck anatomy. The induced changes and respective specific internal neck anatomy landmarks could help to design devices that would modify their shape accordingly to areas of greatest displacement. Also, while external neck landmark measurements overestimate their respective internal neck landmarks, as we previously reported, the concordance of each measurement and their respective conversion factor could continue to be of help in sizing extraglottic airway devices. Due to the pilot nature of the study, more investigations are warranted.
声门外气道装置放置后颈部内部解剖标志及其关系尚未通过超声进行广泛研究。基于我们团队在外部标志以及使用其他技术评估内部标志方面的经验，我们旨在使用超声分析颈部内部解剖标志以及由于独特型喉罩气道放置而引起的相关变化。
观察性试点研究。招募无气道异常证据的非肥胖成年患者。通过卷尺基于经过验证和标准化的方法测量颈部外部标志。在超声引导下还测量了八个内部解剖标志，根据研究假设，这些标志与外部标志相互对应。在声门外气道装置独特型喉罩气道的袖带最佳放置并充气后，重新测量内部标志。
招募了六名受试者。发现使用卷尺测量时，舌骨 - 颏距离、甲状腺 - 环状软骨距离、甲状腺高度和甲状腺宽度的超声测量值被显著高估（<0.05）。放置独特型喉罩气道后，颈部矢状面标志距离如甲状腺高度、胸骨 - 颏距离和甲状腺 - 环状软骨距离显著减小。
独特型喉罩气道导致颈部内部解剖结构发生显著变化。所引起的变化以及相应的特定颈部内部解剖标志有助于设计能够根据最大位移区域相应改变其形状的装置。此外，正如我们之前所报道的，虽然颈部外部标志测量高估了其各自对应的颈部内部标志，但每次测量的一致性及其各自的转换因子在确定声门外气道装置尺寸时可能仍然有用。由于该研究的试点性质，需要进行更多调查。
