Gupta Deepak, Srirajakalidindi Arvind, Ittiara Bryant, Apple Leigh, Toshniwal Gokul, Haber Halim
Department of Anesthesiology, Wayne State University/Detroit Medical Center, Detroit, MI 48201, USA.
Middle East J Anaesthesiol. 2012 Oct;21(6):835-42.
The major drawback of Cormack Lehane classification for airway assessment is its dependence on invasive direct laryngoscopy and hence it is inapplicable for pre-anesthetic assessment of airway in patients with no prior history of tracheal intubation.
The purpose of the study was to compare and correlate the ultrasound view of the airway and the Cormack Lehane classification of the direct laryngoscopy. METHODS/STUDY PROCEDURES: The present study was conducted on patients scheduled for elective surgery and requiring general anesthesia with direct laryngoscopy and endotracheal intubation. In the pre-operative holding area, the following measurements were obtained with the oblique-transverse ultrasound view of the airway: (a) the distance from the epiglottis to the midpoint of the distance between the vocal folds, (b) the depth of the pre-epiglottic space, and (c) the total time taken by the operator to achieve the final ultrasonic image. The data was then compared with the Cormack Lehane classification during direct laryngoscopy in the operating room. Subsequently based on the correlation data, the ultrasonographic modification of Cormack-Lehane Classification was developed.
It was observed that there was a correlation of the distance between the epiglottis and the vocal cords (E-VC) with the Cormack Lehane Grading; correlation was strong negative with regression coefficient of -0.966 (95% CI -1.431 to -0.501; p = 0.0001). Subsequently, the correlation of the pre-epiglottis space (Pre-E) with the Cormack Lehane Grading was strong in positive direction with regression coefficient of0.595 (95% CI 0.261 to 0.929; p = 0.0008). Finally the ratio of Pre-E and E-VC distances with the Cormack Lehane Grading had the strongest positive correlation with regression coefficient of 0.495 (95% CI 0.319 to 0.671; p < 0.0001). Based on these statistical calculations and after rearranging the data, we found that prediction of Cormack Lehane (CL) grades can be adequately (67%-68% sensitivity) made by the ratio of Pre-E and E-VC distances (Pre-E/E-VC) {0 < [Pre-E/E-VC] < 1 approximately CL grade 1; 1 < [Pre-E/E-VC] < 2 approximately CL grade 2; and 2 < [Pre-E/E-VC] < 3 approximately CL grade 3}. The average time taken to complete the ultrasound examination of airway in the preoperative area was 31.7 +/- 12.4 seconds.
The non-invasive ultrasonographic modification of invasive Cormack Lehane classification for pre-anesthetic airway assessment can supplement the presently available noninvasive modalities of pre-anesthetic airway assessment including the Mallampati Classification.
科马克·莱汉内气道评估分类的主要缺点是依赖侵入性直接喉镜检查，因此不适用于无气管插管既往史患者的麻醉前气道评估。
本研究的目的是比较气道的超声视图与直接喉镜检查的科马克·莱汉内分类，并进行相关性分析。
方法/研究步骤：本研究针对计划接受择期手术且需要全身麻醉并进行直接喉镜检查和气管插管的患者。在术前等候区，采用气道斜横位超声视图进行以下测量：（a）会厌至声带间距离中点的距离；（b）会厌前间隙的深度；（c）操作者获得最终超声图像所需的总时间。然后将数据与手术室直接喉镜检查时的科马克·莱汉内分类进行比较。随后根据相关数据，制定了科马克-莱汉内分类的超声改良版。
观察到会厌与声带之间的距离（E-VC）与科马克·莱汉内分级存在相关性；相关性为强负相关，回归系数为-0.966（95%可信区间-1.431至-0.501；p = 0.0001）。随后，会厌前间隙（Pre-E）与科马克·莱汉内分级呈强正相关，回归系数为0.595（95%可信区间0.261至0.929；p = 0.0008）。最后，Pre-E与E-VC距离之比与科马克·莱汉内分级呈最强正相关，回归系数为0.495（95%可信区间0.319至0.671；p < 0.0001）。基于这些统计计算并重新整理数据后，我们发现通过Pre-E与E-VC距离之比（Pre-E/E-VC）可以充分预测科马克·莱汉内（CL）分级（敏感性为67%-68%）{0 < [Pre-E/E-VC] < 1大致为CL 1级；1 < [Pre-E/E-VC] < 2大致为CL 2级；2 < [Pre-E/E-VC] < 3大致为CL 3级}。术前区域完成气道超声检查的平均时间为31.7 +/- 12.4秒。
用于麻醉前气道评估的侵入性科马克·莱汉内分类的非侵入性超声改良版可补充现有的麻醉前气道评估非侵入性方法，包括马兰帕蒂分类法。
