Soltani Mohammadi Sussan, Saliminia Alireza, Nejatifard Nasim, Azma Roxana
Department of Anesthesiology, Critical Care and Pain Medicine, Tehran University of Medical Sciences, Dr Shariati Hospital, Tehran, Iran.
Department of Pediatric Radiology, Shahid Beheshti University of Medical Sciences, Mofid Children's Hospital, Tehran, Iran.
Anesth Pain Med. 2016 Aug 15;6(6):e39566. doi: 10.5812/aapm.39566. eCollection 2016 Dec.
One of the main challenges in anesthesiology is difficult intubation. There are many anatomical parameters for evaluating the feasibility of tracheal intubation; one that can reliably predict a difficult intubation is the Cormack-Lehane classification obtained during direct laryngoscopy. This is an invasive procedure that cannot be performed in an awake patient or for pre-anesthetic airway assessments in patients with no prior history of tracheal intubation. Recently, ultrasound has been successfully used for several airway-related applications.
The aim of this study was to compare and correlate the ultrasound view of the larynx with the Mallampati classification before anesthesia and the Cormack-Lehane classification during direct laryngoscopy under general anesthesia.
This cross-sectional descriptive-analytic study included 53 ASA class I - III patients aged 18 - 70 years who were scheduled for tracheal intubation under general anesthesia. Before anesthesia, an oblique transverse ultrasound view of the airway was obtained; in addition, the total time taken to achieve the final plane, the depth of the pre-epiglottic space, and the distance from the epiglottis to the mid-point between the vocal cords were all recorded. The ultrasound measurements were then compared with the Mallampati class on the preoperative evaluation and with the Cormack-Lehane grade during direct laryngoscopy under general anesthesia.
It was observed that correlations between the pre-epiglottic space (PE) and Cormack-Lehane grades I, II, and III were weak. Correlations between the distance from the epiglottis to the vocal cords (E-VC) and Cormack-Lehane grades I, II, and III were also weak. The PE/E-VC ratio for correlations between the sonographic view and laryngoscopy had 87.5% sensitivity and 30% specificity. There was no correlation between Mallampati class and the PE/E-VC ratio (P = 0.566).
Our study revealed weak correlation between PE/E-VC and Cormack-Lehane grade, with 87% sensitivity and 30% specificity. Therefore, we concluded that sonographic measurement criteria are not accurate in airway evaluations before anesthesia.
麻醉学中的主要挑战之一是困难插管。有许多解剖学参数可用于评估气管插管的可行性；其中一个能够可靠预测困难插管的参数是直接喉镜检查时获得的Cormack-Lehane分级。这是一种侵入性操作，不能在清醒患者中进行，也不能用于无气管插管既往史患者的麻醉前气道评估。最近，超声已成功用于多种与气道相关的应用。
本研究的目的是在麻醉前比较喉部的超声视图与Mallampati分级，并将其与全身麻醉下直接喉镜检查时的Cormack-Lehane分级进行关联。
这项横断面描述性分析研究纳入了53例年龄在18至70岁之间、拟行全身麻醉下气管插管的美国麻醉医师协会（ASA）I-III级患者。在麻醉前，获取气道的斜向横向超声视图；此外，记录达到最终平面所需的总时间、会厌前间隙的深度以及会厌至声带中点的距离。然后将超声测量结果与术前评估时的Mallampati分级以及全身麻醉下直接喉镜检查时的Cormack-Lehane分级进行比较。
观察到会厌前间隙（PE）与Cormack-Lehane I级、II级和III级之间的相关性较弱。会厌至声带的距离（E-VC）与Cormack-Lehane I级、II级和III级之间的相关性也较弱。超声视图与喉镜检查之间相关性的PE/E-VC比值具有87.5%的敏感性和30%的特异性。Mallampati分级与PE/E-VC比值之间无相关性（P = 0.566）。
我们的研究显示PE/E-VC与Cormack-Lehane分级之间的相关性较弱，敏感性为87%，特异性为30%。因此，我们得出结论，超声测量标准在麻醉前气道评估中并不准确。
