Uchida T, Hikawa Y, Saito Y, Yasuda K
Department of Anesthesia, Tokyo Metropolitan Hospital of Fuchu, Japan.
Can J Anaesth. 1997 Jun;44(6):674-6. doi: 10.1007/BF03015455.
The McCoy levering laryngoscope is a modified Macintosh laryngoscope, which has a hinged tip controlled by a lever on the handle. The purpose of this study was to investigate whether the tip elevation of this laryngoscope results in better laryngeal visualization than using the Macintosh laryngoscope when the patient's neck is fixed in the neutral position.
Fifty female patients (ASA physical status I-II) undergoing elective surgery during general anaesthesia were investigated. The patient's neck was manually fixed in the neutral position by an assistant, and laryngeal visualization was attempted first with a size #3 Macintosh laryngoscope (Macintosh trial), and then with a size #3 McCoy levering laryngoscope with blade tip elevation (McCoy trial), and tracheal intubation was attempted. Trials of laryngeal visualization were evaluated with the Cormack score.
In the Macintosh trial, 36 of 50 (72%) patients were evaluated grade 3, and two grade 4. In most of the patients graded 2 and 3 in the Macintosh trial (70% of the grade 2 and 83% of the grade 3 cases), the laryngeal view was improved by using the McCoy levering laryngoscope. The Cormack grade in the McCoy trial was less than that in the Macintosh trial (P < 0.01). No complications were observed during the study.
The McCoy levering laryngoscope improved laryngeal visualization in patients whose neck cannot be extended.
麦考伊杠杆喉镜是一种改良的麦金托什喉镜，其尖端通过手柄上的杠杆控制。本研究的目的是调查当患者颈部固定在中立位时，该喉镜的尖端抬起是否比使用麦金托什喉镜能更好地显露喉部。
对50例接受全身麻醉择期手术的女性患者（美国麻醉医师协会身体状况分级I-II级）进行研究。由一名助手将患者颈部手动固定在中立位，首先用3号麦金托什喉镜尝试显露喉部（麦金托什试验），然后用3号麦考伊杠杆喉镜并抬起刀片尖端尝试显露喉部（麦考伊试验），并尝试进行气管插管。用科马克评分评估显露喉部的试验。
在麦金托什试验中，50例患者中有36例（72%）评估为3级，2例为4级。在麦金托什试验中大多数评为2级和3级的患者（2级患者中的70%和3级患者中的83%），使用麦考伊杠杆喉镜时喉部视野得到改善。麦考伊试验中的科马克分级低于麦金托什试验（P<0.01）。研究期间未观察到并发症。
麦考伊杠杆喉镜改善了颈部无法伸展患者的喉部显露。
