García-Guiral M, García-Amigueti F, Ortells-Polo M A, Muiños-Haro P, Gallego-González J, Carral-Olondris J N
Servicio de Anestesiología, Reanimación y Terapia del Dolor, Hospital Naval de San Carlos, San Fernando, Cádiz.
Rev Esp Anestesiol Reanim. 1997 Mar;44(3):93-7.
To determine the relation between difficult intubation and grade of direct laryngoscopy, as well as the factors that influence them, and prognosis.
In 1,336 patients receiving general anesthesia, seven airway measurements were made to reflect degree of difficulty and predictive value of presurgical tests on direct laryngoscopy and intubation.
The incidences of difficult laryngoscopic and intubation procedures were 1.4 and 3.0%, respectively. Difficult intubation was more frequent in women and in patients between 40 and 65 years of age (p < 0.05). In 105 intubations (64.8%) performed with moderate difficulty (use of a stylette, external laryngeal pressure or two tries) and 17 (41.5%) performed with difficulty (three or more tries), the laryngoscopic procedure was graded as easy (Cormack-Lehane grade I-II). In these cases (easy laryngoscopy with moderate/difficult intubation), the causes recorded were size of endotracheal tube in comparison with the laryngeal opening (n = 11); anterior glotis (n = 36); insufficient relaxation (n = 31); disease in or beyond the vocal cords (n = 29); or undetermined (n = 15). In the easy intubation cases, the laryngoscopic procedures were grade III in 2.9%. Intubation was difficult in 16.3% (n = 39) of patients presenting some type of abnormality upon examination of the airway (p < 0.05). The airway characteristic that best predicted laryngoscopic difficulty was extension of the lower neck to 90 degrees (relative risk of 4.46), mouth opening less than 3.5 cm (3.92), presence of two airway abnormalities (4.25) and presence of three or more abnormalities (5.39) (p < 0.01).
The fact that cases of easy laryngoscopy coincide with difficult intubation suggests that, to the degree of intubation difficulty must be added extrinsic factors (individual skill, maneuvers performed, instrumentation, relaxation of the laryngeal musculature and others) that are hard to standardize and reflect when predicting an intubation by the grade of difficulty in laryngoscopy.
确定困难插管与直接喉镜分级之间的关系，以及影响它们的因素和预后。
对1336例接受全身麻醉的患者进行了7项气道测量，以反映困难程度以及术前检查对直接喉镜检查和插管的预测价值。
困难喉镜检查和插管的发生率分别为1.4%和3.0%。困难插管在女性以及40至65岁的患者中更为常见（p<0.05）。在105例插管操作（64.8%）中存在中度困难（使用管芯、外部喉压迫或尝试两次），17例（41.5%）存在困难（尝试三次或更多次），喉镜检查操作分级为容易（Cormack-Lehane分级I-II级）。在这些病例（喉镜检查容易但插管中度/困难）中，记录的原因包括气管导管尺寸与喉口的比较（n = 11）；前声门（n = 36）；松弛不足（n = 31）；声带内或声带外疾病（n = 29）；或未确定（n = 15）。在插管容易的病例中，喉镜检查操作III级的占2.9%。在气道检查存在某种异常的患者中，16.3%（n = 39）插管困难（p<0.05）。最能预测喉镜检查困难的气道特征是下颈部伸展至90度（相对风险为4.46）、开口小于3.5 cm（3.92）、存在两种气道异常（4.25）以及存在三种或更多异常（5.39）（p<0.01）。
喉镜检查容易的病例与插管困难同时存在这一事实表明，在通过喉镜检查的困难程度预测插管时，除了插管困难程度外，还必须考虑难以标准化和反映的外在因素（个人技能、操作手法、器械、喉肌松弛等）。
