el-Ganzouri A R, McCarthy R J, Tuman K J, Tanck E N, Ivankovich A D
Department of Anesthesiology, Rush-Presbyterian-St. Luke's Medical Center at Rush Medical College, Chicago, Illinois 60612, USA.
Anesth Analg. 1996 Jun;82(6):1197-204. doi: 10.1097/00000539-199606000-00017.
Using readily available and objective airway risk criteria, a multivariate model for stratifying risk of difficult endotracheal intubation was developed and its accuracy compared to currently applied clinical methods. We studied 10,507 consecutive patients who were prospectively assessed prior to general anesthesia with respect to mouth opening, thyromental distance, oropharyngeal (Mallampati) classification, neck movement, ability to prognath, body weight, and history of difficult tracheal intubation. After induction of anesthesia, the laryngeal view during rigid laryngoscopy was graded and the ability of experienced anesthesia personnel to ventilate via a mask was determined. Poor intubating conditions (laryngoscopy Grade IV) and inability to achieve adequate mask ventilation were identified in 107 (1%) and 8 (0.07%) cases, respectively. Logistic regression identified all seven criteria as independent predictors of difficulty with laryngoscopic visualization. A composite airway risk index (derived from nominalized odds ratios calculated from the multivariate model) as well a simplified (0 = low, 1 = medium, 2 = high) risk weighting exhibited higher positive predictive value for laryngoscopy Grade IV at scores with similar sensitivity to Mallampati class III, as well as higher sensitivity at scores with similar positive predictive value. Compared to Mallampati class I fewer false-negative predictions were observed at a risk index value of 0. We conclude that improved risk stratification for difficulty with visualization during rigid laryngoscopy (Grade IV) can be obtained by use of a simplified preoperative multivariate airway risk index, with better accuracy compared to oropharyngeal (Mallampati) classification at both low- and high-risk levels.
利用现成且客观的气道风险标准，开发了一种用于对困难气管插管风险进行分层的多变量模型，并将其准确性与目前应用的临床方法进行比较。我们研究了10507例连续患者，这些患者在全身麻醉前接受了关于张口度、甲状软骨-颏下距离、口咽（Mallampati）分级、颈部活动度、前伸下颌能力、体重和困难气管插管史的前瞻性评估。麻醉诱导后，对硬质喉镜检查时的喉镜视野进行分级，并确定经验丰富的麻醉人员通过面罩通气的能力。分别在107例（1%）和8例（0.07%）患者中发现插管条件差（喉镜检查IV级）和无法实现充分面罩通气。逻辑回归确定所有七个标准均为喉镜可视化困难的独立预测因素。综合气道风险指数（源自多变量模型计算得出的标准化比值比）以及简化的（0 = 低，1 = 中，2 = 高）风险权重在与Mallampati III级敏感性相似的评分时，对喉镜检查IV级具有更高的阳性预测值，在与阳性预测值相似的评分时具有更高的敏感性。与Mallampati I级相比，在风险指数值为0时观察到的假阴性预测较少。我们得出结论，通过使用简化的术前多变量气道风险指数，可以改善硬质喉镜检查（IV级）时可视化困难的风险分层，在低风险和高风险水平下，其准确性均优于口咽（Mallampati）分级。
