Riad Waleed, Ansari Tarek, Shetty Nanda
Department of Anesthesia, Corniche Hospital, Abu Dhabi, United Arab Emirates.
Saudi J Anaesth. 2018 Jan-Mar;12(1):77-81. doi: 10.4103/sja.SJA_385_17.
Failed intubation in obstetrics remains the most common cause of death directly related to anesthesia. Neck circumference has been shown to be a predictor for difficult intubation in morbidly obese patients. The aim of this study was to determine an optimal cutoff point of neck circumference for prediction of difficult intubation in obstetric patients.
Ninety-four parturients scheduled for cesarean section under general anesthesia were included in the study. Preoperative airway assessment and neck circumference were measured. Difficult intubation was the primary outcome according to the intubation difficulty scale (IDS), intubation reported difficult if the IDS score was ≥5.
Univariate analysis showed that Mallampati score and neck circumference were positive predictors for difficult intubation ( = 0.005 and = 0.011, respectively). Mouth opening, thyromental distance, sternomental distance, and the hyomental distance ratio were not useful predictors ( = 0.68, = 0.87, = 0.48, and = 0.27, respectively). Logistic regression for the Mallampati score and neck circumference negative results as independent predictors of difficult intubation in obstetric ( = 0.53). Sensitivity analysis showed that neck circumference of 33.5 cm is the cutoff point to detect difficult intubation with 100% sensitivity (95% confidence interval [CI]: 69.2-100) and 50% specificity (95% CI: 38.9-61.1). The area under the curve for neck circumference was 0.746 (95% CI: 0.646-0.830) with a positive predictive value of 19.2 (95% CI: 9.6-32.5), a negative predicative value of 100 (95% CI: 91.6-100), and a < 0.0001.
In obstetric patients, a neck circumference ≥33.5 cm is a sensitive predictor for difficult intubation.
产科插管失败仍然是与麻醉直接相关的最常见死亡原因。颈部周长已被证明是病态肥胖患者困难插管的一个预测指标。本研究的目的是确定产科患者困难插管预测的颈部周长最佳截断点。
94例计划在全身麻醉下进行剖宫产的产妇纳入本研究。测量术前气道评估和颈部周长。根据插管困难量表（IDS），困难插管是主要结局，如果IDS评分≥5，则报告插管困难。
单因素分析显示，Mallampati评分和颈部周长是困难插管的阳性预测指标（分别为P = 0.005和P = 0.011）。张口度、颏甲距离、胸骨颏距离和舌颏距离比不是有用的预测指标（分别为P = 0.68、P = 0.87、P = 0.48和P = 0.27）。将Mallampati评分和颈部周长阴性结果作为产科困难插管的独立预测指标进行逻辑回归分析（P = 0.53）。敏感性分析显示，颈部周长33.5 cm是检测困难插管的截断点，敏感性为100%（95%置信区间[CI]：69.2 - 100），特异性为50%（95% CI：38.9 - 61.1）。颈部周长的曲线下面积为0.746（95% CI：0.646 - 0.830），阳性预测值为19.2（95% CI：9.6 - 32.5），阴性预测值为100（95% CI：91.6 - 100），P < 0.0001。
在产科患者中，颈部周长≥33.5 cm是困难插管的敏感预测指标。
