Al Ramadhani S, Mohamed L A, Rocke D A, Gouws E
Department of Anaesthesia, Al Corniche Hospital, Abu Dhabi, United Arab Emirates.
Br J Anaesth. 1996 Sep;77(3):312-6. doi: 10.1093/bja/77.3.312.
Sternomental distance and view at laryngoscopy were documented in 523 parturients undergoing elective or emergency Caesarean section under general anaesthesia. Eighteen (3.5%) had a grade III or IV laryngoscopic view (Cormack and Lehane's classification) and were classified as potentially difficult tracheal intubations. There was a significant difference between sternomental distance in those patients with a grade III or IV laryngoscopic view compared with those with a grade I or II (13.17 (SD 1.54) cm vs 14.3 (1.49) cm; P = 0.0013). A sternomental distance of 13.5 cm or less with the head fully extended on the neck and the mouth closed provided, using discriminant analysis, the best cut-off point for predicting subsequent difficult laryngoscopy. A sternomental distance of 13.5 cm or less had a sensitivity, specificity, positive and negative predictive values of 66.7%, 71.1%, 7.6% and 98.4%, respectively. While there was no association between sternomental distance and age, weight, height or body mass index (BMI), there was a significant association between grade of laryngoscopy (III and IV) and older (P = 0.049) and heavier (P = 0.0495) mothers. The results suggest that while sternomental distance on its own may not be an adequate sole predictor of subsequent difficult laryngoscopy the measurement should be incorporated into a series of quick and simple preoperative tests.
对523例行全身麻醉下择期或急诊剖宫产的产妇记录了颏下距离和喉镜检查视野。18例（3.5%）有Ⅲ级或Ⅳ级喉镜视野（根据Cormack和Lehane分类），被归类为潜在的困难气管插管。Ⅲ级或Ⅳ级喉镜视野患者的颏下距离与Ⅰ级或Ⅱ级患者相比有显著差异（分别为13.17（标准差1.54）cm和14.3（1.49）cm；P = 0.0013）。通过判别分析，当颈部完全伸展且口闭合时，颏下距离13.5 cm及以下为预测后续困难喉镜检查的最佳临界点。颏下距离13.5 cm及以下时，敏感度、特异度、阳性预测值和阴性预测值分别为66.7%、71.1%、7.6%和98.4%。虽然颏下距离与年龄、体重、身高或体重指数（BMI）之间无关联，但喉镜分级（Ⅲ级和Ⅳ级）与年龄较大（P = 0.049）和体重较重（P = 0.0495）的产妇之间存在显著关联。结果表明，虽然颏下距离本身可能不足以单独预测后续困难喉镜检查，但该测量应纳入一系列快速简单的术前检查中。
