title: Sternomental distance as the sole predictor of difficult laryngoscopy in obstetric anaesthesia.
abstract: 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.
authors.affiliation: Department of Anaesthesia, Al Corniche Hospital, Abu Dhabi, United Arab Emirates.
authors.forename: S
authors.initials: S
authors.lastname: Al Ramadhani
authors.forename: L A
authors.initials: LA
authors.lastname: Mohamed
authors.forename: D A
authors.initials: DA
authors.lastname: Rocke
authors.forename: E
authors.initials: E
authors.lastname: Gouws
authors.forename: S A
authors.initials: SA
authors.lastname: Ramadhani
mesh_terms: D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D000773:Anesthesia, Obstetrical; D000886:Anthropometry; D002585:Cesarean Section; D002680:Chin / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D007828:Laryngoscopy; D008875:Middle Aged; D011237:Predictive Value of Tests; D011247:Pregnancy; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013249:Sternum / Q000033:anatomy & histology*